Cavitation coupled atomization
Résumé
References In modern high pressure fuel injection systems for internal combustion engines, cavitation inside the injector is frequently observed. In contrast to the cavitation encountered by pure fluid, the cavitation process in a typical fuel injection system is affected by the ambient non-condensable gas. Since the fuel is directly injected in a chamber full of air, a typical two-phase approach for modeling pure liquid cavitation (liquid-vapor) is not sufficient. To this end a three-phase system is typically considered with fuel liquid, fuel vapor and non-condensable gases (NCG, for instance air). In the context of interface resolved numerical methods, one of the options is to treat each phase separately. This, however, comes at a cost, as such multiphase formulations consider each phase immiscible, thus preventing mixing between vapor and NCG. In reality there are only two phases; liquid and gas. As soon as vapor comes in contact with any other NCG , they belong to one phase: the multi-component gas phase. In this work, we have treated cavitation of fuel in an inert gas environment using multiphase formulation, with interface only between liquid and gas. The model is validated and then tested on three dimensional model experiment. Objectives Abstract • Multiphase formulation with liquid, vapor and air to predict in nozzle cavitation and external jet atomization • Surface tension dominated primary and secondary atomization is well captured • LES has the potential to predict the complex internal nozzle flow Conclusions
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