Study on the Statistical Turbulent Characteristics of $45^{\circ}$ Circular Cross Jet Flow

$45^{\circ}$ 圓形 衝突噴流의 統計學的 亂流特性 硏究

45.deg. corss jet flow, at the mixing of two jet flows, was experimentally studied. For this study, only the statistical turbulent characteristics and high order moments will be analysed by on-line computer system (hot-wire anemometer system, dynamic analyser and computer system, plotting and printing system). Since mean velocity distributions, intensities of turbulence, Reynolds stresses, correlation coefficients, and other general results were already studied and presented. One dimensional probability density distributions of u', v', and w' were analysed comparing with Gaussian curve, which showed skew and flat tendency according to the Y and Z directions. For the analysis of the joint flow of turublent components, the joint probability density distributions were examined. The fagures were drawn so as to be read joint probabilities, joint probability densities, fluctuating velocities u', v', and w'. For further detailed examination of the variations of skewness and flatness phenomena, iso-joint probability density contours obtained from the profiles of the joint probability density distributions were studied. According to the displacement of positions from the center of the mixing flow and the directions, the flatness and skewness factors were increased.

본 45。충돌분사에서는 충돌분류의 평균속도, 난류강도, 난류전단응력등을 측정분석하여 기 연구발표한 자료를 토대로 하여 난류의 충돌배합이 활발히 일어나는 영역(X/X$_{0}$=2,3,4)에서 충돌분류의 특성을 통계학적으로 측정연구코저 한다. 따라서 각방향으로 발생하는 난류성분을 Gauss의 확률분포식과 비교검토하고, 2차원 결합확률정도선도를 측정도시하여 2방향의 난류성분들의 결합난동형상을 온라인 컴퓨 터 시스템에 의하여 분석할 계획이다. 또한 난류성분의 고차모멘트를 측정하여 비대칭도와 편평도등도 연구 구명코저 한다.다.