An economical method for direct numerical simulation studies of transitional round jets

A pseudo-spectral method based on Fourier expansions in a Cartesian coordin ate system is shown to be an economical method for direct numerical simulat ion studies of transitional round jets, Several characteristics of the solu tions are presented to establish the validity of the solutions in spite of the unnatural choices. We show that neither periodicity, nor the use of a C artesian system have adversely affected the simulations, Instead, there are benefits in terms of ease of computing and lack of the usual restrictions due to grid structure near the jet axis. By computing the simultaneous evol ution of passive scalers, the process of reaction in round jet burners, bet ween a fuel-laden jet and an ambient oxidizer, was also simulated. Some typ ical solutions are shown and then the results of analysis of these data are summarized. (C) 2001 Elsevier Science Ltd, All rights reserved.