Investigation into gas lubrication performance of porous gas bearing considering velocity slip boundary condition  

作　　者：Xiangbo ZHANG Shuiting DING Farong DU Fenzhu JI Zheng XU Jiang LIU Qi ZHANG Yu ZHOU 

机构地区：[1]School of Energy and Power Engineering,Beihang University,Beijing 100191,China [2]Aircraft/Engine Integrated System Safety Beijing Key Laboratory,Beihang University,Beijing 100191,China [3]Research Institute of Aero-Engine,Beihang University,Beijing 100191,China [4]School of Transportation Science and Engineering,Beihang University,Beijing 100191,China

出　　处：《Friction》2022年第6期891-910,共20页摩擦（英文版）

摘　　要：Porous gas bearings(PGBs)have a proactive application in aerospace and turbomachinery.This study investigates the gas lubrication performance of a PGB with the condition of velocity slip boundary(VSB)owing to the high Knudsen number in the gas film.The Darcy-Forchheimer laws and modified Navier-Stokes equations were adopted to describe the gas flow in the porous layer and gas film region,respectively.An improved bearing experimental platform was established to verify the accuracy of the derived theory and the reliability of the numerical analysis.The effects of various parameters on the pressure distribution,flow cycle,load capacity,mass flow rate,and velocity profile are demonstrated and discussed.The results show that the gas can flow in both directions,from the porous layer to the gas film region,or in reverse.The load capacity of the PGB increases with an increase in speed and inlet pressure and decreases with an increase in permeability.The mass flow rate increases as the inlet pressure and permeability increase.Furthermore,the simulation results using VSB are in agreement with the experimental results,with an average error of 3.4%,which indicates that the model using VSB achieves a high accuracy.The simulation results ignoring the VSB overrate the load capacity by 16.42%and undervalue the mass flow rate by 11.29%.This study may aid in understanding the gas lubrication mechanism in PGBs and the development of novel gas lubricants.

关 键 词：porous gas bearing(PGB) velocity slip boundary(VSB) numerical simulation gas lubrication flow characteristics 

分 类 号：TH117[机械工程—机械设计及理论]