Modeling Atomization and Break Up in High-Pressure Diesel Sprays

Abstract

<div class="htmlview paragraph">Computation of high pressure Diesel injection requires improvement of present spray atomization and droplet breakup models. The surface wave instability atomization (Wave) model of Reitz [<span class="xref">2</span>] has been coupled to a new breakup model (FIPA) which is based on the experimental correlations of Pilch et al.[<span class="xref">3</span>]. It has been integrated in the 3D KMB code [<span class="xref">1</span>] derived from the Kiva 2 code [<span class="xref">4</span>] of Los Alamos already including a stochastic Lagrangian description of sprays. The droplet breakup FIPA model was first fitted and validated using the monodisperse drop breakup experiments of Liu and Reitz [<span class="xref">5</span>]. The response of the modified spray model including the global Wave-FIPA breakup model is compared to well characterized data obtained in a high pressure and temperature vessel. This vessel is fitted with a common-rail injection system with a single hole injector tip. Conditions simulating a direct injection diesel engine are obtained (ρ<sub>g</sub> = 25kg/m<sup>3</sup>, P<sub>g</sub> = 3 MPa and 6.1 MPa, T<sub>g</sub> = 400K and 800K, P<sub>inj</sub> from 40 to 150 MPa). Liquid and vapor penetrations in the vessel are well reproduced, even for high injection pressure cases and with or without evaporation.</div>