COMBUSTION SCIENCE & ENGINEERING, INC. — Department of Defense SBIR Phase I: A17-031

Description

In propulsion systems, liquid fuel is atomized and burned in a way that maximizes engine efficiency and minimizes emissions. To accomplish this task, it is necessary to design injectors and nozzles that lead to adequate mixing of fuel and air. Unfortunately, mathematical models of liquid atomization for CFD are still far from adequate to design injectors and nozzles. This atomization has been divided into three stages (i) primary atomization in which the liquid jet breaks into blobs of fluid termed primary drops henceforth; (ii) secondary atomization in which these primary drops break further into smaller drops; and, (iii) the later evolution of the spray. It is evident that the primary-atomization stage sets the initial conditions for all subsequent processes. Thus, the accurate modeling of primary atomization is critical for the overall accurate modeling of atomization. Unfortunately, primary atomization is the least understood of these three processes. Classic models need a calibration process that is onerous because primary atomization involves many physical parameters disregard most of the physics. Combustion Science & Engineering, Inc. proposes a solution to the above dilemma by developing a novel subgrid-scale (sgs) model of primary atomization based on the so-called Linear-Eddy Model (LEM) / One-Dimensional-Turbulence (ODT) framework.