CONJUGATE HEAT TRANSFER AND BUOYANCY-DRIVEN SECONDARY FLOW IN THE COOLING CHANNELS WITHIN A VERTICAL SLAB

Abstract

The present study is concerned with buoyancy-induced secondary flow and heat transfer characteristics in a series of circular cooling channels within a vertical slab. The fully developed flows, in which the transverse thermal energy diffusion plays a dominant role in the overall heat transfer behavior, are analyzed numerically. Thermal energy transmits transversely from the hotter end surface to the colder end surface across the slab through a domain containing a solid region and a fluid region occupied by the cooling channels. The stream function-vorticity formulation and the finite volume method coupled with a body-fitted coordinate transformation scheme are employed to analyze this conjugate heat transfer problem. Results show that when the Grashof number is higher than approximately 10 ³ , the strength of the secondary flow becomes appreciable and results in a significant increase in overall heat transfer rate. In this study a maximum 120% increase in heat transfer rate, but only 12% increase in friction factor, is found within the parameter ranges considered.

Additional information

Notes on contributors

Chin-Hsiang Cheng

The financial support of this work from the National Science Council, Republic of China, under grant NSC 80-0401-E-036-03 is gratefully acknowledged.