CFD analysis of gas turbine combustor with vortex generator

Swirl flows have been used lately for the modern gas turbine combustion to enhance the mixing and flame stabilization. Instabilities that occur due to such flow are often termed as precessing vortex core (PVC). This precessing vortex core has a greater effect on the flow characteristics and heat release and its interaction with the flame is important. The numerical analysis using Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) turbulence models were used to carry out simulations of gas turbine combustor to study the PVC and flame interaction in the flow fields. The boundary conditions were set as power output – 35 kW, Reynolds number - 52000 and the equivalence ratio - 0.65. The RANS results were more similar to the experimental one than the LES. The LES results were more useful in studying the PVC characteristics, PVC-flame interaction and instantaneous flow field. The RANS results were helpful in understanding the average flow fields. The grid requirement for both turbulence models and their importance was also studied.