Ability of the e-TellTale sensor to detect flow features over wind turbine blades: flow separation/reattachment dynamics

Monitoring the flow features over wind turbine blades is a challenging task that has become more and more crucial. This paper is devoted to demonstrate the ability of the e-TellTale sensor to detect the flow separation/reattachment dynamics over wind turbine blades. This sensor is made of a strip with a strain gauge sensor at its base. The velocity field was acquired using TR- PIV measurements over an oscillating thick blade section equipped with an e-TellTale sensor. PIV images were post-processed to detect movements of the strip, which was compared to movements of flow. Results show good agreement between the measured velocity field and movements of the strip regarding the separation/reattachment dynamics

Characterization of a Wind Tunnel for Use in Offshore Wind Turbine Development with Mitigation Measures for the Wall Effect of Proximal Structures

This thesis supports the development of the Harold Alfond W2 Ocean Engineering Laboratory constructed at the University of Maine through several investigations conducted with a one-third scale wind generation system. The scale wind generator is first tested in what is considered an open-circuit wind tunnel configuration to determine the influence proximal building walls of a facility housing such a device may have on the consistency and capacity of a wind generator. Turbine performance testing with the wind generator to identify any susceptibility to proximal wall influence is also conducted. This is of interest as the full-scale system will operate in different orientations within a rectangular building. Baseline wind generator performance and test turbine performance data in this configuration is established for use in comparison to alternative tunnel configurations. Additional investigations are carried out to determine the effectiveness of mitigation measures intended to reduce or eliminate any influence of proximal facility walls on wind generator performance. In these investigations any associated effects on wind generator performance and turbine performance testing must be understood. One alternative to the wind generator configuration is the conversion of the generator to a traditional wind tunnel, also known as a closed-circuit tunnel configuration, where the test flow is collected and reused by the tunnel making it immune to changes in orientation within the building. Active recirculation in the form of a bank of fans placed at the end of the test section is also investigated as an alternative method of masking the effects of nearby facility walls on wind generator and turbine testing performance. This thesis is organized into 4 chapters. Chapter 1 details the current state of the art of floating offshore wind turbine development; past efforts are discussed along with motivations for future testing endeavors. Chapter 2 outlines the experimental instrumentation and procedures used throughout this body of work. Chapter 3 chronicles the hardware used by the wind generator, its operation, and baseline data collected. Chapter 4 discusses the conversion of the wind generator in chapter 3 to a wind tunnel that is subjected to the same tests and turbine runs as the wind generator in a comparative study. This chapter also tests the sensitivity of the wind generation system, and associated turbine tests, to the intrusion of nearby facility walls. Chapter 4 also investigates the use of active recirculation as a way to mitigate any negative influence of facility infrastructure on the wind generation system. Chapter 5 summarizes the findings of this study

Detection, Diagnosis and Prognosis: Contribution to the energy challenge: Proceedings of the Meeting of the Mechanical Failures Prevention Group

The contribution of failure detection, diagnosis and prognosis to the energy challenge is discussed. Areas of special emphasis included energy management, techniques for failure detection in energy related systems, improved prognostic techniques for energy related systems and opportunities for detection, diagnosis and prognosis in the energy field

HPCCP/CAS Workshop Proceedings 1998

This publication is a collection of extended abstracts of presentations given at the HPCCP/CAS (High Performance Computing and Communications Program/Computational Aerosciences Project) Workshop held on August 24-26, 1998, at NASA Ames Research Center, Moffett Field, California. The objective of the Workshop was to bring together the aerospace high performance computing community, consisting of airframe and propulsion companies, independent software vendors, university researchers, and government scientists and engineers. The Workshop was sponsored by the HPCCP Office at NASA Ames Research Center. The Workshop consisted of over 40 presentations, including an overview of NASA's High Performance Computing and Communications Program and the Computational Aerosciences Project; ten sessions of papers representative of the high performance computing research conducted within the Program by the aerospace industry, academia, NASA, and other government laboratories; two panel sessions; and a special presentation by Mr. James Bailey

NASA patent abstracts bibliography: A continuing bibliography. Section 2: Indexes (supplement 39)

A subject index is provided for over 5000 patents and patent applications for the period May 1969 through June 1991. Additional indexes list personal authors, corporate authors, contract numbers, NASA case numbers, U.S. patent class numbers, U.S. patent numbers, and NASA accession numbers

NASA patent abstracts bibliography: A continuing bibliography. Section 2: Indexes (supplement 42)

A subject index is provided for over 4900 patents and patent applications for the period May 1969 through December 1992. Additional indexes list personal authors, corporate authors, contract numbers, NASA case numbers, U.S. patent class numbers, U.S. patent numbers, and NASA accession numbers

NASA patent abstracts bibliography: A continuing bibliography. Section 2: Indexes (supplement 41)

A subject index is provided for over 5200 patents and patent applications for the period May 1969 through June 1992. Additional indexes list personal authors, corporate authors, contract numbers, NASA case numbers, U.S. patent class numbers, U.S. patent numbers, and NASA accession numbers

NASA patent abstracts bibliography: A continuing bibliography. Section 2: Indexes (supplement 40)

A subject index is provided for over 5100 patents and patent applications for the period May 1969 through December 1991. Additional indexes list personal authors, corporate authors, contract numbers, NASA case numbers, U.S. patent class numbers, U.S. patent numbers, and NASA accession numbers

High Reynolds investigations on the ability of the full scale e-TellTale sensor to detect flow separation on a wind turbine blade section

Abstract. The complexity of the flow over a wind turbine blade makes its understanding and monitoring a challenging task, especially on operating wind turbines. The innovative e-Telltale sensor is developed for that purpose : detecting the flow separation on wind turbines blades. In this paper, high Reynolds wind tunnel tests have been performed with different configurations of full scale e-Telltale sensors and wall pressure measurements on a wind turbine blade section. A comparison between the lift curve and the e-Telltale signal was used to evaluate the ability of the sensor to detect flow separation. Results show different interesting properties of the sensor response depending on its size, position along the chord and its fitting process that could be used in real applications

NASA patent abstracts bibliography: A continuing bibliography. Section 2: Indexes (supplement 45)

A subject index is provided for over 5600 patents and patent applications for the period May 1969 through June 1994. Additional indexes list personal authors, corporate authors, contract numbers, NASA case numbers, U.S. patent class numbers, U.S. patent numbers, and NASA accession numbers