Advanced Infrared Thermography Data Analysis for Unsteady Boundary Layer Transition Detection

Christoph Mertens, C. Christian Wolf, Anthony D. Gardner, Ferdinand Schrijer, Bas van Oudheusden

Research output: Contribution to journalArticleScientificpeer-review

10 Citations (Scopus)
37 Downloads (Pure)


Advanced data processing methods for detecting unsteady boundary layer transition in periodic aerodynamic processes by means of infrared thermography measurements are presented. The thermal radiation emitted from the heated suction surface of a pitching airfoil model in subsonic flow is measured with an infrared camera. The unsteady boundary layer transition location is detected by analyzing the difference in the infrared radiation signal over short periods of time with differential infrared thermography (DIT). The DIT method is optimized and automated in the present study, which facilitates the extension of the part of the motion period where valid DIT transition measurements are produced. Additionally, a new infrared thermography data processing method is introduced in this study. The extraction of the extrema of the measured radiation signal at fixed locations on the model surface yields instants of the motion period that relate to the occurrence of boundary layer transition. The local infrared thermography (LIT) approach can be extended to measuring the two-dimensional unsteady boundary layer transition front.
Original languageEnglish
Article number015301
Number of pages13
JournalMeasurement Science and Technology
Issue number1
Publication statusPublished - 2020

Bibliographical note

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project
Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.


  • unsteady aerodynamics
  • boundary layer transition
  • wind tunnel testing
  • pitching airfoil model
  • infrared thermography
  • data analysis


Dive into the research topics of 'Advanced Infrared Thermography Data Analysis for Unsteady Boundary Layer Transition Detection'. Together they form a unique fingerprint.

Cite this