Abstract
With the increasing prominence of energy and environmental issues, research in the field of internal combustion engines is becoming more and more refined. Engines are affected by the coupling of many factors, it is necessary to decouple and quantify the impact of inputs on the objectives. In this paper, effect of engine configuration parameters, operating conditions, and fuel parameters on fuel efficiency and emissions, were investigated, based on support vector machine coupling Sobol method. The results of Sobol sensitivity analysis show that the most sensitive parameters to brake specific fuel consumption and carbon monoxide emission both are excess air ratio, total hydrocarbon emission and nitrogen oxides emission are engine load and intake pressure, the first order indices are 0.72, 0.27, 0.17, and 0.20, respectively. The most sensitive combustion parameters are maximum pressure in cylinder, indicated mean effective pressure, maximum temperature in cylinder, and high temperature range, and the first order indices are 0.40, 0.25, 0.39, and 0.57, respectively. It can be summarized through all the Sobol indices that, on the one hand, some input parameters, such as excess air ratio, affect fuel efficiency and emissions through the combustion process. On the other hand, such as oxygen mass fraction, directly affects carbon monoxide emission and total hydrocarbon emission by affecting the oxygen concentration in cylinder. Sensitivity analysis based on Sobol method coupling support vector machine was proved to be feasible and will provide valuable guidance for the optimization of internal combustion engines.
