A mathematical correlation is developed, based on the thermodynamic model of a
downsized gasoline engine, to establish the numerical relationship among the
thermodynamic parameters of the combustion chamber. In the developed numerical
model, the in-cylinder pressure curves of various operation condition are simulated by
varying the air-fuel ratio in the cylinder, and the associated knock characteristics are
recorded. The accuracy of the numerical simulation results is verified against the
knock excitation experiment. Then, based on the Rover K16 gasoline engine, a
simulation model is developed to simulate the engine knock in the combustion
chamber and observe the force acting on the top surface of the piston. The results
show that the forces act on the piston top surface are varying at various locations at
the same time, and the largest forces occur at the edge of the piston and followed by
the piston centre. Then, by comparing the thermo-mechanical coupling strength of the
piston under different operating conditions, the results show that the occurrence of the
knocking does not exceed the piston's strength limit. However, the stress and
deformation value of the piston is increased significantly, and the failure point of the
piston position is changed. Finally, based on the calibrated strength results, the piston
durability is predicted for various engine knock conditions. The results show that the
initial damage of piston in the process of detonation at the surface of the piston pin
hole and the joint of the piston cavity. The gasoline engine finally has a predicted
mileage of 253,440 km continuously which meet the prescribed mileage of 220,000
km
