- Author
-
Soteriou, M.
- Title
- Lagrangian Simulation of Single/Two-Phase Unsteady Reacting Shear Flows. BFRL Fire Research Seminar. VHS Video.
- Coporate
- University of Connecticut, Storrs
- Report
-
Video
November 2, 1999
- Keywords
-
simulation
- Abstract
- The evolution of single/two-phase reacting/non-reacting unsteady shear flows is investigated using Lagrangian numerical simulations. The objective is to exemplify the effectiveness of the Lagrangian approach in accurately reproducing the transient flow dynamics and, also, to probe the flow physics using the numerical results. The Transport Element Method (TEM), an extension of the Vortex Element Method capable of resolving exothermically reacting flowfields, forms the main part of the methodology. In the TEM the equations of fluid motion and of any transported scalar fields are solved in their vorticity and scalar-gradient form, respectively. This is accomplished by discretising the dependent variables among a field of elements that are convected by the flow and by directly solving the governing equations locally for each element. The Lagrangian nature of the method is exploited to simplify these equations using flow kinematics. In disperse two-phase flows the evolution of the particle/droplet phase is accomplished in a Lagrangian fashion by integrating the equation of particle motion along individual particle trajectories. Results from a variety of canonical single-phase non-premixed reacting shear flows such as shear layers, jets, and buoyant plumes, are to be presented to showcase the capabilities of the method. Analysis will focus on elucidating the impact of combustion exothermicity on the flow dynamics. The dynamics of two-phase disperse shear flows is to be investigated with the aid of simulations of the particle/droplet laden non-reacting shear layer. In particular, the impact of a variable density and viscosity carrier phase on the evolution of the dispersed phase will be assessed. Finally, results will be presented from simulations of planar Helium-Air buoyant plumes. Through comparisons with experimental data the ability of the method to quantitatively reproduce the flow unsteady features will be documented. The numerical results are to be used to investigate the nature of the flow near field pulsating instability.