Numerical simulation of combustion characteristics at wall burning condition in a diesel engine was conducted using software AVL FIRE

and the thermal boundary conditions of finite element calculation for piston at wall burning condition were obtained. Moreover

the finite element analysis of piston during ablation process was carried out using software ANSYS

and the rules of influence of wall burning on piston ablation were achieved. Meanwhile

a corresponding experiment of piston ablation was made on the diesel engine

and the calculated results accorded with the experimental results. The results show that the resolving method established can be used to simulate the ablation process of piston. The abrasion of injection nozzle

which leads to bigger gas temperature and wall heat transfer coefficient of gas on piston throat in a wide crank angle range

may cause ablation failure of piston. Meanwhile

the ablation amount firstly increases and then decreases with the increase of diameter of injection nozzle

and peaks when the diameter increases by 15%. The ablation amount increases with the ablation time

but the speed of ablation reduces slowly.