On Kelvin-Voigt model and its generalizations
|
|
- Gladys Lang
- 5 years ago
- Views:
Transcription
1 Nečas Center for Mathematical Moeling On Kelvin-Voigt moel an its generalizations M. Bulíček, J. Málek an K. R. Rajagopal Preprint no Research Team 1 Mathematical Institute of the Charles University Sokolovská 83, Praha 8
2 ON KELVIN-VOIGT MODEL AND ITS GENERALIZATIONS MIROSLAV BULÍČEK, JOSEF MÁLEK, AND K.R. RAJAGOPAL Abstract. We consier a generalization of the Kelvin-Voigt moel where the elastic part of the Cauchy stress epens non-linearly on the linearize strain an the issipative part of the Cauchy stress is a nonlinear function of the symmetric part of the velocity graient. The assumption that the Cauchy stress epens non-linearly on the linearize strain can be justifie if one starts with the assumption that the kinematical quantity, the left Cauchy-Green stretch tensor, is a nonlinear function of the Cauchy stress, an linearizes uner the assumption that the isplacement graient is small. Long-time an large ata existence, uniqueness an regularity properties of weak solution to such a generalize Kelvin-Voigt moel are establishe for the non-homogeneous mixe bounary value problem. The main novelty consists in incluing nonlinear issipation into the analysis. 1. Introuction The classical Kelvin-Voigt viscoelastic soli (see Kelvin [6], Voigt [8]) can be viewe as a mixture of a linearize elastic soli an a linearly viscous flui that co-exist. The one-imensional moel is represente as a linear spring in parallel with a linearly viscous ashpot. A generalization of the mechanical analog is to consier a non-linear spring in parallel with a non-linearly viscous ashpot. Such a one-imensional moel can be appropriately generalize to obtain a three imensional moel. Recently, Rajagopal [4] (see also [5]) has consiere generalizations of the classical Kelvin- Voigt moel wherein he allows for both the elastic soli an viscous flui to be escribe through implicit constitutive relations. That is, the elastic soli is escribe by a constitutive relation of the form 1 (1.1) H(T e, B) =, where T e is the stress in the elastic soli, an B the right Cauchy-Green stretch, while the flui is escribe by a constitutive relation of the form (1.) G(T v, D) =, where T v is the stress in the flui, an D is the symmetric part of the velocity graient. The Cauchy stress T in the viscoelastic soli is given by (1.3) T = T e + T v. Key wors an phrases. Kelvin-Voigt moel, viscoelastic soli, non-linear wave equation, weak solution, large ata existence, uniqueness, regularity. Miroslav Bulíček thanks the Jinřich Nečas Center for Mathematical Moeling (the project LC65 finance by MŠMT) for its support. Josef Málek s contribution is a part of the research project MSM finance by MŠMT; the support of GAČR 1/9/917 is also acknowlege. K. R. Rajagopal thanks the National Science Founation an the Jinřich Nečas Center for Mathematical Moeling for their support. 1 The kinematical quantities in the introuction are efine in the next section. 1
3 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL The aitive ecomposition reflects the fact that the boy uner consieration is a mixture of coexisting components. The above moel is one for a compressible viscoelastic boy. If one is intereste in a moel for an incompressible material, we replace T e an T v in (1.1) an (1.) by S e an S v, where S e an S v are the eviatoric part of the stress in the elastic an viscous boies an (1.3) takes the form (1.6) T = pi + S e + S v or T = pi + S with S = S e + S v. In the case of the incompressible flui we woul replace (1.1) an (1.) by (1.7) ĤH(S e, B) =, an (1.8) ĜG(S v, D) =. In general, one woul have to solve (1.1) (1.3) an the balance of mass an linear momentum simultaneously, or, in the case of an incompressible boy, the moifie equations (1.7), (1.8) an (1.6), an the balance of linear momentum an the constraint of incompressibility, simultaneously. Solving such systems, for compressible an incompressible viscoelastic boies, woul seem much more aunting than what one oes usually, that is, to substitute the expression for the stress in the balance of linear momentum to obtain a partial ifferential equation for the isplacement fiel. However, such a proceure increases the orer of the partial ifferential equation for the isplacement fiel one eals with an leas to issues concerning the orer of the ifferentiability an hence the space of functions in which one seeks a solution. It is not merely the mathematical issue concerning the ifferentiability of solutions that warrants one to look at the type of generalizations consiere by Rajagopal [4]. In fact, the much more important an interesting reason for consiering such moels is the ability to consier general elastic response that cannot be capture within the context of either Cauchy elasticity or Green elasticity an the issipative response that allows one to consier fluis that have a threshol, such as Bingham flui 3, an/or fluis whose viscosity epens on the mean normal stress in the flui an the symmetric part of the velocity graient. Such elastic an issipative response is escribe by the implicit moels (1.1) an (1.), respectively. (In the case of an incompressible boy, such response is given by (1.7) an (1.8).) The Cauchy stress in a classical incompressible three-imensional Kelvin-Voigt soli is given by (1.4) T = pi + µb + ηd, where pi is the reaction stress ue to the constraint of incompressibility, B is the right Cauchy-Green stretch tensor an D is the symmetric part of the velocity graient. Also µ enotes the shear moulus of the elastic component an η is twice the shear viscosity of the flui component. The compressible counterpart to (1.4) takes the form (1.5) T = µb + ηd. While the moel (1.4) is use often to escribe a variety of polymeric solis an geological materials, the moel (1.5) is not use that often. The moel (1.5) might be appropriate for a class of compressible polymeric foams. 3 If one accepts the efinition that a flui is a boy that cannot support a shear stress, then the notion of a Bingham flui is an untenable concept. However, the moel seems to capture the behavior of certain flui-like boies within the context of observable length scales, time scales an force scales.
4 KELVIN-VOIGT VISCOELASTIC SOLID 3 If one is intereste in the strains being small 4, then (1.1) woul take the form (1.9) H(T e, ε) =, where ε is the linearize strain. While the special subclass of moels (1.1) ε = H (T e ) (H is in general a non-linear function) can be properly justifie (see Rajagopal [4]), the moel (1.11) T e = H(ε), where H is non-linear is inconsistent, if one starts with the notion of a Cauchy elastic boy, as one has alreay presume the nonlinear part of the strain is to be ignore. However, if (1.1) is invertible, then one can justify the use of (1.11), but only as approximation that stems from a totally ifferent stanpoint (see Rajagopal [4] for a etaile iscussion of the issues). In this paper, we shall consier both compressible an incompressible viscoelastic solis that are mixtures of an elastic soli given, in the case of a compressible soli, by (1.11), with the constitutive relation for the flui given by (1.1) T v = G(D). At this juncture it woul be appropriate to point out that there have been several papers that consier partial ifferential equations that are motivate as stemming from a consieration of the equations of motion for a viscoelastic material; one such an example is the recent paper by Tvet [7]. Unfortunately, the motivation is not very accurate. If the boy uner consieration is an incompressible viscoelastic soli, then the equations (1.1) in [7] shoul contain a pressure graient an if it is a compressible material, the ensity shoul appear in the governing equations (1.1) of the paper an one woul also have to solve the balance of mass that gets couple to Eq.(1.1) by the ensity. The papers by Tvet [7], Frieman an Nečas [] an others are primarily concerne with mathematical issues, their relevance to physics take a back seat. For instance in [7] one is not mae aware of what strain measure an stress measure are being use, or for that matter whether they are ealing with with a non-linear measure of strain or the linearize strain. Of course, in one imension these issues o not arise (as also pointe out in Sect. 3 below), however the author clearly mentions that he is ealing with vector-value functions. In this paper we stuy the existence of a weak solution (an its uniqueness an regularity) to equations (1.3), (1.11) an (1.1) an the balance of linear momentum (an the balance of mass that is in our setting however uncouple from the balance of linear momentum), an we also investigate the same to the governing equations for an incompressible viscoelastic boy. When we cast a compressible viscoelastic generalization of a Kelvin-Voigt soli as (1.13) B = H 1 (T e ), an (1.14) D = G 1 (T v ), 4 The linearization that leas to classical linearize elasticity is not that the strains be small, rather the assumption is that the isplacement graient be small which implies that max u = o(δ), < δ << 1. x B,t R The above conition implies that both the strains an rotations are small an not merely that the strains are small.
5 4 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL with T being given by (1.3), we cannot substitute for the stress T given by (1.3) into the balance of linear momentum, but we nee to solve the system of partial ifferential equations given by (1.13), (1.14), (1.3) an the balance of mass an linear momentum simultaneously. We now have equations for the unknowns ϱ, u, T e, T v an T. In the case of an incompressible material, the constitutive relations take the form (1.15) B = H (S e ), an (1.16) D = G (S v ). We will have to solve (1.15), (1.16), (1.6), the constraint of incompressibility an the balance of linear momentum simultaneously for the unknowns p, u, S e, S v an T. We shall make a few brief remarks concerning the linearize version for the compressible moel. In this case, we consier the constitutive relations to be given by (1.17) ε = H 3 (T e ), an (1.18) ε = G 3 (T v ). We woul nee to solve (1.17), (1.18) in conjunction with the balance of mass an linear momentum. If we are to restrict ourselves to solving Quasi-Static problems wherein the inertial term in the balance of linear momentum is neglecte, the problem simplifies consierably as we have to solve (1.17), (1.18), (1.3) in conjunction with (1.19) iv T =. The balance of mass gets uncouple from the other equations an can be use to etermine the ensity. Thus, the unknowns are u, T e, T v, T an the appropriate equations are (1.17), (1.18), (1.3) an (1.19).. Kinematics an Balance laws Let B enote a boy an let κ t : B E, where E is a three imensional Eucliean space, be a family of placers parameterize by time t [, ) an κ t (B) the configuration of the boy at time t. We shall assume that for any t the placers are one to one. Such a family of placers is calle a motion an one can ientify the motion with a mapping χ κ : κ (B) R κ t (B) such that 5 (.1) x = χ κ (X, t). The isplacement u is efine as the ifference between x an X that are relate through (.1), i.e., (.) u(t, X) = χ κ (t, X) X. (.3) The velocity v an the eformation graient F are efine through v = χ κ t = u t, (.4) F = χ κ X. 5 In what follows we suppress notation of the epenence of the quantities on κt.
