Geometry of the Fuel Cloud Created by Impingement of a Diesel Jet onto a Small Heated Target

The work presented was performed to increase the understanding of the important variables involved in the radial penetration of the droplet cloud formed by a liquid jet impinging on a target placed a short distance from the injector orifice. The experiments studied a spray produced in a high pressure, ambient temperature bomb by a Lucas CAV injector system with a Bosch pump. Three experimental procedures were performed. The first experiment used a laser interrupt method to determine the radial penetration of the impinged spray. The conclusions from these tests are that the important parameters are nozzle size, impingement distance, ambient density, and target diameter. The second experiment used high speed movies to determine the droplet cloud penetration and height at discrete time steps. This experiment yielded a series of diagrams which illustrate the development of the impinged spray. The third experiment determined the heat transfer from the heated target to the impinging liquid. The heat transfer measurements were also used to determine the total amount of thermal energy transferred into the spray.

The hydrodynamic data collected are compared to two different spray correlations based on configurations different from that of the present study. These comparisons show that the configuration of the present study will have less radial penetration than conventional or flat plate impingement injection configurations.