沉没辊装置液固耦合数值模拟及振动实验

针对热镀锌线沉没辊装置出现剧烈振动的问题,基于湿模态的结构非完全液固耦合方法,数值模拟了装置在锌液中的振动模态,分析各阶振型及固有频率,并进行现场振动实验.锌液中沉没辊的局部振型改变轴承的装配关系,而在实测信号的时域波形中出现削波现象,表明锌液中滑动轴承存在碰摩;幅值谱中波峰对应的频率为45.05 Hz,与湿模态的第4阶固有频率接近且振型相似,表明实验中的装置主要以第4阶固有振动为主;液固耦合的非线性振动引起倍频振动;锌液流场的持续作用是导致幅值谱中波峰两侧出现边频带的主要原因.理论及数值分析与实验研究有显著的关联性,结构非完全液固耦合方法能有效应用于工程实践.

Numerical simulation and vibration test on the liquid-solid coupling system of a sink roll device

For violent vibration of the sink roll device of a hot-dip galvanizing line, an incomplete liquid-solid coupling method based on the wet modal was studied, the vibration modal of the device was numerically simulated, the natural frequencies and vibration modes were discussed, and the vibration test was performed. The partial mode of the sink roll changed the assembly relationship in bearings, and the clipping appeared in the time domain waveform of measured signals, indicating that crashing and friction existed in the sliding bearings. The frequency of the peak in the amplitude spectrum was 45.05 Hz, close to the fourth order frequency and mode, which showed that the fourth order natural vibration of the device was dominant. The double-frequency vibration was caused by nonlinear vibration of liquid-solid coupling. The main cause of sidebands near the peak in the amplitude spectrum came from the continuous action of the zinc liquid flow field. The numerical analysis and experimented research have significant correlation, and the incomplete solid-liquid coupling method can be effectively applied to engineering practice.