Transcript
Page 1: Second All-Union Conference on “present-day problems of thermal convection∝

CHRONICLE

SECOND ALL-UNION CONFERENCE ON "PRESENT-DAY

PROBLEMS OF THERMAL CONVECTION"

G. Z. Gershuni and E. M. Zhukhovitskii UDC 532.5.01 : 536.25(06)

The c o n f e r e n c e was held in P e r m f r o m May 27-30, 1975. It was o r g a n i z e d by the Sc ien t i f i c Counci l of the A c a d e m y of S c i e n c e s of the USSR on tile M e c h a n i c s of L iqu ids and G a s e s . the D i v i s i o n of the P h y s i c s of P o l y m e r s of the Ura l Sc i en t i f i c C e n t e r of the A c a d e m y of S c i e n c e s of tae USSR, P e r m S t a t e U n i v e r s i t y , and the P e r m P e d a g o g i c a l In s t i t u t e ( c h a i r m a n of the o r g a n i z i n g c o m m i t t e e P r o f e s s o r I. G. Shaposhnikov) .

The c o n f e r e n c e was a t t ended by r e p r e s e n t a t i v e s of the m a i n s c i e n t i f i c o r g a n i z a t i o n of the coun t ry , c a r r y - ing out i n v e s t i g a t i o n s in the f ie ld of t h e r m a l c o n v e c t i o n : t h e s e inc luded a c a d e m i c and b r a n c h ins t i tu t e , h ighe r i n s t i t u t i o n s of l e a r n i n g , c o n s t r u c t i o n o f f i ces , and i n d u s t r i a l e n t e r p r i s e s (89 o r g a n i z a t i o n s in a l l ) . 215 s c i e n t i s t s f r o m 32 c i t i e s of the c o u n t r y took p a r t in the w o r k of the c o n f e r e n c e . At the 22 s e s s i o n s , 144 p a p e r s w e r e h e a r d and d i s c u s s e d .

T~hree p a p e r s w e r e g iven at the p l e n a r y s e s s i o n .

G. A. O s t r o u m o v and Yu. K. S t i shkov (Len ing rad ) devoted t h e i r p a p e r to a g e n e r a l a n a l y s i s of e l e c t r o - c o n v e c t i v e p h e n o m e n a in w e a k l y conduc t ing l iqu ids in a c o n s t a n t e l e c t r i c a l f i e ld . Tl~e p r i n c i p a l s t r e s s was l a id on a d i s c u s s i o n of ti~e m e c h a n i s m s of i n s t a b i l i t y , s p e c i f i c a l l y , of the m e c h a n i s m due to t h r e e - d i m e n s i o n a l i n - h o m o g e n e i t y of the c o n d u c t i v i t y . They a l so d i s c u s s e d the e f fec t of an e l e c t r i c a l f ie ld on hea t t r a n s f e r . The p a p e r was a c c o m p a n i e d b y d e m o n s t r a t i o n s of e x p e r i m e n t s .

The p a p e r of Yu. P. B u l a s h e v i c h and Yu. V. Khach ' (Sverd lovsk) d i s c u s s e d a t w o - c o m p o n e n t m o d e l of a c o n v e c t i v e l y uns t ab l e a s t h e n o s p h e r i c a l l a y e r of the upper m a n t l e of the E a r t h . On the b a s i s of this mode l , the m e t h o d s of the t h e r m o d y n a m i c s of i r r e v e r s i b l e p r o c e s s e s w e r e used to s t u d y the cond i t ions for c o n v e c t i v e i n - s t a b i l i t y and the s p e c i a l c h a r a c t e r i s t i c s of the m i g r a t i o n of r a d i o a c t i v e e l e m e n t s . A m e c h a n i s m is p r o p o s e d which e x p l a i n s the d i s t r i b u t i o n of s o m e e l e m e n t s in the s u b s t a n c e of the E a r t h .

M. P. V la syuk and V. I. P o l e z h a e v (Moscow) gave a r e v i e w p a p e r on the r e s u l t s of n u m e r i c a l i n v e s t i g a - t ions c a r r i e d out by the a u t h o r s on c o n v e c t i o n in l a y e r s of a p e r m e a b l e p o r o u s m a t e r i a l . Data on hea t t r a n s f e r a s a funct ion of the o r i e n t a t i o n of the l a y e r s a r e d i s c u s s e d . E x a m p l e s a r e g iven of the use of the r e s u l t s ob- t a i n e d in e n e r g e t i c s , in c o n s t r u c t i o n t e chn iques , in h i g h - t e m p e r a t u r e and h i g h - p r e s s u r e t echn iques , e t c .

At the c o n f e r e n c e , t h r e e s e c t i o n s w o r k e d in p a r a l l e l .

I. Convec t ion in c a v i t i e s and c h a n n e l s . The c onve c t i ve b o u n d a r y l a y e r . II . Convec t ive i n s t a b i l i t y . Q u e s - t ions in g e o - and a s t r o p h y s i c s . III . Convec t ion in m e d i a wi th s p e c i a l p r o p e r t i e s . The ac t ion of an e l e c t r o - m a g n e t i c f ie ld . Mixed q u e s t i o n s of h y d r o d y n a m i c s and hea t t r a n s f e r .

