Publikationsdatum:
2019
Beschreibung:
〈p〉Publication date: 15 November 2019〈/p〉
〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 397〈/p〉
〈p〉Author(s): T. Allen, M. Zerroukat〈/p〉
〈h5〉Abstract〈/h5〉
〈div〉〈p〉With the increasing resolution of numerical weather prediction models the slopes of orographic features such as hills and mountains is becoming much better resolved with the consequence that the gradients encountered are becoming ever steeper. The commonly used terrain following coordinate, which actually becomes singular at 90°, is becoming more problematic due to the resulting stiffness making the elliptic boundary value problem difficult to solve. Even when a solution is obtainable the feedback of the pressure correction onto the momentum will generally cause instabilities and/or unphysical solutions. This paper uses an alternative representation of the orography, namely the immersed boundary method, in a semi-implicit-semi-Lagrangian model of the inviscid compressible Euler equations. The results show that the method not only performs well but, due to the chosen method of implementation, that the computational overhead of the geometry can be decoupled from implicit treatment of the vertical gravity wave component.〈/p〉〈/div〉
Print ISSN:
0021-9991
Digitale ISSN:
1090-2716
Thema:
Informatik
,
Physik
