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The behavior of diesel spray impinging on an inclined wall was experimentally investigated in a pressurized vessel. To clarify the wall effect on a diesel spray, a relative angle of the inclined wall to a spray axis was varied. Spray penetration along the wall was observed optically and it was compared with that of a free spray. To evaluate various spray motion quantitatively, a spray path penetration which described a development of a spray tip along the wall was newly introduced. To observe an internal structure of the spray, it was visualized by a YAG laser sheet light and its tomographic image was captured on a film. The photo-image on a film was taken into an image analyzing computer using a high resolved image scanner. A high density zone in the tomographic image was extracted to clarify the internal structure of an impinging spray. The main parameter of the relative position of the wall was its inclined angle which was defined as the angle between the spray axis and wall.

In this paper, a new concept of an attitude control of a diesel spray was proposed. The Coanda effect known in the fields of the fluidics was applied to control a penetrating direction of a diesel spray injected into a combustion chamber of a D.I. diesel engine. In general, a jet moving along a wall was deviated by the Coanda effect. So if the shape of a cavity crown of the combustion chamber would be suitably designed and a diesel spray behavior would be similar to a gaseous jet, the spray might penetrate along the cavity wall. Furthermore, the switching effect of the penetrating direction might appear with a piston movement. To establish this method for an attitude control of a diesel spray, behavior of a diesel spray that was affected by a fixed interference plate located near the spray axis was experimentally investigated.