Study of wake characteristics behind an oscillating NACA 0012 airfoil in deep dynamic stall regime
Aircraft Engineering and Aerospace Technology
ISSN: 0002-2667
Article publication date: 1 February 2022
Issue publication date: 26 April 2022
Abstract
Purpose
This study aims to investigate the wake behind an oscillating airfoil at a various angle of incidence and Reynolds number in a deep dynamic stall condition.
Design/methodology/approach
NACA 0012 airfoil is allowed to undergo harmonic pitching motion about the quarter chord axis at Reynolds numbers of 0.5 * 105, 1.17 * 105, 1.7 * 105 and 2.12 * 105, and the reduced frequency of 0.1. The experiments are conducted at a set of mean and amplitude angle of attack that covered the angle of incidence from −5° to 25°. The wake rake is placed at a distance of one chord from the trailing edge of the airfoil.
Findings
The hysteresis of the flow during the upstroke and the downstroke motion are captured. The huge growth in the velocity defect and the wake thickness beyond the angle of attack of 15° explicate the appearance of the strong unsteady effects on the wake. The results also show that at the reduced frequency of 0.1, the wake structure is of drag producing type due to the momentum deficit.
Originality/value
Streamwise velocity profile and the turbulent intensity profiles are presented to show the effects of Reynolds number and angle of incidence on the wake behind the oscillating airfoil at the reduced frequency of 0.1, and in the intermediate range of Reynolds number is the novelty of the study.
Keywords
Acknowledgements
The authors are indebted to Dr Kamal Poddar and Mr Anshul Khandelwal of Indian Institute of Technology, Kanpur, for their help in conducting the wind tunnel experiments. Their support and encouragement are gratefully acknowledged.
Citation
D., S.R.S. and R., R. (2022), "Study of wake characteristics behind an oscillating NACA 0012 airfoil in deep dynamic stall regime", Aircraft Engineering and Aerospace Technology, Vol. 94 No. 6, pp. 871-880. https://doi.org/10.1108/AEAT-11-2021-0324
Publisher
:Emerald Publishing Limited
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