Effect of Grid Geometry on Turbulence Decay

Abstract

Longitudinal and lateral turbulence intensities u2¯ and v2¯ are measured behind homogeneous grids of various geometries. For all grids used, the ratio u2¯/v2¯ is essentially constant during decay and lies between 1.2 and 1.35, depending on the grid geometry. The turbulence intensity u2¯∼t−n where n is constant during decay but depends on the grid geometry and varies from 1.22 to 1.48. This implies that the rate of decay depends on the initial energy spectrum and the energy-containing (large) eddies maintain a similarity during decay.