6 KELVIN-VOIGT VISCOELASTIC SOLID 5 We assume that et F > in κ (B). The right an left Cauchy-Green stretch tensors are efine through (.5) C = F T F, B = FF T, (A T enotes transpose to A) respectively, an the Green-St. Venant an the Almansi-Hamel strains are efine through E = 1 (C I), e = 1 ( I B 1), respectively. The linearize strain is efine through (.6) ε = 1 ( X u + ( X u) T ). The velocity graient L an its symmetric part D are efine through (.7) L = x v, D = 1 (L + LT ). Any property ϕ associate with a boy B can be expresse as (.8) ϕ = ˆϕ(t, X) = ϕ(t, x), which results to the introuction of the following Lagrangean an Eulerian temporal an spatial erivatives: ϕ ˆϕ (.9) := t t, ϕ,t := ϕ t, Xϕ = ˆϕ X, xϕ := ϕ x. The Lagrangean an Eulerian ivergence operators will be expresse as iv X an iv x, respectively. It follows from the notations an efinitions given above, in particular from (.9) an (.3) that ϕ (.1) t = ϕ,t + x ϕ v. Since we consier, in this stuy, processes that take place at uniform temperature we provie merely the formulation for the balance of mass an balance of linear momentum. Their Eulerian formulation is escribe by (.11) ϱ,t + iv x (ϱv) = an (ϱv),t + iv x (ϱv v) = iv x T in κ t (B), while their Lagrangean formulation is (.1) t (ϱ et F) = an ϱ v t = iv ( X (et F)TF T ) in κ (B), where ϱ : R enotes the initial istribution of the ensity, i.e., ϱ(, ) = ϱ. Note that in the Lagrangean formulation the balance of linear momentum inclues the initial (given) ensity an if T is inepenent of ϱ the equation for v can be solve separately from the equation for ϱ. If the boy is incompressible, i.e., iv v = in the Eulerian escription an et F = 1 in the Lagrangean framework, the Eulerian formulation of the balance of equations is given by (.13) iv v =, ϱ,t + x ϱ v = an ϱ (v,t + iv x (v v)) = x p + iv x S in κ t (B), while the Lagrangean form reuces to (.14) et F = 1, t ϱ = an ϱ v t = ( Xp + iv X TF T ) in κ (B).
7 6 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL Finally, in the linearize theory, when the isplacement graient is small an the Cauchy stress T an the Piola-Kirchoff stress (et F)TF T are of the same orer O(1), the governing equations for a compressible boy then rea (.15) ϱ(t, )(1 + tr ε(t, )) = ϱ an ϱ v t = iv X T in κ (B). It follows from (.15) 1 that ϱ an ϱ are of the same orer as tr ε is of the orer O(δ). Thus, in the linearize theory, it oes not matter whether one uses ϱ or ϱ. For the (inhomogeneous) incompressible soli, the governing equations take the form (.16) ϱ(t, ) = ϱ an ϱ v t = Xp + iv X S in κ (B). Since we focus our analysis on the moel for a compressible boy, we eal with the equation (.15) where T is given through the constitutive relations (1.3), (1.11) an (1.1). Thus, we are intereste in unerstaning the properties of the weak solution to relevant initial an bounary value problems (for given initial ensity, isplacement an velocity, an for given isplacement or traction on the bounary) associate with the system of partial ifferential equations (.17) ϱ u t = iv[ H(ε) + G(D)], where iv stans for iv X. Note that the graient of the pressure appears at the right-han sie of (.) if the boy is incompressible. In Sections 4 6, where the mathematical analysis of the initial an bounary value problem associate to (.17) is presente, we shall however use a slightly ifferent notation to express (1.11) an (1.1), namely (.18) T e = H(D(u)), an (.19) T v = G(D(v)), where D(u) an D(v) enote the symmetric part of the graients of the isplacement an the velocity respectively. Then the equation (.17) takes the form u (.) ϱ = iv[h(d(u)) + G(D(v))]. t While (.) is obtaine for small graient of the isplacement, we will show next that one can en-up with the scalar equation of the form (.) if one restricts ourself to special oneimensional eformations an start with the fully non-linear moel (it means that the graient of the isplacement is not necessarily small). 3. A special motion Let us consier the special shearing motion of an incompressible Kelvin-Voigt soli (1.4), with a view towars a generalization which will follow, given by (3.1) x = X + u(y, t), y = Y, z = Z with the pressure fiel being given by (3.) p = p(t, x).
8 KELVIN-VOIGT VISCOELASTIC SOLID 7 The above motion (3.1) automatically satisfies the constraint of incompressibility. It immeiately follows that the balance of linear momentum reuces to ϱ u,tt = p,x + µu,yy + ηu,yyt, (3.3) = p,y, = p,z. This implies that the pressure can almost be a function of time an linear in x. Let us seek a solution wherein the pressure is a constant; in this case the problem reuces to (3.4) ϱ u,tt = µu,yy + ηu,yyt. In the above equation the ensity ϱ is given. We coul also stuy the above motion within the context of a compressible Kelvin-Voigt soli (1.5). Even in this case we obtain only one non-trivial component for the balance of linear momentum, namely (3.4). If one consiers generalizations of both the incompressible an compressible Kelvin-Voigt moels given by T e = H(B), an T v = G(D), with T given by (1.3), then in the case of simple shear we obtain that (3.5) ϱ u,tt = [H 1 (u,y )],y + [G 1 (u,yt )],y, where ϱ is given. To conclue, we aime to show that the governing system of equations to a class of fully nonlinear Kelvin-Voigt moels reuces, at a simple shearing motion, to the form (.) without necessity to restrict ourselves to small eformation graients. 4. Existence, uniqueness an regularity of weak solution 4.1. Equations an assumptions. Let := κ (B) R be an open boune omain with Lipschitz bounary that contains two smooth parts Γ D an Γ N such that = Γ D Γ N. For such an for T >, an for given ϱ : R, u : R, v : R, u D : (, T ) Γ D R an g : (, T ) Γ N R, we consier the following problem: to fin u : (, T ) R fulfilling (4.1) ϱ u,tt iv T = in (, T ), u(, ) = u in, u,t (, ) = v in, u = u D on (, T ) Γ D, Tn = g on (, T ) Γ N, where the stress tensor T is suppose to be of the form { G(D(u,t (t, x))) + H(D(u(t, x))) for compressible boy, T(t, x) := G(D(u,t (t, x))) + H(D(u(t, x))) p(t, x)i for incompressible boy, where pi enotes the unetermine part of the stress. In the latter case, we have to a the constraint of incompressibility expresse in the form iv u = iv v =. Regaring the tensorial functions G an H we assume that they are continuous on R an that there are r, q (1, ) an C 1, C > such that for arbitrary D 1, D R the following
9 8 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL conitions hol: (A1) (A) 1 (G(D 1 ) G(D )) (D 1 D ) C 1 D 1 D (1 + D 1 + s(d D 1 ) ) r s, 1 (H(D 1 ) H(D )) (D 1 D ) C 1 D 1 D (1 + D 1 + s(d D 1 ) ) q s, G(D 1 ) G(D ) C D 1 D H(D 1 ) H(D ) C D 1 D Moreover, we assume that 1 1 (1 + D 1 + s(d D 1 ) ) r s, (1 + D 1 + s(d D 1 ) ) q s. (A3) G() = an H() =. Note that (A1) (A3) lea to the stanar coercivity an growth conitions (see for example [3] for etails an note that the precise value of the constants C 1, C may iffer from C 1 an C use in (A1) an (A)) (4.) (4.3) G(D) D C 1 ( D r 1), H(D) D C 1 ( D q 1), G(D) C (1 + D ) r 1, H(D) C (1 + D ) q 1. Since, the methos we use later are inepenent of solving the compressible or the incompressible case, we will focus only on the compressible one in what follows. However, all results that we shall prove can be formulate also for incompressible boies. Before we efine the notion of a weak solution we first introuce the function spaces neee later. The Lebesgue spaces L p () an the Sobolev spaces W 1,p () are efine, for 1 p, in a stanar way. Moreover, we efine W 1,p Γ D () := {u W 1,p (); u ΓD = }. In aition, if u L p () an v L p () we use the notation (u, v) := uv x. Similarly, we also abbreviate bounary integrals. The same comment concerns vector- an tensor-value functions as well. Finally, for any Banach space X, we enote X := } X. {{.. X }. times Next, we efine the notion of a weak solution to (4.1). Definition 4.1. Let C,1, T > an G, H satisfy (4.) (4.3). In aition, assume that g L r (, T ; (W 1 1 r,r (Γ N ) ) ), u W 1,q (), v L () an u D W 1,r (, T ; W 1 1 r,r (Γ D ) ). Moreover, let m, M be such that < m ϱ (x) M < for a.a. x. We say that u is a weak solution (4.1) if (4.4) u L (, T ; W 1,q () ) W 1, (, T ; L () ) W 1,r (, T ; W 1,r () ), ϱ u,tt L min(r,q ) (, T ; (W 1,max(r,q) Γ D () ) ), u (,T ) ΓD = u D, u,t (,T ) ΓD = v D := (u D ),t, the following weak formulation of (4.1) hols (4.5) T ϱ u,tt, ϕ + ( G(D(u,t )) + H(D(u)), D(ϕ) ) T t = g, ϕ ΓN t for all ϕ L max(r,q) (, T ; W 1,max(r,q) Γ D () ),
