Overlapping of Communication and Computation in nb3dfft for 3D Fast Fourier Transformations

For efficiency and accuracy of Direct Numerical Simulations(DNS) of turbulent flows pseudo-spectral methods can be employed,where the governing equations are solved partly in Fourier space. Theinhouse-developed 3d-FFT library nb3dfft is optimized to the specialneeds of pseudo-spectral DNS, particularly for the scientific code psOpen,used by the Institute for Combustion Technology at RWTH Aachen Uni-versity. In this paper we discuss the method of overlapping communica-tion and computation of multiple FFTs at the same time