Page 181 - Fundamentals of The Finite Element Method for Heat and Fluid Flow

7

Convection Heat Transfer

7.1 Introduction

In the previous six chapters, the conduction mode of heat transfer has been discussed in
detail. Occasionally, convective heat transfer boundary conditions were discussed in these
chapters whenever appropriate. However, little information on fluid flow characteristics was
given in any of the previous chapters. In the present chapter, the heat transfer mechanism
due to a fluid motion is discussed in detail. This method of heat transfer, which is caused
by fluid motion, is referred to as heat convection.
The study of fluid motion (fluid dynamics) is an important subject that has wide applica-
tion in many engineering disciplines. Several industries use computer-based fluid dynamics
analysis (Computational Fluid Dynamics or CFD) tools for both design and analysis. For
instance, aerospace applications, turbo-machines, weather forecasting, electronic cooling
arrangements and flow in heat exchangers are merely a few examples. There has been a
vast increase in the use of CFD tools in engineering industries in the last two decades,
mainly because of an ever-increasing computing power. In the 1980s, a solution for a rea-
sonably sized three-dimensional fluid dynamics problem was rarely possible on a personal
computer (PC). However, now it is very common for researchers to solve reasonably sized
fluid dynamics problems in three dimensions using such computers.
There are several books written on the topic of computational fluid dynamics, which
include texts explaining the basic solution scheme underlying a successful CFD soft-
ware (Cheung 2002; Donea and Huerta 2003; Fletcher 1988; Gresho and Sani 2000;
Hirsch 1989; Lewis et al. 1996; Pironneau 1989; Zienkiewicz and Taylor 2000), or books
on practical fluid dynamics calculations such as data structure and parallel computing
(L¨ ohner 2001). Several chapters could be written in the present text on the topic of
CFD alone. However, our main interest is to give a practical introduction to the role
of fluid dynamics in heat transport. It is intended that this chapter will give a good start-
ing point to pursue a further education and/or research in fluid dynamics–assisted heat
transport.

Fundamentals of the Finite Element Method for Heat and Fluid Flow R. W. Lewis, P. Nithiarasu and K. N. Seetharamu
 2004 John Wiley & Sons, Ltd ISBNs: 0-470-84788-3 (HB); 0-470-84789-1 (PB)