A Study of Swirl Generation in DI Engines Using KIVA-3V

A computational study of a directinjection (DI) engine intake system using KIVA-3V was conducted. The engine considered had two intake ports designed to generate a swirling motion of the intake charge in the cylinder. 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 prevent airflow on the backside of the valves. The effect of port diameters on air flow and swirl motion was also investigated. In this case, ports with two different diameters were modeled. In addition, the effect of using one or two intake ports on swirl generation was determined by blocking one of the ports. The results show that higher swirl was generated with a single port and a shrouded valve.