경사충돌분류에 관한 연구

A study on an oblique impinging jet

본 연구에서는 2차원 경사충돌분류에 대한 실험을 수행하였고, 이 결과를 수] 치해석에 의한 계산치와 비교하였다. 실험에서는 난류특성을 구명하기 위하여 열선 풍속계를 사용해 충돌각의 변화에 따른 평균속도, 각 난류응력성분, 압력등을 측정하 였다.수치해석을 위한 난류모델로는 표준 K-.epsilon.모델을 사용하였다.

Oblique impinging plane jets were investigated experimentally and numerically at Reynolds number 21000. The inclination angle was varied from 90.deg.(normal to the impinging plate) to 60.deg.. The distance H between the nozzle exit and the stagnation point on the impinging plate was fixed at H/D=8. The working fluid was air. The mean velocity components and turbulent quantities were measured by a hot-wire anemometer. And the static pressure distributions on the impinging plate were measured by a Pitot tube. In numerical computation, the governing partial differential equations of elliptic type were solved with conventional k-.epsilon. turbulence model. The measurements show that, after impingement, the jet half width alone the wall increases in both directions, and that similarity for each turbulent quantity such as Reynolds shear stress or turbulent kinetic energy is revealed in the wall jet region. The computed results show some deviation from experimental data in the impingement region, where streamline curvature is significant. However, the computed results agree qualitatively well with measurements.