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Sectional Prediction of 3D Effects for Separated Flow on Rotating Blades.

PB94201696

Publication Date	1992
Personal Author	Snel, H.; Houwink, R.; Piers, W. J.
Page Count	31
Abstract	A method is presented which allows the computation of air load coefficients for rotor blade sections at attached and separated flow conditions, including leading effects of blade rotation. The method consists of an existing computer code for 2D unsteady flow with strong viscous-inviscid interaction, in which the turbulent boundary layer integral method has been modified by including leading terms for steady 3D effects on a high aspect ratio rotating blade. A summary is presented of the approach made, and a first set of results are compared with wind-tunnel data for a wind-turbine model. Computed 2D polars and corresponding pressure distributions for a non-rotating and rotating blade section appear to be qualitatively similar to experimental data, including high values of the lift coefficient measured at 30% of the tip radius. For sufficient accuracy in practice, however, various aspects of the method need further analysis and improvement.
Keywords	Interactional aerodynamics Wind turbines Turbine blades Separated flow Aerodynamic coefficients Unsteady aerodynamics Aerodynamic stalling Pressure distribution Mathematical models Leading edges
Source Agency	Netherlands Participating Organizations
NTIS Subject Category	97O - Miscellaneous Energy Conversion & Storage 51A - Aerodynamics
Corporate Authors	National Aerospace Lab., Amsterdam (Netherlands).
Supplemental Notes	Presented at the European Rotorcraft Forum (18th), Avignon, France, September 15-18, 1992.
Document Type	Technical Report
NTIS Issue Number	199421

Sectional Prediction of 3D Effects for Separated Flow on Rotating Blades.

Sectional Prediction of 3D Effects for Separated Flow on Rotating Blades.
PB94201696

Publication Date	1992
Personal Author	Snel, H.; Houwink, R.; Piers, W. J.
Page Count	31
Abstract	A method is presented which allows the computation of air load coefficients for rotor blade sections at attached and separated flow conditions, including leading effects of blade rotation. The method consists of an existing computer code for 2D unsteady flow with strong viscous-inviscid interaction, in which the turbulent boundary layer integral method has been modified by including leading terms for steady 3D effects on a high aspect ratio rotating blade. A summary is presented of the approach made, and a first set of results are compared with wind-tunnel data for a wind-turbine model. Computed 2D polars and corresponding pressure distributions for a non-rotating and rotating blade section appear to be qualitatively similar to experimental data, including high values of the lift coefficient measured at 30% of the tip radius. For sufficient accuracy in practice, however, various aspects of the method need further analysis and improvement.
Keywords	Interactional aerodynamics Wind turbines Turbine blades Separated flow Aerodynamic coefficients Unsteady aerodynamics Aerodynamic stalling Pressure distribution Mathematical models Leading edges
Source Agency	Netherlands Participating Organizations
NTIS Subject Category	97O - Miscellaneous Energy Conversion & Storage 51A - Aerodynamics
Corporate Authors	National Aerospace Lab., Amsterdam (Netherlands).
Supplemental Notes	Presented at the European Rotorcraft Forum (18th), Avignon, France, September 15-18, 1992.
Document Type	Technical Report
NTIS Issue Number	199421