空气动力学学报2019，Vol.37Issue(3)：406-411,6.
硅基防热材料表面流动特性研究
Surface flow character study of silicone thermal protection material
GAO He 1ZHANG Zhi 1CHEN Lianzhong 1WANG Xian 2FENG Xue2
作者信息
- 1. China Academy of Aerospace Aerodynamics ,Beijing 100074,China
- 2. Tsinghua University ,Beijing 100084,China
- 折叠
摘要
Abstract
There is plenty of melting substance on the surface of silicone thermal protection material (TPM)in ablation process,and the melting silicone is shaped into a liquid layer by the flow force.The surface temperature,mass lose,and recession of the TPM are directly affected by this surface flow character.Moreover,the ablation performance and heat insulation performance are indirectly determined by this character.The surface flow character of the silicone TPM is studied regarding two aspects in this paper.The first aspect is the ablation mechanism analysis with the melting silicone defined as a liquid boundary layer.The movement character between the liquid boundary layer and the solid TPM surface is investigated in consideration of the mass inj ection effect and evaporation phenomenon.The relationship is formulated between the velocity of liquid boundary layer and the flow shear stress,the thickness and dynamic viscosity of the layer.The second aspect is the optical contactless measurement based on 3D vision technique with PIV image processing and optical flow.The study obj ective is unitary and single movement character of the melting silicone blob on the solid TPM surface.The result shows that,there is strong interactive force between blobs and the velocity of blobs is very different.The mechanism analysis and the 3D vision technique are used to evaluate the velocity of blobs under a test condition.The cold wall heat flux and the recovery enthalpy of the test flow field are, respectively,1 1 70 kW/m2 and 5 480 kJ/kg,and the surface temperature of the TPM is 1 8 1 5 K. The result of ablation mechanism analysis is 26 mm/s,while the optical contactless measurement one is 10 mm/s.The differences between the two results are mainly contributed by the different theoretical assumption,the material parameters,and the measurement region.The ablation mechanism analysis can be used as an engineering calculation method to estimate the test result. The optical contactless measurement can be recognized as a verification tool with the capability of revealing the ablation characteristic of TPM during the test.关键词
硅基防热材料/表面流动/烧蚀机理分析/光学非接触测量/液滴速度/烧蚀试验Key words
silicone thermal protection material/surface flow/ablation mechanism analysis/optical contactless measurement/velocity of blobs/ablation test分类
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GAO He,ZHANG Zhi,CHEN Lianzhong,WANG Xian,FENG Xue..硅基防热材料表面流动特性研究[J].空气动力学学报,2019,37(3):406-411,6.
