Low Reynolds Number Vertical Axis Wind Turbine for Mars

A low Reynolds number wind turbine is designed to extract the power from wind energy on Mars. As compared to solar cells, wind turbine systems have an advantage on Mars, as they can continuously produce power during dust storms and at night. The present work specifically addresses the design of a 500 W Darrieus-type straight-bladed vertical-axis wind turbine (S-VAWT) considering the atmospheric conditions on Mars. The thin atmosphere and wind speed on Mars result in low Reynolds numbers (2000–80000) representing either laminar or transitional flow over airfoils, and influences the aerodynamic loads and performance of the airfoils. Therefore a transitional model is used to predict the lift and drag coefficients for transitional flows over airfoils. The transitional models used in the present work combine existing methods for predicting the onset and extent of transition, which are compatible with the Spalart-Allmaras turbulence model. The model is first validated with the experimental predictions reported in the literature for an NACA 0018 airfoil. The wind turbine is designed and optimized by iteratively stepping through the following tasks: rotor height, rotor diameter, chord length, and aerodynamic loads. The CARDAAV code, based on the “Double-Multiple Streamtube” model, is used to determine the performances and optimize the various parameters of the straight-bladed vertical-axis wind turbine.

[1]  Hans Bernhoff,et al.  Design of a 12kW vertical axis wind turbine equipped with a direct driven PM synchronous generator , 2006 .

[2]  R..  THRESHOLD-OF-MOTION WIND FRICTION SPEEDS AT THE MARS PATHFINDER LANDING SITE , 2001 .

[3]  Hongxing Yang,et al.  The ultra-low Reynolds number airfoil wake , 2010 .

[4]  Wassim Basha.  Accurate drag prediction for transitional external flow over airfoils , 2006 .

[5]  H. Haslach.  Wind Energy: a Resource for a Human Mission to Mars , 1989 .

[6]  R. E. Sheldahl,et al.  Aerodynamic Characteristics of Seven Symmetrical Airfoil Sections Through 180-Degree Angle of Attack for Use in Aerodynamic Analysis of Vertical Axis Wind Turbines , 1981 .

[7]  Farooq Saeed,et al.  Inverse Airfoil Design Method for Low-Speed Straight-Bladed Darrieus-Type VAWT Applications , 2011 .

[8]  Nicholas Jenkins,et al.  Wind Energy Technology , 1997 .

[9]  D. Thomas,et al.  Wind as a Geological Process on Earth, Mars, Venus and Titan , 1988 .

[10]  Tuncer Cebeci.  An Engineering Approach to the Calculationof Aerodynamic Flows , 1999 .

[11]  Shigeru Sunada,et al.  Airfoil Section Characteristics at a Low Reynolds Number , 1997 .

[12]  Wassim A. Basha,et al.  Drag Prediction in Transitional Flow Over Airfoils , 2007 .

[13]  R. Templin.  Aerodynamic performance theory for the NRC vertical-axis wind turbine , 1974 .

[14]  Mats Wahl.  Designing an H-rotor type Wind Turbine for Operation on Amundsen-Scott South Pole Station , 2007 .

[15]  L. Landberg,et al.  Aspects Of The Atmospheric Surface Layers On Mars And Earth , 2002 .