Fuel Deposition on Wall Impingement of a Spray

The deposition of an impinging diesel spray is studied experimentally to improve the understanding of wall-spray-interactions. Experiments are performed under atmospheric pressure conditions as well as in a pressure chamber filled with nitrogen where the pressure is varied between 0.1 Mpa and 2 MPa. In both cases a light reflection method is used to observe size, shape and time development of the wetting imprints of the spray. The duration of the injection pulse is 2 ms. The mean injection pressure is 47 MPa. Additional experiments under atmospheric pressure conditions are performed without the pressure chamber. Here a shadow-graph optic is added to the apparatus to allow the simultaneous observation of the impinging spray and the wetted area of the wall. It is found that the diameter of the impinging spray increases faster than that of the imprint which suggests that the wall spray separates from the wall.