Numerical study on the performance, combustion characteristics and energy flow distribution of gasoline-powered vehicle under synthetic actual driving test cycle

Abstract

In order to meet the requirements of vehicle performance prediction and optimization under actual urban road conditions, a synthetic actual driving test cycle (ADTC) is proposed to accurately predict the performance and energy distribution characteristics of vehicles. Meanwhile, a multi-physical field vehicle energy management simulation model is built and verified carefully. Thus, numerical analysis was conducted on the performance of vehicles under ADTC and the characteristics of energy distribution were revealed. The results show that, the brake thermal efficiency (BTE) of the engine under ADTC varies in the range of 14.88 %–30.54 %, that is lower than worldwide harmonized light vehicles test cycle (WLTC) and new European driving cycle (NEDC). Besides, the proportion of combustion loss is WLTC, ATDC and NEDC from the largest to the smallest, which is mainly related to the complexity of speed variation. Based on this, unlike traditional testing cycles, ADTC synthesized from local actual road test data can more accurately evaluate the actual performance of vehicles under local characteristic road conditions and provide guidance for deep optimization, which is beneficial for energy conservation and emission reduction.