EFFECT OF TOLLMIEN-SCHLICHTING WAVE ON CONVECTIVE HEAT-TRANSFER IN A WAVY CHANNEL - PART 1 - LINEAR-ANALYSIS

Hydrodynamic instabilities in wavy channels and their effect on the co nvective heat transfer are investigated using both linear stability an alysis and integration of the rime dependent Navier-Stokes and energy equations. The linear stability of the fully developed flow is determi ned from a generalized eigenvalue problem resulting from a Galerkin ap proach using divergence free Chebychev basis functions and trigonometr ic polynomials. Several axial periodicity lengths to geometry length r atios have been considered. For our geometry, the instability is found to set in as a Tollmien Schlichting wave, at a Reynolds number approx imately equal to 90. The dynamics of the detachment and reattachment p oints and of temperature field for constant wall temperature are exami ned under the assumption of small amplitude fluctuations. It is shown that, although the average heat transfer remains almost constant, larg e amplitude variations of the local heat transfer coefficient can be o bserved, this effect is increasing with increasing Prandtl number. (C) 1998 Published by Elsevier Science Inc. All rights reserved.