基于两相流模型的挤压油膜阻尼器空化流场特性数值模拟

基于气液两相流理论中的Mixture模型和Zwart-Gerber-Belamri空化模型,采用动网格技术建立了两端开口中心槽供油型挤压油膜阻尼器三维非定常空化流场求解模型。数值模拟表明:随着阻尼器内环进动,考虑两相流动的油膜低压区在中心槽的两侧产生两道对称的条状负压带,条状带内具有较高的气相体积分数;阻尼器低压区的压力和气相体积分数对进油孔位置十分敏感,阻尼器油膜力和流场气穴比的变化频率与进油孔数密切相关。内环同心进动半径、进动频率对阻尼器空化流场影响的数值计算表明,进动半径和频率的增大均会使得流场内的空化现象加剧,同时气穴比的相位滞后现象愈加显著。 

Numerical simulation on cavitation flow field characteristics of squeeze film damper based on two-phase flow model

A computational fluid dynamics model was established for squeeze film damper with a central feeding groove, based on the Mixture model and the Zwart-Gerber-Belamri vapor cavitation model. The unsteady gas-liquid two-phase flow field in squeeze film damper was simulated by employing the dynamic mesh technique. Numerical simulations showed that with the precession of damper inner ring, two negative-pressure strips were generated in the low-pressure zone of damper symmetrically about the central feeding groove, and there was a high vapor volume fraction in the strips. It demonstrated that pressure distribution in the low-pressure zone and vapor volume fraction were sensitive to position of inlet hole, and variation frequencies of the oil film force and flow field cavitation ratio were closely related to the number of inlet holes. The simulation of the influence of centered precession radius and frequency of inner ring on cavitation flow field shows that the increasing precession radius and frequency both aggravate the cavitation phenomenon, and the phase lag phenomenon of the cavitation ratio becomes more significant.