very-large-eddy simulation of nonreactive turbulent flow for annular trapped vortex combustor

A hybrid reynolds-averaged navier-stokes (rans) large eddy simulation (les) method is applied in thiswork. it called very-large-eddy simulation (vles) turbulence closure model. the aim of this present study is firstly to validate the accuracy of this method for a specific engineering application (a trapped vortexcombustor) and secondly to describe its flow characteristics. the trapped vortex combustor is a new concept that utilizes a large recirculation vortex to stabilize the flame. an accurate prediction of the turbulent flow is meaningful for the trapped vortex combustor. the time-averaged velocity, root-mean-square (rms) velocity, and flow pattern are compared with the experimental data. and the les model, rans bsl k-ω model, and rans k-ɛ model are also applied for the simulation with different mesh resolutions. the results show that the vles bsl k-ω model provides improved accuracy for velocity prediction. the classical large vortex structure for the trapped vortex combustor is captured qualitatively by the vles bsl k-ω model also. in addition, the vortex breakdown and processing vortex cone are visualized using the q-criterion. furthermore, the vles bsl k-ω model is not sensitive to the gird resolution. the vles method is able to predict the turbulent flow of trapped vortex combustor relatively well.