Numerical Simulation of CNG Engine Cycl
...me parameters that affect the engine performance and emission characteristic are analyzed. The main research work include: (1)The whole CNG engine model is built up with BOOST, and the thermodynamics process is described macroscopically. The correctness of the engine model is proved by speed characteristics test at full load. On the base of the working model, performance simulation is carried out with changed compression ratio, ignition advance angle and valve timing. The influence of these parameters on CNG engine performance is studied by analyzing the simulation result. Some suggestions for engine development are put forward. (2) The three–dimensional moving meshes including intake port, cylinder and exhaust port are generated with FIRE, and reasonable boundary conditions and calculation model are selected. Good convergence result is achieved. Based on the computed result, the detail of fluid in intake port and cylinder, temperature distribution and the features of the combustion product are analyzed. Some suggestions for detail are put forward. The degree of thermal load and the incline of deflagrate at some operation conditions is appraised, whic...