Abstract
The inner flow situated just behind the regular pyramidal diffuser inlet is a complicated turbulence with a shear voitex produced by separated flow at the diffuser inlet wall and voltex produced by secondary flow at the four corners of the diffuser. This turbulent flow could be visualized by the tuft grid method. The averaged fluctuation pattern in cross section across inlet flow of reguler pyramidal diffuser, in which unsteadily flow, is visualized by the improved tuft grid method, and recorded by using the photographic film and video imaging. On the other hand, the amplitude of the fluctuation was measured by used hot-film probe. The diffusers are presented for following condition : length ratio N/W = 10 and total divergence angles 2Θ = 2°, 4°, 6° and 8°.
