热解气体流动的二维烧蚀热防护数值仿真研究

Numerical Simulation Research on Two-Dimensional Ablative Thermal Protection with Pyrolysis Gas Flow

研究了热解型碳化复合材料二维烧蚀的计算模型和计算方法。采用碳化层—热解面—原始材料层模型;将热解气体与碳化层之间的换热作为热载荷处理;计算了热解气体在碳化层中的流动和传热过程,获得了热解气体质量流量分布从而为烧蚀材料温度场计算提供边界条件。计算结果表明热解气体质量流量在碳化层明显成二维分布,不同位置的流量相差很大,并且对碳化层温度和烧蚀率有很大影响,因此,内部热响应计算需要考虑热解气体在碳化层中的流动和换热过程。

Both numerical simulation model and computational method of internal thermal response of carbonized composite material with pyrolysis reaction are researched deeply. At first, the method of ablative rate computation is researched. A charring layer-pyrolysis surface-original material layer model is applied and convection heat transfer between pyrolysis gas and charring layer is treated as heat source. The mass flux distribution of pyrolysis gas is obtained by computing flow and heat transfer process of pyrolysis gas inside charring layer and provides boundary conditions for temperature computation of ablative material. It is demonstrated by computational results that the mass flux of pyrolysis gas is two-dimensional distribution and it has big difference in different position; the pyrolysis gas has important effect on temperature of charring layer and ablative rate ; internal thermal response computation needs to consider the flow and heat transfer process of pyrolysis gas inside the charring layer.