Numerical and experimental investigation of an impinging gasoline low- pressure spray

Wall film formation by gasoline low-pressure spray and the droplet rebound are important processes to be taken into account in the design of the inlet ducts and in the control optimization. Numerical simulations are nowadays the only tool able to give some information on the evolution of liquid film in the inlet duct or in the combustion chamber of gasoline engines. This paper presents an extensive numerical and experimental study of the behavior of a low- pressure gasoline injector impinging spray. Spray impingement process was analyzed using an experimental setup that is capable to elaborate spray images gathered in different time steps before and after the impact. Calculations were performed using a modified version of the KIVA3V code. New spray, wall film and post-impingement sub-models were introduced in the code. The numerical and experimental results are expressed in terms of impact velocity, spray morphology and radial and axial evolution of the post-impingement jet, as a function of characteristic parameters such as injector-wall distance and impact angle. The results provide useful information for a better understanding of the impinging of a jet on a solid wall, and for the validation of physical models implemented in the CFD code, in order to obtain more reliable simulations of the injection process.