Turbulence Structure of Flow in a Porous Tube With Annular Outer Flow

Turbulence measurements were conducted inside a porous-wall tube insert placed coaxially in a solid-wall outer tube. The outer tube diameter was 8 inches. The diameter of the inner tube was 6.5 inches. Three different porosities of 7.5, 15 and 22.5 percent were used for the inner tube. The average velocity of the flow in the outer tube was 55 ft/sec. The nominal Reynolds Number, based on diameter and mean velocity of the flow in the outer tube, is 2 × 10⁵. Results are presented for the three rms fluctuations, the Reynolds stress and the turbulence kinetic energy. The nature of the turbulence activity was examined by using the quadrant splitting scheme.