A numerical investigation of CO2 dilution on the thermochemical characteristics of a swirl stabilized diffusion flame

Abstract

The turbulent combustion flow modeling are performed to study the impacts of CO 2 addition to the fuel and oxidizer streams on the thermochemical characteristics of a swirl stabilized diffusion flame SM1. A flamelet approach along with three well-known turbulence models are utilized to model the turbulent combustion flow field. The k−ω SST shows the best agreement with the experimental fields compared to other methods. Then, the k−ω SST is employed to study the effects of CO 2 dilution on the flame structure and strength, temperature distribution, and CO concentration. To determine the chemical effects of CO 2 dilution, a fictitious species is replaced with the regular CO 2 in both fuel and oxidizer streams.The results indicate that the flame temperature is decreased when CO 2 is added to either fuel or oxidizer streams. The flame length reduction is observed at all levels of CO 2 dilution. The H radical concentration indicating the flame strength decreases following by the thermochemical effects of CO 2 dilution processes. In comparison with fictitious species dilution, chemical effects of CO 2 addition enhance CO mass fraction. The numerical simulations show that by increasing the

Large eddy simulation of separated flow to investigate heat transfer characteristics in an asymmetric diffuser subjected to constant wall heat flux

“…Adverse pressure and comparatively separation can be observed in some engineering equipment. In some of them, heat transfer also plays an important role, such as Turbine blades [1][2][3], turbines [4], compressors, diffusers, heat exchangers [5,6], and combustion chambers [7,8] are some of the devices including heat transfer where the flow separation is possible. Heat transfer inside the diffusers is also important in micro-gas turbines, significantly influencing the device's thermal and overall efficiencies.…”