Analysis Of The Radiometer And HDPE Pipe

Thermal analysis is an important mission in manufacture. Many kinds of devices are required strict precisions. So the temperature,thermal stress and displacement of the devices in their working environment and the manufacturing process should be known.Radiometer is a device working in the space. Analyzing the thermal stress and displacement is a crucial task for knowing whether the device can work in the terrible temperature condition. The thermal analysis can be a hard task because of the huge amount of the temperature multi-fields which can not be typed or imported to the FEA software easily. For inputting the data into the software, a new way is created. Doing the interpolation by Matlab then writing down the result into the bdf file in the bdf thermal load format can get a familiar thermal field with the Patran's and make the data inputting automatic. Comparing the answer of Patran field with the Matlab's to prove the feasibility of the Matlab field. Then the huge temperature data can be inputted into the bdf file.High Density Polyethylene (HDPE) is a material with excellent properties of water resisting and heat insulation. Analyzing thermal problems of HDPE can be helpful to choose or design the device of manufacturing HDPE pipe. But the materials like HDPE have a big coefficient of linear expansion, so when their temperature change in a huge range, the volume and the shape of the material may change in a big degree, too. And in the FEA work, the density of the material can only be fixed to one number, so especially in a long time process, the result can not be as accurate as it should be. Consider two ways to deal with this nonlinear problem. First, separate the whole time into several steps and adjust the FEA model in every step to simulate the change of the model. Second, fix the FEA model then adjust the conductivity of the material as if the model is changing before the analysis begin. Then increase the number of steps and decrease the length of steps to study the change of the result. And set a extreme conductivity to get the range of the result. Compare the results of the two methods to prove the feasibility of the methods and find the better way.