Unsteady Non-Reacting and Reacting Flow Simulations of a Triangular Bluff-Body Flameholder

Abstract

Abstract Triangular bluff-body flame-holders, commonly called v-gutters, are used in gas turbine engine afterburners for flame stabilization. Unsteady flow dynamics in the v-gutter wake plays an important role in phenomenon such as combustion instability. The objective of the present work is to simulate the flow features for flow past v-gutter with Unsteady Reynolds-Averaged Navier–Stokes equations (URANS) and Large Eddy Simulation (LES) approach using Eddy Dissipation Model (EDM) for turbulent combustion. Volvo’s bluff body flame-holder rig configuration has been used for the current study. Both non-reacting and reacting simulations have been carried out in commercial Computational Fluid Dynamics (CFD) code FLUENT. In the case of non-reacting flow, the structure of instantaneous velocity field of LES differs from URANS approach. The predicted velocity profiles with LES have shown good agreement with the experiment in most of the regions than URANS for the case of non-reacting flow. In the case of reacting flow, LES simulations have shown unsteady flame with eddy structures. In contrast, URANS simulations have shown more like a steady flame. Overall, the temperature and velocity profiles were better predicted by LES than by URANS approach. In addition, simulations were carried out with circular flame-holder in an annular duct. The oscillation characteristics were found to be more or less similar for both straight and circular flame-holder.