軸対称乱流噴流中の乱流拡散係数の分布(流体工学, 流体機械)

抄録

The axial velocity, radial velocity and concentration of a high Schmidt number matter were measured simultaneously in an axisymmetric turbulent jet. The diffusing fluid is a water solution of the commercial dye (Schmidt number Sc≃3800), and an issuing Reynolds number is 6400. A combined probe of a fiber optic concentration sensor and a X type hot film was used to measure the axial velocity, radial velocity and concentration simultaneously. The normalized axial and radial mass flux show similar profiles. Eddy diffusivities are the function of only r/L_U (the radial distance normalized by the half width of axial mean velocity). The effect of the axial concentration gradient is dominant for the axial mass flux near the jet centerline, and also the effect of the radial concentration gradient becomes significant far from the jet centerline.