Feedback control of instability waves in a transitional flat-plate boundary layer

Y. Fukunishi, T. Sakai, K. Sasaki, S. Izawa, A. K. Xiong

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


A semi-automatic and active control of T-S waves and oblique waves in a transitional flat plate boundary layer is carried out in a wind-tunnel experiment and a numerical simulation. An array of piezo-ceramic actuators attached on a surface is used to generate counter waves that cancel the incoming instability waves. The actuator's operating amplitudes and phases are successively updated using the velocity fluctuations monitored downstream by a rake of hotwires. Experimental results show that the system is effective in weakening these waves when their inclination angles are less than 15 degrees. However, the system encountered difficulty in controlling the waves of large inclination angles. In the numerical simulation, it is shown that the control can be accomplished much easier. The numerical results show that controllability of the large inclination angle waves can be improved by shortening the spanwise length each actuator piece. The danger of pursuing this kind of research solely by a numerical simulation is pointed out.

Original languageEnglish
Pages (from-to)283-289
Number of pages7
JournalJournal of Visualization
Issue number3
Publication statusPublished - 2006
Externally publishedYes


  • Active Control
  • Feedback
  • Oblique Wave
  • T-S Wave
  • Transitional Boundary Layer

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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