Study on 3D Shape Optimization for Hydrodynamic Journal Bearing Using Goal Attainment Multi-Objective Function

Abstract

This paper is focused on multi-objective optimization to find the best performance related to the geometrical design of the hydrodynamic journal bearing in three dimensions 3D. The mathematical model for 3D film thickness profile was driven using Fourier’s series function and axial waviness value to represent in circumferential and axial direction respectively. A Goal attainment function was used as an optimization tool with goals to minimize the power loss and side leakage and to maximize the load capacity, while the amplitude (a), number of wave (m) and Fourier's series coefficients of the general film thickness were taken as design variables subjected to several bounds and constraints. The optimized results show the cylindrical plain bearing is the best to load capacity due to changing the axial shape does not enhance the load capacity without violation of the minimum film thickness. Comparison was made between goal attainment multi-objective optimization and GA single-objective optimization. The new method for shape optimization based on 3D general film thickness is more evident than GA.