Static and dynamic performances of refrigerant-lubricated foil bearings

7th International Conference on Advanced Concepts in Mechanical Engineering

Bouchehit, B.^1 ; Bou-Saïd, B.^1 ; Garcia, M.^2

Université de Lyon, CNRS, INSA Lyon, LaMCoS UMR5259, F-69621, France^1

LTS, 408 avenue des Etats-Unis, Toulouse Cedex 2

F-31016, France^2

关键词: Compressible fluids;    Controlled environment;    Fluid temperatures;    Phenomenological approach;    Static and dynamic behaviours;    Static and dynamic performance;    Theoretical and numerical modeling;    Variable viscosity;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/147/1/012043/pdf
DOI  :  10.1088/1757-899X/147/1/012043

来源: IOP

【 摘 要 】

Gas bearings are successfully used over a large panel of turbo-machineries. Some of these systems run in controlled environments such as refrigerating gas. We present in this paper a theoretical and numerical model which consider the vapor/liquid lubricant transition, the laminar/turbulent flow transition and both temperature and viscosity 3D variations in the fluid and the solids for both static and dynamic situations. The foil deflection is considered using the Heshmat's approach. This model involves: the resolution of the generalized Reynolds equation for compressible fluids with 3D variable viscosity, the description of the turbulence effects by the phenomenological approach of Elrod, using a 3D eddy viscosity field, the resolution of a non-linear equation of state for the lubricant, able to describe the vapor/liquid transition and a local thermal approach to obtain a 3D estimation of the fluid temperature, thanks to the thin-film energy equation and an actualisation of the film thickness. The thermal effects in solids are also taken into account. Both static and dynamic behaviours of GFBs are analysed.