For the limitations as using the well-known film thickness equation in shape optimization,a new approach for shape optimization of hydrodynamic journal bearing following the general film thickness equation was proposed.

We consider a generalized thin film equation.

Thin film equations, as a class of important higher order nonlinear diffusion equations, come from the diffusion phenomena on the surface of crystal.

Thin film equations, as a class of important higher order nonlinear diffusion equations, come from the diffusion phenomena on the surface of crystal [1].