TL;DR: In this paper, an algorithm for the rapid calculation of the convolution sums appearing in the Fourier-transformed Navier-Stokes equations in three dimensions is given. But the algorithm is only a factor of 4 more efficient than previously suggested algorithms.
Abstract: An algorithm is given for the rapid calculation of the convolution sums appearing in the Fourier‐transformed Navier‐Stokes equations. In three space dimensions, the new algorithm is a factor of 4 more efficient than previously suggested algorithms.