1. Model: 3D Piston

2. Diesel Engine Piston Studies the deformation and distribution of stresses in a suggested design at steady-state conditions Applied piston loads at steady-state analysis are: –Peak combustion pressure –Thermal loads –Inertia loads Calculates the stresses, which should be below the levels for fatigue of the material

3. Piston Geometry symmetry ¼ is modeled due to symmetry

4. Crown Top land Bowl Boundary Conditions - Mechanical The peak cylinder pressure is applied over the crown, combustion bowl and top land area.

5. No displacement in the normal direction No displacement in the normal direction Boundary Conditions – Mechanical Symmetry boundary constraints

6. Boundary Conditions – Mechanical The pin is assumed to be rigid Contact boundary conditions at the pin hole

7. Boundary Conditions – Thermal Combustion gas temperature T inf = 900 o C All other boundaries: Cooling water and oil temperature T inf = 80 o C Convective boundary conditions

8. Weak formulation for the mechanical part: Internal virtual strain energy Strong formulation for the heat transfer equation Domain Equations

9. Results - Temperature Distribution Highest temperatures at the crown and bowl area  Lowest fatigue limit

10. Results - Deformation The gas pressure causes a bending action over the pin The thermal loading causes an expansion

11. Results - von Mises Stresses Maximum effective stress at the pin boss area and at the bowl edge above the pin hole

12. Results A high tensile stress at the bowl edge causes fatigue cracks