Heat Transfer in Aerospace Applications

Chapter 4

Low-Density Heat Transfer

Rarefied Gas Heat Transfer

Abstract

The basics of low density in gas flows are described. How to deal with noncontinuum effects is presented. The various flow regimes are presented. A few numerical examples are used to illustrate simple calculation procedures and the importance of rarefaction. The relevance of heat transfer in microchannels is also considered.

Keywords

Flow regimes; Knudsen number; Mach number; Microchannels; Molecular mean free path

4.1. Introduction

When an aerospace vehicle flies through the atmosphere at very high speeds, it is subjected to aerodynamic heating. The extent of heating depends, among other factors, on the density of air through which the vehicle is traveling. Aerospace missions involve ...