Recirculation and vortex breakdown in isothermal and reacting swirling flows: insights from two different large eddy simulation programs [Published as: Large eddy simulations of swirling non-premixed flames with flamelet models: a comparison of numerical methods]
journal contributionposted on 03.12.2009, 14:26 by A. Kempf, Weeratunge Malalasekera, K.K.J. Ranga-Dinesh, O. Stein
This work investigates the application of large eddy simulation (LES) to selected cases of the turbulent non-premixed Sydney swirl flames. Two research groups (Loughborough University, LU and Imperial College, IC) have simulated these cases for different parameter sets, using two different and independent LES methods. The simulations of the non-reactive turbulent flow predicted the experimental results with good agreement and both simulations captured the recirculation structures and the vortex breakdown without major difficulties. For the reactive cases, the LES predictions were less satisfactory, and using two independent simulations has helped to understand the shortcomings of each. Furthermore one of the flames (SMH2) was found to be exceptionally hard to predict, which was supported by the lower amount of turbulent kinetic energy that was resolved in this case. However, the LES has identified modes of flame instability that were similar to those observed in some of the experiments.
- Mechanical, Electrical and Manufacturing Engineering