Accession Number : ADA606728


Title :   First-Order Hyperbolic System Method for Time-Dependent Advection-Diffusion Problems


Descriptive Note : Technical rept.


Corporate Author : NATIONAL INST OF AEROSPACE ASSOCIATES HAMPTON VA


Personal Author(s) : Mazaheri, Alireza ; Nishikawa, Hiroaki


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a606728.pdf


Report Date : Mar 2014


Pagination or Media Count : 37


Abstract : A time-dependent extension of the first-order hyperbolic system method [J. Comput. Phys., 227 (2007)[315-352] for advection-diffusion problems is introduced. Diffusive/viscous terms are written and discretized as a hyperbolic system, which recovers the original equation in the steady state. The resulting scheme orders advantages over traditional schemes: a dramatic simplification in the discretization, high-order accuracy in the solution gradients, and orders-of-magnitude convergence acceleration. The hyperbolic advection-diffusion system is discretized by the second-order upwind residual-distribution scheme in a unified manner, and the system of implicit-residual-equations is solved by Newton's method over every physical time step. The numerical results are presented for linear and nonlinear advection-diffusion problems, demonstrating solutions and gradients produced to the same order of accuracy, with rapid convergence over each physical time step, typically less than five Newton iterations.


Descriptors :   *SPECIAL FUNCTIONS(MATHEMATICS) , DIFFUSION , NONLINEAR SYSTEMS , TIME DEPENDENCE , UNSTEADY FLOW


Subject Categories : Operations Research
      Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE