Numerical Simulation of an Accelerating Reacting Mixing Layer in Transition
Abstract
A direct numerical simulation of a two-dimensional, unsteady Navier-Stokes flow with parallel air and gaseous fuel streams is performed using finite-difference methods. The mixing-layer flow undergoes acceleration, spatial development, mixing, and reaction while in the early stages of transition to turbulence. Convergent-divergent channels are used to accelerate the flow from low subsonic speeds upstream to low supersonic speeds at the downstream computational boundary. Important parameters that are surveyed include the ratio of the inflow velocities for the two streams, the Reynolds number for one of the streams, the channel dimensions normalized by the inflow momentum thickness, ratios of the inflow temperatures for the two streams, Damkohler number, Schmidt number, and Prandtl number. Results show the mixing layer instability and the subsequent formation and pairing of vortex structures. The strains associated with the acceleration and with the hydrodynamic instabilities do modify the mixing rates and thereby the energy and mass conversion rates.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2003
- Bibcode:
- 2003APS..DFD.JL001S