Abstract

The impinging jet flame is studied experimentally and numerically accounting for the complex flame-wall interactions in practical combustion devices. Flame dynamics and heat transfer with the effect of impinging wall are analyzed. The 3-D large eddy simulation coupled with detailed chemical reaction mechanism and particle image velocimetry experiment based on cross-correlation measurement principle are performed for verification and further analysis. Results show that vortices are generated due to the Kelvin-Helmholtz instability originated from velocity gradient. The 3-D vortex interactions involving vortex rings and spirals are also indicated by vorticity and the convection of streamwise vorticity is responsible for the effect of vortex spirals associated with turbulent flow transition. In addition, results calculated from four wall thermal conditions are compared and analyzed. Dirichlet condition is inferred to be more suitable for the case of wall materials with higher thermal conductivity. It is indicated that wall thermal condition mainly affects the heat transfer in the near-wall region, but has little effect on the momentum transfer. This study provides references for the adoption of wall conditions in numerical simulation and near-wall treatment in combustion systems.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call