フラクタル形状の稜線を持つ平板の後流特性について

抄録

It is known that the isotropy of grid-generated turbulence is improved by introducing the change of the shape of intersecting bars. It is therefore planned to add a fractal-edge to the grid and it is interesting to see how turbulence properties are ameliorated. To this end, the turbulence properties in the wake of fractal-edged plate has been investigated as a preliminary. Fractal-edges are added so that the area of the base square plate remains the same and that the Fractal dimension equals 5/3. Comparison of the present results with those of the previous research on the different fractal-edged plate as well as the theoretical results of axisymmetric wake shows that the exponent of the growth rate of wake width is the greater and the wake width grows up to the size of the plate before around 16 times the size of the plate. It suggests that grid-formation of the fractal-edged plate studied here could produce homogeneous turbulence in the more upstream than the conventional grid.