Numerical study on the effect of vortex generator geometry and placement on single-blade performance in vertical axis current turbines
Volume
77
Issue number
4
Article number
77401
Received
17 June 2025
Received in revised form
13 March 2026
Accepted
16 March 2026
Available online
30 March 2026
Authors
Daif Rahuna1,2, I Ketut Aria Pria Utama 3,*, Erwandi Erwandi2, Dendy Satrio1
1Department of Ocean Engineering, Faculty of Marine Technology, Institut Teknologi Sepuluh Nopember (ITS), Surabaya 60111, Indonesia
2Research Center for Hydrodynamic Technology (PRTH), Research Organization for Energy and Manufacture (OREM), National Research and Innovation Agency (BRIN), Indonesia
3Department of Naval Architecture, Faculty of Marine Technology, Institut Teknologi Sepuluh Nopember (ITS), Surabaya 60111, Indonesia
Corresponding author email
Abstract
This study investigates the effect of adding vortex generators (VGs) to a single NACA 0021 blade applied in vertical axis current turbines (VACTs). The focus is on rectangular and trapezoidal VG shapes and their placement between 10 and 30 % of the chord length on the hydrofoil surface. CFD analyses were carried out under steady state conditions using the Reynolds-Averaged Navier–Stokes (RANS) approach, coupled with the k-ω SST turbulence model. The results demonstrate performance improvements of the hydrofoil with the inclusion of VGs. Specifically, rectangular VGs positioned at 10 % of the chord length increased the average lift coefficient (CL) by 31.5 % and reduced the average drag coefficient (CD) by 8 %. Similarly, trapezoidal VGs placed at 15 % of the chord length increased CL by 29.5 % and decreased CD by 7.1 %. Optimizing the geometry and placement of VGs can significantly enhance turbine efficiency by improving boundary layer control and delaying flow separation.
Keywords
Drag Coefficient (CD), Lift Coefficient (CL), NACA 0021, Rectangular VG, Trapezoidal VG