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Computation of low‐speed compressible flows with time‐marching procedures
Author(s) -
Merkle Charles L.,
Choi YunHo
Publication year - 1988
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.1620250203
Subject(s) - reynolds number , inviscid flow , mach number , mathematics , reynolds equation , compressibility , mechanics , compressible flow , computation , wavenumber , convergence (economics) , mathematical analysis , classical mechanics , physics , algorithm , optics , turbulence , economics , economic growth
The extension of time‐marching procedures to low Mach number and low Reynolds number conditions is considered. It is shown that the disparate speeds of the acoustic and particle waves prevent convergence at high Reynolds numbers, while the requirement that both the Courant and the von Neumann numbers be of order one prevents convergence in very viscous flows. A perturbation expansion is used to introduce pseudo‐acoustic waves that propagate at speeds similar to the particle speed at high Reynolds numbers and that allows both the inviscid and viscous time step parameters to be of order one at low Reynolds numbers. The resulting algorithm is shown to give convergence rates that are independent of either Mach number or Reynolds number over a range of five orders of magnitude in both parameters. Results are shown for strong heat addition in low‐speed flow encompassing this broad range of variables.