10 KELVIN-VOIGT VISCOELASTIC SOLID 9 an the initial conitions are met in the following sense ( (4.6) lim u,t (t) v + u(t) u q ) t 1,q =. + Theorem 4.1 (Existence an Uniqueness). Assume that all the assumptions of Definition 4.1 are satisfie. Let G, H satisfy (A1) 1, (A) an (A3) with 1 < q r <. Moreover, let u W 1, () an ũ D W,r (, T ; W 1,r () ) be such that u ũ D (, ) W 1,r Γ D () an ũ D (,T ) Γ = u D. Then there exists unique weak solution to (4.1). Before formulating the results concerning the regularity properties of the weak solution to (4.1) we slightly strengthen the assumptions (A1) an (A) concerning G an H. We shall suppose that G an H are continuously ifferentiable on R an that there are C 1, C > such that for arbitrary A, D R the following conitions hol: (A1*) (A*) C 1 (1 + A ) r D G D (A) (D D) C (1 + A ) r D H D (A) (D D) C (1 + A ) q D Theorem 4. (Regularity). Let all the assumptions of Theorem 4.1 be satisfie an H an G fulfil (A1*) (A*). i) If in aition ϱ C,1 () an v W 1, loc () then (4.7) (4.8) (4.9) (1 + D(v) ) r D( v) L (, T ; L loc () ), v L (, T ; W 1, loc () ), v,t L r (, T ; L r loc () ). ii) Moreover, if ϱ C,1 (), v W 1, (), g W 1,r (, T ; W 1+ 1 r,r (Γ D )) an either Dirichlet or Neumann bounary conitions hol on connecte components of the bounary, then (4.1) (4.11) (4.1) v,t L (, T ; L () ), (1 + D(v) ) r D(v,t ) L (, T ; L () ), (1 + D(v) ) r D( v) L (, T ; L () ). The main novelty of Theorem 4.1 an Theorem 4. consists in allowing a nonlinear epenence of G on the symmetric part of the velocity graient D(v) (here we are able to analyze the case r > ) an investigating the problem with non-constant (given) ensity. Moreover, we o not nee to assume the existence of potentials to H an G in orer to prove the results state in both theorems. Such generalizations were not consiere in the earlier stuies by Tvet [7], an were solve only in some special cases (G growing at most linearly with D(v), an = or C C 1 being small) by Frieman an Nečas []. We also remark that we coul also prove that v L (, T ; W 1,r () ) if we assume the existence of a potential to G. Since one of our aims was to avoi the assumptions of this type, we o not inclue corresponing regularity result in the statement of Theorem 4..
11 1 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL For our analysis it is suitable to rewrite (4.1) in the form (4.13) ϱ v,t iv G(D(v)) iv H(D(u)) = in (, T ), u,t = v in (, T ), u(, x) = u, v(, x) = v in, u = u D, v = v D on (, T ) Γ D, (G(D(v)) + H(D(u)))n = g on (, T ) Γ N. 5. Proof of Theorem Galerkin approximation. Since W 1,r Γ () is separable there is a basis {w n } n=1 that is in aition orthonormal in L (). Let P n enote the projection W 1,r Γ D () to the span generate by {w i } n i=1 an un := P n (u ũ D ()) + ũ D () an v n := P n (v ṽ D ()) + ṽ D (). We look for the approximate solution u n of the form n u n (t, x) := c i (t)w i (x) + ũ D (t, x) satisfying (note that v n enotes u n,t) (5.1) i=1 (ϱ v n,t, w i ) + (G(D(v n )), D(w i )) +(H(D(u n )), D(w i )) = g, w i ΓN for all i = 1,,..., n, u n (, ) = u n an v n (, ) : = u n,t(, ) = v n. It follows from the Carathéoory theory (see [1, Chapter ]) that there exists a local-in-time solution to (5.1). Moreover, using the uniform estimates erive in the next subsection, we can exten such a solution to the whole time interval [, T ]. 5.. Uniform estimates. Multiplying the i-th equation in (5.1) by c i (t) an taking the sum over i = 1,..., n, we obtain (recall that ṽ D = (ũ D ),t ) the following ientity (5.) (ϱ v n,t, v n ṽ D ) + (G(D(v n )), D(v n ṽ D )) + (H(D(u n )), D(v n ṽ D )) = g, v n ṽ D ΓN, which we rewrite in the form (ϱ (v n ṽ D ),t, v n ṽ D ) + (G(D(v n )), D(v n )) = g, v n ṽ D ΓN (5.3) + (ϱ (ṽ D ),t, ṽ D v n ) + (G(D(v n )), D(ṽ D )) (H(D(u n )), D(v n ṽ D )). Next, using the assumptions (A1) 1, (A) an (A3) (an their consequences (4.) an (4.3)), we get (note that we assume q ) (5.4) t ϱ (v n ṽ D ) + C 1 D(v n ) r r C 1 + g, v n ṽ D ΓN + (ϱ (ṽ D ),t, ṽ D v n ) + C 1 + D(v n ) r 1 r D(ṽ D ) r + C (1 + D(u n ) ) ( D(v n ) + D(ṽ D ) ) x. Then, aing the inequality t D(un ) = (D(u n ), D(v n )) D(v n ) D(u n ) x
12 KELVIN-VOIGT VISCOELASTIC SOLID 11 to (5.4) an using the continuous embeing of W 1,r () into W 1 1 r,r (Γ N ), the assumptions concerning ṽ D, the Höler an the Young inequalities we obtain (5.5) ( ϱ (v n ṽ D ) + D(u n ) ) + C1 D(v n ) r r t ( ) C 1 + g r (W 1 1 r,r (Γ N )) + ṽ D r 1,r + ϱ (ṽ D ),t r (W 1,r Γ ()) + D(un ). D Finally, using the Gronwall lemma an the Korn inequality, an combining them with the assumptions concerning g, ϱ an ũ D, we euce from (5.5) the following uniform estimate (5.6) ( T sup v n + u n 1,) + v n r 1,r t C(u, v, g, ϱ, ũ D, ) C. t (,T ) Consequently, using (4.3) an (5.1) we euce that (5.7) sup H(D(u n )) + t (,T ) T G(D(v n )) r r t + T ϱ v n,t r ( ) W 1,r t C. Γ () D 5.3. Limit n. Having the estimates (5.6) (5.7), using (4.3) an the continuity of the projection P n, we can fin (not relabele) subsequences such that (5.8) (5.9) (5.1) (5.11) (5.1) (5.13) (5.14) (5.15) u n u strongly in W 1,r (), v n v strongly in L (), u n u weakly in L (, T ; W 1, () ), v n v weakly in L (, T ; L () ), v n v weakly in L r (, T ; W 1,r () ), ϱ v n,t ϱ v,t weakly in L r (, T ; (W 1,r Γ () ) ), G(D(v n )) G weakly in L r (, T ; L r () ), H(D(u n )) H weakly in L (, T ; L () ). Having on han (5.1) (5.15), it is then easy to take the limit in (5.1) to obtain (5.16) T ϱ v,t, w + (G, D(w)) + (H, D(w)) t = T g, w t, for all w L r (, T ; W 1,r Γ () ), T (, T ], where in aition v = u,t. Thus, it remains to show that H = H(D(u)) an G = G(D(v)). For this purpose it is enough to show that there is a subsequence that we enote again as the original sequence such that (5.17) D(v n ) D(v) an D(u n ) D(u) a.e. in (, T ). To o this, we integrate (5.) over the time interval (, T ), where T (, T ) is arbitrary, take the limit n, use weak lower semicontinuity of the norm an the convergence properties
13 1 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL (5.8) (5.15) an finally obtain (5.18) lim sup n T T (G(D(v n )), D(v n ṽ D )) + (H(D(u n )), D(v n ṽ D )) t ϱ v,t, v ṽ D + g, v ṽ D ΓN t 1 ϱ (v(t ) ṽ D (T )) + 1 ϱ (v ṽ D ()). Next, setting w := v ṽ D in (5.16) an comparing the result with (5.18) we observe that (note that here, we use that fact that v() = v, which will be prove in the next subsection an the proof is base only on (5.16)) (5.19) lim sup n T (G(D(v n )), D(v n )) + (H(D(u n )), D(v n )) t T Finally, using (5.14), (5.15) an (5.19), it is easy to euce that for all T (, T ) (5.) lim sup n T (G + H, D(v)) t. (G(D(v n )) G(D(v)) + H(D(u n )) H(D(u)), D(v n v)) t. Next, for arbitrary but fixe T 1 (, T ) we efine Q 1 := (, T 1 ) an we set 1 (5.1) J n : = C 1 D(v n v) (1 + D(v) + sd(v n v) ) r s x t, Q 1 (5.) I n : = C Q 1 D(v n v) D(u n u) 1 an we observe that (5.), (A1) 1 an (A) leas to 6 (1 + D(u) + sd(u n u) ) q s x t, (5.3) J n g(n) + I n, where lim sup g(n) =. n This is our starting point to achieve (5.17). Using (5.4) u n (t) u(t) = t v n (τ) v(τ) τ + u n u, an the fact that q, we arrive at T1 T1 t I n C D(v n v) D(u n u ) t + C D(v n v) D(v n v) t (5.5) T1 ( T1 ) g(n) + C D(v n v) D(v n v) s t, where we use (5.8) an (5.1) to conclue that that the first integral on the right han sie of (5.5) tens to zero as n. Applying the Höler inequality to the secon integral on the right han sie of (5.5) we observe from (5.3) that T1 (5.6) J n g(n) + C T 1 D(v n v) t 6 We use the symbol g(n) to enote any quantity fulfilling lim supn g(n) = ; its exact efinition can change from line to line.
