Optical spray investigations and 3D-CFD numerical analysis of the nozzle flow of a methanol HPDI injector for maritime applications

This article presents results of the optical spray investigations of a methanol high-pressure direct injector for maritime applications. The injector is a two-in-one fuels injector, with a diesel path to inject diesel centrally for the diesel mode or to inject a small pilot amount of diesel for igniting methanol. The methanol will be injected via three nozzles, which are placed around the central diesel needle. The experimental studies were performed at a pressurized injection chamber with three different injection pressures, two fuels and three nozzle designs to evaluate first the basic spray characteristics of the spray of this two-in-one fuel’s injector concept with four needles as well as the impacts of the varied parameters. For the injection analysis, ethanol was used instead of methanol due to the extensive safety requirements for methanol. Furthermore, a 3D-CFD numerical analysis of the nozzle flow of the methanol path is presented in this article. Correlations between the calculated nozzle flow and the experimental measured spray data are given.