A Study On The Heat Transfer And The Thermal Intensity Of Piston

The great competition of automobile market has urged the factories to shorten the product development time; and on the other hand, with the development of turbo, high power and light engine, the researchers have kept their eyes on the intensity more than the past. Many new methods have applied the study to resolve the reliability problem that will affect the normal operation of engine.The piston is the critical part of engine. It stands the great thermal load; the thermal load and thermal intensity have greatly affected the durability, reliability and economy. The study on thermal load has stepped into the domain on lubrication and deposit, which also affect the thermal load and thermal intensity of engine as the rotary speed and gas temperature on abroad. The work has begun later in China than on abroad. Now the model of thermal load is transforming from two-dimensional to three-dimensional.The quarter model of piston of JL466Q engine has been built in this paper, and its mechanical intensity, temperature field, thermal stress and thermal fatigue have been analyzed, and the result is reasonable. This paper has investigated the mechanism of the stress and deflection that the piston withstands the gas pressure and temperature load. The result reveals that the thermal stress is prominent in the piston head, and the mechanical stress is prominent in the skirt of piston. Finally, this paper has investigated the relation between the thickness of piston head and temperature field , thermal stress:â‘ The whole temperature field will rise while the thickness has been reduced. The temperature difference will also go up.â‘¡The maximum thermal stress will rise while the thickness has been reduced, the intensity of piston will decline, and the progress of the engine power will be affected.