-R',9 A DISK WHICH IS R0

Transcription

1 -ib626 DETERMNNG THE LOCAL COEFFICIENTS OF HEAT EMISSION OF 1/1 (U) FOREIGN TECHNOLOGY DIV URIGHT-PATTERSON APR ON4 A L KUZUETSOV 29 JAN U8 -R',9 A DISK WHICH IS R0 UNCLASSIFIED FDD-ID(RS)T F/G 2912 I

2 U, 1=sI IiII1I ~-!glitn I -_ MICROCOPY RESOLUTION TEST CHART NATIONAL 13UREAU,,TANDARDS-196"3 A -. - : I. 'li' 'l Q0..,-04

3 IDC FILE GP0 (0FTD-ID(RS)T Q FOREIGN TECHNOLOGY DIVISION DETERMINING THE LOCAL COEFFICIENTS OF HEAT EMISSION OF A DISK WHICH IS ROTATING IN A HOUSING WITH JET BLOWING OFF WITH AIR by A.L. Kuznetsov DTIC S LECTE FB D -4= - Approved for public release; Distribution unlimited

4 DISCLAIMER NOTICE THIS DOCUMENT IS BEST QUALITY PRACTICABLE. THE COPY FURNISHED TO DTIC CONTAINED A SIGNIFICANT NUMBER OF PAGES WHICH DO NOT REPRODUCE LEGIBLY. U I I

5 FTD- ID(RS)T DTIC Copy HUMAN TRANSLATION "4S- rt c, C 6 FTD-ID(RS)T January 1988 MICROFICHE NR: FTD-88-C L DETERMINING THE LOCAL COEFFICIENTS OF HEAT EMISSION OF A DISK WHICH IS ROTATING IN A HOUSING WITH JET BLOWING OFF WITH AIR Accession For NTIS GRA&I DTIC TAB Unannounced Justification By: A.L. Kuznetsov Distribution/ English pages: 14 Availability Codes Aval and/or Source: Energomashinostroyeniye, Nr. 3, Dist Special March 1967, pp Country of origin: USSR A1-l Translated by: Charles T. Ostertag, Jr. Requester: FTD/TQTA Approved for public release; Distribution unlimited. THIS TRANSLATION IS A RENDITION OF THE ORIGI- NAL FOREIGN TEXT WITHOUT ANY ANALYTICAL OR EDITORIAL COMMENT. STATEMENTS OR THEORIES ADVOCATED OR IMPLIED ARE THOSE OF THE SOURCE AND DO NOT NECESSARILY REFLECT THE POSITION OR OPINION OF THE FOREIGN TECHNOLOGY DIVISION. PREPARED BY: TRANSLATION DIVISION FOREIGN TECHNOLOGY DIVISION WPAFB, OHIO. FTD ID(RS)T Date 29 January 1988

6 U. S. BOARD ON GEOGRAPHIC NAMES TRANSLITERATION SYSTEM Block Italic Transliteration Block Italic Transliteration A a A a A, a H P P R, r 56 B, b C C C C S, s B ab * V, V T T T N T, t r i r o G, g Y y Y y U, U.4 8q D, d co 0 os F E e E a Ye, ye; E, e* X X X X Kh, kh M W Zh, zh ~ I u Ts, ts 3 3 s a z, z C h, ch K HH U I, i L Sh, sh R i Y, y L UA li u Shch, shch C K K, k 'b-6 20i 'F )1 A L, 1 bl i h Y, y M M M M,rnb h I H H N, n E e 0o 0 0, 0 10~ to Yu, yu n, 17 n p, P R a Ya, ya 'Ay initially, after vowels, and after b, b; e elsewhere. When written as P. in Russian, transliterate as y1a or #. RUSSIAN AND ENGLISH TRIGONOMETRIC FUNCTIONS Russian English Russian English Russian English sin sin sh sinh arc sh sinh- 1 Cos Cos ch cosh arc ch cosh I tg tan th tanh arc th tanh- 1 ctg cot cth coth arc cth coth I sec sec sch sech arc sch sech- 1 cosec csc csch csch arc csch csch 1 Russian rot lg English curl log GRAPHICS DISCLAIMER All figures, graphics, tables, equations, etc. merged into this translation were extracted from the best quality copy available i ll llilllill iiillllll 1 11

