Abstract: Calculations of flow field with fuel injection and heat release inside an annular reverse-flow combustor of a small aeroengine have been performed with a 3-D elliptic turbulent reacting thermo-aerodynamic software.In the program the turbulence is simulated by the k-ε two-equations model,the combustion after vaporization is determined by a two-step chemical reaction model,the reaction rate is calculated with Arrhenius and eddy breakup model.The SIMPLE algorithm is used to solve the finite-difference equations.The complex boundary conditions are treated particularly.Predictions of gas temperature,velocity,and fuel/air ratio show that a strong vortex emerges in the primary zone of liner;the velocity circumferential distributions have a similarity;the combustor performance is satisfactory due to favourable matching between velocity and fuel/air ratio distributions.The small circumferential velocities contribute to a reasonalble velocity distribution at turbine stator.