基于L-M算法的液体火箭推力室壁面热流密度测量方法

Method to Measure Wall Heat Flux of Liquid Rocket Thrust Chambers Based on L-M Algorithm

关键词:  推力室  热防护  L-M算法  壁面热流密度  过氧化氢

Key words:  Thrust chamber  Thermal protection  L-M algorithm  Wall heat flux  Hydrogen peroxide

摘要:

为获取液体火箭推力室热防护方案构建的基础数据，结合单点瞬态法，提出了基于L-M算法测量壁面热流密度的方法。通过模拟热流密度分析算法中关键参数对求解精度的影响，给出关键参数的选取建议。在此基础上，对过氧化氢煤油推力室典型试验工况进行热流密度测量。结果表明：圆筒段末端壁面热流密度为3.35MW/m²，喉部位置单组元工况下壁面热流密度为2.21MW/m²，双组元工况下壁面热流密度为10.59MW/m²，热流密度变化过程与室压变化过程完全对应。变工况过程中近壁处燃气温度存在恢复过程，燃气温度稳定后，壁面热流密度也达到稳定状态。本文提出的方法可迅速、准确地测量推力室壁面热流密度。

Abstract:

To obtain basic data for designing thermal protection of liquid rocket thrust chambers， a method to measure wall heat flux based on L-M algorithm was proposed， which could be implemented with the transient temperature data obtained by a thermocouple. And through simulation heat flux comparison and discussion， the key parameters’ value suggestion which would influence the solution accuracy was also given. Then， apply it in the typical hot firing test of a hydrogen peroxide biopropellant thrust chamber. The results indicate that wall heat flux at the end of cylinder is 3.35MW/m². The wall heat flux at throat is 2.21MW/m² in the monopropellant mode and 10.59MW/m² in the bipropellant mode， which matches the change process of chamber pressure well. The gas temperature near the wall will recover for a certain time when the test condition changes.After the gas temperature stabilizes， the wall heat flux also reaches a steady state. The proposed method can be used to measure the wall heat flux rapidly and accurately.