합성가스(H2/CO)/공기 예혼합 충돌화염의 연소 및 열전달 연구 Part II : 열전달 특성

Abstract

3† 1 Graduate School of Sunchon National Univ., 413, Jungang-ro, Sunchoen-Si, Jellanam-do, 540-742, Korea 2 School of Mechanical and Automotive Engineering of Chonnam Nat. Unv., 50, Daehak-ro, Yeosui, Jellanam, 550-749 3 School of Mechanical and Aerospace Engineering, Sunchon Nat. Univ., 413, Jungang-ro, Sunchoen, Jellanam, 540-742 Abstract >> An experimental study has been conducted to investigate the heat transfer characteristics of laminar syngas/air mixture with 10% hydrogen content impinging normally to a flat plate of cylinder. Effects of impinging distance, Reynolds number and equivalence ratio as major parameters on heat fluxes of stagnation point and radial direction were examined experimentally by the direct photos and data acquisitions from heat flux sensor. In this work, we could find the incurved flame behavior of line shaped inner top-flame in very closed distance between flat plate and burner exit, which has been not reported from general gas-fuels. There were 3 times of maximum and 2 times minimum heat flux of stagnation point with respect to the impinging distance for the investigation of Reynolds number and equivalence ratio effect. It was confirmed that the maximum heat flux of stagnation point in 1'st and 2'nd peaks increased with the increase of the Reynolds number due to the Nusselt number increment. There was a third maximum rise in the heat flux of stagnation point for larger separation distances and this phenomenon was different each for laminar and turbulent condition. The heat transfer characteristics between the stagnation and wall jet region in radial heat flux profiles was investigated by the averaged heat flux value. It has been observed that the values of averaged heat flux traced well with the characteristics of major parameters and the decreasing of averaged heat flux was coincided with the decreasing trend of adiabatic temperature in spite of the same flow condition, especially for impinging distance and equivalence ratio effects.