Evaluation of Different Nonlinear Film Force Models for Journal Bearing

In the analysis and design of the nonlinear dynamic rotor-bearing system,the different nonlinear oil film force models of journal bearings will essentially affect the final results.To evaluate the difference of the results from normally used nonlinear oil film force models and solutions to Reynolds equation by finite difference method,the infinite short bearing model、infinite long bearing model、unsteady oil film force model、nonlinear oil film force database method based on Poincare transformation and finite difference solution to Reynolds equation are employed respectively in the system dynamic analysis.It is indicated that the results of former models deviate to that of finite difference method dissimilarly under different bearing aspect ratios.This is very helpful to choose suitable nonlinear oil film force model in the dynamic analysis for rotor-bearing systems.