Heat Transfer and Exergy Analysis of Methane-Air Flame Impinging on Plane Surfaces

Manmatha K. Roul; Satyananda Tripathy; Prateek D. Roul; Ashok K. Pradhan; Sibakanta Sahu; Saipad B.B.P.J. Sahu

Abstract

Exergy and heat flow have been numerically investigated for flame impinging on flat circular plates. The maximum work available when the system is brought to thermodynamic equilibrium state with its surrounding is known as the exergy of a system. This state of equilibrium of the system depends on the pressure, temperature, and composition of environment. Efficiency based on exergy is otherwise known as the second-law efficiency which measures the usefulness of a system relative to its performance in reversible conditions. For the present case, thermodynamic usefulness of flame impingement heat transfer of premixed and diffusion flame has been explained. Second law efficiency was found to be increasing with augmentation of separation distance value up to an estimation of 16 and beyond the value of H/d =16, it remains approximately stable. In case of premixed flame, for H/d=16 and Re = 6000, the ratio of surface heat flux to irreversibility is found to be maximum. With reduction in H/d value, the value of Q/I decreases. But when H/d value increases beyond 16, the value of Q/I further decreases. In case of diffusion flame, when the value of H/d increases from 4 to 16, the Q/I value increases for any value of Re. But further increasing H/d value beyond 16, the value of Q/I decreases appreciably.

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