Colloquia

Summary

In this feasibility study on the sealing mechanisms of a hard on soft seal an approach to model the system is presented. The study starts with the material properties, the mechanical properties and roughness of the surface. These are key factors in the contact mechanisms of the contacting bodies. A few contact models are discussed such as the Hertzian contact mechanism, Greenwood & Williamson model, Persson model and the BEM model. In this study the BEM model is used as the contact model to calculate the deformation of the materials under a given load. The fluid between the materials can be seen as a thin film, so the Reynolds thin film theory will be used to examine the fluid pressure distribution through the seal. This is a numerical calculation, known and new models are presented. The finite difference method is used as the basis for the model with two relaxations added to gain some computational speed such as the Gauss-Seidel relaxation and the successive over relaxation. A multigrid model is tried to apply but this approach did not succeed. A spin off model of the mechanics of the multigrid model is presented. The last step in the model that is presented is the flow model which computes the leakage of the seal. All the models are validated by the analytical solutions of the Rayleigh step bearing and incline pad bearing. A model validation with test results of a test setup is tried but the test setup didn't provide sufficient results to compare.