14 Since r it follows from the efinition of J n that (5.7) KELVIN-VOIGT VISCOELASTIC SOLID 13 T1 J n C 1 D(v n v) t. Setting T 1 := C 1 C, the inequalities (5.6) an (5.7) finally imply that T1 (5.8) D(v n v) x t = D(v n v) g(n). Q 1 To prove the strong convergence (5.8) on the whole time cyliner (, T ) we continue inuctively. We efine T k := kt 1 an assume that (5.8) hols on Q k := (, T k ). The aim is to show that (5.8) hols also on Q k+1. We procee analogously as in (5.)-(5.5), replacing T 1 by T k+1 (in particular in the efinitions of J n an I n ). Doing so, we are able to euce from the strong convergence (5.8) on Q k that Tk+1 t J n g(n) + C D(v n v) D(v n v) s t Tk+1 g(n) + C D(v n t v) D(v n v) s t T k Tk+1 g(n) + C D(v n t v) D(v n v) s t T k T k g(n) + (T k+1 T k ) C }{{} =T 1 Tk+1 T k D(v n v) t g(n) + 1 J n. Consequently, the convergence properties (5.8) on Q k+1 follow. (5.17), at least for a selecte subsequence. Thus, (4.5) hols. This completes the proof of 5.4. Initial conitions. In this subsection we prove that the initial ata meet (4.6). Note that this property has been alreay use in the proof of point-wise convergence of D(v n ). Thus, we cannot incorporate (4.5) into our consieration. We can however use (5.16). First, we integrate (5.1) with respect to time over (, t) an observe that (5.9) (ϱ v n (t),w i ) + = t t (G(D(v n )), D(w i )) + (H(D(u n )), D(w i )) τ g, w i ΓN τ + (ϱ v n, w i ) for all i = 1,,..., n. Next, we use (5.1) (5.15) (note that ϱ v C weak (, T ; L () ), which follows from (5.11), (5.13) an the embeing theorem) to obtain for all time t (, T ) (5.3) (ϱ v(t), w i ) + = t t (G, D(w i )) + (H, D(w i )) τ g, w i ΓN τ + (ϱ v, w i ) for all i N.
15 14 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL Finally, since {w n } n=1 that is a basis for W 1,r Γ D () that is ense in L () we conclue from (5.3) (5.31) lim t + (ϱ v(t), w) = (ϱ v, w) for all w L (). Next, integrating (5.5) over (, t), applying the Gronwall lemma, letting n an using weak lower semicontinuity of the L -norm, we observe that (5.3) lim sup t + ϱ (v(t) ṽ D (t)) ϱ (v ṽ D ()). Then, we combine (5.31), (5.3) an the assumptions concerning ṽ D to get lim ϱ (v(t) v ) ( = lim ϱ (v(t) ṽ D (t)) + ϱ (ṽ D (t) v ) ) t + t + + lim t + (ϱ (v(t) ṽ D (t)), ṽ D (t) v ) (5.3),(5.31) ϱ (v ṽ D ()) + ϱ (ṽ D () v ) =. + (ϱ (v ṽ D ()), ṽ D () v ) Finally, using the fact that ϱ is boune from below, we obtain (4.6) 1. It remains to establish (4.6). We shall prove it for q =. We first multiply (5.1) consiere at time τ by τ an integrate the result over (, t). We obtain (5.33) (ϱ v n (t), tw i ) (ϱ u n (t), w i ) + (ϱ u n, w i ) = t (τg(d(v n (τ))), D(w i )) + (τh(d(u n (τ))), D(w i )) τ g(τ), w i ΓN for all i = 1,,..., n. Next, letting n in (5.33) we come to the conclusion that (5.34) lim t + (ϱ u(t), w) = (ϱ u, w) for all w L (). Then, we observe that the following simple relation hols for any τ t T : t ) (5.35) ϱ u(t) = (ϱ v s, u(t) + (ϱ u(τ), u(t)). τ Thus, first letting τ + an using (5.34) an then letting t + an using (5.34) again we observe that (5.36) lim sup t + ϱ u(t) ϱ u. Using (5.34) again, we conclue from (5.36) that (5.37) lim t + u(t) u =, which is the first part of (4.6). It follows from (5.1) an (5.37) that (5.38) lim t + ( u(t), w) = ( u, w) for all w W 1, (). τ
16 Thus, using the relation ( t u(t) = together with (5.38) we finally obtain (4.6). KELVIN-VOIGT VISCOELASTIC SOLID 15 τ ) v s, u(t) + ( u(τ), u(t)) 5.5. Uniqueness. Assume that u 1 an u are two weak solutions of (4.13) that satisfy the same initial an bounary ata. Set v 1 := u 1,t an v := u,t an enote w := u 1 u an z := v 1 v. Then subtracting (4.5) for u 1 from (4.5) for u an setting ϕ := z (note that this is an amissible test function) we come to the ientity (5.39) 1 t ϱ z + (G(D(v 1 )) G(D(v )), D(z)) = (H(D(u )) H(D(u 1 )), D(z)). Next, aing the inequality t D(w) D(w) D(z), to (5.39), an using (A1) 1, (A), the fact that q, an the Höler an the Young inequality, we obtain ( ϱ z + D(w) ) (5.4) + C1 D(z) C D(w) t, which implies, after applying the Gronwall lemma, that z in (, T ) (an consequently also w ). The proof of uniqueness is complete. 6. Proof of Theorem 4. In this section we establish regularity properties of any weak solution to (4.1) provie that ata are smooth enough, i.e., we will prove Theorem 4.. Here, we only give a formal proof, but the whole proceure can be one rigorously by using the stanar ifference quotient technique an by using uniqueness of weak solution. We start by proving the interior regularity result as formulate in the part i) of Theorem 4.. For arbitrary h > we set h := {x ; ist(x, ) h} an we consier a nonnegative ϕ D() such that ϕ = 1 in h. Then we multiply (4.13) 1 by iv(ϕ v) an integrate over. Doing so, we come, after integration by parts, to the ientity (note that all bounary integrals vanish ue to our choice of ϕ) (6.1) 1 t ϱ ϕ v + ( (G(D(v)) + H(D(u)), ϕ D( v)) = ( ϱ ϕ v,t, v) ( (G(D(v)) + H(D(u)), ϕ ϕ v). Next, we estimate the secon term on the left han sie of (6.1) by means of (A1*) (A*) an obtain ( (G(D(v)) + H(D(u)), ϕ D( v)) C 1 (1 + D(v) ) r D( v) ϕ x (6.) C (1 + D(u) ) q D( u) D( v) ϕ x.
