The authors who pioneered Spectral Methods in Fluid Dynamics Calculations in 1988 have now incorporated the many improvements in the algorithms and the theory of spectral methods made since then into this new edition. This improved book retains the tight integration between the theoretical and practical aspects of spectral methods, and the chapters are enhanced with material on the Galerkin with numerical integration version of spectral methods. The discussion of direct and iterative solution methods is also greatly expanded, as are the set of numerical examples that illustrate the key properties of the various types of spectral approximations and the solution algorithms. In short, this book provides the most comprehensive, up-to-date theory and state-of-the-art algorithms of spectral methods written by the authors who pioneered the subject.