Research On The Effective Thermal Conductivity And Thermal Resistance Of Spacecraft Antenna Composite Materials

During the operation of spacecraft antenna in orbit,it has to experience severe space thermal environment,in order to ensure the spacecraft antenna to work normally,it is necessary to carry out thermal analysis and thermal design,and design a reasonable thermal control scheme.The heat transfer performance and interface thermal resistance of carbon fiber composite materials and complex mechanism components are important factors for the heat conduction control among the components of the satellite antenna,and are the basis for the thermal analysis and design of the satellite antenna.However,the thermal parameters of the composite structure and components can only be obtained from the partial volume or sporadic test,and the data accumulation is limited and the discreteness is large,so it is necessary to further data acquisition of thermal physical properties of antenna materials and research on thermal properties of structural components.Based on the principle of one-dimensional heat conduction,an experimental system is designed and built in this paper.The thermal conductivity parameters and interface contact thermal resistance of antenna materials and components of spacecraft are measured by steady-state method.The experimental system consists of five parts:vacuum system,temperature control system,heating system,data acquisition system and test piece.The test piece is placed in the vacuum container tank,and the vacuum container is suspended in the high and low temperature constant temperature tank.The high-power RF coaxial cable and antenna pointing structure(mainly bearing and bearing mating parts)are tested by the built internal circulation vacuum experimental system,and the radial thermal conductivity and interface contact thermal resistance of the test piece in the temperature range of-40??120? are obtained,and the test results are analyzed,and the radial equivalent thermal conductivity of the test piece is proportional to the test temperature.Then,the equivalent thermal conductivity parameters of composite honeycomb sandwich panel are obtained by measuring the thermal conductivity of composite honeycomb sandwich panel with NETZSCH GHP 456 protective hot plate method.The experimental results show that the thermal conductivity parameters of the tested materials are all small,and increase with the increase of temperature.The temperature distribution and heat flux distribution under the corresponding working conditions are obtained by thermal analysis of high-power RF coaxial cable,antenna pointing mechanism,composite honeycomb sandwich plate and carbon fiber reinforced plate bonding structure,and the numerical analysis results are compared with the experimental data,in order to verify the accuracy and reliability of the internal circulation vacuum test system.Through experimental tests and numerical simulation calculations,the relevant thermal performance parameters of the common composite materials and mechanism components of the spacecraft can be obtained,which can provide basic data references for the thermal design and thermal analysis of the spacecraft antenna,which has a certain practical value in engineering.