17 16 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL To estimate the secon term on right han sie of (6.1) we use (A1*) (A*) an the fact that q an we euce that (6.3) ( (G(D(v)) + H(D(u)), ϕ ϕ v) C((1 + D(v) ) r D( v) ϕ, (1 + D(v) ) r v ) + C( D( u) ϕ, v ) C 1 ((1 + D(v) ) r D( v) ϕ x + C(1 + v r r + v + D( u)ϕ ). Inserting (6.3) an (6.) into (6.1), applying the Höler inequality to the first term on the right han sie of (6.1), an again using the fact that q an the Young inequality to estimate the secon term on the right han sie of (6.), we finally observe that (6.4) t ϱ ϕ v + C 1 (1 + D(v) ) r D( v) ϕ x C( v r r + v + D( u)ϕ ) + ϱ ϕ v,t ϕ r v r. In orer to estimate the last term on the right han sie of (6.4), we use (4.13) an (A1*) (A*) an observe that (6.5) v,t ϕ r iv(g(d(v)) + H(D(u)))ϕ r C ( (1 + D(v) ) r D( v)ϕ r + (1 + D(u) ) q ) D( u)ϕ r ) C ( (1 + D(v) ) r D( v)ϕ (1 + D(v) ) r r + D( u)ϕ r ( ) C (1 + D(v) ) r D( v)ϕ 1 + v r r + D( u)ϕ Upon inserting (6.5) into (6.4), we obtain (using also the Young inequality) t ϱ ( v)ϕ + (1 + D(v) ) r D( v) ϕ x (6.6) C ( D( u)ϕ + (1 + ϱ ϕ ) 1 + v r r + ϱ ϕ ). Next, aing the inequality to (6.6) we get (6.7) t D( u)ϕ D( u)ϕ D( v)ϕ 1 D( v)ϕ + 4 D( u)ϕ ( ϱ vϕ + D( u)ϕ ) + (1 + D(v) ) r D( v) ϕ x t C ( D( u)ϕ + g(t) ), where g(t) := (1 + ϱ ϕ ) 1 + v r r + ϱ ϕ L 1 (, T ) accoring to our assumptions. Thus, applying the Gronwall lemma, we obtain (4.7) (4.8). The regularity property (4.9) is then a consequence of (6.5) an (6.7). In the next part, we prove the properties (4.1) an (4.11) that concern the regularity of v,t. Although we will procee formally, one can obtain the same type result rigorously by eriving uniform estimates for the Galerkin approximations an conclue (4.1) an (4.11) for their (uniquely etermine) weak limit. Here, we ifferentiate (4.13) 1 with respect to time an take
18 KELVIN-VOIGT VISCOELASTIC SOLID 17 the scalar prouct of the result an v,t. Integrating the output over we obtain (for simplicity we restrict ourselves to homogeneous Dirichlet bounary conitions on (, T ) ) ( ) ( ) 1 G H (6.8) t ϱ v,t + D (D(v)), D(v,t ) D(v,t ) + D (D(u)), D(v) D(v,t ) =. It then follows from (A1*), (A*) an the fact that q that t ϱ v,t + C 1 (1 + D(v) ) r D(v,t ) x (1 + D(u) ) q D(v) D(v,t ) x (6.9) (1 + D(v) ) (r )/ D(v,t ) (1 + D(v) ) (4 r)/ x C 1 (1 + D(v) ) r D(v,t ) x D(v) 4 r Since 4 r r we easily euce (4.1) an (4.11) from (6.9) an (4.4) 1. The final part of this subsection is evote to the regularity properties near the bounary. For simplicity, we prove the result only for a part of the bounary where we prescribe homogeneous Dirichlet conition 7, i.e. ṽ D =. In aition we simplify the proof by assuming that this part of the bounary is locate at ( 1, 1) 1 {} an within the support of a smooth function ϕ D(( 1, 1) ) such that ϕ = 1 in the neighborhoo of a part of Γ D we are intereste in. Next, we efine i h f(x) := f(x + hei ) f(x). an we take, for any fixe i = 1,..., 1 an sufficiently small h >, ϕ i := i h (ϕ i h v) as a test function in (4.5). Note that this choice is possible since ϕ i = on [, T ]. Also note that the bounary integral in (4.5) vanishes. Hence, we have (6.1) (ϱ v,t, ϕ i ) + (G(D(v)) + H(D(u)), D(ϕ i )) =. We start by estimating the first term. One easily observes that 4 r. (6.11) Next, enoting (ϱ v,t, ϕ) = ( i h (ϱ v,t ), ϕ i h v) 1 t ϱ ϕ i h v Ch v,t ϕ i h v ϱ. 1 Ih i := D(v(x + he i ) v(x)) (1 + D(v(x + he i )) s(d(v(x + he i ) v(x))) ) r s, 7 The technique of the proof for inhomogeneous Dirichlet ata an for ΓN is the same.
19 18 M. BULÍČEK, J. MÁLEK, AND K.R. RAJAGOPAL we observe by using (A1*), (A*) an the Höler an the Young inequalities that (G(D(v)), D(ϕ i )) C 1 Ih i ϕ x (6.1) ( ( 1 ) ) 1 C (Ih i ) 1 ϕ, i h v (1 + D(v(x + he i )) s(d(v(x + he i ) v(x))) ) r s C 1 I i h ϕ x Ch (1 + v r). Similarly, using (A) an the fact that q, we get (6.13) (H(D(u)), D(ϕ i )) C ϕ D( i h u) D( i h v) x C 1 4 Thus, inserting (6.11) (6.13) into (6.1) an aing the inequality (r ) ϕ I i h x + C ϕd( i h u). t D( i h u)ϕ D( i h u)ϕ D( i h v)ϕ C 1 D( i h v)ϕ + C D( i h u)ϕ C 1 Ih i ϕ x + C D( i h u)ϕ we obtain (iviing the result by h ) ( h ϱ i h t v + h D( i ) h u)ϕ + h ϕ Ih i (6.14) x C(h D( i h u)ϕ + v,t ). At this juncture, we apply the Gronwall lemma to (6.14), using (4.1), an conclue that (6.15) sup h> which implies that T (6.16) T ϕ h Ih i x t C, (1 + D(v) ) r D( xi v) ϕ x t C for all i = 1,..., 1. Finally, we rewrite the ith equation in (4.1) 1 in the form (6.17) x G i (D(v)) = 1 xj H ij (D(u)) xj G ij (D(v)) ϱ (v i ),t. j=1 Multiplying (6.17) by x D(v), taking the sum over i = 1,...,, integrating the result over, an then using the assumptions (A1*) an (A*) we obtain (6.18) (1 + D(v) ) r D( x v) C D( x u) D( x v) + g(t), whereby g enotes a function satisfying, by (4.1) an (6.16), that g L 1 (, T ). Aing the inequality t D( x u) D( x v) D( x u) i=1
20 KELVIN-VOIGT VISCOELASTIC SOLID 19 to (6.18), using the Young inequality an applying the Gronwall lemma, we finally get (4.1) (incorporating (6.16) again). The proof of Theorem 4. is complete. References [1] E. A. Coington an N. Levinson. Theory of orinary ifferential equations. McGraw-Hill Book Company, Inc., New York-Toronto-Lonon, [] A. Frieman an J. Nečas. Systems of nonlinear wave equations with nonlinear viscosity. Pacific J. Math., 135(1):9 55, [3] J. Málek, J. Nečas, M. Rokyta, an M. Růžička. Weak an measure-value solutions to evolutionary PDEs. Chapman & Hall, Lonon, [4] K. R. Rajagopal. A note on a reappraisal an generalization of the Kelvin-Voigt Moel. Mechanics Research Communications, 36:3 35, 9. [5] K. R. Rajagopal. Rethinking constitutive relations. 9. [6] W. Thompson. On the elasticity an viscosity of metals. Proc. Roy. Soc. Lonon, A14:89 97, [7] B. Tvet. Quasilinear equations for viscoelasticity of strain-rate type. Arch. Ration. Mech. Anal., 189():37 81, 8. [8] W. Voigt. Ueber innere Reibung fester Körper, insbesonere er Metalle. Annalen er Physik, 83: , 189. Mathematical Institute of Charles University, Sokolovská 83, Prague, Czech Republic aress: mbul86@karlin.mff.cuni.cz Mathematical Institute of Charles University, Sokolovská 83, Prague, Czech Republic aress: malek@karlin.mff.cuni.cz Department of Mechanical Engineering, Texas A&M University, College Station, TX 77845, USA aress: krajagopal@tamu.eu
PDE Notes, Lecture #11
PDE Notes, Lecture # from Professor Jalal Shatah s Lectures Febuary 9th, 2009 Sobolev Spaces Recall that for u L loc we can efine the weak erivative Du by Du, φ := udφ φ C0 If v L loc such that Du, φ =
More informationSchrödinger s equation.
Physics 342 Lecture 5 Schröinger s Equation Lecture 5 Physics 342 Quantum Mechanics I Wenesay, February 3r, 2010 Toay we iscuss Schröinger s equation an show that it supports the basic interpretation of
More informationMath 342 Partial Differential Equations «Viktor Grigoryan
Math 342 Partial Differential Equations «Viktor Grigoryan 6 Wave equation: solution In this lecture we will solve the wave equation on the entire real line x R. This correspons to a string of infinite
More informationAbstract A nonlinear partial differential equation of the following form is considered:
M P E J Mathematical Physics Electronic Journal ISSN 86-6655 Volume 2, 26 Paper 5 Receive: May 3, 25, Revise: Sep, 26, Accepte: Oct 6, 26 Eitor: C.E. Wayne A Nonlinear Heat Equation with Temperature-Depenent
More informationLectures - Week 10 Introduction to Ordinary Differential Equations (ODES) First Order Linear ODEs
Lectures - Week 10 Introuction to Orinary Differential Equations (ODES) First Orer Linear ODEs When stuying ODEs we are consiering functions of one inepenent variable, e.g., f(x), where x is the inepenent
More informationAgmon Kolmogorov Inequalities on l 2 (Z d )
Journal of Mathematics Research; Vol. 6, No. ; 04 ISSN 96-9795 E-ISSN 96-9809 Publishe by Canaian Center of Science an Eucation Agmon Kolmogorov Inequalities on l (Z ) Arman Sahovic Mathematics Department,
More informationBasic Thermoelasticity
Basic hermoelasticity Biswajit Banerjee November 15, 2006 Contents 1 Governing Equations 1 1.1 Balance Laws.............................................. 2 1.2 he Clausius-Duhem Inequality....................................
More informationThe total derivative. Chapter Lagrangian and Eulerian approaches
Chapter 5 The total erivative 51 Lagrangian an Eulerian approaches The representation of a flui through scalar or vector fiels means that each physical quantity uner consieration is escribe as a function
More informationEuler equations for multiple integrals
Euler equations for multiple integrals January 22, 2013 Contents 1 Reminer of multivariable calculus 2 1.1 Vector ifferentiation......................... 2 1.2 Matrix ifferentiation........................
More informationθ x = f ( x,t) could be written as
9. Higher orer PDEs as systems of first-orer PDEs. Hyperbolic systems. For PDEs, as for ODEs, we may reuce the orer by efining new epenent variables. For example, in the case of the wave equation, (1)
More information05 The Continuum Limit and the Wave Equation
Utah State University DigitalCommons@USU Founations of Wave Phenomena Physics, Department of 1-1-2004 05 The Continuum Limit an the Wave Equation Charles G. Torre Department of Physics, Utah State University,
More informationEnergy Splitting Theorems for Materials with Memory
J Elast 2010 101: 59 67 DOI 10.1007/s10659-010-9244-y Energy Splitting Theorems for Materials with Memory Antonino Favata Paolo Poio-Guiugli Giuseppe Tomassetti Receive: 29 July 2009 / Publishe online:
More informationA note on the Mooney-Rivlin material model
A note on the Mooney-Rivlin material moel I-Shih Liu Instituto e Matemática Universiae Feeral o Rio e Janeiro 2945-97, Rio e Janeiro, Brasil Abstract In finite elasticity, the Mooney-Rivlin material moel
More informationChapter 6: Energy-Momentum Tensors
49 Chapter 6: Energy-Momentum Tensors This chapter outlines the general theory of energy an momentum conservation in terms of energy-momentum tensors, then applies these ieas to the case of Bohm's moel.
