Question

The cut-off width dependent on the finite volume grid size is equal to _____________

(a) the square of the grid cell volume

(b) the cube of the grid cell volume

(c) the square root of the grid cell volume

(d) the cube root of the grid cell volume

I got this question in examination.

My doubt is from Large Eddy Simulation for Turbulent Models in portion Turbulence Modelling of Computational Fluid Dynamics

Answer 1

Correct option is (d) the cube root of the grid cell volume

Easy explanation: If Δx, Δy and Δz are the grid sizes in the x, y and z-directions, the cut-off width should be the cube root of the cell volume (\(\sqrt[3]{\Delta x \Delta y \Delta z}\)). This is because the cut-off width is in a single direction.