Influence of Combustion Chamber Configuration on Combustion Process of Natural Gas-fueled Rotary Engines

Abstract

Taking a side ported pre-mixed natural gas-fueled rotary engine converted from a gasoline rotary engine as the study object. On the basis of the Fluent simulation software, a three-dimensional dynamic simulation model is established by writing dynamic mesh programs and choosing the reasonable turbulent model, combustion model, CHEMKIN mechanism. The three-dimensional dynamic simulation model based on the chemical reaction kinetics is also validated by the experimental data. On this basis, the three-dimensional dynamic characteristics for flow, temperature field and the combustion intermediate product under different combustion chamber configuration are analyzed. The results show that when the rotor pocket is located at the front end of rotor surface along length direction and the center of the rotor surface along width direction, a tumble in the rear of combustion chamber and a high speed flow in the middle of combustion chamber are made full use to increase flame speed. The flame propagation speed reaches the maximum value. The indicator diagram is best and the production of OH is biggest. Comparing with mid pocket combustion chamber, the front pocket combustion chamber shows a 19.9 percent increase in the peak pressures, but NO emission mass fraction still stay within 0.5 percent.