空间相机碳纤维桁架导热增强设计

由于空间相机桁架结构常用的碳纤维复合材料热导率较低,从而导致结构内部易形成较大温度梯度。本文提出通过在碳纤维复合材料表面附着铜网和粘贴铝膜,以实现某空间相机桁架结构的导热增强设计。首先,建立了碳纤维复合材料热导率模型。然后,针对碳纤维复合材料平板表面附着铜网/粘贴铝膜的结构特点,建立了平板的传热模型,并对未经处理的碳纤维复合材料平板以及在其表面分别粘贴0.05mm和0.5mm铝膜、附着等效直径为0.08mm铜网4种不同状态进行了热分析。接着,通过试验测试获得了不同状态平板结构的等效热导率。试验结果表明,表面附着铜网/粘贴铝膜可以使面内等效热导率得到不同程度的改善。其中,在碳纤维复合材料平板表面粘贴0.5mm铝膜效果最好,其可使结构的等效热导率提升至41.3 W/(m·K)。最后,根据试验所得结构等效热导率,对某空间相机碳纤维桁架进行了热设计。桁架结构热分析结果表明,单根桁架杆的轴向温差已由6.8℃减小为0.8℃,桁架结构温度均匀性得到显著改善。

Thermal conductivity enhancement design for carbon-fiber truss of space camera

As the carbon-fiber reinforced polymer (CFRP) composite material common used for truss structure of space camera has the draw back of low thermal conductivity ,great temperature gradient is easily formed in the truss .The method that copper grid was adhered and aluminum film was pasted on the surface of CFRP was proposed to enhance thermal conductivity for carbon-fiber truss of a space camera .Firstly ,thermal conductivity model of CFRP was established .Then heat transfer models for four kinds of plates(including bare CFRP plate ,two plates respectively pasted aluminum films of 0 .05 mm and 0 .5 mm ,and one plate adhered copper grid with equivalent diameter as 0 .08 mm on the surface) were established ,and corresponding thermal analysis was conducted on the four different states of plates .Then equivalent thermal conductivities of four kinds of plates were obtained through finite element software .Test result indicates :equivalent thermal conductivity could be improved in different degrees through adhering copper grid/pasting aluminum film on the surface of CFRP . Structural equivalent thermal conductivity was increased to 41 .3 W/(m · K ) to paste aluminum film of 0 .5 mm on the plate surface of CFRP .Finally ,thermal design was conducted on carbon-fiber truss of a certain space camera according to structural equivalent thermal conductivity in the test .Thermal analysis result of truss structure indicates that axial temperature difference of a single truss rod reduces from 6 .8 ℃ to 0 .8 ℃ ,and the temperature uniformity of truss structure is significantly improved .