Computation of internal incompressible separated flows
Abstract
A spacemarching technique was used to compute internal separated flows accurately and efficiently. Spacemarching the NavierStokes equation with the pressure implicit and backward differenced is not wellposed. To avoid this, the mathematical character of the streamwise transport equation was changed to hyperbolic. The coupled system satisfies the continuity equation exactly at each point without the use of a correcting Poisson equation or a staggered grid. The separated flow in a suddenly expanding channel was solved with one sweep with no initial pressure or velocity field. Results compare very well with the experimental data and previous computations. The separated flow in a cascade of airfoils was also computed and results compared to the experimental data. The ellipticity of the cascade flow was transmitted through an initial inviscid pressure field computed from a panel method code. A Poisson equation for the pressure was included to improve the prediction of the pressure field and to allow for multiple sweeps of the domain for large interaction regions.
 Publication:

24th AIAA Aerospace Sciences Meeting
 Pub Date:
 January 1986
 Bibcode:
 1986aiaa.meetU....K
 Keywords:

 Channel Flow;
 Computational Fluid Dynamics;
 Computational Grids;
 Incompressible Flow;
 Separated Flow;
 Time Marching;
 Airfoils;
 Algorithms;
 Cascade Flow;
 Eddy Viscosity;
 NavierStokes Equation;
 Poisson Equation;
 Turbulent Flow;
 Fluid Mechanics and Heat Transfer