374 / 2018-12-12 19:30:03

高压圆盘气体轴承热力耦合分析 Thermal-mechanical Coupled Analysis of High Pressure Circular Gas Bearing

气体轴承；热力耦合；热变形；有限元分析 Gas Bearing; Thermal-mechanical Coupling; Thermal Deformation; Finite Element Analysis

全体主题 > 数值模拟、建模与CFD

高压圆盘气体轴承中的气流速度可达超音速，气流温度梯度大，气流与轴承壁面存在明显的对流换热，因此，需对轴承的热变形问题进行研究。对流换热系数是进行热力耦合分析的重要参数，计算了轴承壁面与气膜气流间的强制对流换热系数，并用Bartz公式验证了换热系数的准确性；采用有限元分析方法，计算了轴承在压力载荷和热载荷共同作用下的变形量，结果表明:压力载荷造成碳钢轴承的形变量仅为热变形量的20.2%，热变形对高压圆盘气体轴承的性能有着重要影响；分析了材质、轴承圆盘厚度对轴承圆盘温度分布和热变形的影响，结果表明:随着轴承圆盘厚度的增加，碳钢轴承圆盘的热变形量增大，而透明石英玻璃轴承圆盘受热载荷的影响较小，其变形量减小；分析了不同轴承结构对轴承圆盘热变形的影响，确定了不同材料时高压圆盘气体轴承实验模型的适宜结构。
In the high pressure circular gas bearing, the velocity of airflow can reach supersonic speed, the temperature gradient of airflow is large, so the study on thermal deformation of high pressure circular gas bearing is necessary. The convective heat transfer coefficient is an important parameter for thermal-mechanical coupling analysis. The convective heat transfer coefficient is calculated and compared with the Bartz formula, the reliability of the method of calculation and the accuracy of the calculation results are verified. The deformation of bearing under the combined action of pressure load and thermal load is calculated by the finite element analysis method. The results show that the deformation of carbon steel bearing caused by pressure load is only 20.2% of the thermal deformation, and the thermal deformation has an important effect on the performance of the high pressure circular gas bearing. The influence of material quality and bearing disc thickness on the temperature distribution and thermal deformation of the bearing disc is analyzed. The results show that the thermal deformation of carbon steel bearing disk increases with the increase of bearing disc thickness. However, due to the less effect of thermal load on the transparent quartz glass bearing disk, the deformation is reduced with the increase of bearing disc thickness. The influence of different bearing structure on the thermal deformation of bearing disk is analyzed, and the suitable structure of the experimental model of high pressure circular gas bearing with different materials is determined.