Bansal, A

Holmes, AS

Howey, DA

English

D A Howey

A Bansal

A S Holmes

Crossref

Smart Materials and Structures

Design and performance of a centimetre-scale shrouded wind turbine for energy harvesting

Spiral - Imperial College Digital Repository

Design and performance of a cm-scale shrouded wind turbine for energy harvesting

A miniature shrouded wind turbine aimed at energy harvesting for power delivery to wireless sensors in pipes and ducts is presented. The device has a rotor diameter of 2 cm, with an outer diameter of 3.2 cm, and generates electrical power by means of an axial-flux permanent magnet machine built into the shroud. Fabrication was accomplished using a combination of traditional machining, rapid prototyping, and flexible printed circuit board technology for the generator stator, with jewel bearings providing low friction and start up speed. Prototype devices can operate air speeds down to 3 ms⁻¹, and deliver between 80 μW and 2.5 mW of electrical power at air speeds in the range 3-7 ms⁻¹. Experimental turbine performance curves, obtained by wind tunnel testing and corrected for bearing losses using data obtained in separate vacuum run-down tests, are compared with the predictions of an elementary blade element momentum (BEM) model. The two show reasonable agreement at low tip speed ratios. However, in experiments where a maximum could be observed, the maximum power coefficient (~9%) is marginally lower than predicted from the BEM model and occurs at a lower than predicted tip speed ratio of around 0.6

Howey, David A.

Bansal, Anshu

Holmes, Andrew S.

Oxford University Research Archive

A miniature shrouded wind turbine aimed at energy harvesting for power delivery to wireless sensors in pipes and ducts is presented. The device has a rotor diameter of 2cm, with an outer diameter of 3.2cm, and generates electrical power by means of an axial-flux permanent magnet machine built into the shroud. Fabrication was accomplished using a combination of traditional machining, rapid prototyping, and flexible printed circuit board technology for the generator stator, with jewel bearings providing low friction and start up speed. Prototype devices can operate at air speeds down to 3 ms-1, and deliver between 80νW and 2.5mW of electrical power at air speeds in the range 3-7 ms-1. Experimental turbine performance curves, obtained by wind tunnel testing and corrected for bearing losses using data obtained in separate vacuum run-down tests, are compared with the predictions of an elementary blade element momentum (BEM) model. The two show reasonable agreement at low tip speed ratios. However, in experiments where a maximum could be observed, the maximum power coefficient (∼9%) is marginally lower than predicted from the BEM model and occurs at a lower than predicted tip speed ratio of around 0.6. © 2011 IOP Publishing Ltd

Howey, David

A miniature shrouded wind turbine aimed at energy harvesting for power delivery to wireless sensors in pipes and ducts is presented. The device has a rotor diameter of 2 cm, with an outer diameter of 3.2 cm, and generates electrical power by means of an axial-flux permanent magnet machine built into the shroud. Fabrication was accomplished using a combination of traditional machining, rapid prototyping, and flexible printed circuit board technology for the generator stator, with jewel bearings providing low friction and start up speed. Prototype devices can operate air speeds down to 3 ms⁻¹, and deliver between 80 μW and 2.5 mW of electrical power at air speeds in the range 3-7 ms⁻¹. Experimental turbine performance curves, obtained by wind tunnel testing and corrected for bearing losses using data obtained in separate vacuum run-down tests, are compared with the predictions of an elementary blade element momentum (BEM) model. The two show reasonable agreement at low tip speed ratios. However, in experiments where a maximum could be observed, the maximum power coefficient (~9%) is marginally lower than predicted from the BEM model and occurs at a lower than predicted tip speed ratio of around 0.6.The full-text of this article is not available in ORA, but you may be able to access the article via the publisher copy link on this record page. N.B. Dr Howey is now based at the Energy and Power Group, Engineering Faculty, University of Oxford and St Hilda's College, University of Oxford

Oxford University Research Archive (ORA)

ORA - Oxford University Research Archive

https://ora.ox.ac.uk/objects/uuid:80f8e817-0dc7-45ae-afc0-7830850938f8/files/m5a51b622c31097f2275b353494dbe819

Design and performance of a cm-scale shrouded wind turbine for energy harvesting

Abstract

Similar works

Full text

Available Versions

Crossref

Spiral - Imperial College Digital Repository

Oxford University Research Archive

Oxford University Research Archive

Oxford University Research Archive (ORA)

ORA - Oxford University Research Archive

Oxford University Research Archive (ORA)