More information12.11 Laplace s Equation in Cylindrical and
SEC. 2. Laplace s Equation in Cylinrical an Spherical Coorinates. Potential 593 2. Laplace s Equation in Cylinrical an Spherical Coorinates. Potential One of the most important PDEs in physics an engineering
More informationA simple model for the small-strain behaviour of soils
A simple moel for the small-strain behaviour of soils José Jorge Naer Department of Structural an Geotechnical ngineering, Polytechnic School, University of São Paulo 05508-900, São Paulo, Brazil, e-mail:
More informationORDINARY DIFFERENTIAL EQUATIONS AND SINGULAR INTEGRALS. Gianluca Crippa
Manuscript submitte to AIMS Journals Volume X, Number 0X, XX 200X Website: http://aimsciences.org pp. X XX ORDINARY DIFFERENTIAL EQUATIONS AND SINGULAR INTEGRALS Gianluca Crippa Departement Mathematik
More informationON ISENTROPIC APPROXIMATIONS FOR COMPRESSIBLE EULER EQUATIONS
ON ISENTROPIC APPROXIMATIONS FOR COMPRESSILE EULER EQUATIONS JUNXIONG JIA AND RONGHUA PAN Abstract. In this paper, we first generalize the classical results on Cauchy problem for positive symmetric quasilinear
More informationarxiv: v1 [math.ap] 6 Jul 2017
Local an global time ecay for parabolic equations with super linear first orer terms arxiv:177.1761v1 [math.ap] 6 Jul 17 Martina Magliocca an Alessio Porretta ABSTRACT. We stuy a class of parabolic equations
More informationThe Generalized Incompressible Navier-Stokes Equations in Besov Spaces
Dynamics of PDE, Vol1, No4, 381-400, 2004 The Generalize Incompressible Navier-Stokes Equations in Besov Spaces Jiahong Wu Communicate by Charles Li, receive July 21, 2004 Abstract This paper is concerne
More informationSINGULAR PERTURBATION AND STATIONARY SOLUTIONS OF PARABOLIC EQUATIONS IN GAUSS-SOBOLEV SPACES
Communications on Stochastic Analysis Vol. 2, No. 2 (28) 289-36 Serials Publications www.serialspublications.com SINGULAR PERTURBATION AND STATIONARY SOLUTIONS OF PARABOLIC EQUATIONS IN GAUSS-SOBOLEV SPACES
More information6 General properties of an autonomous system of two first order ODE
6 General properties of an autonomous system of two first orer ODE Here we embark on stuying the autonomous system of two first orer ifferential equations of the form ẋ 1 = f 1 (, x 2 ), ẋ 2 = f 2 (, x
More informationGlobal Solutions to the Coupled Chemotaxis-Fluid Equations
Global Solutions to the Couple Chemotaxis-Flui Equations Renjun Duan Johann Raon Institute for Computational an Applie Mathematics Austrian Acaemy of Sciences Altenbergerstrasse 69, A-44 Linz, Austria
More informationIntroduction to the Vlasov-Poisson system
Introuction to the Vlasov-Poisson system Simone Calogero 1 The Vlasov equation Consier a particle with mass m > 0. Let x(t) R 3 enote the position of the particle at time t R an v(t) = ẋ(t) = x(t)/t its
More informationarxiv: v1 [physics.flu-dyn] 8 May 2014
Energetics of a flui uner the Boussinesq approximation arxiv:1405.1921v1 [physics.flu-yn] 8 May 2014 Kiyoshi Maruyama Department of Earth an Ocean Sciences, National Defense Acaemy, Yokosuka, Kanagawa
More informationANALYSIS OF A PHASE FIELD NAVIER-STOKES VESICLE-FLUID INTERACTION MODEL. Qiang Du, Manlin Li and Chun Liu
DISCRETE AND CONTINUOUS Website: http://aimsciences.org DYNAMICAL SYSTEMS SERIES B Volume 8, Number 3, October 27 pp. 539 556 ANALYSIS OF A PHASE FIELD NAVIER-STOKES VESICLE-FLUID INTERACTION MODEL Qiang
More informationNONLINEAR QUARTER-PLANE PROBLEM FOR THE KORTEWEG-DE VRIES EQUATION
Electronic Journal of Differential Equations, Vol. 11 11), No. 113, pp. 1. ISSN: 17-6691. URL: http://eje.math.txstate.eu or http://eje.math.unt.eu ftp eje.math.txstate.eu NONLINEAR QUARTER-PLANE PROBLEM
More informationA COMBUSTION MODEL WITH UNBOUNDED THERMAL CONDUCTIVITY AND REACTANT DIFFUSIVITY IN NON-SMOOTH DOMAINS
Electronic Journal of Differential Equations, Vol. 2929, No. 6, pp. 1 14. ISSN: 172-6691. URL: http://eje.math.txstate.eu or http://eje.math.unt.eu ftp eje.math.txstate.eu A COMBUSTION MODEL WITH UNBOUNDED
More informationMartin Luther Universität Halle Wittenberg Institut für Mathematik
Martin Luther Universität alle Wittenberg Institut für Mathematik Weak solutions of abstract evolutionary integro-ifferential equations in ilbert spaces Rico Zacher Report No. 1 28 Eitors: Professors of
More informationConservation laws a simple application to the telegraph equation
J Comput Electron 2008 7: 47 51 DOI 10.1007/s10825-008-0250-2 Conservation laws a simple application to the telegraph equation Uwe Norbrock Reinhol Kienzler Publishe online: 1 May 2008 Springer Scienceusiness
More informationConservation Laws. Chapter Conservation of Energy
20 Chapter 3 Conservation Laws In orer to check the physical consistency of the above set of equations governing Maxwell-Lorentz electroynamics [(2.10) an (2.12) or (1.65) an (1.68)], we examine the action
More informationMARKO NEDELJKOV, DANIJELA RAJTER-ĆIRIĆ
GENERALIZED UNIFORMLY CONTINUOUS SEMIGROUPS AND SEMILINEAR HYPERBOLIC SYSTEMS WITH REGULARIZED DERIVATIVES MARKO NEDELJKOV, DANIJELA RAJTER-ĆIRIĆ Abstract. We aopt the theory of uniformly continuous operator
More informationANALYSIS OF A GENERAL FAMILY OF REGULARIZED NAVIER-STOKES AND MHD MODELS
ANALYSIS OF A GENERAL FAMILY OF REGULARIZED NAVIER-STOKES AND MHD MODELS MICHAEL HOLST, EVELYN LUNASIN, AND GANTUMUR TSOGTGEREL ABSTRACT. We consier a general family of regularize Navier-Stokes an Magnetohyroynamics
More informationWELL-POSEDNESS OF A POROUS MEDIUM FLOW WITH FRACTIONAL PRESSURE IN SOBOLEV SPACES
Electronic Journal of Differential Equations, Vol. 017 (017), No. 38, pp. 1 7. ISSN: 107-6691. URL: http://eje.math.txstate.eu or http://eje.math.unt.eu WELL-POSEDNESS OF A POROUS MEDIUM FLOW WITH FRACTIONAL
More informationChapter 2 Governing Equations
Chapter 2 Governing Equations In the present an the subsequent chapters, we shall, either irectly or inirectly, be concerne with the bounary-layer flow of an incompressible viscous flui without any involvement
More informationOn the Cauchy Problem for Von Neumann-Landau Wave Equation
Journal of Applie Mathematics an Physics 4 4-3 Publishe Online December 4 in SciRes http://wwwscirporg/journal/jamp http://xoiorg/436/jamp4343 On the Cauchy Problem for Von Neumann-anau Wave Equation Chuangye
More informationTOWARDS THERMOELASTICITY OF FRACTAL MEDIA
ownloae By: [University of Illinois] At: 21:04 17 August 2007 Journal of Thermal Stresses, 30: 889 896, 2007 Copyright Taylor & Francis Group, LLC ISSN: 0149-5739 print/1521-074x online OI: 10.1080/01495730701495618
More information3 The variational formulation of elliptic PDEs
Chapter 3 The variational formulation of elliptic PDEs We now begin the theoretical stuy of elliptic partial ifferential equations an bounary value problems. We will focus on one approach, which is calle
More informationNON-SMOOTH DYNAMICS USING DIFFERENTIAL-ALGEBRAIC EQUATIONS PERSPECTIVE: MODELING AND NUMERICAL SOLUTIONS. A Thesis PRIYANKA GOTIKA
NON-SMOOTH DYNAMICS USING DIFFERENTIAL-ALGEBRAIC EQUATIONS PERSPECTIVE: MODELING AND NUMERICAL SOLUTIONS A Thesis by PRIYANKA GOTIKA Submitte to the Office of Grauate Stuies of Texas A&M University in
More informationGLOBAL SOLUTIONS FOR 2D COUPLED BURGERS-COMPLEX-GINZBURG-LANDAU EQUATIONS
Electronic Journal of Differential Equations, Vol. 015 015), No. 99, pp. 1 14. ISSN: 107-6691. URL: http://eje.math.txstate.eu or http://eje.math.unt.eu ftp eje.math.txstate.eu GLOBAL SOLUTIONS FOR D COUPLED
More informationLeast-Squares Regression on Sparse Spaces
Least-Squares Regression on Sparse Spaces Yuri Grinberg, Mahi Milani Far, Joelle Pineau School of Computer Science McGill University Montreal, Canaa {ygrinb,mmilan1,jpineau}@cs.mcgill.ca 1 Introuction
More informationAPPROXIMATE SOLUTION FOR TRANSIENT HEAT TRANSFER IN STATIC TURBULENT HE II. B. Baudouy. CEA/Saclay, DSM/DAPNIA/STCM Gif-sur-Yvette Cedex, France
APPROXIMAE SOLUION FOR RANSIEN HEA RANSFER IN SAIC URBULEN HE II B. Bauouy CEA/Saclay, DSM/DAPNIA/SCM 91191 Gif-sur-Yvette Ceex, France ABSRAC Analytical solution in one imension of the heat iffusion equation
More informationLinear First-Order Equations
