A simple digital-optical system to improve accuracy of hot-wire measurements

E. R. Gowree, C. J. Atkin, S. Gruppetta

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


A high precision traverse mechanism with micro-resolution was designed to capture accurately the velocity profile of the very thin turbulent attachment line on a swept body. To ensure that the traverse mechanism could position the hot wire reliably, a simple digital optical system was designed to check the performance of the traverse by measuring the displacement of the hot wire: a vertical displacement of 2.4 mu m was achievable and this could be further reduced to 0.6 mu m using micro-stepping. Due to the simplicity of the set-up it was equally useful for probe wall positioning and the velocity profiles captured clearly demonstrated that the optical set-up helped in resolving the near wall flow more accurately, regardless of the thinness of the boundary layer. The captured data compare well with the results from similar investigations, with arguably higher precision achieved.

Original languageEnglish
Article number095303
Number of pages12
JournalMeasurement Science and Technology
Issue number9
Publication statusPublished - Sep 2015
Externally publishedYes


  • optical
  • hot wire
  • probe wall position

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