喷管喉衬结构瞬态温度测量及导热反问题方法应用

Transient Temperature Measurement of Nozzle Throat Insert and Application of Inverse Heat Conduction Problem Method

关键词:  固体火箭发动机  喉衬  温度测量  导热反问题方法

Key words:  Solid rocket motor  Throat insert  Temperature measurement  Inverse heat conduction problem method

摘要:

为了获得实时可靠的固体火箭发动机喉衬结构瞬态温度，采用内埋快响应烧蚀热电偶对发动机喉衬结构瞬态温度进行测量，并应用导热反问题方法(Beck序列函数法)计算其喉部内壁面温度和热流密度。采用的试验方案有效避免了传感器探头与喉衬内壁面烧蚀速率不同而干扰流场或中途烧毁等现象发生。试验结果显示越靠近内壁面的测量点温度峰值越高，测点温度瞬态变化与发动机工作状态同步性越好。计算结果显示，计算的平均误差为5.6%，最大误差为7.9%，其内壁温度最高出现在发动机工作结束时，热流密度在0.1s内迅速上升，而后又迅速下降，最大值约为30MW/m2。在发动机停止工作2s后，喉衬开始向外界传热。

Abstract:

In order to obtain the reasonable temperature of the nozzle throat insert in the SRM，the embedded fast-response Eroding thermocouple is used to measure the transient temperature of the nozzle throat insert structure. And the inverse heat conduction problem method (Beck’s sequence function method) is also applied to calculate the temperature and the heat flux of the throat internal surface. In this experiment，both the disturbed flow field caused by the different erosion rate between the thermocouple and the throat internal surface and the burning phenomenon of the thermocouple are avoided. The experimental results show that when the measured point is closer to the internal surface，the temperature is higher，and the synchronism to the state of the motor is better. The numerical results show that the average error is around 5.6%，and the maximum error is 7.9%. In addition，the internal surface temperature reaches its maximum at the end of the working. The heat flux increases rapidly within 0.1s and decreases at the rest of time. The maximum of heat flux is about 30MW/m2. The throat insert begin to transfer heat to the environment within 2s after the SRM stops working.