Aryan R. Improving Efficiency Simulation of Heat Stress Piston ICE in Multi- CAD/CAE

Processes of loss of strength of pistons of internal combustion engines. All the experimental and theoretical studies performed are based on the fundamental concepts of the theory of internal combustion engines, thermal conductivity, thermoelasticity, and strength. The experimental method is used to identify the boundary conditions of the heat conduction problem in the zone of the piston combustion chamber. When modeling the temperature and thermo-stressed states of the piston in stationary and nonstationary formulations, the finite element method is used. In determining the level of thermal stress of the piston in the circumferential direction of the edge of the combustion chamber and predicting the loss of strength in critical zones, a calculation and experimental method based on the use of the Pospeshil equation, the Sosnin energy criterion and the creep hardening theory is applied. A dependence of the heat transfer coefficient for the surface of the combustion chamber of the piston is proposed, taking into account the diesel fuel advance timing. The technique for analyzing the heat stressed state and resource strength of heat-stressed zones of pistons is improved, which provides for guaranteed provision of their specified resource with an allowable minimization of time spent at the initial stages of design. The influence of design parameters of the piston on the level of temperatures, thermal stresses and strength of the combustion chamber edge is determined, namely: the presence of samples under the valves, additional samples in the zone of the combustion chamber edge, forming the oil cooling cavity. New designs of pistons with cavities of oil cooling are offered. It is shown for the first time that local changes in the geometry of the piston fire surface can lead to multidirectional changes in the temperature and thermo-stressed state of such zones. For the first time, the influence of the fuel lead advance angle on the level of the heat transfer coefficient in the combustion chamber of the diesel engine, the thermally stressed state and the loss of strength of the edge of the combustion chamber of the piston are estimated. For the first time, the influence of simplifications in geometry, the boundary conditions of the thermal conductivity of the piston and the level of forcing the engine on the results of calculating the temperatures, thermal stresses and the resource strength of the edge of the combustion chamber of the piston is determined. These results are used in IPMash them. A.М. Pіdgorny National Academy of Sciences of Ukraine, as well as in the practice of scientific research and in the educational process of the Department of Internal Combustion Engines of NTU "KhPI". Engine building.