Study of Swirl Effects on Spray Formations in D.I. Engines by 3D Numerical Calculations 910264

Spray formations of three injection directions against swirl have been investigated by means of 3D numerical calculation, in-cylinder measurement, and engine performances tests. A direct injection type engine which has a single hole nozzle and a spark plug, has been operated, and three injection directions; a forward (same) direction, a reverse one, and a right-angled (central) one against a swirl direction, have been selected. Three types of intake port, futhermore, have been selected owing to create three types of in-cylinder flow, low swirl, middle swirl, and high swirl. Spray formations in 3D cylinder flow have been investigated by using a ‘KIVA’ code. Initial conditions of in-cylinder flow are based on data which have been measured in three dimensional by a LDV system under a motoring operation. Analysis results of spray formations by numerical calculations can explain well data of engine performance tests qualitatively, and some interesting results have been obtained.