Modeling Atomization and Break Up in High-Pressure Diesel Sprays 970881
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  has been coupled to a new breakup model (FIPA) which is based on the experimental correlations of Pilch et al.. It has been integrated in the 3D KMB code  derived from the Kiva 2 code  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 . 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 (ρg = 25kg/m3, Pg = 3 MPa and 6.1 MPa, Tg = 400K and 800K, Pinj 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.