Accession Number:

ADA164080

Title:

Numerical Simulation of Turbulent Flames Using Vortex Methods.

Descriptive Note:

Annual progress rept. no. 1, 1 Sep 84-31 Aug 85,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

Report Date:

1985-10-01

Pagination or Media Count:

14.0

Abstract:

Vortex schemes for direct numerical simulation of turbulence are developed to study the propagation and stability of turbulent flames. Attention is focused on the construction of accurate and efficient computational algorithms that are easily extendable to three dimensional reacting flow at high Reynolds numbers. A Lagrangian vortex scheme, which incorporates stochastic simulation of diffusion, was used to obtain solutions for a recirculating flow and a mixing layer. Results showed good agreement with experimental data at intermediate Reynolds number for the first case, and was used to establish the convergence of the numerical method, the sources of errors and the appropriate scheme to improve the accuracy efficiently. For the mixing layer, the simulation predicted the average velocity and the streamwise fluctuations accurately, but overpredicted the cross-stream fluctuation, indicating that the latter are governed by the three dimensional effects. The response of the layer to harmonic modulations was analyzed revealing the nature of the flow and indicating how entrainment can be enhanced in shear flow. The relationship between the flow instability and the combustion stabilization in both cases indicated the premixed flames have a narrow range of stable existence in terms of the equivalence ratio. Keywords Combustion Turbulent shear flow Flame propagation and Navier Stokes equations.

Subject Categories:

  • Statistics and Probability
  • Fluid Mechanics
  • Combustion and Ignition

Distribution Statement:

APPROVED FOR PUBLIC RELEASE