Numerical Simulations in a High Swirl Methanol-Fueled Directly-Injected Engine

Three-dimensional transient simulations using KIVA-3V were conducted on a 4-stroke high-compression ratio, methanol-fueled, direct-injection (DI) engine. The engine had two intake ports that were designed to impart a swirling motion to the intake air. In some cases, the intake system was modified, by decreasing the ports diameter in order to increase the swirl ratio. To investigate the effect of adding shrouds to the intake valves on swirl, two sets of intake valves were considered; the first set consisted of conventional valves, and the second set of valves had back shrouds to restrict airflow from the backside of the valves. In addition, the effect of using one or two intake ports on swirl generation was determined by blocking one of the ports. This study examines the effect of swirl motion on turbulence generation and methanol combustion, The results showed that the swirl ratio could be varied by modifying the intake system, and higher swirl was generated with a single port and a shrouded valve.