Dynamic Lift and Vortex Breakdown during an Unsteady Flow over a Pitching Airfoil
DOI:
https://doi.org/10.3849/aimt.01227Keywords:
unsteady aerodynamics, dynamic lift, vortex, pitching, airfoil, NACA 0012, CFDAbstract
Computational fluid dynamics techniques are used to give a detailed insight into unsteady phenomena taking place in the vicinity of a pitching airfoil. The vortex formation and breakdown are analyzed using the time history of pressure distribution, vorticity and injected massless particle trajectories. Different cases of flows are modeled to determine the effect of reduced frequency on unsteady lift. Finally, a comparison of lift coefficients for steady and unsteady cases is provided.
References
MCALLISTER, K., CARR, L. and MCCROSKEY, W. Dynamic Stall Experiments on the NACA 0012 Airfoil [Technical report No. 1100]. NASA, 1978.
AHMAD, K.A. et al. Numerical Modelling of a Pitching Airfoil. Jurnal Mekanikal, 2010, vol. 30, no. 1, p. 37‐47. ISSN 2289-3873.
ROZEHNAL, D. and SVOBODA, A. Unsteady Measurement of Aerodynamic Characteristics of a Profile During Dynamic Stall [Internal Report]. Brno: University of Defence, K‐204/A, 2008.
LOWSON, M. Some Experiments with Vortex Breakdown. The Aeronautical Journal, 1964, vol. 68, no. 641, p. 343-346. ISSN 0001-9240
KRISHNAMOORTHY, V. Vortex Breakdown and Measurements of Pressure Fluctuations over Slender Wings [Ph.D. thesis]. The University of Southampton, 1966.
WOODGATE, L. Measurements of the Oscillatory Pitching-Moment Derivatives on a Sharp-Edged Delta Wing at Angles of Incidence for Which Vortex Breakdown Occurs. Aeronautical Research Council, R.&M. 3628, Part III, 1971.
WOLFFELT, K. Investigation on the Movement of Vortex Burst Position with Dynamically Changing Angle of Attack for a Schematic Delta Wing in a Water Tunnel with Correlation to Similar Studies in Wind Tunnel, Aerodynamic and Related Hydrodynamic Studies Using Water Facilities. AGARD-CP-413, 1987.
ATTA, R. and ROCKWELL, D. Hysteresis of Vortex Development and Breakdown on an Oscillating Delta Wing. AIAA Journal, 1987, vol. 25, no. 11, p. 1512-1513. ISSN 0001-1452.
ATTA, R. and ROCKWELL, D. Leading-edge Vortices due to Low Reynolds Number Flow Past a Pitching Delta Wing. AIAA Journal, 1990, vol. 28, no. 6, p. 995-1004. ISSN 0001-1452.
Downloads
Published
License
Copyright (c) 2018 Advances in Military Technology
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Authors who publish with this journal agree to the following terms:
1. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
2. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
3. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.
Users can use, reuse and build upon the material published in the journal for any purpose, even commercially.
How to Cite