7 DETERMINING THE LOCAL COEFFICIENTS OF HEAT EMISSION OF A DISK WHICH IS ROTATING IN A HOUSING WITH JET BLOWING OFF WITH AIR A.L. Kuznetsov, candidate of technical sciences, The article sets forth the results of tests for determining the local coefficients of heat emission of a rotating disk in the case of jet blowing off with air. The results of t.ests on the heat emission of a disk, rotating in a houising wit:. let fl w arc--rc. t.e. descr~ption of tne experirer'tal installati'rn., me-tod and system cf measurements were given in work 1l]. Fcwe~ver, subsequ.ent processing of tze test data prompted the necessity of making cert airi changes in 'hem. These are covered in this article. For example, an wc,-- 'I. it -as pointed o--t that the average dirensionlesre coefficien~t of heat emission Nu, for a ring with widtht (F-gure :,, with an average radius i is determined from the expression Nu, - a ReoA i+b 1 (8)O] where Nu =Ld ;Ree 0O15ag 04- ave-age coefficient of heat emission from the s-_rface f=ztre; Gc - flow rate of air through the nozzle; d

8 -diameter of the n--zz~.ec- number ot nozzles: R - ia:1i--s 0± mounting of the ncz --es; Mi =,054," e -OO2. d 0.2 ad u:g.jf - per: Fhe:-al velcc:ty of the disit on the radius of Tountinq of the nozzles; CC - velocity of adiabatic discharge from the nozzle;,and A. - physical parameters of the air in the case of the temperature of the air in front of the nozzle to. The aumournt of heat removed from the disk from the surface by means of convection was deterr.:;ed using formula - Q~-g At, where -tempe:--at7re head, determined as the difference betwee7. tr.e7 ten;-e±atjire of the surfa-e nf the metal of the disk and the temperature c: the air cn the irnput to the nozzles. In acco,:dance with equation (1) the values of the coefficient of heat emission and the cr-,terion Nu on the radius of mounting of the nozzles are found from the expressions.85d 0s NR0,054? 0 - Re' 8 3 In this case c~p and Nup virtually do not depend on the simplex u/c. 0,O-c. On the basis of the thecory of heat exchange OCR and Nup are 2

9 the av',,ege,- valtes: ci th, cc-ef c ernt of heat ewirsion and the criterion Nu for the area of a ring with width I=d with an average ra~iu:. ret kk. Figure 1. Layout of the installation: I - jet input of cooling air; r e mc c r f ;:Ii. As was pointed z ut :n work [I1, such a treatment of the test data alsc makes it possible to find the distribution of local coefficients of heat emission over the radius of the disk under the assumption of a symmetry of tneiv profile relative to R("I R + I 1±). However, further processing of the test data showed that when rotation apresent and there is a relatively small z there is considerable asymmetry of the profile of local coefficients of heat emission over the radius of the diski. However, a calculation of the temperature field cf the disks of specific gas-turbine installations, cooled by jet bli.wa of. showed that disiegard of the asymmetry a on the radius of S1

10 the disk: 1ead,- to a nc: :z'a b-e difference between the ce-ru '.'ated distribution of temperature and actual. It follows from what has been sa. tha* -- r :hesa rc c. o-* data haf to ' c;. - - " wh-1e taking into account the local coefficients of heat emission separately for the radii of the disk r <R and for r>r. Results of the tests for determining the local values of heat emission. The characteristics of the tests which were used for determ n:in the locil values i the coefficients of heat emission on the rad:us of a disk in the case of jet blowing off are given in the j-- d if t* Rec,' &I, 8; 12,3; ,965 ;4; 8 8;. 12,3; ; 207; ; 6.17; ,0; 6.17; ' 0, S 8: 12.3; j), ,66.10' ' 0,0079-0,963 4

11 Tta results of the tests were piocessed in criteria of similarity Nad an e G, Nu an,z.ec=,7&5zdg The structure of the criterial dependence was selected similar to equation (1) Nu = are fi, (4) W. coe f f :ert: ust a: ir. f r~a deperjijng on the magnitudes z, d, R, relative distance of the calorimeter from the rad -us cif iroun7: Ing o.- tlhi rn7zz-',es y=!p-r )/d f or r and y= (r-r )/d f or r > P. ana rne w Idth of the gap s. Tht- 1oca I va lue of the coe ff ic ient of heat emiss ion o( or, the average radius cf the calorimeter r was found from equation QX 2nrb (t- to)' where -amount of heat, removed from the calorimeter by means of convection; b - width of the calorimeter. The influence of the magnitude of the gap on local heat emission in the case of a change of its values from s=d to s=8d 0A~= )

