发动机燃烧室内壁材料热环境的气动热试验模拟技术研究

Investigation on Aerothermodynamic Simulation Technology for Thermal Environment of Engine Combustor Inner Surface Material

关键词:  发动机燃烧室  内流热环境  外流热环境  湍流导管  电弧加热器 

Key words:  Engine combustor  Inner flow thermal environment  Outer flow thermal environment  Turbulent duct  Arc heater

摘要:

利用超声速矩形湍流导管和等离子电弧加热器模拟了发动机燃烧室内流和高超声速飞行器外壁面外流热环境,进行了平板表面冷壁热流测量和燃烧室内壁材料考核试验。结果表明:由于辐射换热的影响,在选取的两个典型来流条件下,发动机燃烧室内流热环境下的冷壁热流比外流热环境下的高出21%和40%,但是冷壁热流的增量基本相当,约为0.70~0.80MW/m²。随着冷壁热流的增加,辐射换热产生的热流增量的影响力会逐渐减小。材料考核时,相同配方的C/SiC复合材料在内流热环境下的表面温度高出约400℃,背面温度高出约90℃,这种差异对于发动机燃烧室内壁面材料考核至关重要,必须在材料考核试验中加以考虑。 

Abstract:

The inner flow and outer flow thermal environment has usually taken place in the inner surface of engine combustor and the outer surface of hypersonic vehicle, respectively. The two kinds of thermal environment have been compared by using the supersonic rectangle turbulent flow duct and arc heater. The cold-wall heat flux was measured and the engine combustor inner surface material was tested in two kinds of thermal environment. Due to the effect of thermal radiation heat transfer, the cold-wall heat flux of inner flow is respectively 21% and 40% higher than that of outer flow in two kinds of representative flow conditions. And the increments of the cold-wall heat fluxes are nearly equal, about 0.70~0.80MW/m². So when the cold-wall heat flux increases, the effect of radiation heat transfer will gradually decrease. In material test experiment, the surface and rear temperature of the C/SiC composites in the inner flow is respectively higher about 400℃ and 90℃ than those with same formulation design in the outer flow, which is very significant to test the engine combustor inner surface material and must be considered in the material test experiment. 