旋转条件下AP/HTPB二维火焰结构的数值分析

为了研究底排推进剂高氯酸铵/端羟基聚丁二烯(AP/HTPB)旋转条件下微尺度燃烧特性,建立了AP/HTPB二维周期性三明治定常旋转燃烧模型,气相采用两步总包反应,耦合气固热边界层,拟合旋转动量,并对燃烧压力为0.1～5 MPa,转速0～10800 r·min~(-1)条件下的二维火焰结构进行了数值模拟。结果表明,转速在10200 r·min~(-1)的工况下,当燃烧压力为0.1～0.5 MPa时,火焰呈预混燃烧特性;当燃烧压力为0.5～3.5 MPa时,火焰呈现扩散、预混燃烧双重特性;当燃烧压力大于3.5 MPa时,形成狭长的扩散化学反应带。分别针对不同燃烧压力和不同转速下的稳态燃烧过程进行了数值分析,得知气相火焰偏转角与压力呈线性正相关;转速在0～10200 r·min~(-1)之间时气相火焰偏转角与转速呈线性增长,但是当转速在10200～10800 r·min~(-1)时,气相火焰偏转角与转速近似呈指数增长。燃面平均雷诺数的变化趋势与气相火焰偏转角度基本一致,因此可以通过燃面平均雷诺数来描述旋转与压力对气相火焰偏转角度的影响。

Numerical Simulation of 2D AP / HTPB Flame Structure Under Spinning Conditions

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.