Effect of Impingement Distance on Fuel Adhesion of Hole-Nozzle Spray under Various Injection Pressures

Abstract

The direct injection is a very attractive technology for improving fuel economy and engine performance in gasoline engines. However, the fuel films formed on the piston surface have a significant influence on combustion efficiency and emissions. In order to get a better understanding of the fuel film formation, this work investigated the spray and impingement on a flat wall by a mini-sac injector with a single hole. Different impingement distances and injection pressures were investigated. The evolution of the impinging spray was obtained by the Mie scattering method. The spray tip penetration and vortex height under different conditions were discussed. The bottom view of the fuel film was acquired by the Refractive Index Matching method. The fuel film mass, area, and thickness under different conditions were compared.