Eventos Anais de eventos
ENCIT 2020
18th Brazilian Congress of Thermal Sciences and Engineering
Compressibility effects on the onset of dynamic stall in a periodic plunging airfoil
Submission Author:
Renato Fuzaro Miotto , SP , Brazil
Co-Authors:
Renato Fuzaro Miotto, William Wolf
Presenter: Renato Fuzaro Miotto
doi://10.26678/ABCM.ENCIT2020.CIT20-0073
Abstract
The effects of compressibility on the onset of the dynamic stall vortex (DSV) over a wing section are analyzed by means of large eddy simulations. A SD7003 airfoil is considered at two different freestream Mach numbers, being $M_{\infty} = 0.1$ and $0.4$, and at a chord-based Reynolds numbers of $\mbox{Re}_c = 6 \times 10^4$. The profile undergoes a periodic plunging motion. Results show that compressibility causes the DSV to form further downstream the leading edge. Moreover, higher compressibility also leads to weaker DSVs with lower residency time. For the current flow configuration and airfoil kinematics, the mechanisms of dynamic stall onset involve the upstream propagation of Kelvin-Helmholtz instabilities that trigger separation of a shear layer formed at the leading edge. In order to better characterize the onset of the DSV, two empirical criteria are assessed for the cases investigated: the leading edge suction parameter and the chord normal shear layer height. The application of both criteria show that the leading edge suction parameter is highly dependent on compressibility.
Keywords
dynamic stall, Large Eddy Simulation (LES), Unsteady Aerodynamics
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