On Entropy Production in Adiabatic Flow in Turbomachines

Abstract

In three recent papers, Smith [1], Marsh [2], and Novak [3] have given general equations for the flow in turbomachines and methods for their solution. Each author has worked from momentum equations for an inviscid fluid, but has introduced entropy increases in adiabatic flow. Such increases are inconsistent with the basic assumption of inviscid flow in the momentum equations, as the authors have stated. The purpose of this paper is to examine the nature of this inconsistency and to suggest modifications of the equations used by the three authors by the introduction of dissipative forces into the momentum equations. A particular example is calculated, with and without the dissipative force term, to illustrate the order of magnitude of the effect.