A novel two-stroke boosted uniflow scavenged direct-injection gasoline (BUSDIG) engine has been proposed and designed in order to achieve aggressive engine downsizing and down-speeding for higher engine performance an...A novel two-stroke boosted uniflow scavenged direct-injection gasoline (BUSDIG) engine has been proposed and designed in order to achieve aggressive engine downsizing and down-speeding for higher engine performance and efficiency. In this paper, the design and development of the BUSDIG engine are outlined discussed and the key findings are summarized to highlight the progress of the development of the proposed two-stroke BUSDIG engine. In order to maximize the scavenging performance and produce sufficient in-cylinder flow motions for the fuel/air mixing process in the two-stroke BUSDIG engine, the engine bore/stroke ratio, intake scavenge port angles, and intake plenum design were optimized by three-dimensional (3D) computational fluid dynamics (CFD) simulations. The effects of the opening profiles of the scavenge ports and exhaust valves on controlling the scavenging process were also investigated. In order to achieve optimal in-cylinder fuel stratification, the mixture-formation processes by different injection strategies were studied by using CFD simulations with a calibrated Reitz–Diwakar breakup model. Based on the optimal design of the BUSDIG engine, one-dimensional (1D) engine simulations were performed in Ricardo WAVE. The results showed that a maximum brake thermal efficiency of 47.2% can be achieved for the two-stroke BUSDIG engine with lean combustion and water injection. A peak brake toque of 379 N·m and a peak brake power density of 112 kW·L^-1 were achieved at 1600 and 4000 r·min^-1, respectively, in the BUSDIG engine with the stoichiometric condition.展开更多
To experimentally match performance and structural features of an opposed-piston two- stroke engine （ OPTSE ）, two calculation models, a one-dimensional （ 1-D ） model and a three-di- mensional （3-D） model, of th...To experimentally match performance and structural features of an opposed-piston two- stroke engine （ OPTSE ）, two calculation models, a one-dimensional （ 1-D ） model and a three-di- mensional （3-D） model, of the combined charging matching simulation of an OPTSE was established by using the GT-Power software. To test and verify the one dimensional model, the three-dimension- al computational fluid dynamics simulation model was established using AVL FIRE software. Cylinder pressure curves in these two models match perfectly, showing that it is reasonable to use the one-di- mensional model to simulate the work process of an OPTSE. Moreover, the effects of delivery ratio, nozzle ring diameter and exhaust back pressure on brake specific fuel consumption （ BSFC ） were studied.展开更多
基金financial support from the Engineering and Physical Sciences Research Council (EPSRC)
文摘A novel two-stroke boosted uniflow scavenged direct-injection gasoline (BUSDIG) engine has been proposed and designed in order to achieve aggressive engine downsizing and down-speeding for higher engine performance and efficiency. In this paper, the design and development of the BUSDIG engine are outlined discussed and the key findings are summarized to highlight the progress of the development of the proposed two-stroke BUSDIG engine. In order to maximize the scavenging performance and produce sufficient in-cylinder flow motions for the fuel/air mixing process in the two-stroke BUSDIG engine, the engine bore/stroke ratio, intake scavenge port angles, and intake plenum design were optimized by three-dimensional (3D) computational fluid dynamics (CFD) simulations. The effects of the opening profiles of the scavenge ports and exhaust valves on controlling the scavenging process were also investigated. In order to achieve optimal in-cylinder fuel stratification, the mixture-formation processes by different injection strategies were studied by using CFD simulations with a calibrated Reitz–Diwakar breakup model. Based on the optimal design of the BUSDIG engine, one-dimensional (1D) engine simulations were performed in Ricardo WAVE. The results showed that a maximum brake thermal efficiency of 47.2% can be achieved for the two-stroke BUSDIG engine with lean combustion and water injection. A peak brake toque of 379 N·m and a peak brake power density of 112 kW·L^-1 were achieved at 1600 and 4000 r·min^-1, respectively, in the BUSDIG engine with the stoichiometric condition.
基金Supported by the National Natural Science Foundation of China(B2220110005)
文摘To experimentally match performance and structural features of an opposed-piston two- stroke engine （ OPTSE ）, two calculation models, a one-dimensional （ 1-D ） model and a three-di- mensional （3-D） model, of the combined charging matching simulation of an OPTSE was established by using the GT-Power software. To test and verify the one dimensional model, the three-dimension- al computational fluid dynamics simulation model was established using AVL FIRE software. Cylinder pressure curves in these two models match perfectly, showing that it is reasonable to use the one-di- mensional model to simulate the work process of an OPTSE. Moreover, the effects of delivery ratio, nozzle ring diameter and exhaust back pressure on brake specific fuel consumption （ BSFC ） were studied.
