UNIVERSITY OF WALES INSTITUTE OF NON-NEWTONIAN FLUID MECHANICS CONFERENCE ON INDUSTRIAL RHEOLOGY. Hoole Hall Hotel, Chester 5-7 April 2004 PROGRAMME

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1 UNIVERSITY OF WALES INSTITUTE OF NON-NEWTONIAN FLUID MECHANICS CONFERENCE ON INDUSTRIAL RHEOLOGY Hoole Hall Hotel, Chester 5-7 April 24 PROGRAMME 27. Mar. 24

2 PROGRAMME Monday 5 April - Afternoon 2:3 Lunch Session Chairman: K Walters 4: - 4:4 D V Boger Something old, something new, and something very new in industrial rheology 4:4-5:2 J R A Pearson The role of diffusion in non-newtonian fluid mechanics 5:2-5:45 D R Oliver Simultaneous shear and squeezing flow applied to a ceramic paste 5:45-6:5 Coffee/Tea Session 2 Chairman: K Walters 6:5 6:45 I Emri The effect of boundary conditions on structure formation of PA fibers 6:45-7:5 G N Greaves Solid state rheology of zeolites under thermobaric stress 7:5-7:4 B Debbaut The double convected pom-pom model: a numerical validation for the contraction flow 7:4-8:5 E I Frenkin Thermophysical characteristics of PP/LCP blends under high pressure 9:3 Dinner 27. Mar. 24

3 PROGRAMME Tuesday 6 April - Morning Session 3 Chairman: M H Wagner 9: - : H M Laun Thirty years of industrial polymer rheology at BASF : - :25 P Moldenaers Morphology development of two-phase blends during capillary flow :25 - :55 Coffee/Tea Session 4 Chairman: M H Wagner :55 - :35 C Gallegos Rheology of recycled-eva modified bitumen :35-2:5 M P Escudier Experiments and numerical simulations of laminar viscoelastic flow through sudden expansions 2:5 2:3 J M Maia Influence of the operating conditions on the gelatinisation of rice flour during extrusion 2:3-4: Lunch 27. Mar. 24

4 PROGRAMME Tuesday 6 April - Afternoon 2:3 3:45 Lunch Session 5 Chairman: A R Davies 3:45-4:4 H A Barnes Thirty years of industrial dispersion rheology at Unilever 4:4-5:2 J-M Piau Macro and micro rheometry of carbopol gels 5:2-5:45 H P Hürlimann A new multipass-type polymer compounding machine approaches industrial application 5:45-6:5 Coffee/Tea Session 6 Chairman: A R Davies 6:5-6:55 D G Baird Rheology of highly filled polymers using squeezing flow 6:55-7:35 M H Wagner Melt rheology of industrial polymers: relating stress to strain and energy 7:35 8: O Kulikov The use of thermoplastic and raw elastomers to delay the melt fracture onset in extrusion of polyethylene 9: for 9:3 Conference Dinner 27. Mar. 24

5 PROGRAMME Wednesday 7 April - Morning Session 7 Chairman: P Townsend 9: - 9:4 G C Maitland Complex fluids for hydrocarbon recovery - rheology in extremus 9:4 - :2 R Keunings The CRAFT tube model: a new constitutive equation for blends of entangled linear polymers :2 - :45 Ch Bailly Prediction of linear viscoelastic properties from molecular structure for blends of linear and x entangled polymers :45 - :5 Coffee/Tea Session 8 Chairman: P Townsend :5 - :4 F T Pinho Optimisation of profile extrusion dies: numerical and experimental work :4-2: F Chinestra α-nem and model reduction: two new and powerful numerical techniques for simulating complex flows 2: - 2:3 O Wallevik Rheology of coarse particle suspensions such as fresh concrete 2:3 End of Conference 27. Mar. 24

6 Experiments and numerical simulations of laminar viscoelastic flow through sudden expansions M P Escudier, P J Oliveira 2, F T Pinho 3, A Afonso 3 and R J Poole Department of Engineering, University of Liverpool, UK 2 Departmento de Engenharia Electromecanica, Universidade da Beira Interior, Portugal 3 Departamento de Engenharia Mecanica, Universidade do Minho, Portugal Industrial Rheology Conference, Hoole Hall, Chester, UK. April 5 th 7 th 24

7 Outline Introduction Expansion geometry Fluid Rheology (Shear rheology, N, extensional viscosity) Approach flow (smooth contraction) Downstream flow (sudden expansion) Conclusions

8 Introduction Experimental and numerical investigation of laminar viscoelastic fluid flow Why? through a plane sudden expansion of expansion ratio (D/d).43 and aspect ratio (w/h) 3.3. Investigate viscoelastic fluid flow in a basic geometry which exhibits interesting fluid-dynamic behaviour. Extend previous studies (Re < ) to higher Reynolds numbers where inertia starts to play an important role. Are there qualitative changes compared to Newtonian fluid flow? Is the flow 2D? Extend previous studies by providing L.D.A velocity data for quantitative comparisons with numerical simulations.

