基于分形接触理论的拉杆转子瞬态温度场分析

Analysis on transient temperature field of the rod fastening rotor based on fractal contact theory

拉杆转子轮盘互相接触,接触热阻对于接触传热及温度场的分布十分重要。在表面分形特征的基础上,结合Mandelbrot-Tian(M-T)分形网络模型和经典接触导热理论,通过选用不依赖于观测尺度的Cantor集分形理论,整理公式及编程获得接触面间压力与接触热阻的关系。在确定接触热阻的情况下通过有限元分析得出拉杆转子瞬态温度场分布。分析发现,预紧力对于拉杆转子瞬态温度场影响不大,做拉杆转子动力学分析的时候可以忽略瞬态温度场的影响。

When the disk of tie-bolted fastened rotor contact each other, the thermal contact resistance between the disk contact surfaces play a critical role in heat transfer and the distribution of temperature field. On the basis of the surface fractal characteristics, combining Mandelbrot-Tian（M-T） fractal network model and the classical conduction theory, the Cantor set, which is not dependent on the observation scale,is chosen to obtain the pressure and heat transfer coefficient of the relationship between contact surfaces. The condition of rotor transient temperature field distribution are obtained through determining the contact thermal resistance. Analysis found that the thermal conductivity caused by the pre-tightening force has a little influence on the transient temperature field, when the rotor dynamics analysis can ignore the influence of the transient temperature field.