석유 팬 히터의 연소실 주변 압력 분포 특성

Abstract

This paper was studied to understand the characteristics of surface pressure distributions around a circular combustion chamber within the heat-intercept duct of kerosene fan heater. The experiment was carried out in the heat-intercept duct of kerosene fan heater attached to the blow-down-type subsonic wind tunnel with a test section of 240 [mm] × 240 [mm] × 1200 [mm] in condition of the flowrate Q = 2.903, 3.456, 3.94 [m3/min] respectively. Also the drag coefficient and the lift coefficient were obtained from these surface pressure distributions. The purpose of this paper was to determine the position of the air-supply holes for a secondary combustion in order to prohibit unstable flame and local heat concentration on the combustion chamber. Consequently it was found that ( i ) the positive surface pressure distributions occurred in the range of θ = 330°∼90°, but the negative surface pressure distributions occurred in the range of θ = 255°∼340° due to the arrangement between axial fan and the position of surface pressure measurement in the heat-intercept duct when axial fan rotated clockwise, and ( ii ) the optimum position of the air-supply holes for secondary combustion chamber corresponded to the range of θ = 45°∼105° within the height of H = 40 mm under the condition that the flame did not reach on the inner part of a circular combustion chamber directly.