Drag Reduction Using Riblet Film Applied to Airfoils for Wind Turbines

sections of the airfoil in order to determine the optimal riblet location in terms of drag reduction. Results showed that the magnitude of drag reduction depended on the angle of attack, Reynolds number, riblet size, and riblet location. For some congurations, riblets produced signicant drag reduction of up to 5%, while for others riblets were detrimental. Trends in the results indicated an optimum riblet size of 62- m for the range of Reynolds numbers at which tests were conducted. The airfoil chord was 18 in (0.457 m). Results also showed that each riblet size performed best at a given Reynolds number with the optimal Reynolds number decreasing with an increase in riblet size.

[1]  P. R. Viswanath,et al.  Turbulent drag reduction using riblets on a supercritical airfoil at transonic speeds , 1995 .

[2]  M. Drela.  XFOIL: An Analysis and Design System for Low Reynolds Number Airfoils , 1989 .

[3]  W. A. Timmer,et al.  Summary of the Delft University Wind Turbine Dedicated Airfoils , 2003 .

[4]  J. Spurk.  Boundary Layer Theory , 2019, Fluid Mechanics.

[5]  S. Sundaram,et al.  Viscous Drag Reduction Using Riblets on NACA 0012 Airfoil to Moderate Incidence , 1996 .

[6]  Channa Raju,et al.  Base Drag Reduction Caused by Riblets on a GAW(2) Airfoil , 1998 .

[7]  J. L. Tangler,et al.  NREL airfoil families for HAWTs , 1995 .

[8]  William H. Rae,et al.  Low-Speed Wind Tunnel Testing , 1966 .

[9]  P. R. Viswanath,et al.  Aircraft viscous drag reduction using riblets , 2002 .

[10]  J M Caram,et al.  Effect of riblets on turbulence in the wake of an airfoil , 1991 .

[11]  M. J. Walsh,et al.  Optimization and application of riblets for turbulent drag reduction , 1984 .

[12]  M. J. Walsh,et al.  Riblets as a Viscous Drag Reduction Technique , 1983 .

[13]  Wolf-Ernst Reif,et al.  On the Drag Reduction of the Shark Skin , 1985 .

[14]  M. J. Walsh,et al.  Turbulent boundary layer drag reduction using riblets , 1982 .

[15]  S. Sundaram,et al.  Drag Reduction Due to Riblets on a GAW(2) Airfoil , 1999 .

[16]  P. Viswanath.  Riblets on airfoils and wings - A review , 1999 .

[17]  Fabrication of a micro-riblet film and drag reduction effects on curved objects , 2003, TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664).

[18]  Michael S. Selig,et al.  Wind Turbine Performance Under Icing Conditions , 1998 .

[19]  Sam Lee,et al.  Effects of Supercooled Large -Droplet Icing on Airfoil Aerodynamics , 2001 .