旋转固体火箭发动机统一流场计算

Numerical Simulation of United Flow Field of Spinning SRM

为了进一步研究旋转对固体火箭发动机工作的影响,采用RSM湍流模型对内孔燃烧、内孔与端面同时燃烧管状装药旋转固体火箭发动机统一流场进行了仿真。采用UDF编程给出质量入口边界,获得了旋转条件下发动机内流场结构参数特点,并给予理论说明。计算结果表明,内孔燃烧装药发动机切向速度流场类似于典型的Rankine涡,端面和内孔同时燃烧装药发动机切向速度流场呈现出Rankine涡和由端面燃烧引起的强迫涡的复杂组合涡;在发动机前封头和喷管喉部涡核切向速度峰值非常大,使燃烧室前封头和喷管喉部工作环境显著恶化;旋转使发动机燃烧室压力沿径向逐渐增大,强迫涡附近的压力梯度远大于推进剂表面的压力梯度。

Aiming to further find out the effect of spinning on the solid rocket motor （ SRM）, the RSM turbulent model was employed to calculate the united flow filed in a spinning SRM with inner-burning tube solid propellant, as well as inner-burning and end-burning tube solid propellant. The user defined function （UDF） was adopted to offer the condition of mass flow inlet, and the configuration characteristics of inner flow filed was obtained. The theoretical explanation was given. The calculational results show that the tangential velocity distribution of swirl flow in the inner -burning tube solid propellant is similar to the typical Rankine vertex. The swirl flow of the inner-burning and end- burning tube solid propellant presents the complex combination of Rankine vortex and forced vortex caused by end- burning tube solid propellant. The tangential velocity of swirl core at the front of the combustion chamber and nozzle throat is very high, which leads to the former head of combustion chamber and nozzle throat working in a significantly deteriorating condition. Another effect of the spinning is that the radial pressure increases in the radius direction, and the pressure gradient near the force vertex is much higher than that near the surface of the solid propellant.