Optimization of an optical test bench and analysis of a double injection GDI spray

Two experimental studies have been performed. First of all, a study of the shadowgraph image deformation varying the optical bench set-up and its optimization. The study has consisted in the modification of the two main optical angles (β and γ). Secondly, an experimental analysis of a GDI double injection has been performed by using the new accepted optical system. The study consists in the realization of 12 tests keeping constant the fuel type, the chamber air pressure (4 bar), and the fuel and air temperatures (30 ºC). But modifying key parameters as the fuel pressure (100/200 bar), the type of injection (single/double), and the second injection duration (500/1000 μs) or its delayed start (2000/2500/3000 μs).