This paper reports on the characteristics of in-cylinder flow at the time of fuel injection and subsequent interaction with fuel spray, which are helpful in validating the engine performance and exhaust emissions for a Diesel Engine. The in-cylinder flow is largely determined by the swirl and tumble motion during the intake stroke and the squish flow into and out of the piston bowl.

The flow was simulated (Using CFD software) for steady state conditions from which the characteristics of the helical ports are analyzed in terms of flow rate for different valve lift positions, generation of angular momentum and induced in-cylinder flow motion. The transient flow simulation shows the different characteristics of the flow motion in cylinder and piston bowl during intake and compression strokes.

The intake port fluid dynamics also significantly affects the ignition delay, the magnitude and timing of the diffusion burn, the magnitude of premixed burn and the emission of nitrous oxide and soot. Computations are used to optimize the swirl flow characteristic of an intake port system over a wide range of operating conditions. The relative success of the computational approach is evaluated through comparison with experimental data obtained from the AVL’s (Ansalt fur Verbrennungsmotoren, Prof. List Graz, Austria) paddle wheel principle of swirl measurement test rig, which have been dealt within this paper.