5 Linear First-Orer Equations Linear first-orer ifferential equations make up another important class of ifferential equations that commonly arise in applications an are relatively easy to solve (in theory)
More informationStable and compact finite difference schemes
Center for Turbulence Research Annual Research Briefs 2006 2 Stable an compact finite ifference schemes By K. Mattsson, M. Svär AND M. Shoeybi. Motivation an objectives Compact secon erivatives have long
More informationChaos, Solitons and Fractals Nonlinear Science, and Nonequilibrium and Complex Phenomena
Chaos, Solitons an Fractals (7 64 73 Contents lists available at ScienceDirect Chaos, Solitons an Fractals onlinear Science, an onequilibrium an Complex Phenomena journal homepage: www.elsevier.com/locate/chaos
More informationOn some parabolic systems arising from a nuclear reactor model
On some parabolic systems arising from a nuclear reactor moel Kosuke Kita Grauate School of Avance Science an Engineering, Wasea University Introuction NR We stuy the following initial-bounary value problem
More informationComputing Exact Confidence Coefficients of Simultaneous Confidence Intervals for Multinomial Proportions and their Functions
Working Paper 2013:5 Department of Statistics Computing Exact Confience Coefficients of Simultaneous Confience Intervals for Multinomial Proportions an their Functions Shaobo Jin Working Paper 2013:5
More informationCOUPLING REQUIREMENTS FOR WELL POSED AND STABLE MULTI-PHYSICS PROBLEMS
VI International Conference on Computational Methos for Couple Problems in Science an Engineering COUPLED PROBLEMS 15 B. Schrefler, E. Oñate an M. Paparakakis(Es) COUPLING REQUIREMENTS FOR WELL POSED AND
More informationWUCHEN LI AND STANLEY OSHER
CONSTRAINED DYNAMICAL OPTIMAL TRANSPORT AND ITS LAGRANGIAN FORMULATION WUCHEN LI AND STANLEY OSHER Abstract. We propose ynamical optimal transport (OT) problems constraine in a parameterize probability
More information'HVLJQ &RQVLGHUDWLRQ LQ 0DWHULDO 6HOHFWLRQ 'HVLJQ 6HQVLWLYLW\,1752'8&7,21
Large amping in a structural material may be either esirable or unesirable, epening on the engineering application at han. For example, amping is a esirable property to the esigner concerne with limiting
More informationIntroduction to variational calculus: Lecture notes 1
October 10, 2006 Introuction to variational calculus: Lecture notes 1 Ewin Langmann Mathematical Physics, KTH Physics, AlbaNova, SE-106 91 Stockholm, Sween Abstract I give an informal summary of variational
More informationHyperbolic Moment Equations Using Quadrature-Based Projection Methods
Hyperbolic Moment Equations Using Quarature-Base Projection Methos J. Koellermeier an M. Torrilhon Department of Mathematics, RWTH Aachen University, Aachen, Germany Abstract. Kinetic equations like the
More informationSeparation of Variables
Physics 342 Lecture 1 Separation of Variables Lecture 1 Physics 342 Quantum Mechanics I Monay, January 25th, 2010 There are three basic mathematical tools we nee, an then we can begin working on the physical
More informationWell-posedness of hyperbolic Initial Boundary Value Problems
Well-poseness of hyperbolic Initial Bounary Value Problems Jean-François Coulombel CNRS & Université Lille 1 Laboratoire e mathématiques Paul Painlevé Cité scientifique 59655 VILLENEUVE D ASCQ CEDEX, France
More informationEuler Equations: derivation, basic invariants and formulae
Euler Equations: erivation, basic invariants an formulae Mat 529, Lesson 1. 1 Derivation The incompressible Euler equations are couple with t u + u u + p = 0, (1) u = 0. (2) The unknown variable is the
More informationProblem set 2: Solutions Math 207B, Winter 2016
Problem set : Solutions Math 07B, Winter 016 1. A particle of mass m with position x(t) at time t has potential energy V ( x) an kinetic energy T = 1 m x t. The action of the particle over times t t 1
More informationGradient flow of the Chapman-Rubinstein-Schatzman model for signed vortices
Graient flow of the Chapman-Rubinstein-Schatzman moel for signe vortices Luigi Ambrosio, Eoaro Mainini an Sylvia Serfaty Deicate to the memory of Michelle Schatzman (1949-2010) Abstract We continue the
More informationTopological Sensitivity Analysis for Three-dimensional Linear Elasticity Problem
Topological Sensitivity Analysis for Three-imensional Linear Elasticity Problem A.A. Novotny, R.A. Feijóo, E. Taroco Laboratório Nacional e Computação Científica LNCC/MCT, Av. Getúlio Vargas 333, 25651-075
More informationTractability results for weighted Banach spaces of smooth functions
Tractability results for weighte Banach spaces of smooth functions Markus Weimar Mathematisches Institut, Universität Jena Ernst-Abbe-Platz 2, 07740 Jena, Germany email: markus.weimar@uni-jena.e March
More informationCHAPTER 1 : DIFFERENTIABLE MANIFOLDS. 1.1 The definition of a differentiable manifold
CHAPTER 1 : DIFFERENTIABLE MANIFOLDS 1.1 The efinition of a ifferentiable manifol Let M be a topological space. This means that we have a family Ω of open sets efine on M. These satisfy (1), M Ω (2) the
More informationThe Principle of Least Action
Chapter 7. The Principle of Least Action 7.1 Force Methos vs. Energy Methos We have so far stuie two istinct ways of analyzing physics problems: force methos, basically consisting of the application of
More informationASYMPTOTICS TOWARD THE PLANAR RAREFACTION WAVE FOR VISCOUS CONSERVATION LAW IN TWO SPACE DIMENSIONS
TANSACTIONS OF THE AMEICAN MATHEMATICAL SOCIETY Volume 35, Number 3, Pages 13 115 S -9947(999-4 Article electronically publishe on September, 1999 ASYMPTOTICS TOWAD THE PLANA AEFACTION WAVE FO VISCOUS
More informationLecture Introduction. 2 Examples of Measure Concentration. 3 The Johnson-Lindenstrauss Lemma. CS-621 Theory Gems November 28, 2012
CS-6 Theory Gems November 8, 0 Lecture Lecturer: Alesaner Mąry Scribes: Alhussein Fawzi, Dorina Thanou Introuction Toay, we will briefly iscuss an important technique in probability theory measure concentration
More informationChapter 4. Electrostatics of Macroscopic Media
Chapter 4. Electrostatics of Macroscopic Meia 4.1 Multipole Expansion Approximate potentials at large istances 3 x' x' (x') x x' x x Fig 4.1 We consier the potential in the far-fiel region (see Fig. 4.1
More informationJUST THE MATHS UNIT NUMBER DIFFERENTIATION 2 (Rates of change) A.J.Hobson
JUST THE MATHS UNIT NUMBER 10.2 DIFFERENTIATION 2 (Rates of change) by A.J.Hobson 10.2.1 Introuction 10.2.2 Average rates of change 10.2.3 Instantaneous rates of change 10.2.4 Derivatives 10.2.5 Exercises
More informationThe derivative of a function f(x) is another function, defined in terms of a limiting expression: f(x + δx) f(x)
Y. D. Chong (2016) MH2801: Complex Methos for the Sciences 1. Derivatives The erivative of a function f(x) is another function, efine in terms of a limiting expression: f (x) f (x) lim x δx 0 f(x + δx)
More informationOn a class of nonlinear viscoelastic Kirchhoff plates: well-posedness and general decay rates
On a class of nonlinear viscoelastic Kirchhoff plates: well-poseness an general ecay rates M. A. Jorge Silva Department of Mathematics, State University of Lonrina, 8657-97 Lonrina, PR, Brazil. J. E. Muñoz
More informationWELL-POSTEDNESS OF ORDINARY DIFFERENTIAL EQUATION ASSOCIATED WITH WEAKLY DIFFERENTIABLE VECTOR FIELDS
WELL-POSTEDNESS OF ORDINARY DIFFERENTIAL EQUATION ASSOCIATED WITH WEAKLY DIFFERENTIABLE VECTOR FIELDS Abstract. In these short notes, I extract the essential techniques in the famous paper [1] to show
More informationINVERSE PROBLEM OF A HYPERBOLIC EQUATION WITH AN INTEGRAL OVERDETERMINATION CONDITION
Electronic Journal of Differential Equations, Vol. 216 (216), No. 138, pp. 1 7. ISSN: 172-6691. URL: http://eje.math.txstate.eu or http://eje.math.unt.eu INVERSE PROBLEM OF A HYPERBOLIC EQUATION WITH AN
More informationALGEBRAIC AND ANALYTIC PROPERTIES OF ARITHMETIC FUNCTIONS
ALGEBRAIC AND ANALYTIC PROPERTIES OF ARITHMETIC FUNCTIONS MARK SCHACHNER Abstract. When consiere as an algebraic space, the set of arithmetic functions equippe with the operations of pointwise aition an
More informationThe effect of dissipation on solutions of the complex KdV equation
Mathematics an Computers in Simulation 69 (25) 589 599 The effect of issipation on solutions of the complex KV equation Jiahong Wu a,, Juan-Ming Yuan a,b a Department of Mathematics, Oklahoma State University,
