Effect of spray impingement distance on piston top fuel adhesion in direct injection gasoline engines

Abstract

Direct injection is an attractive technology for improving fuel economy and engine performance in gasoline engines. However, the adhered fuel formed on the piston surface has significant influence on the combustion efficiency and emissions. To obtain a better understanding of fuel adhesion, this work involved investigation of the spray and impingement on a flat wall through 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 refractive index matching method was applied to measure fuel adhesion. The mass, area, and thickness of adhesion under different conditions were compared. The experimental results show that the fuel adhesion on the wall increases significantly with a large impingement distance. Moreover, the maximum thickness increases and the thickness uniformity of the fuel adhesion declines under a large impingement distance condition.

Experimental Investigations on Fuel Spray and Impingement for Gasoline Direct Injection Engines

“…Then the film mass can be calculated through the scale and density of toluene (867 kg/m 3 ). Additional details about RIM method and calibration can be seen in the previous publications [10][11][12][13].…”

Enabling robust simulation of polyoxymethylene dimethyl ether 3 (PODE3) combustion in engines

“…As HRR was the only output that is of interest in CVCC validations, it is worth noting that the size and shape of combustion chamber is insignificant, as long as wall impingement is avoided. [111][112][113][114] Furthermore, grid dependency analysis was conducted. However, the grid resolution displayed negligible effects, hence the analysis is omitted for simplicity.…”

Special Issue on COMODIA 2017

“…In direct injection gasoline engines, the fuel-film formation on the piston top is a major source of particulate emissions. 4 Luo et al 5 investigate the effect of the distance between the fuel injector tip and the impinging surface on the fuel film formation using optical diagnostics in a constant-volume test rig. The analysis makes it clear that there exists a certain injector-tosurface distance that maximizes fuel-film formation.…”