The s e s s i o n s of s e c t i o n I d i s c u s s e d p a p e r s devo ted to t h e o r e t i c a l and e x p e r i m e n t a l i n v e s t i g a t i o n s of l a m i n a r and t u r b u l e n t c o n v e c t i o n in c l o s e d v o l u m e s and in an open s p a c e . A c o n s i d e r a b l e amount of a t t en t ion was pa id to c o n v e c t i v e p r o b l e m s a r i s i n g in v a r i o u s a p p l i e d f i e lds ( t h e r m a l s t r a t i f i c a t i o n in v e s s e l s for the s t o r a g e of p e t r o l e u m p r o d u c t s and c r y o g e n i c l i qu ids , c onve c t i ve p h e n o m e n a in op t i c a l uni ts , e t c . ) .

At the s e s s i o n s of s e c t i o n II t h e r e w e r e d i s c u s s i o n s o f t h e r e s u l t s of new i n v e s t i g a t i o n s r e l a t e d to l i n e a r and n o n l i n e a r q u e s t i o n s of the c o n v e c t i v e s t a b i l i t y of e q u i l i b r i u m and the s t a b i l i t y of c onve c t i ve m o t i o n s . The g r e a t e s t amoun t of a t t en t ion was a t t r a c t e d by q u e s t i o n s connec t ed wi th the c l a r i f i c a t i o n of the ac t i on of v a r i o u s c o m p l i c a t i n g f a c t o r s on s t a b i l i t y , i . e . , a m a g n e t i c f ie ld , r o t a t i o n , d i f fus ion , m o d u l a t i o n of the p a r a m e t e r s , i n - t e r n a l hea t s o u r c e s , i n f i l t r a t i o n , s p e c i a l c h a r a c t e r i s t i c s of the t h e o l o g i c a l b e h a v i o r of the m e d i u m , e t c . A s e p a r a t e s e s s i o n was devo ted to a d i s c u s s i o n of m i x e d p r o b l e m s of g e o - and a s t r o p h y s i c s .

T r a n s l a t e d f r o m I z v e s t i y a A k a d e m i i Nauk SSSR, Mekhan ika Zh idkos t i i Gaza , No. 6, pp. 174-175 ,Novem-

b e r - D e c e m b e r , 1975.

This material is protected by copyright registered in the name o f Plenum Publishing Corporation, 227 West 17t h Street, New York, N. Y. 10011. No part [ o f this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, t microfilming, recording or otherwise, without written permission o f the publisher. A copy o f this article is available from the pubtisher for $ 7. 50.

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Page 2: Second All-Union Conference on “present-day problems of thermal convection∝

The theme of s e s s i o n IlI was ma in ly connected with quest ions of the cour se of convect ive phenomena in the p re sence of a l l kinds of compl ica t ing c i r c u m s t a n c e s . Here there were d i scussed convective phenomena in c h e m i c a l l y act ive, non-Newtonian, and d i s p e r s e media . A g rea t deal of i n t e r e s t was evoked by communica t ions on convect ion under s i n g l e - p h a s e condit ions in conducting and f e r r om a gne t i c l iquids. Separa te s e s s i o n s were devoted to quest ions of hydrodynamics and neat t r a n s f e r in f i lms and j e t s , as wel l as to e l ec t roconvec t ive

phe nome ha.

The conference demons t r a t ed that in r ecen t yea r s there has been fur ther development of inves t iga t ion in the field of t ime ly p rob lems of convect ive heat and mass t r a n s f e r . Significant new r e s u l t s have been ob- ta ined in the study of fundamental and appl ied quest ion. At the s a m e t ime, it was brought out that ce r t a in im- por tant d i rec t ions have not been developed with suff icient in tens i ty . Thus, m o r e at tent ion should be paid to quest ions of turbulent convect ion, as well as to the in t roduct ion of new up- to -da te e x p e r i m e n t a l methods of in- ves t iga t ion (holography, l a s e r tecnniques) .

A r e so lu t i on adopted at the conference noted the mos t impor tan t d i r ec t ions of inves t iga t ions . Among them a r e : intense convect ion under turbulent and t r ans i t i ona l condit ions; convect ive phenomena in s t rong cen t r i fuga l f ie lds; convect ion in l iquids with spec i a l t heo log ica l p r o p e r t i e s , in porous, mul t iphase , and p o l a r - izing media ; the cont ro l of convect ive s t a b i l i t y using var ious phys ica l fac to rs ; the development of effect ive ana ly t i ca l and numer i ca l methods for the solut ion of nonlinear p rob lems , in p a r t i c u l a r , t h r e e - d i m e n s i o n a l p rob l ems of convection.

A b r i e f s u m m a r y of the contents of a l l the papers at the conference is contained in a co l lec t ion of ab- s t r a c t s put out at the opening of the conference .

rne nexr conference on convect ion is scheduled for 1978 in Leningrad .

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