Heat transfer characteristics of methane-air diffusion flames impinging normally on plane surfaces

Theoretical investigation of turbulent flame impinging normally on plane surfaces isdone to determine the average Nusselt number and the plate heat flux distribution as functions of jet Reynolds number, equivalence ratio, and separation distance. The analysis is established on the mathematical formulation of the governing equations for conservation of mass, momentum, and energy. The turbulence phenomenon is analyzed with the help of the RNG k-ε turbulence model.  The radiative heat transfer model has been designed by using the Discrete Ordinates radiation model. Results show that the heat flux graduallyincreases with the radial distance towards the plate center and attains a maximum value at a location slightly away from the stagnation point. The peak value in the local heat flux comes closer to the stagnation point when the height between the plates and the nozzle increases. Effects of variation of dimensionless separation distance on heat transfer characteristics are investigated. It is observed that heat flux gradually improves when the value of separation distance changes from ۱۲ to ۸ and decreases near the stagnation region with the further decrease in separation distance from ۸ to ۴.

Keywords:

Diffusion flame , heat transfer , equivalence ratio , Nusselt number , Reynolds number