基于代理模型的气门大小对功率影响的研究

Surrogate-based Investigation in Influence of Valve Sizes on Engine Power Output

针对某型号高增压柴油机,利用基于代理模型的数据拟合方法,研究了不同工况下功率随气门大小变化的规律,并得到每个工况下最优功率和相应的进排气门尺寸.研究结果表明:在研究范围内,对于排气背压较低的工况,同工况下进气门增大使得功率增大,排气门增大使得功率先增大后减小;排气背压逐渐升高时,功率逐渐减小,最优功率点的进排气门直径比增大.对于排气背压很高的工况,进、排气门增大均会使得功率先增大后减小.

By means of the data fitting method based on a surrogate model, the law of its power with the valve size was investigated under different work conditions for a high -turbocharged change diesel engine. The optimal power output and its corresponding size of the intake and exhaust valve were obtained under each working condition. The results showed that, for the conditions with the lower exhaust back pressure, the power output increased with increase of the intake valve size but the increase of the exhausted valve size made the power output increase at first and then decrease. As the exhaust back pressure increased, the power output gradually decreased and the diameter ratio of the intake and exhaust valve increased at the optimal power point. Under the conditions with higher exhaust back pressure, the increase of the intake and exhaust valve size would make the power output increase at first and then decrease.