Development and validation of a new hybrid break-up model for the modelling of hollow-cone fuel spray

In the present study, a numerical study and an experimental study on the break-up process of a hollow-cone fuel spray were performed. This was done to develop a new hybrid break-up model and to validate this model under various ambient pressure conditions. The new hybrid break-up model was composed of the linearized instability sheet atomization (LISA) model for the primary break-up and the aerodynamically progressed Taylor analogy break-up (APTAB) model, with consideration for the deformed droplet shape, for the secondary break-up. The APTAB model was used instead of the Taylor analogy break-up (TAB) model used in the previous hybrid break-up model (the LISA—TAB model). The hybrid break-up models were implemented in modified KIVA code. The calculated results of the spray characteristics, such as the spray tip penetration, spray width, Sauter mean diameter, and droplet velocity, by means of the LISA—APTAB model were compared with the calculated results via the LISA—TAB model and the experimental results found with the laser-induced exciplex fluorescence technique and the phase Doppler anemometry (PDA) system. The calculations and the experiment were performed under ambient pressures of 0.1 MPa and 0.5 MPa and an ambient temperature of 293 K. It was found that the calculated results from the LISA—APTAB model showed good agreement with the experimental results. The discrepancies between the calculated results and the experimental results in spray characteristics were reduced by a considerable margin by adopting the APTAB model instead of the TAB model for the secondary break-up process.