Abstract:To research the micro-scale combustion characteristics of base bleed propellant ammonium perchlorate/hydroxyl terminated polybutadiene (AP/HTPB) under spinning condition, a two-dimensional periodic sandwich steady rotating combustion model of AP/HTPB was established. The gas phase adopts the two-step total reaction, coupled the gas-solid heat boundary layer, fitted the spinning momentum, and the two-dimensional flame structure under the conditions of combustion pressure of 0.1-5.0 MPa and spinning speed of 0-10800 r·min-1 were numerically simulated. Results show that under the working condition of spinning speed as 10200 r·min-1 when the combustion pressure is 0.1-0.5 MPa, the flame shows premixed combustion characteristics. When the combustion pressure is 0.5-3.5 MPa, the flame presents the dual characteristics of diffusion and premixed combustion. When the pressure is more than 3.5 MPa, a narrow diffusion chemical reaction zone is formed. The numerical analysis is carried out on steady combustion process at different combustion pressures and different spinning speeds. It is found that the deflecting angle of gas flame is linearly positive with the pressure. When the spinning speed is between 0-10200 r·min-1, deflecting angle and spinning speed of gas flame show a linear increase. However, when the spinning speed is between 10200-10800 r·min-1, the deflection angle of gas flame approximately shows an exponential growth with the spinning speed. The variation trend of the average Reynolds number of the combustion surface is basically the same as deflecting angle of the gas flame. Therefore, the average Reynolds number of the combustion surface can be used to describe the influence of the spinning and pressure on the deflecting angle of the gas phase flame.