22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-7.7.5
SIMPLIFIED THEORY ON MATHEMATICAL MODEL OF AXIAL COMPRESSOR CHARACTERISTICS WORKING OVER SOUND SPEED
Á. Veress
Lehrstuhl für Fluidmechanik, Technische Universität München, Germany
Keywords: numerical simulation, navier-stokes equations, dynamic stall
This paper describes the application of the
noncommercial CFD-code FLOWer to the
problem of a sinusoidally pitching NACA 0012
airfoil with high amplitude and reduced
frequency under incompressible flow conditions.
As FLOWer allows the approximate solution of
the nonlinear conservation laws governing
viscous fluid flow, i. e. the Navier-Stokes
equations, a numerical investigation of the
unsteady boundary layer separation occurring
during such a motion becomes feasible.
Employing FLOWer under the incompressible
conditions that correspond to the regarded
experimental regime required an extensive
preliminary analysis of the numerical
parameters imbedded into the code. Having
been primarily developed for transonic flow, it
was possible to adjust FLOWer to the
incompressible flow problem after studying the
behavior of its various mechanisms for
accelerating convergence and increasing
stability. The necessary methodology to obtain
optimal parameter settings was developed by
critically examining steady state solutions at
low angles of attack. The knowledge gained
from these cases was then applied to simulate
the sinusoidal movement of the NACA 0012
airfoil. FLOWer’s accuracy in predicting the
phenomena of the unsteady boundary layer
separation was then assessed.
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