The Thermo-Aerodynamical Analysis of Combustion Gas Flow (1st Report)

Abstract

This paper deals with the thermo-aerodynamical analysis of one-dimensional steady flow in a combustion chamber for gas turbine or jet engine. The phenomena, which were taken into account in this report, include : (1) area change, (2) wall friction, (3) external heat exchange and (4) chemical reaction (combustion). The distribution of heat release by combustion, dqc/dx, is assumed as follows : (i) dqc/dx=200Hu(Gf/G)xe-100x2 ( ii ) dqc/dx=30Hu(Gf/G)e-30x where qc : heat release by combustion per unit mass of flow, kcal/kg x : coordinate (in the direction of flow), m Hu : heat of combustion of fuel, kcal/kg Gf/G : fuel-air ratio (weight) and dqc/dx≅0 at x=0.3m. The following results were obtained : Though the temperature, velocity and pressure-distribution in the direction of flow are different in the both cases of dqc/dx until x=0.3 m where the combustion ends, but those which are obtained by completion of combustion have almost no concern with the type of dqc/dx. The increases of temperature and velocity and also the decrease of pressure are linearly proportional to the fuel-air ratio in the case of constant area of duct. The pressure drop of convergent flow is larger than those of divergent flow and constant area flow.