Application of the Reynolds Analogy to Combustion of Solid Fuels

Abstract

THE analogy which was pointed out by Osborne Reynolds between heat transfer and friction in the flow of fluids is well known. In its simplest form the relation is established by an argument of the following type. The frictional resistance is considered to be due to the transport of molecules to the surface, where their mass motion at the average velocity v is considered to be stopped. The heat transfer process is considered to be due to molecules which reach the surface coming into temperature equilibrium with the surface and then remixing with the rest of the fluid. The simplest equation from the Reynolds analogy is obtained by considering that the molecules which reach temperature equilibrium with the surface in the heat transfer process are those the mass motion of which is stopped at the surface in friction process so that the numbers can be equated. The resultant relationship is where f is the friction coefficient, h is the heat transfer coefficient, ρ is the fluid density and v is mass velocity, c_p being its specific heat, at constant pressure for a gas.