Abstract
An experimental study using high speed, focused shadow photography was made on the trajectory and dispersion of a spray impinging on a wall in a high pressure bomb. The impinging wall had a two dimensional shape that simulated the cross sectional shape of a combustion chamber surrounded by a piston cavity, piston top and a cylinder head of a direct injection diesel engine. The ambient gas conditions were high pressure, room temperature and quiescent. The effects of several engine variables such as the injection direction and the piston top clearance on the trajectory and dispersion of the impinging spray were investigated. The trajectory and dispersion of the spray impinging on the round cavity wall were also observed.