School of Transportation and Vehicle Engineering, Shandong University of Technology
Engines equipped with camless valve trains will have greater space for performance optimization. In this paper, based on the electromagnetic actuated valve train system, one-dimensional and three-dimensional simulation models on engine thermodynamic cycle and in-cylinder charge motion are established, respectively. With the application of early-intake-valve closing (EIVC) strategy，unthrottled load control and Miller cycle are obtained and their effects on engine pumping losses and NOx emission are researched. The variation of engine in-cylinder charge movement intensity， pumping losses and volumetric efficiency are also revealed at variable intake valve actuation (VIVA). In addition, a particular variation trend of engine pumping losses, increasing in proportion to the engine load, is detected with the application of unthrottled load control. Finally, Genetic Algorithm (GA) is adopted to optimize engine performance with the EAVT system. Compared to engine with a camshaft valve train, the electromagnetic actuated valve train (EAVT)-driven engine shows a significant improvement on fuel consumption, power performance and NOx emission.