针对某款重型商用车在高速行驶时由于行星齿轮式轮边减速器发热量过大,导致传递到轮胎的温度过高而使其爆裂的情况,提出安装散热片的解决方案.首先对此散热片在不同工况车速下分别处于静止和流动空气中时流动和换热性能进行仿真计算,拟合出努塞尔数、雷诺数等相似准则数间的关联式,并与相关文献得出的盘式散热片关联式对比,验证所建计算流体力学模型的准确性;其次,预测散热片在汽车高速行驶过程中的散热量;最后,将计算所得行星齿轮式轮边减速器摩擦产生的热流密度和仿真所得盘式散热片的对流换热系数作为边界条件,对车轮(轮辋和钟形鼓)进行了温度场仿真分析,结果表明,安装散热片后,轮辋表面温度有所下降.盘式散热片有效地改善了轮边减速器的散热条件,高速行驶时轮胎发生爆裂的可能性得以降低,安装散热片的方案有效.%In order to solve explosion of the heavi-duti commercial vehicle tires under high speed conditions which was caused by the high temperature derived from the planetary wheel reductor, a disk fin was proposed. Firstly, heat transfer and aerodynamics characteristics of the rotating fin in still and crossfiow air were studied by numerical simulation, and appropriate correlations were derived for Nusselt number as function of similarity numbers which could be served as the verification for accuracy of computation fluid dynamic model by comparing with correlations obtained in related literatures. Then, heat dissipating capacity of fin was also predicted in high speed conditions. Finally, temperature field of the wheel (rim and dram) was simulated with calculated applied heat and simulated heat transfer coefficient to be the boundary conditions, which shows that the temperature of rim surface was decreased after the installation of fin which verified the heat dissipating effect of the disk fin. Consequently, the heat dissipating solution was proved to be effective that heat transfer characteristic of wheel reductor was improved a lot by disk fin and the possibilities of fires explosion under high speed condition were reduced.
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