Abstr:High Reynolds Number Flow around Airfoil in Deep Stall
High Reynolds Number Flow around Airfoil in Deep Stall
Flows Around Bodies
Underlying Flow Regime 2-11
Abstract
The flow around airfoils at high (beyond stall) angles of attack is a
fundamental problem of external aerodynamics. Conventional RANS
turbulence models are not only incapable of predicting a steady mean
flow for this UFR with acceptable accuracy but also "by definition"
cannot capture its essential features (inherent 3-dimensionalty and
unsteadiness) which are of significant interest for aero-acoustics and
aero-elasticity applications. These circumstances have defined the
primary choice of specific test case, namely the flow around a NACA0021
airfoil at 60° angle of attack, as the only one for which experimental
data on unsteady as well as mean flow characteristics are available
[27, 28] and for which a wide spectrum of computations with different
CFD codes has been carried out in the framework of the EU DESider
Project [5]. The very similar case of the thinner NACA0012 airfoil in
deep stall is employed as a related secondary test case from which past
experience allows additional best practice advice (BPA) to be
extracted. Two principal purposes are envisaged for this UFR case and
BPA. Firstly, to document the experience gained with respect to the
most suitable computational techniques, in order to advise users
considering the practical computation of similar flows. Secondly, the
case is envisaged as an ideal verification case for testing new
developments or implementations of turbulence-resolving models, such as
hybrid RANS-LES approaches.
Contributed by: Charles Mockett; Michael Strelets — CFD Software GmbH and Technische Universitaet Berlin; New Technologies and Services LLC (NTS) and St.-Petersburg State Polytechnic University
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