[연구논문] 콘형 가스 스월버너의 3차원 난류 유동장 구조

The Structure of Three-dimensional Turbulent Flow Fields of a Cone Type Gas Swirl Burner

This paper represents axial mean velocity, turbulent kinetic energy and swirl number based on momentum flux measured in the X-Y plane and Y-Z plane respectively of a cone type gas swirl burner by using X -probe from the hot-wire anemometer system This experiment is carried out at flow rates 350 and 450 ℓ/min respectively, which are equivalent to the combustion air flow rate necessary for heat release 15,000 kcal/hr in gas furnace, in the test section of a subsonic wind tunnel. Axial mean velocities and turbulent kinetic energies show that their maximum values exist centering around narrow slits situated radially on the edge of and in the forefront of a burner until X/R≒ 1.5, but they have a peculiar shape like a starfish diffusing and developing into inward and outward of a burner by means of the mixing between flows ejected from narrow slits, an inclination baffle plate and swirl vanes respectively according to downstream regions. Moreover, they show a relatively large value in the inner region of 0.5<r/R<1 until X/R<3. Consequently the combustion reaction is anticipated to occur actively near these regions. On the other hand, the swirl number Sm obtained by integration of velocity profiles shows a characteristic that has an inflection point composing of the maximum and minimum value until X/R<3, but shows close agreement with the geometric swirl number after a distance of X/R=3.