Eddy is a fundamental research code for advancing spectral methods for complex geometry. The software is intended to enable researchers to collaborate through a common framework that supports three-dimensional simulations on practical problems. Areas of interest include advanced numerical algorithms, computational optimization, scale-resolving turbulence models, and high-order mesh generation.

The focus of the software is maximizing the efficiency of the computational schemes to allow for unsteady simulations with a large number of spatial and temporal degrees of freedom. A collocation scheme is combined with optimized computational kernels to provide a residual evaluation with computational cost independent of order of accuracy up to 16th order. The optimized residual routines are used in a low-memory implicit scheme based on a matrix-free Newton-Krylov method. A preconditioner based on the finite-difference diagonalized ADI scheme is included that maintains the low memory of the matrix-free implicit solver, while providing improved convergence properties. Emphasis on low memory usage throughout the solver development is leveraged to implement a coupled spacetime DG solver that enables adaptivity in both space and time.

This work was done by Scott Murman of Ames Research Center and Laslo Diosady of Oak Ridge Associated Universities, Inc.This software is available for use. To request a copy, please visit here .