Numerical and experimental investigations of buffet on a diamond airfoil designed for space launcher applications
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 19 June 2019
Issue publication date: 20 August 2020
Abstract
Purpose
The development of reusable space launchers requires a comprehensive knowledge of transonic flow effects on the launcher structure, such as buffet. Indeed, the mechanical integrity of the launcher can be compromised by shock wave/boundary layer interactions, that induce lateral forces responsible for plunging and pitching moments.
Design/methodology/approach
This paper aims to report numerical and experimental investigations on the aerodynamic and aeroelastic behavior of a diamond airfoil, designed for microsatellite-dedicated launchers, with a particular interest for the fluid/structure interaction during buffeting. Experimental investigations based on Schlieren visualizations are conducted in a transonic wind tunnel and are then compared with numerical predictions based on unsteady Reynolds averaged Navier–Stokes and large eddy simulation (LES) approaches. The effect of buffeting on the structure is finally studied by solving the equation of the dynamics.
Findings
Buffeting is both experimentally and numerically revealed. Experiments highlight 3D oscillations of the shock wave in the manner of a wind-flapping flag. LES computations identify a lambda-shaped shock wave foot width oscillations, which noticeably impact aerodynamic loads. At last, the experiments highlight the chaotic behavior of the shock wave as it shifts from an oscillatory periodic to an erratic 3D flapping state. Fluid structure computations show that the aerodynamic response of the airfoil tends to damp the structural vibrations and to mitigate the effect of buffeting.
Originality/value
While buffeting has been extensively studied for classical supercritical profiles, this study focuses on diamond airfoils. Moreover, a fluid structure computation has been conducted to point out the effect of buffeting.
Keywords
Acknowledgements
This work is partially funded by the French Space Agency (CNES); this support is greatly acknowledged. The authors particularly thank Jean Oswald and FlorentPuel from DLA (Direction des LAnceurs) at CNES for their help on this study. The experimental campaign was conducted with the technical team of ISAE-Supaero (special thanks to Emmanuel Rivet, Patrick Cheze and Marc Grellet). The simulations performed were achieved using CALMIP computing means, under project p1425 and GENCI A0042 A07178.
Citation
Dumon, J., Bury, Y., Gourdain, N. and Michel, L. (2020), "Numerical and experimental investigations of buffet on a diamond airfoil designed for space launcher applications", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 30 No. 9, pp. 4203-4218. https://doi.org/10.1108/HFF-07-2018-0353
Publisher
:Emerald Publishing Limited
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