抄録
Turbulence statistics and scalar diffusion field ill all axisymmetric turbulent water jet are experimentally investigated. A commercial dye (Sc ≃ 3,800) is used as a diffusion matter. Instantenous two-component velocities and instantenous concentration are simultaneously measured using a combined probe of an X-type hot-film probe and a fiber-optic concentration sensor. The results of preparatory concentration measurements show that the radial profiles of the mean concentration agree well with Gaussian distribution. The probability density functions of fluctuating concentration are skewed negatively. The power spectra of fluctuating concentration show the -5/3 scaling region. These results are consistent with the past data of scalar field in the turbulent jet. The joint statistics of velocity and concentration will be shown at the conference.
