76th Annual Meeting of the Division of Fluid Dynamics
Sunday–Tuesday, November 19–21, 2023;
Washington, DC
Session T40: Reacting Flows: Detonations and DDT II
4:25 PM–6:09 PM,
Monday, November 20, 2023
Room: 204C
Chair: Matei Radulescu, University of Ottawa
Abstract: T40.00007 : Some thoughts on colliding reactive fuel droplets in a supersonic combustion field
5:43 PM–5:56 PM
Abstract
Presenter:
Foluso Ladeinde
(Stony Brook University)
Author:
Foluso Ladeinde
(Stony Brook University)
Collaboration:
Foluso Ladeinde
Liquid-fuel droplets in an environment of atmospheric air at supersonic speeds characterize the early stage of fuel-air mixture in high-speed combustion systems intended for devices that propel air vehicles. Examples of these devices include the scramjet and rotating detonation engines. Modeling the reactive system occurs at different levels of complexity. In the simplest form, the inertia of the droplets is weak, the droplets do not collide, and the only velocities involved are those of the continuous phase (with turbulence fluctuations) and the rigid-solid velocities of the droplets. The limit in which the droplets collide, though without coalescence, is of interest in the present study, with an additional velocity component that arises from the microscopic field surrounding a droplet. For this component, previous research, particularly in atmospheric science, has assumed the dominance of viscosity in the environment surrounding the droplet, such that the solution of a Stoke’s flow around the droplet is obtained to represent the velocity field in the ambient of the particle. By a judicious application of boundary conditions, this field is made to be compatible with the velocity field of the continuous phase. In this manner, the net velocity that appears in the equation for the dispersed phase has contributions from the four components of velocity. The problem of our interest differs from the foregoing in the sense that a mathematically hyperbolic system obtains, as opposed to the elliptic limit of the Stokes problem. Our approach is to obtain a solution of the hyperbolic flow problem that is consistent with the velocity field of the continuous phase. The implication of this approach for the flow and chemical reaction processes, and hence the power and efficiency of a high-speed propulsive device is what we seek to investigate. Preliminary results along this direction will be reported.