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Conference programme 

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Poster session

Lead Session Chair:
Stephan Barth, Managing Director, ForWind - Center for Wind Energy Research, Germany
John Obrecht Siemens, United States
Co-authors:
John Obrecht (1) F P Jennifer Frankland (1) Alonso Zamora (1) Justin Creaby (1)
(1) Siemens Wind Power, Boulder, CO, United States

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Poster
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Presenter's biography

Biographies are supplied directly by presenters at OFFSHORE 2015 and are published here unedited

Dr. Obrecht has been a Research & Development Engineer with Siemens Wind Power for the past 6 years, working in areas associated with the design and validation of wind turbine blades. Most recently, his work has been focused on rotor validation, utilizing the highly-instrumented Siemens test turbine located at the National Wind Technology Center in Boulder, CO.

Abstract

Measurement of Vortex Shedding from Flatback Airfoils on Wind Turbine Blades

Introduction

Vortex shedding is a known aerodynamic flow-field phenomenon that occurs in the wake of a blunt body’s trailing edge, such as that of a flatback airfoil. This phenomenon can add challenges to wind turbine blade design, as the periodic changes in pressure around the airfoil can introduce problematic loads to wind turbine blades. This measurement campaign set out to investigate this phenomenon on an industrial-scale wind turbine in the field.

Approach

This measurement campaign looked into measuring vortex shedding on a flatback airfoil of a wind turbine blade through the use of a highly-instrumented test turbine (SWT-2.3-108) at the National Wind Technology Center in Boulder, CO. Pressure measurements were made around the flatback airfoil, with a particular interest in the pressure fluctuations on the trailing edge of the airfoil, where vortex shedding occurs.

Main body of abstract

Vortex shedding is a known aerodynamic flow-field phenomenon that occurs in the wake of a blunt body’s trailing edge, such as that of a flatback airfoil. This phenomenon was directly measured on a Siemens wind turbine (SWT-2.3-108) at the National Wind Technology Center in Boulder, CO. Pressure taps placed along the trailing edge of a flatback airfoil were used to measure flow-field pressure fluctuations that were consistent with vortex shedding. Such measurements showed excellent agreement with theoretical models and CFD simulations, demonstrating a clear understanding of vortex shedding on flatback airfoils.

Conclusion

Pressure taps placed along the trailing edge of a flatback airfoil were used to measure flow-field pressure fluctuations that were consistent with vortex shedding. Such measurements showed excellent agreement with theoretical models and CFD simulations, demonstrating a clear understanding of vortex shedding on flatback airfoils.


Learning objectives
This campaign set out to measure vortex shedding from flatback airfoils on an industrial-scale wind turbine to not only demonstrate the measurement capabilities and competence of pressure-tap measurement systems, but also to corroborate physical measurements of vortex shedding with computational models and theories.