An improved second moment method for solution of pure advection problems

✍ Scribed by Abdolreza Ghods; Farhad Sobouti; Jafar Arkani-Hamed

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 327 KB
• Volume: 32
• Category: Article
• ISSN: 0271-2091
• DOI: 10.1002/(sici)1097-0363(20000430)32:8<959::aid-fld995>3.0.co;2-7

✦ Synopsis

The second moment numerical method (SMM) of Egan and Mahoney [Numerical modeling of advection and diffusion of urban area source pollutant. Journal of Applied Meteorology 1972; 11: 312 -322] is adapted to solve for the pure advection transport equation in a variety of flow fields. SMM eliminates numerical diffusion by employing a procedure that takes into account the first and second moments of mass distribution in each grid element. For pure translational flow fields, the method is conservative, positive definite and shape-preserving. In rotational and/or shear flows, the accuracy of SMM is significantly reduced. Two improvements are presented to make the SMM applicable to a wider range of flow problems. It is shown that the improved SMM (ISMM) is less diffusive and more shape-preserving than the SMM in rotational and/or deformational flows. The ISMM can also be used to solve for a color function in compressible flow fields. The computational efficiency of this method is compared with that of other methods and, for a given accuracy, it is shown that ISMM is a cost-effective, non-diffusive and shape-preserving method.