9 Experimental arrangement Fully-developed inlet flow through a square duct 8mm x 8 mm (2 D H development length) Upstream spanwise profiles (x-z plane) at x/h=-8.33 and d = 28mm, h = 6mm, D = 4mm, w = 8mm Downstream profiles at <x/h< in x-y plane Aspect ratios A = w/h = 3.3 A 2 = w/d= 2.86 Area ratio R = d/d =.7 (area ratio > 2/3! double backward-facing step )

10 Rheology Fluid: Polyacrylamide (PAA) Seperan AP 273 E.5%,.%.4% w/w including Carreau-Yasuda (5-parameter) model fits 2.5%.%.4% CY fit Viscosity (Pa s) - -2! c Re =!! C =! U B h µ c U B h Shear rate (/s)

11 Rheology Fluid: Polyacrylamide (PAA) Seperan AP 273 E.%,.4% w/w First normal stress difference N (Pa) 3 2.4% PAA.% PAA N = a! b N /2!.% PAA.4% PAA N /2! >.5 2! (Pa) 2! (Pa)

12 Extensional rheology Fluid: Polyacrylamide (PAA) Seperan AP 273 E.5%,.%, % and.4% w/w Thermo Haake CaBER Extensional rheometer 6 Extensional viscosity (Pa.s) % concentration of PAA (w/w)

13 Extensional rheology c (%) µ (Pa.s) µ! (mpa.s) µ EXT (Pa.s) µ EXT µ µ EXT µ!

14 Results: Flow through smooth contraction Spanwise variation of streamwise velocity (U/U B ) profiles within smooth contraction.5% PAA and.% PAA Re " x / h =.4.2 x / h = U / UB x / h = U / UB.8 x / h = z / w.5% PAA Newtonian Carreau-Yasuda PTT.4.4 Newtonian Carreau-Yasuda PTT z / w.% PAA.4

15 Results: Flow through smooth contraction Spanwise variation of streamwise velocity (U/U B ) profiles within smooth contraction.4% PAA Re " 5 2 x / h = 2 2 x / h = y/d = y/d = U / UB.2.2 U / UB y/d = % PAA Newtonian Carreau-Yasuda PTT y/d = 5 PTT.4% PAA y/d = z / w z / w

16 Results: Flow downstream of expansion Streamwise velocity (U/U B ) profiles downstream of expansion for.5% PAA Re= y / D U = x/h Newtonian Carreau-Yasuda PTT

17 Results: Flow downstream of expansion Streamwise velocity (U/U B ) profiles downstream of expansion for.5% PAA Re= y / D U =.5 Newtonian X R = 7.5 x/h Carreau-Yasuda PTT

18 Results: Flow downstream of expansion Streamwise velocity (U/U B ) profiles downstream of expansion for.% PAA Re= y / D.5.5. U =..5.5 X R = x/h 3 4 Newtonian Carreau-Yasuda PTT

19 Results: Flow downstream of expansion Streamwise velocity (U/U B ) profiles downstream of expansion for.% PAA Re= y / D x/h 8 Newtonian Carreau-Yasuda PTT

20 Results: Flow downstream of expansion Streamwise velocity (U/U B ) profiles downstream of expansion for.4% PAA Re= y / D 5.5. No recirculation x/h Newtonian Carreau-Yasuda PTT

21 Results: Flow downstream of expansion Streamwise velocity (U/U B ) profiles downstream of expansion for.4% PAA Re= y / D x/h Newtonian Carreau-Yasuda PTT

22 Conclusions Flow through smooth contraction Flow becomes increasingly three-dimensional (but symmetrical about x-y centreplane) and complex with increasing concentration. Simulations fail to predict velocity overshoot near side-walls. Flow over double backward-facing step Flow symmetrical about x-z centreplane..5% PAA flow predicted reasonably well by PTT model (consequence of flow being more two-dimensional?).% and.4% PAA profiles not predicted well by any model (consequence of poor agreement through contraction and hence inlet velocity profiles?) PTT model corrects shear-thinning over-prediction

23 Latest experimental study Plane sudden expansion d = mm D = 4 mm h = 5 mm R = d/d = 5 (< 2/3) A = w/h = 5.33 (<) Spanwise variation of streamwise velocity (U/U B ) profiles within smooth contraction.5 % PAA (x-z centreplane).2.8 U / UB.6 x / h = x / h = % PAA Re " 2.4 x / h = x / h = z / w