C/SiC复合材料波纹点阵结构进气道前缘设计与制备

Design and Preparation of Inlet Leading Edge with Corrugated Lattice Structure of C/SiC Composites

目的C/SiC复合材料进气道前缘轻量化设计与制备。方法基于进气道气动外形和结构要求,建立波纹点阵夹芯结构的进气道前缘有限元模型,然后按照德国航空中心H2K超声速风洞试验室试验的数据进行反演,得到进气道前缘的热流密度分布,据此进行边界条件加载,在模型中考虑固体导热、表面辐射以及空腔辐射三种传热方式。采用瞬态传热算法,求解100 s下进气道前缘的温度场,为了进一步降低C/SiC复合材料波纹点阵结构进气道前缘的最高温度,设计不同的进气道前缘尖端半径,并进行优化。最后根据优化得到的波纹点阵进气道几何参数,采用PIP法制备出C/SiC复合材料点阵结构进气道前缘。结果进气道尖端半径小于0.5mm时,最高温度高于1800℃,超过C/SiC复合材料极限温度;进气道尖端半径大于1.0 mm时,最高温度为1520℃,低于C/SiC复合材料极限温度;进气道尖端半径大于2.0 mm时,增大半径对降低进气道前缘最高温度没有明显的作用。不同进气道前缘尖端半径下,最高温度达到稳态的时间不一样,半径等于0.5 mm时,进气道前缘达到稳态的时间约为30 s左右。随着前缘尖端半径增大,最高温度达到稳态的时间增加,半径为1.0 mm时,达到稳态时间约为60 s。结论进气道前缘最高温度随着尖端半径增大明显降低,当半径大于2.0 mm时,增大半径对降低进气道前缘最高温度没有明显的作用。

The paper aims to complete lightweight design and preparation of C/SiC composite inlet leading edge.Firstly,the finite element model of the inlet leading edge with corrugated lattice sandwich structure was established based on the requirements on aerodynamic shape and structure of inlet.Then the heat flux distribution at the inlet leading edge was obtained by inversion according to the data of the H2K supersonic wind tunnel test in the German aviation center.On this basis,the boundary condition was loaded.Three heat transfer models,including thermal conduction,surface radiation and cavity radiation,were considered in the heat transfer process.Secondly,the transient heat transfer algorithm was used to solve the temperature field of the inlet leading edge in 100 seconds.To further reduce the highest temperature at the C/SiC composite inlet leading edge with corrugated lattice sandwich structure,different inlet leading edge tip radii were designed and optimized.Finally,the leading edge of C/SiC composite lattice structure inlet was prepared by the PIP method according to the optimized geometric parameters of the corrugated lattice inlet.When the radius of the inlet tip was less than 0.5 mm,the maximum temperature was higher than 1800℃,which exceeded the limit temperature of C/SiC composite material.When the radius of the inlet tip was greater than 1.0 mm,the maximum temperature was 1520℃,which was lower than the limit temperature of C/SiC composite material.When the inlet tip radius was greater than 2.0 mm,increasing the radius had no obvious effect on reducing the maximum temperature of the inlet leading edge.It took different time for the maximum temperature to reach the steady state under different inlet leading edge radii.When the radius was equal to 0.5 mm,it took about 30 s for the leading edge of the inlet to reach the steady state.As the radius of the leading edge tip increased,the time for the maximum temperature to reach the steady state increased.When the radius was 1.0 mm,it took about 60 s for the leading edge to reach the steady state.The maximum temperature of the inlet leading edge decreases significantly with the increase of the tip radius.When the radius is greater than 2.0 mm,increasing the radius has no significant effect on reducing the maximum temperature on the inlet leading edge.