固液发动机固体燃料瞬态退移速率

Study of instantaneous regression rate in hybrid rocket motor

关键词:  固液混合火箭  瞬态退移速率+  数值仿真  动网格+

Key words:  Hybrid rocket  Instantaneous regression rate+  Numerical simulation  Dynamic mesh+

摘要:

为了研究固液混合火箭发动机中固体燃料退移速率在发动机工作过程中的变化特性,基于固液混合火箭发动机的工作特点,利用燃烧流动与固体区域传热耦合计算以及动网格技术,建立了固液混合火箭发动机固体燃料瞬态退移速率预示的数值模型,并对某带预燃室、补燃室以及扰流环结构的模型发动机进行了研究。计算结果表明,固体燃料热解表面的温度以及退移速率随着发动机的工作逐渐降低;在同一时刻沿发动机轴线燃料热解表面上各点的退移速率以及温度不同;扰流环可以提高它后面局部区域固体燃料的退移速率以及表面温度。

Abstract:

In order to study the characteristics of the changes in regression rate of solid grain in hybrid rocket motor,a numerical model to indicate the instantaneous regression rate in hybrid rocket motor was developed based on the operational traits.The model was based on coupled simulation of gas-phase combustion and heat transfer in solid fuel,as well as dynamic mesh.An experimental motor with pre-combustion chamber,after-combustion chamber and diaphragm was then studied using the model.The temperature of the pyrolysis surface of solid grain decreases as the motor works,and so does the regression rate;at the same moment,the regression rates of the pyrolysis surface of solid grain differ along the axial direction,so does the temperature;diaphragm is capable of raising the local regression rate and surface temperature of the solid grain just after the diaphragm.