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为了降低液体火箭发动机推力室壁温和冷却剂压力损失,对再生冷却通道尺寸参数进行优化设计。以再生冷却通道高度、宽度、数目和推力室内壁厚为设计变量,推力室平均壁温、最高壁温和冷却剂压力损失为目标函数,采用Box-Behnken试验设计方法获取样本点,根据样本点建立再生冷却通道计算模型,利用传热分析程序针对不同方案得到目标函数关于设计变量的二阶响应面模型,分别用梯度投影、积极集法和遗传算法进行优化计算,同时利用逐步回归法和样本点更新技术提高模型精度。计算结果表明,建立的响应面模型能以较小的计算成本准确地反映设计变量和目标函数的关系;存在一个最佳的通道高宽比和通道数目使得冷却通道传热特性最优;对于两种不同优化方案,优化设计后的目标函数最多比初始设计降低13.5%和23.5%;使用遗传算法优化后得到的目标函数值最低。
In order to reduce the pressure loss of the mild rocket engine thrust wall, the size parameters of regenerative cooling channels are optimized. Taking the height, width and number of regenerative cooling channels as the design variables, the average wall temperature of the thrust chamber, the maximum wall temperature and the pressure drop of the coolant as the objective function, the sample points were obtained by the Box-Behnken experimental design method, and the sample points were established Regenerative cooling channel calculation model, using heat transfer analysis program for different programs to obtain the objective function of the second-order response surface model for the design variables, respectively, using gradient projection, active set method and genetic algorithm to optimize the calculation, using stepwise regression and sample points Updated technology to improve model accuracy. The results show that the established response surface model can accurately reflect the relationship between the design variables and the objective function with a small computational cost. There exists an optimal channel aspect ratio and the number of channels to optimize the heat transfer characteristics of the cooling channel. For the two According to different optimization schemes, the objective function after optimization design is reduced by 13.5% and 23.5%, respectively, at the most, compared with the original design. The objective function value optimized by genetic algorithm is the lowest.