Modares Mechanical Engineering

Modares Mechanical Engineering

Numerical Investigation and Improvement of the Aerodynamic Performance of a Wing Equipped with a Slotted Flap Using CFD

Document Type : Original Article

Authors
Amir Mohammad Mohammadi 1
Sina Alimohammadian 2
1 Aerospace Engineering Department, University of Tehran, Tehran, Iran
2 Aerospace Engineering Department, Amir Kabir University of Technology, Tehran, Iran
10.48311/mme.2026.118924.82962
Abstract
In this study, the aerodynamic performance of a wing equipped with a slotted flap is investigated and compared using three-dimensional computational fluid dynamics simulations. To evaluate the influence of flap configuration on aerodynamic characteristics, three main designs are considered, including a baseline configuration (wing with a simple flap), a double-slotted flap configuration, and a four-bar linkage flap mechanism. Lift, drag, and pitching moment coefficients are computed and analyzed over a range of angles of attack for different flap configurations, and flow patterns are examined to identify flow separation and stagnation phenomena.

The results indicate that although the baseline configuration improves lift at low angles of attack and enhances performance during takeoff and landing phases, it suffers from reduced aerodynamic efficiency and increased drag and pitching moment at higher angles of attack due to intensified flow separation. In contrast, the double-slotted flap configuration significantly increases the lift coefficient and delays flow separation by increasing the effective camber and forming a flow channel between the flaps, albeit at the expense of increased drag. The analysis of the four-bar linkage mechanism demonstrates that simultaneous control of the flap gap and overlap plays a crucial role in regulating the aerodynamic behavior of the wing. Among the investigated cases, the G3 configuration provides the best balance between lift enhancement, drag control,, and pitching moment stability.
Keywords
Slotted Flap
Computational Fluid Dynamics
Aircraft Wing
Aerodynamics
Lift and Drag

Subjects

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Modares Mechanical Engineering
Volume 26, Issue 6
May 2026
Pages 413-436