船舶柴油机机体与曲轴间耦合模式对其振动的影响

为准确、高效地计算船舶柴油机曲轴和机体的整体振动形态，运用模态综合法对机体和曲轴动态缩减，建立二者间NONL、EHD、TEHD三种耦合模式的计入各非线性因素的缩减的柔性系统动力方程，采用Newmark方法数值求解.对比发现：NONL耦合模式计算效率最高，EHD次之，TEHD最低；精算精度则相反；不同耦合方式对机体和曲轴振动的影响也不同.因此，综合考虑计算效率和计算精度，若研究重点为机体振动与噪声，则选择NONL耦合模式；若研究重点为曲轴振动，则选择EHD或TEHD耦合模式；若同时考虑二者振动，则选择EHD耦合模式.
To accurately and quickly calculate the whole vibration of the crankshaft and the engine block of a marine diesel engine, the component mode synthesis method was used to dynamically reduce block and crankshaft, the nonlinear condensed and flexible system dynamic equations with NONL, EHD and TEHD coupled each other mode were built, and the numerical solution was solved by using Newmark method. Comparison shows that the calculation efficiency of NONL mode is the highest, EHD mode follows, and TEHD mode is the lowest. But the calculation precision is just inverse. The effect of different coupling modes on vibration of the block and the crankshaft is also different. Therefore, by considering the calculation efficiency and precision, NONL mode is better if engine block is the focus, EHD or TEHD are better if crankshaft vibration is the emphasis, and EHD mode is better if both of block and crankshaft are concerned simultaneously.