نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
In internal combustion engines, exhaust valve and its seat gain considerable temperature as the hot gases exit through the exhaust valves. To avoid damage to the valve, the rate of heat transfer should be under control. Because the main part of heat during the contact of the valve and seat transfers through conduction, study on thermal contact conductance and the effect of important parameters on TCR is necessary. In this study, the thermal contact resistance between exhaust valve and seat has been estimated. To accomplish this, a test device including an Air-Cooled internal combustion engine cylinder head was designed and built. This analysis is based on the measured temperatures of sensors located in specific locations of the exhaust valve and the seat. Using the measured temperatures and the method of linear extrapolation, the surface contact temperatures and periodic thermal contact resistance were calculated and the effects of some parameters such as contact frequency and contact pressure on TCR were examined. According to the results, increasing the contact pressure decreases TCR. Also, increasing the contact frequency, TCR increases. The average calculated error is 12.96%.
کلیدواژهها [English]