12 the z values cf the cciefficient of neat emission on the radius of a disk can be found conveniently and in a methodically correct manner in a comparison with the coefficient of heat emission on the radius of mounting of the nozzles, i.e., based on the ratio (4/a(R)=(Nu/Nup). The magnitudes of o4 R and NUR are found by using equation (3). 4 el 0 *.,I 4? _ o- - * 44 0 of "45 45 l/c. Figure 2. Dependence of Nu/NuR on u/c 0 for r -R: d 92.d-.4, Z-9=S. 8+32AaC 2-y-~ z-4. k, 3,: S-- R _ , d-g. 2-8, X 4-f = 9.25d s-12.3a, Local values of the coefficients of heat emission for r<r. In Figure 2 the rat:.c Nu/NuF, is given as it depends on u/c 0 for r. R with different corbination: of z, d, R, r, s, y. As is evident from the 6

13 ga p t f or ce.iirtt E!,. -F ve! age i ad-us of± wh :cn I5 s-ess than the rad~ius oi mountirng of the nozzles, the rate of rotation of the disk has - ~a'~-rs - &::Vale -.y 'the fact that the flow, induced by the rotation of the disk, presses out toward the periphery that part of thp jet flow which is flowing toward the center. Consequently on the surface of a disk lower than R there should be a lowerirno cf heat emission, conditioned ty Jet blowing; off. With an :ncrease irn the rate of rotation there is an. increase in heat er':ssicr.. causec. iry the- rct-:ir. cfthe disk. Apparently tirese two fac,:: rs 7-mernsate each other and the Nu number virtually does not denerg ti.- e c:r th:is result cannct Le extended to a -- c w-. is -CrE re:ec nr :ce adius :of mount2lng :-t 'he nozzles e -r t Ic r. w ~ 7-f ic t t ha t for r< R the variable u/c 0 does nit infi-cerc4 hea~el r~no the criterial dependence (4) is simplified VNu a Re,(5) an~d the ratio Nu _ a - d (6) In eypressing the test values of Nu/NuR in a dependence on y=p r/d, I :- pose-. b1 to establ i h in semi loga r,.thm -c coordinates if~g. 21 r'.at this dejendence is determined by the equation S7

14 Nu e (M-o,5) (i--o.s) Nu,, " I ' - I N o 2 4 It? 0 2k F.i- E 3. D e p e n d e n. of -te ra ti c N<NR and N/u or. y for A -,-,d for > P 0 The test valueo -e.f ratio Nu/Nu- fo- each cz.tbina:icn Cf z, d,?, were.c,-"e.r :. fz cr th E-:,e'-:" n Nu Nu R Nu where n - number of tests for a fixed combination of z, d, R, y, from which the coefficient & w-th respect to equations (6) and (7) turned out to be equal to a= OO54z o 5 d '-, Is (-0,S). (8) S - ;%~-~

15 "I'.- It~ 7tZS ~ RJ Fi'zure~~~~~~~~ 4. DIedec tertio-o If rrdi hc r cve~~~~~~~to ~ ~ ~ N n I~c Iesrt;r a.scimutac h cz f f U - N.' _ Nu/NuR=(1-0.Q64y~e y - ocal -*:ai'ez of Nu/rEup. obtained from equation (') with u/c 0 )=C; N/!N"j - accoid-.g t o equation (4) with u/co=0.5; z=4; r> R. Local values of coefficients of heat emission for r >R. In this case the ratio Nu/NuR depends on y and u/c 0, as a result of which the coefficients of heat emission are determined rationally in conformity with equation (4). Coefficient CL was found from tests, in which the influence of U/on) was negligible (u/c- 0 ). Plotting the test values of NuO/NuR in a 9

16 depernden:-" or y ir. the ser:.iogarithmic coordinates (Figure 3), it can be es- ta.rhec "-.e" th- de;endence is described by the equation Nu -01M6 (Ma-O.) * NuR where Nu = Nu.o Ce (9) 7r.- --st values of NuC, *N.- : - ic.. combination of z, d, R, y were d ermi ned f!or the expressior SNus Nu, Ng I NuR N uj R = where. nunrzer of tests for a given combination of z, d, R, y and c 3 The magntude of coefficxent 0. when z >R in accordance with equ *icr.s, ani (9 is obtained equal to a = o.os4z. d C-o.18 (i,-os) (10) Thus for the case r<r - when rotation is present and absent, and for r >R - when rotation is absent, the profile of the local coefficients of heat emission turned out to be symmetric relative to R. 10 0