More informationCalculus and optimization
Calculus an optimization These notes essentially correspon to mathematical appenix 2 in the text. 1 Functions of a single variable Now that we have e ne functions we turn our attention to calculus. A function
More informationA nonlinear inverse problem of the Korteweg-de Vries equation
Bull. Math. Sci. https://oi.org/0.007/s3373-08-025- A nonlinear inverse problem of the Korteweg-e Vries equation Shengqi Lu Miaochao Chen 2 Qilin Liu 3 Receive: 0 March 207 / Revise: 30 April 208 / Accepte:
More information19 Eigenvalues, Eigenvectors, Ordinary Differential Equations, and Control
19 Eigenvalues, Eigenvectors, Orinary Differential Equations, an Control This section introuces eigenvalues an eigenvectors of a matrix, an iscusses the role of the eigenvalues in etermining the behavior
More informationTable of Common Derivatives By David Abraham
Prouct an Quotient Rules: Table of Common Derivatives By Davi Abraham [ f ( g( ] = [ f ( ] g( + f ( [ g( ] f ( = g( [ f ( ] g( g( f ( [ g( ] Trigonometric Functions: sin( = cos( cos( = sin( tan( = sec
More informationNOTES ON EULER-BOOLE SUMMATION (1) f (l 1) (n) f (l 1) (m) + ( 1)k 1 k! B k (y) f (k) (y) dy,
NOTES ON EULER-BOOLE SUMMATION JONATHAN M BORWEIN, NEIL J CALKIN, AND DANTE MANNA Abstract We stuy a connection between Euler-MacLaurin Summation an Boole Summation suggeste in an AMM note from 196, which
More informationA Note on Exact Solutions to Linear Differential Equations by the Matrix Exponential
Avances in Applie Mathematics an Mechanics Av. Appl. Math. Mech. Vol. 1 No. 4 pp. 573-580 DOI: 10.4208/aamm.09-m0946 August 2009 A Note on Exact Solutions to Linear Differential Equations by the Matrix
More informationThe continuity equation
Chapter 6 The continuity equation 61 The equation of continuity It is evient that in a certain region of space the matter entering it must be equal to the matter leaving it Let us consier an infinitesimal
More informationFLUCTUATIONS IN THE NUMBER OF POINTS ON SMOOTH PLANE CURVES OVER FINITE FIELDS. 1. Introduction
FLUCTUATIONS IN THE NUMBER OF POINTS ON SMOOTH PLANE CURVES OVER FINITE FIELDS ALINA BUCUR, CHANTAL DAVID, BROOKE FEIGON, MATILDE LALÍN 1 Introuction In this note, we stuy the fluctuations in the number
More informationTMA 4195 Matematisk modellering Exam Tuesday December 16, :00 13:00 Problems and solution with additional comments
Problem F U L W D g m 3 2 s 2 0 0 0 0 2 kg 0 0 0 0 0 0 Table : Dimension matrix TMA 495 Matematisk moellering Exam Tuesay December 6, 2008 09:00 3:00 Problems an solution with aitional comments The necessary
More informationDiagonalization of Matrices Dr. E. Jacobs
Diagonalization of Matrices Dr. E. Jacobs One of the very interesting lessons in this course is how certain algebraic techniques can be use to solve ifferential equations. The purpose of these notes is
More informationThe Exact Form and General Integrating Factors
7 The Exact Form an General Integrating Factors In the previous chapters, we ve seen how separable an linear ifferential equations can be solve using methos for converting them to forms that can be easily
More informationCalculus of Variations
16.323 Lecture 5 Calculus of Variations Calculus of Variations Most books cover this material well, but Kirk Chapter 4 oes a particularly nice job. x(t) x* x*+ αδx (1) x*- αδx (1) αδx (1) αδx (1) t f t
More informationMath 300 Winter 2011 Advanced Boundary Value Problems I. Bessel s Equation and Bessel Functions
Math 3 Winter 2 Avance Bounary Value Problems I Bessel s Equation an Bessel Functions Department of Mathematical an Statistical Sciences University of Alberta Bessel s Equation an Bessel Functions We use
More informationSecond order differentiation formula on RCD(K, N) spaces
Secon orer ifferentiation formula on RCD(K, N) spaces Nicola Gigli Luca Tamanini February 8, 018 Abstract We prove the secon orer ifferentiation formula along geoesics in finite-imensional RCD(K, N) spaces.
More informationarxiv: v1 [math.ap] 17 Feb 2011
arxiv:1102.3614v1 [math.ap] 17 Feb 2011 Existence of Weak Solutions for the Incompressible Euler Equations Emil Wieemann Abstract Using a recent result of C. De Lellis an L. Székelyhii Jr. ( [2]) we show
More informationSturm-Liouville Theory
LECTURE 5 Sturm-Liouville Theory In the three preceing lectures I emonstrate the utility of Fourier series in solving PDE/BVPs. As we ll now see, Fourier series are just the tip of the iceberg of the theory
More information2.20 Marine Hydrodynamics Lecture 3
2.20 Marine Hyroynamics, Fall 2018 Lecture 3 Copyright c 2018 MIT - Department of Mechanical Engineering, All rights reserve. 1.7 Stress Tensor 2.20 Marine Hyroynamics Lecture 3 1.7.1 Stress Tensor τ ij
More informationL p Theory for the Multidimensional Aggregation Equation
L p Theory for the Multiimensional Aggregation Equation ANDREA L. BERTOZZI University of California - Los Angeles THOMAS LAURENT University of California - Los Angeles AND JESÚS ROSADO Universitat Autònoma
More informationLOCAL AND GLOBAL MINIMALITY RESULTS FOR A NONLOCAL ISOPERIMETRIC PROBLEM ON R N
LOCAL AND GLOBAL MINIMALITY RSULTS FOR A NONLOCAL ISOPRIMTRIC PROBLM ON R N M. BONACINI AND R. CRISTOFRI Abstract. We consier a nonlocal isoperimetric problem efine in the whole space R N, whose nonlocal
More informationQuantum Mechanics in Three Dimensions
Physics 342 Lecture 20 Quantum Mechanics in Three Dimensions Lecture 20 Physics 342 Quantum Mechanics I Monay, March 24th, 2008 We begin our spherical solutions with the simplest possible case zero potential.
More informationFractional Geometric Calculus: Toward A Unified Mathematical Language for Physics and Engineering
Fractional Geometric Calculus: Towar A Unifie Mathematical Language for Physics an Engineering Xiong Wang Center of Chaos an Complex Network, Department of Electronic Engineering, City University of Hong
More informationApplication of the homotopy perturbation method to a magneto-elastico-viscous fluid along a semi-infinite plate
Freun Publishing House Lt., International Journal of Nonlinear Sciences & Numerical Simulation, (9), -, 9 Application of the homotopy perturbation metho to a magneto-elastico-viscous flui along a semi-infinite
More informationMomentum and Energy. Chapter Conservation Principles
Chapter 2 Momentum an Energy In this chapter we present some funamental results of continuum mechanics. The formulation is base on the principles of conservation of mass, momentum, angular momentum, an
More informationContinuum Mechanics Lecture 4 Fluid dynamics
Continuum Mechanics Lecture 4 Flui ynamics Prof. http://www.itp.uzh.ch/~teyssier Outline - Flui kinematics - Mass an momentum conservation laws - The energy equation - Real fluis - Ieal fluis - Incompressible
More informationMath Notes on differentials, the Chain Rule, gradients, directional derivative, and normal vectors
Math 18.02 Notes on ifferentials, the Chain Rule, graients, irectional erivative, an normal vectors Tangent plane an linear approximation We efine the partial erivatives of f( xy, ) as follows: f f( x+
More informationME338A CONTINUUM MECHANICS
global vs local balance equations ME338A CONTINUUM MECHANICS lecture notes 11 tuesay, may 06, 2008 The balance equations of continuum mechanics serve as a basic set of equations require to solve an initial
More informationON THE OPTIMALITY SYSTEM FOR A 1 D EULER FLOW PROBLEM
ON THE OPTIMALITY SYSTEM FOR A D EULER FLOW PROBLEM Eugene M. Cliff Matthias Heinkenschloss y Ajit R. Shenoy z Interisciplinary Center for Applie Mathematics Virginia Tech Blacksburg, Virginia 46 Abstract
More informationarxiv: v1 [math-ph] 5 May 2014
DIFFERENTIAL-ALGEBRAIC SOLUTIONS OF THE HEAT EQUATION VICTOR M. BUCHSTABER, ELENA YU. NETAY arxiv:1405.0926v1 [math-ph] 5 May 2014 Abstract. In this work we introuce the notion of ifferential-algebraic
More informationarxiv:hep-th/ v1 3 Feb 1993
NBI-HE-9-89 PAR LPTHE 9-49 FTUAM 9-44 November 99 Matrix moel calculations beyon the spherical limit arxiv:hep-th/93004v 3 Feb 993 J. Ambjørn The Niels Bohr Institute Blegamsvej 7, DK-00 Copenhagen Ø,
More information