Title: Flow separation control in a three-element airfoil system at moderate Reynolds number

Authors: Deepak Kumar Singh; Dilip Lalchand Parmar; Arjun Sharma

Addresses: Department of Applied Mechanics, Indian Institute of Technology Delhi, New Delhi – 110016, India ' Department of Applied Mechanics, Indian Institute of Technology Delhi, New Delhi – 110016, India ' Department of Applied Mechanics, Indian Institute of Technology Delhi, New Delhi – 110016, India

Abstract: The flow past a three-element, high-lift system is studied using Reynolds-averaged Navier-stokes simulations at Reynolds number of 1.5 × 10⁵. Two values of free-stream angles of attack, 5° and 13°, are considered that correspond to linear-lift and post-stall limits, respectively, for the main element plus flap system. The effects of increase in camber of slat geometry are examined at different deflection angles in terms of an effective angle of incoming stream towards the slat. Viscous effects including boundary layer separation on slat, emergence of a thick wake from slat and rapid merging of slat wake with boundary layer on main element are observed to adversely impact the net lift coefficient for values of deflection angle below a certain threshold. In the presence of slat, a lift coefficient of 1.5, an increase of 7% above the value corresponding to the main element plus flap configuration, is obtained at α = 5°.

Keywords: high-lift system; boundary layer separation; active flow control.

DOI: 10.1504/PCFD.2024.139342

Progress in Computational Fluid Dynamics, An International Journal, 2024 Vol.24 No.4, pp.204 - 214

Received: 21 Dec 2022
Accepted: 05 Apr 2023
Published online: 01 Jul 2024 *

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