A fluid flow is simulated by causing a computer to perform operations on data stored in the memory to compute at least one eddy of a fluid flow at a first scale and perform operations to compute at least one eddy of the fluid flow at both the first scale and a second scale. The second scale is a finer scale than the first scale, and the computation of the at least one eddy of the fluid flow at the second scale is constrained by results of the computation of the at least one eddy of the fluid flow at the first scale.