Study On Cavitation Flow Field Characteristics And Damping Coefficient Of Squeeze Film Damper

Squeeze film dampers are widely used in aerospace engines,marine gas turbines,and other rotating mechanical shaftings to increase damping,reduce vibration,and improve rotor stability.During the working process of the squeeze film damper,the low-pressure zone of the liucha flow field produces two kinds of cavitation phenomena:oil-vapor cavitation and suction air cavitation.It is found that the existence of cavitation directly affects the pressure distribution of the flow field in the squeeze film damper and affects the dynamic characteristics of the damper.Therefore,when studying the cavitation flow field characteristics and damping coefficient of the squeeze film damper,it is necessary to consider the two-phase flow phenomenon of oil and gas mixing in the squeeze film damper flow field,and to explore the influence of geometric structure and physical parameters.Based on computational fluid dynamics technology,this paper studies the numerical simulation of squeeze film damper.The main research contents are as follows:Firstly,for the three multiphase flow models Volume of Fluid model,Mixture model,Eulerian model and three kinds of cavitation models Singhal et al.model,Zwart-Gerber-Belairi model and Schnerr-Sauer model in Ansys-Fluent commercial software,Its basic principles and principles of use.The Gambit software was used to establish a three-dimensional physical model of the oil-supply squeeze film damper with open center groove at both ends.The equivalent damping formula for calculating the damping coefficient of the squeeze film damper is derived.Then,three kinds of multiphase flow models and three kinds of cavitation models are used to numerically simulate the cavitation flow field and damping coefficient of the squeeze film damper.The calculation results are compared and analyzed.Finally,the Mixture multiphase flow model and the Schnerr-Sauer cavitation model are selected to further study the influence factors of the cavitation flow field characteristics and damping coefficient of the squeeze film damper.Finally,the effects of geometric structure and physical parameters on the cavitation flow field characteristics and damping coefficient of squeeze film dampers are studied.The effects of the number of oil inlet holes,oil groove structure,oil groove depth,oil groove width,inner ring precession radius,inner ring static eccentricity,inner ring precession frequency and oil inlet pressure on the performance of the squeeze film damper are simulated.The research shows that increasing the number of oil inlet holes,increasing the inner ring precession eccentricity,inner ring precession frequency and oil inlet pressure can improve the damping performance of the squeeze film damper;however,increase the oil groove structure and increase the oil groove depth.And the oil groove width,so that the damping performance of the squeeze film damper is weakened.