AN EXPERIMENTAL INVESTIGATION OF FLOW PARAMETERS INSIDE A SPHERICAL SWIRL PRECHAMBER OF A DIESEL-ENGINE UNDER MOTORING CONDITION

The main aim of the present investigation is to experimentally study t he flow parameters inside a spherical combustion chamber of an indirec t injection diesel engine. For this a spherical chamber has been fitte d in the cylinder head. Using a constant temperature hot-wire anemomet er, measurements have been made under non-firing condition at 400 and 500 rpm during compression stroke. Mean velocity and turbulence intens ity values are evaluated from the hot-wire signal. Measurements are ma de at three axial planes, six angular locations and four radial positi ons. Large variations of mean velocity and turbulence intensity have b een observed within the chamber. From the measurements, the mean veloc ity and turbulence intensity are found to be maximum at 30 degrees bef ore compression TDC and these values are found to decrease towards the centre of the pre-chamber. The mean velocity and turbulence intensity distribution with respect to various locations and crank angles are p resented and discussed.