固液混合火箭发动机燃烧室和喷管流动数值模拟

Numerical Simulation of Combustion Chamber and Nozzle Flow in Classical Hybrid Rocket Motors

固液混合火箭发动机是采用液体作为氧化剂,固体作为燃料的一种典型的混合火箭发动机。固液混合火箭发动机中的燃烧和流动问题是固液混合火箭发动机设计中的关键问题,对固液混合火箭发动机的燃烧室和喷管进行一体化计算很有必要。利用二维轴对称N-S方程和组分方程对选用液氧/端羟基聚丁二烯推进剂的固液混合火箭发动机的燃烧室和喷管进行了一体化计算。计算采用LU时间隐式格式、MUSCL空间离散和Van Leer矢通量分裂方法,采用有限速率化学反应模型,对化学源相进行了点隐式处理。计算中分别采用了一步化学反应模型和两步化学反应模型方案,计算了多个氧化剂流速和燃烧室压强下的燃烧室和喷管流场分布,对化学模型进行了选择,为固液混合火箭发动机的设计提供了依据。

In a typical hybrid, the fuel is a solid and the oxidizer is a liquid. A combustion and flow characteristic is the key problem in a hybrid rocket motor. Making research on computation of a combustion chamber and nozzle flow of a hybrid rocket motor is necessary. Numerical solutions of full Navier-Stokes equations with chemical reaction flow were obtained for of the LOX/HTPB hybrid rocket motor. Lower-Upper decomposition scheme and MUSCL-type and VanLeer approach were used. One step chemistry model and two steps chemistry model were adopted. The combustion chamber and the nozzle flow under oxidizer velocity and combustion pressure were calculated. The better chemistry model was chosen by the result, which will be useful for the hybrid rocket motor design.