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Generalized characteristic relaxation boundary conditions for unsteady compressible flow simulations

Pirozzoli, Sergio and Colonius, Tim (2013) Generalized characteristic relaxation boundary conditions for unsteady compressible flow simulations. Journal of Computational Physics, 248 . pp. 109-126. ISSN 0021-9991. doi:10.1016/

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We develop numerical boundary conditions for the compressible Navier–Stokes equations based on a generalized relaxation approach (GRCBC), which hinges on locally one-dimensional characteristic projection at the computational boundaries, supplemented with available information from the flow exterior. The basic idea is to estimate the amplitude of incoming characteristic waves through first-order one-sided finite-difference approximations which involve the value of the reference flow state at the first exterior (ghost) point. Unlike other characteristic-based relaxation methods, the present one requires minimal user-supplied input, including the reference flow state, which may be totally or partially known, and in general may vary both in space and time. Furthermore, it can be applied to any type of computational boundary, either inflow or outflow, either subsonic or supersonic. The method is theoretically predicted to convey reduced reflection of waves at computational boundaries compared to other ones, and to have better properties of frequency response to injected disturbances. Numerical tests confirm the improvement of the nonreflecting performance, and demonstrate high degree of flexibility, also for problems with non-trivial far-field boundary conditions (e.g. flows in rotating reference frames) and for the artificial stimulation of subsonic turbulent boundary layers.

Item Type:Article
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URLURL TypeDescription DOIArticle
Colonius, Tim0000-0003-0326-3909
Additional Information:© 2013 Elsevier Inc. Received 11 October 2012; Received in revised form 25 March 2013; Accepted 10 April 2013; Available online 28 April 2013.
Subject Keywords:Numerical boundary conditions; Compressible flows; Characteristic decomposition
Record Number:CaltechAUTHORS:20130718-085055399
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Official Citation:Sergio Pirozzoli, Tim Colonius, Generalized characteristic relaxation boundary conditions for unsteady compressible flow simulations, Journal of Computational Physics, Volume 248, 1 September 2013, Pages 109-126, ISSN 0021-9991,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:39436
Deposited By: Tony Diaz
Deposited On:18 Jul 2013 15:57
Last Modified:09 Nov 2021 23:44

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