Active flow control of laminar boundary layers for variable flow conditions

作者：Simon B^*; Nernitz T; Rohlfing J; Fischer F; Mayer D; Grundmann S

来源：International Journal of Heat and Fluid Flow, 2015, 56: 344-354.

DOI：10.1016/j.ijheatfluidflow.2015.09.003

• Laminar flow control
• Active wave cancelation
• Plasma actuator
• fxLMS
• Adaptive secondary path

This work investigates the stability of a fxLMS controller for active wave cancelation of broad-band Tollmien-Schlichting disturbances in a flat plate boundary-layer with a single DBD plasma actuator. In particular the influence of a changing free stream velocity and the resulting off-design operation of the control algorithm is analyzed up to an unstable behavior. As the main reason for unstable controller operation in the off-design case the difference between actual and predicted phase angle of the disturbances at the position of the error sensor is identified. A method for an online adjustment of the secondary-path model to different free-stream velocities is presented. Finally a wall-bounded method based on the disturbances phase speed is developed that can cope with changes of the physical secondary path not only due to changes of the free-stream velocity but also due to changes of the pressure distribution. This method enables the extension of the stable operation range of the control system significantly.

• 出版日期2015-12