The Effect of Grid Geometry on the Scale-by-Scale Budget of Decaying Turbulence

The approximately homogeneous, isotropic turbulence (HIT) produced by three grids with different geometries was measured over the range 30 ≤ x/M ≤ 80. The scale-by-scale budget of decaying grid turbulence obtained from the transport equation for (δq)2 is used to study the effect of grid geometry in an attempt to quantify the influence of initial conditions of the tur-bulence decay. Although Rλ is too small for a scaling range to exist, the initial conditions show negligible effect on scales smaller than λ. The solidity of the grid influences only the very large scales. The shape of the grid elements can significantly affect the overall shape of the inhomogeneous term in the trans-port equation fo