A computational investigation of centrifugal force effects on backward-facing-step stabilized turbulent premixed propane-air flames is conducted. The centrifugal force acts from the high-density reactants towards the low-density products creating a Rayleigh-Taylor instability. A straight channel with an infinite radius of curvature and a backward-facing step is used as the baseline. A curved channel (referred to as a centrifuge in this work) with a finite radius of curvature and a backward-facing step on the outer radius is used to evaluate the effects of centrifugal force on turbulent flame speeds. Three-dimensional simulations are performed using Reynolds-averaged Navier-Stokes (RANS) simulations and large eddy simulations (LES). The computational results are compared with broadband chemiluminescence and shadowgraph images reported in the literature for similar conditions and geometries. The past experiments and current simulations show that increasing the inlet velocity in the straight channel and centrifuge results in a flame cannot withstand the high stretch rates and the flame is positioned behind the backward-facing step. The measured and computed shadowgraphs for the straight channel and centrifuge demonstrate that by increasing the inlet flow velocity the flame becomes hydrodynamically unstable, characterized by heterogeneous and anisotropic turbulent flow, and a large density variation occurs further downstream. The RANS and LES computations qualitatively capture these trends, but the LES results show better agreement with the experimental broadband chemiluminescence and shadowgraph images. It is challenging to decouple the combined effects of turbulence fluctuations and Rayleigh-Taylor induced centrifugal acceleration on turbulent flames speeds. However, the combined effects of turbulence fluctuations and centrifugal acceleration appear to promote increased turbulent flame speeds and at high enough inlet velocities, allow the flame to exist where it would otherwise blowout.
Skip Nav Destination
ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition
June 26–30, 2017
Charlotte, North Carolina, USA
Conference Sponsors:
- International Gas Turbine Institute
ISBN:
978-0-7918-5085-5
PROCEEDINGS PAPER
Effect of Rayleigh-Taylor Instability on Backward-Facing-Step Stabilized Turbulent Premixed Flames Available to Purchase
Brandon S. Long,
Brandon S. Long
University of Dayton Research Institute, Dayton, OH
Search for other works by this author on:
Alejandro M. Briones,
Alejandro M. Briones
University of Dayton Research Institute, Dayton, OH
Search for other works by this author on:
Scott D. Stouffer,
Scott D. Stouffer
University of Dayton Research Institute, Dayton, OH
Search for other works by this author on:
Brent A. Rankin
Brent A. Rankin
Air Force Research Laboratory, WPAFB, OH
Search for other works by this author on:
Brandon S. Long
University of Dayton Research Institute, Dayton, OH
Alejandro M. Briones
University of Dayton Research Institute, Dayton, OH
Scott D. Stouffer
University of Dayton Research Institute, Dayton, OH
Brent A. Rankin
Air Force Research Laboratory, WPAFB, OH
Paper No:
GT2017-64547, V04BT04A027; 9 pages
Published Online:
August 17, 2017
Citation
Long, BS, Briones, AM, Stouffer, SD, & Rankin, BA. "Effect of Rayleigh-Taylor Instability on Backward-Facing-Step Stabilized Turbulent Premixed Flames." Proceedings of the ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. Volume 4B: Combustion, Fuels and Emissions. Charlotte, North Carolina, USA. June 26–30, 2017. V04BT04A027. ASME. https://doi.org/10.1115/GT2017-64547
Download citation file:
21
Views
Related Proceedings Papers
Related Articles
Flame Structure and Stabilization Mechanisms in a Stagnation-Point Reverse-Flow Combustor
J. Eng. Gas Turbines Power (May,2008)
Temperature Ratio Effects on Bluff-Body Wake Dynamics Using Large Eddy Simulation and Proper Orthogonal Decomposition
J. Eng. Gas Turbines Power (December,2015)
On the Adequacy of Chemiluminescence as a Measure for Heat Release in Turbulent Flames With Mixture Gradients
J. Eng. Gas Turbines Power (June,2010)
Related Chapters
Introduction and Background
Introduction to Finite Element, Boundary Element, and Meshless Methods: With Applications to Heat Transfer and Fluid Flow
CFD Simulations of a Mixed-flow Pump Using Various Turbulence Models
Mixed-flow Pumps: Modeling, Simulation, and Measurements
Two Advanced Methods
Applications of Mathematical Heat Transfer and Fluid Flow Models in Engineering and Medicine