轴承腔典型结构热防护性能模型实验研究

Model Test on Thermal Protection Performance of Typical Structure for Bearing Chamber

关键词:  航空发动机  轴承腔典型结构  热防护  隔热性能  模型试验

Key words:  Aero-engine  Typical structure of bearing chamber  Thermal protection  Heat insulation performance  Model test

摘要:

针对航空发动机轴承腔中带隔热夹层的典型热防护结构，开展了模型试验件的隔热性能实验研究。通过搭建专用试验平台测量不同热防护结构在典型工作温度下的隔热性能，使用稳态法开展相应结构的等效导热率研究。结果表明，气凝胶材料厚度增加可快速提升结构整体热阻，在相同厚度条件下空气夹层与气凝胶隔热性能相当；在组合隔热夹层1/3处增加反射屏后可提升隔热温差20.4％；考虑安装“热短路”效应影响，典型组合隔热试验件热导率最小为0.58W/（m·K），远大于单独隔热材料的热导率。

Abstract:

The thermal insulation performance experiment of the model test piece was carried out to study the typical thermal protection structure with thermal insulation interlayer for the bearing chamber of aero-engine.A special test platform was built to measure the thermal insulation performance of different thermal protection structures at typical working temperatures. The steady-state method was used to conduct research on the equivalent thermal conductivity of the corresponding structures. The results show that increasing the thickness of the aerogel material can rapidly improve the overall thermal resistance of the structure. The thermal insulation performance of the air interlayer is equivalent to that of the aerogel under the same thickness. After adding a reflective screen to 1/3 of the thermal insulation interlayer， the thermal insulation temperature difference can be increased by 20.4%. Due to the influence of the ‘thermal short-circuit’ effect of installation， the thermal conductivity of the typical combined thermal insulation test piece is at least 0.58W/（m·K）， which is significantly larger than that of the single thermal insulation material.