Home > Research > Publications & Outputs > Ad-hoc Boundary Conditions for CFD Analyses of ...

Associated organisational unit

View graph of relations

Ad-hoc Boundary Conditions for CFD Analyses of Turbomachinery Problems with Strong Flow Gradients at Farfield Boundaries

Research output: Contribution to Journal/MagazineJournal articlepeer-review

Article number041010
<mark>Journal publication date</mark>20/04/2011
<mark>Journal</mark>Journal of Turbomachinery
Issue number4
Number of pages9
Publication StatusPublished
<mark>Original language</mark>English


This paper reports on the improvements of flux enforcement and auxiliary state farfield boundary conditions for Euler and Navier–Stokes computational fluid dynamics (CFD) codes. The new conditions are based on 1D characteristic data and also on the introduction in the boundary conditions of certain numerical features of the numerical scheme used for the interior of the domain. In the presence of strong streamwise gradients of the flow field at the farfield boundaries, the new conditions perform significantly better than their conventional counterparts in that they (a) preserve the order of the space discretization and (b) greatly reduce the error in estimating integral output. A coarse-grid CFD analysis of the compressible flow field in an annular duct for which an analytical solution is available yields a mass flow error of 62% or 2%, depending on whether the best or the worst farfield boundary condition (BC) implementation is used. The presented BC enhancements can be applied to structured, unstructured, cell-centered, and cell-vertex solvers.