An Experimental Study on the Turbulence Characteristics of a Cross Jet with Respect to Cross Angle Variations

충돌분사의 충돌각 변화에 따른 난류특성의 실험적 연구

This investigation was carried out for the purpose of studying the turbulent flow and mixing characteristics after collision of two jets depending upon the cross angle variations. For effectuating this experimental study, a subsonic wind tunnel and a constant temperature type two channel hot-wire anemometer system have been utilized. The jets issuing from two nozzles have same Reynolds numbers and their cross angle was variable. After collision of two jets, the cross section of the mixing flow, mean and fluctuating velocities and Reynolds stresses have been measured, and analyzed comparing them with semi-empirical equations. It was found that the nondirectional contour of the cross section agreed well with an elliptic formula and the mean velocities along the centerline had a good similarity independent of cross angle variations. The distributions of U over bar-components measured in the Y direction have a good similarity and agree well with semi-empirical equations of Hinze and Gortler. The Reynolds stresses of u'v' over bar on the Y axis show a similar distributions and their agreement with the theoretical curve is remarkable but those of u'w' over bar measured along the Z axis are randomly scattered.

본 연구에서는 충돌각을 변수로 한 실험적 연구를 수행하기 위하여 여타의 변수를 고정하였으며, 유속은 R$_{e}$=5.2*$10^{4}$의 결과를 제시하였다.