中央に長方形切欠をもつ二次元的ノズルから流出する乱流噴流 : 乱流場の流れ方向変化(流体工学, 流体機械)

抄録

The turbulent flowfield of a turbulent air jet issuing from a quasi two-dimensional nozzle with a rectangular notch at the midspan, has been measured using linearized constant temperature anemometers. The aim of this study is to examine the streamwise variation of the turbulent quantities and the turbulent scales, and to clarify the asymptotic process of the present jet toward the two-dimensional jet. Throughout this experiment, Reynolds number based on the nozzle width and the exit velocity, was kept constant 13000. From this experiment, in the upstream region of the quasi two dimensional jet, it is revealed that the development of the turbulent kinetic energy is suppressed by means of the rectangular notch. In the far downstream region, the decreasing rate of the turbulent velocity scale at the jet center region approaches to that of the two-dimensional jet. Furthermore, the turbulent kinetic energy flux in the interactive region takes the minimum value at the section of x/d=15 due to the inward secondary flow.