| The power improvement with exhaust gas turbocharger of a 1.5L naturally aspirated gasoline engine was studied in this paper, and the way of fuel injection was altered from intake manifold injection to direct injection (DI) in cylinder. The matching and performance of the turbocharger and gasoline engine were analyzed, and the three-dimensional numerical simulation of the designed exhaust gas system was carried out, on the meanwhile, the performance of exhaust gas system was evaluated.A complete model of DI gasoline engine with turbocharger was designed with AVL-BOOST based on the 1.5L intake manifold injection and naturally aspirated gasoline engine. The turbocharger and DI gasoline engine was matched, and the combined operation line was drawn to analyze the efficiency of the turbocharger and gas flow characteristics of the turbine. The main performance index of the turbocharged engine were calculated and compared with the original model, and one-dimensional pressure distribution of the exhaust gas pipe was analyzed to obtain boundary conditions for three-dimensional numerical simulation.A three-dimensional model of new exhaust gas system was designed using Pro/Engineer. The model mesh was auto-generated in GAMBIT, which is a fore-treatment program in ANSYS FLUENT. The characteristic points of full exhaust circulation were simulated to analyze the flow field distribution in exhaust gas pipe of different cylinders, which thereby provided theoretic support for exhaust gas pipe design of the turbocharged gasoline engine.The working process simulation, matching and experimental result of the exhaust gas turbo-charging system were compared and analyzed, while the engineering application was fully considered in the improvement design of exhaust gas system. |
PDF Full Text Request