National Technical Reports Library

The National Technical Information Service acquires, indexes, abstracts, and archives the largest collection of U.S. government-sponsored technical reports in existence. The NTRL offers online, free and open access to these authenticated government technical reports. Technical reports and documents in its repository may be available online for free either from the issuing federal agency, the U.S. Government Publishing Office’s Federal Digital System website, or through search engines.

Details

Design and Experimental Results for the S825 Airfoil. Period of Performance: 1998-1999.

DE200515011673

Publication Date	2005
Personal Author	Somers, D. M.
Page Count	94
Abstract	A 17%-thick, natural-laminar-flow airfoil, the S825, for the 75% blade radial station of 20- to 40-meter, variable-speed and variable-pitch (toward feather), horizontal-axis wind turbines has been designed and analyzed theoretically and verified experimentally in the NASA Langley Low-Turbulence Pressure Tunnel. The two primary objectives of high maximum lift, relatively insensitive to roughness and low-profile drag have been achieved. The airfoil exhibits a rapid, trailing-edge stall, which does not meet the design goal of a docile stall. The constraints on the pitching moment and the airfoil thickness have been satisfied. Comparisons of the theoretical and experimental results generally show good agreement.
Keywords	Airfoils Design Wind turbines Roughness NASA Performance Wind power
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Airfoils, Inc., State College, PA.; Department of Energy, Washington, DC.; National Renewable Energy Lab., Golden, CO.
Supplemental Notes	Sponsored by National Renewable Energy Lab., Golden, CO. and Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200522

Design and Experimental Results for the S825 Airfoil. Period of Performance: 1998-1999.

Design and Experimental Results for the S825 Airfoil. Period of Performance: 1998-1999.
DE200515011673

Publication Date	2005
Personal Author	Somers, D. M.
Page Count	94
Abstract	A 17%-thick, natural-laminar-flow airfoil, the S825, for the 75% blade radial station of 20- to 40-meter, variable-speed and variable-pitch (toward feather), horizontal-axis wind turbines has been designed and analyzed theoretically and verified experimentally in the NASA Langley Low-Turbulence Pressure Tunnel. The two primary objectives of high maximum lift, relatively insensitive to roughness and low-profile drag have been achieved. The airfoil exhibits a rapid, trailing-edge stall, which does not meet the design goal of a docile stall. The constraints on the pitching moment and the airfoil thickness have been satisfied. Comparisons of the theoretical and experimental results generally show good agreement.
Keywords	Airfoils Design Wind turbines Roughness NASA Performance Wind power
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Airfoils, Inc., State College, PA.; Department of Energy, Washington, DC.; National Renewable Energy Lab., Golden, CO.
Supplemental Notes	Sponsored by National Renewable Energy Lab., Golden, CO. and Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200522