Turbulent flow past over a 3-dimensional triangular bluff-body flameholder using direct numerical simulations.

摘要

In gas turbine combustion system, pollution emissions like CO and NOx produce a hard impact on ecosystem. These emissions are due to combustion instability during which the flame undergoes rapid oscillations and eventually blows out completely. In gas turbine, flame stabilization is often achieved through the use of recirculation zone created by a bluff body usually called "flamehoder". A flame holder improves the mixing of hot combustion products with the incoming fuel and air mixture.;In the present study, a detailed bluff--body flameholder is studied. Direct Numerical Simulations (DNS) at low Reynolds number have been performed. Various quantities as mean velocities, turbulent fluctuations and static pressures are measured. Behind the flameholder the wake is similar to a Karman Vortex. The pressure distribution around the flame holder shows a high variability corresponding to the oscillation of the streamlines. Visualization of streamlines, pressure contours, rms of velocity are shown in this work.