摘要
针对气动激励引起的增压器整机高振动响应问题,以某型柴油发动机涡轮增压器为研究对象,采用单向瞬态流固耦合方法,建立涡轮增压器整机流固耦合模型,开展气动激励下关键零部件振动响应研究.讨论并对比了涡轮及压气机叶轮气动激励的时域和频域特性,并定量分析了该激励下的结构振动响应特性,同时通过增压器振动试验验证了模型及方法的精度,各工况下壳体振动加速度量级的绝对误差不超过6dB,相对误差不超过4％.结果表明:在转子系统中,压气机叶轮压力波动幅值为涡轮机涡轮的4倍,由此导致压气机叶轮的振动幅值平均为涡轮和转轴的3～4倍,最大振动幅值发生在压气机叶轮轮盘外边缘叶顶间隙处,为209.5pm;壳体振动烈度最大的部位发生在压气机出口内壁靠近轴承体一侧,为322.2 m/s2.
Abstract
In order to investigate the high vibration response of a diesel engine turbocharger caused by aerodynamic excitation,a fluid structure coupling model for the whole turbocharger was established using the unidirectional transient fluid structure coupling method,and the vibration response of key components was studied.The time-domain and frequency-domain characteristics of aerodynamic excitation of the turbine and impeller blades were thoroughly compared and discussed,and the structural vibration response characteristics under such excitation were quantitatively analyzed.The accuracy of the model was verified by the turbocharger vibration measurement.The absolute error of the accelerated vibration level under each condition does not exceed 6 dB,and the relative er-ror does not exceed 4％compared to the measured data.The results show that in the goose system,the amplitude of the pressure fluctuation of the leaf turbine is 4 times of the turbine end,which causes the vibration amplitude of the impeller to be an average of 3 to 4 times of the turbine and the rotating shaft.The maximum vibration amplitude of 209.5 pm occurs at the gap between the leaf top.The largest housing vibration intensity of 322.2 m/s2 occurs at the inner wall of the compressor outlet close to the side of the bearing body.
维普
万方数据