Research On Method Of Thermal Design And Analysis Of Spaceborne Mechanism With Sinda And TMG

Spaceborne mechanism-solar array drive mechanism is an important part of asatellite. Its main function is to transfer energy and signals, and the life of itdetermines the performance of the satellite. In the complex space environment, thespaceborne mechanism is prone to be thermally damaged, it is thus much essenial toconduct detailed thermal design and analysis. At present, available thermal analysismethods are not cost-effective, time-comsuming and difficult to use. Therefore, it isimportant to propose a novel and efficient thermal analysis method for the practicalapplications. In this thesis, the methods for the thermal design and analysis ofspaceborne mechanism are investigated by applying thermal resistance networkmethod and finite element method respectively. An effective finite element-thermalresistance network method is proposed based on the principles of both thermalresistance network method and finite element method. The main research works aredescribed as follows:The space environment of satellite mechanism is firstly introduced, followedby the mode of the heat transfer inside the drive mechanism including thermalradiation and heat conduction. The models of the thermal design and analysis arethen simplified according to the three-dimensional model of the drive mechanismstructure. Moreover, an equivalent model is estabilishd so as to explain topologicalrelationship between the thermal design and thermal analysis of the drivemechanism.Based on the simplified topological relationship of the drive mechanism, athermal resistance network model of the drive mechanism is proposed. Dissipationnodes are distributed and applied on various components of solar array drivemechanism, and heat capacity on the dissipation nodes as well as thermal resistancebetween them are calculated for corresponding thermal analysis.The equivalent finite element thermal model of the solar array drive mechanismhas been established in steady state and transient state process based on thegeometric model of the solar array drive mechanism, simplified principle of thelarge complex structure and the thermal analysis equivalence principle of connectionbearing. The thermal conductivity between parts with assembly relationship hasbeen identified by the thermal coupling, the thermal coupling parameter and contactresistance between the parts.This thesis presents a finite element-thermal resistance network method,incorporating the ideas of the finite element method and the finite thermal resistancenetwork method. By comparing the thermal resistance network method and finite element-thermal resistance network method, it is found that the finite thermalresistance network method is much better than the thermal resistance networkmethod in terms of quick and accuracte temperature distribution in the early designprocess. In this case, spacecraft thermal design efficiency can be greatly enhanced.The proposed method enables the thermal design and thermal analysis of thestructure being carried out simultaneously. The thermal analysis results are in goodagreement with the experimental results, which verifies the effectiveness of finiteelement method for the thermal analysis and the thermal resistance network methodfor thermal design. Therefore, the proposed finite element-thermal resistancenetwork method can be employed for the thermal design and thermal analysis of thespace mechanisms accurately, quickly and efficiently.