Passive Flow Control Over NACA 23018 Airfoil Using Semi-Circular Dimples Across Different Reynolds Numbers

Navid Ibne Newaz Chowdhury; Mohammad Tanveer Ahmed Rafi; Puspita Tasnim; S. M. Taufiq Imrose

doi:10.38032/scse.2026.4.205

Authors

Navid Ibne Newaz Chowdhury Department of Aeronautical Engineering, Military Institute of Science and Technology, Dhaka-1216, Bangladesh
Mohammad Tanveer Ahmed Rafi Department of Aeronautical Engineering, Military Institute of Science and Technology, Dhaka-1216, Bangladesh
Puspita Tasnim Department of Aeronautical Engineering, Military Institute of Science and Technology, Dhaka-1216, Bangladesh
S. M. Taufiq Imrose Department of Aeronautical Engineering, Military Institute of Science and Technology, Dhaka-1216, Bangladesh

DOI:

https://doi.org/10.38032/scse.2026.4.205

Keywords:

Flow Separation, NACA-23018, Dimple, Angle Of Attack (AoA, Airfoil

Abstract

The objective of this research is to examine the influence of surface modification on the aerodynamic performance of a NACA-23018 airfoil. Semi-circular dimples, each measuring 10 mm in diameter, were implemented on the upper surface at 75% of the chord length from the leading edge to mitigate boundary layer detachment. Experimental investigations were performed in a subsonic wind tunnel featuring a test section of 600 × 305 × 300 mm³ across a spectrum of angles of attack. The results showed that the dimpled configuration delayed flow separation compared to the smooth airfoil, leading to improved stall characteristics and enhanced aerodynamic efficiency. It delayed stall from 10° to 18° and achieved a 4.23% increase in lift, up to a 1.4% improvement in lift-to-drag ratio, and up to an 11.1% reduction in drag.

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References

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