A Study on the Thermal Properties of Oil-Film Viscosity in Squeeze Film Dampers

Considering the variation in temperature of the oil film in squeeze film dampers (SFDs) caused by squeezing, a more comprehensive analysis of SFD can be obtained. Aiming to investigate the viscosity thermal effect of the oil film in SFDs, this study established a 3D CFD solution model. Based on the total energy model, the viscosity thermal effect was performed. With the mixture multi-phase flow model, the Zwart-Gerber-Belamri (Z-G-B) cavitation model, and the use of the additional mass coefficient, the two-phase flow phenomenon in SFDs was discussed. The oil film at various temperatures and the temperature distribution of different oil types under different working conditions were analyzed. Furthermore, the influence of the SFD thermal effect on the two-phase flow phenomenon were particularly carried out. Meanwhile, the simulation results of the SFD thermal effect were experimentally verified. The results revealed that the maximum temperature of the SFD oil film was enhanced with the increase in the eccentricity ratio and precession frequency. The temperature of the oil film was closely related to the oil dynamic viscosity. The dynamic viscosity of the oil was reduced, which was caused by the SFD thermal effect, thus leading to decreased oil-film damping, enlarging the vaporization level and the range of vapor cavitation, as well as the ingested air amount. CFD simulation results of the thermal effect were in good agreement with the experimental data, which verified the accuracy of the proposed model.