Pneumatic Engine Working Process, Theoretical And Experimental Study

The development of auto is challenged by the more serious pollution and the shortage of petroleum. Many countries make many rules and policies for its further development, which are strict with the deleterious exhaust and encourage the research of clean auto.The air-powered car is one of the clean autos, which is driven by the air-powered engine, which is the power mechanism through changing the energy stored in compressed air into mechanical energy. It not only makes autos have more resources, but also makes autos no pollution.The air-powered engine was studied in this paper and all of the following were completed during this course.1. The ideal work process was established on theory. The reasonable initial pressure and the mode of expand were discussed by the analysis of available energy. Multi stages of expand was put forward for the compressed air with the pressure 30MPa and the optimal stages of expand was reached.2. The circumrotating valve was designed and the theoretical model was established for the pressure in the cylinder. The model can forecast the trend of the pressure, but there is some difference in the quantity.3. Based on the characters of intake flow, the flow field was simulated with theRNGk- turbulence model.4. As the results, the energy of the air in the cylinder includes the energy of flow and the static pressure energy. This is the one of the most important reason for the difference between the theoretical and experimental indicated diagram. The jaw opening influenced the coefficient of flow mostly.5. The experimental bench was established. The optimal time of inlet was obtained by analyzing the influence of inlet open time on the performance of engine.6. When the intake process begins at TDP, many experiments were done. As the results, the output power is most at the speed of 1 OOOr/min. When the speed is lower than 1200r/min, the engine has better economical performance. When the engine operates with high load, it also has better economical performance.7. Based on these results, a design scheme of valve with high efficiency was put forward.