固液火箭发动机工作过程三维数值仿真

根据固体燃料壁面与气相间的流固耦合得出了固体燃料燃速模型,对采用星形装药的H₂O₂/HTPB(hydroxyl-terminated polybutadiene)固液火箭发动机进行了燃烧流动三维数值仿真,得到了流场参数的分布及不同位置的固体燃料燃速,与二维轴对称仿真结果进行了对比.计算结果表明:装药截面的火焰层形状与装药星孔型面形状相似,但火焰层厚度与位置在星根与星角处存在差异;随着轴向位置的增加,氧化剂不断消耗,火焰层向通道中心移动;固体燃料燃速与氧化剂流率及不同装药位置有关,其大小随氧化剂流率的增加而增加,星根处燃速比星角处大;在相同氧化剂流率下,三维星形装药比二维轴对称装药的平均固体燃料燃速大.

Three-dimensional numerical simulation of hybrid rocket motor operation process

According to the coupling between the solid fuel and gaseous phases,the solid fuel regression rate model was established.Three-dimensional numerical simulation of a star-shaped fuel grain hybrid rocket motor with hydrogen peroxide(H₂O₂) and hydroxyl-terminated polybutadiene(HTPB) propellants combination was presented.The flow field and the solid fuel grain regression rate distribution were obtained,and the results were compared with that of two-dimensional axial symmetry engine.The results indicate that the flame layer profile is similar with the star-shaped fuel port,while the thickness and the location of the flame makes differences in the root and the slot of the star-shape.With the axial coordinate increasing,the oxidizer consumes continually,and the flame layer shifts toward the centre of the fuel grain port.The solid fuel regression rate relates with the oxidizer mass flux and solid fuel location.It increases with the oxidizer mass flux growing,and is higher in the root of the star-shape than in the slot.The solid fuel regression rate of three-dimensional fuel grain is larger than two-dimensional axial symmetry under the same oxidizer mass flux.