Heat Transfer in Aerospace Applications

Appendix 1

Governing Equations for Momentum, Mass, and Energy Transport

Abstract

This appendix presents the governing equations for mass, momentum, and energy transport. Boundary layer versions of the equations are formulated and finally dimensional analysis and similarity rules are presented.

Keywords

Boundary layer; Energy equation; Mass conservation equation; The Navier–Stokes equations; Similarity

A1.1. Continuity Equation (Mass Conservation Equation)

The continuity equation (K.E.) expresses that mass is constant, or not destroyable. If one considers a mass balance for the volume element in Fig. A1.1, the following equation appears where ρ is the density of the fluid and u, v, and w are the velocity components in the x-, y-, and z-directions, respectively. ...