Thermal fluid-structure interaction analysis on the piston/cylinder interface leakage of a high-pressure fuel pump for diesel engines

Leakage at the piston/cylinder interface of a high-pressure fuel pump for diesel engines becomes more severe due to the increase in delivery pressure. Therefore, a thermal fluid-structure interaction model that can simulate the complex phenomena that take place at the interface is presented in this paper. In the model, the nonisothermal flow, the physical properties of the fluid such as dynamic viscosity and density versus pressure and temperature relationships, the coupled heat transfer between the fluid and structure as well as thermal and pressure-induced elastic deformations of the structure are considered. The calculated leakage rates from the model show good agreement with the experimental results. The impacts of pressure-induced and thermal elastic deformations of the structure on the leakage are discussed. A new direction for reducing the interface leakage is proposed.