17 ,5 4, (y - 0,5) Fi',r Dependence c-. zt on. y-0.5): -zb=c.0e,y-o.5, (the pcints ccrrespond Ir, -', averaged from tests). Figure 4 shows te ratlc NJ/NuR when r< R and NuO/NuR when r> R de~r~ir~ r- y. 1- it E*,ldent from the drawin~g that a satisfactory agreernent o-f the test values is attained both with the dependences (8) and (9,1 and with: t!h ( dep'endence obtained from equationi (1) (broken line ). The dependence Nu/NuR according to equation (4) produces a concept about the nature of the increase in heat emission from rotation of the disk for the case r> R.

18 D:r Y- ct ation c f th. d _sl- in ccn:orr-. ty with eq.at on f4) t t, tezt valu.es :f -cefficler. b, taking into account the :n=rease of heat NU- _= " - \ 0 z,(11) bn where n - number of tests for the fixed combination of z. d, R, y. The dependence cf coefzicient b on the number of nozzles z for f -ed combina-:on..f d P., y is described satisfactorily by equation I (12) t fcll ws frc: n.,., that it is adv:-sable to conduct further processing of the test data in the form of the dependence zb = (d, R. y). It turned out that the variable zb depends only on y=(r-r/d). The influence of the radius of mounting of nozzles R and their diameter d on the variable zb could not be established. Figure 5 gives in logarihtmic coordinates the test dependence of zt on y-c.5), vhich is apnroimated satisfactorily by the expression I lil~!,lrl r Irll lli i li -

19 zb =0,05 (y 0,5)"~,1 or s-t a~ cc e n. t-. e e x ip:d n t we r e f.e te-r rt r. h e method of least squares. The gen~eral~izing dependence for coefficient b has the form b = 05 (Y 0,5) ) the -es- data fo! heat er ss: cn of a disk. i-otat..ng in a housingz witl 1et thzw:.nc cf a;.r, and depending on the num~ber Re 0, are g-vern in Figu~e 6, frcr, wnc.ncr it Is eviden~t that the test points in bcth 7ases agree'.with a cuw,-e wh-,ch is proportional to Re. 8. BIBLIOGRAPHY 1. 3 eysieo a A. A1. TenJaooraqa8 AMUa epaumamerocn S KO2KyXe nps. CTPYflHOM 06Ayse 0oaA~Yxom. - c3nepromaum- HocrpoeHmeb, 1964, M* 12. a2. K y 3 H e ua o a A. A. TenitooTnAaa ANCKa, SapajaoueroCij 3KaYXe C PIANSAJIHoI foaaq~ea oxjiazkaamn~ero njo3yxa. - Ten. Jioo. OCOUHC OTOP09 H IANHAPo8 napoehix m raaoehx Typ- 6IN. HAA-8O 4MaWH~oc~poeHmev, 19(64.

20 - U 00 Figure 6. teper.'dercze of heat emlssior; of a dis'. rctating in a housing with jet bicwirng off by air, on the Rec number: a- Nu - f(rec) 9 AA. '>R; 6-2u; I(Rec) 0ue <R 14

21 DISTRIBUTION LIST DISTRIBUTION *tazct T6 UCt?Zr6T A210 DNAAC 9344 DWRS-2C 9 C043 USA.%1lIA I CHOO TAADOC 1 C509 LLLISflc U us IA CS1O BA? UiIS/AVADCOI'1 CS2, AIMDCOM 2 C3 AVWACOK/TSAACOM 1 C339 TWAA 1 C391 PSIC C619 MIA IDSTONE 0001 visc NQ US#J/IK I 9406 ADC/DOF L 9429 SD/flIND2 P00$ WUEISAIDDI I P050 CWAOC/&DD/SD Afll/LDC co4 vwfks L/Code I,-389 PASAINST-44 4 SAITS13/TDL. I I I I FSL/NIX-3 1?T-ID(RS)T

22 I I II I HI H I!!... h I/'! /i *T** /.. S S5 _D S