Feasibility of using dynamically oscillating surfaces to control Tollmien-Schlichting waves
Author
Dell'Orso, HaleyOther Contributors
Amitay, Michael; Sahni, Onkar; Hicken, Jason;Date Issued
2016-08Subject
Mechanical engineeringDegree
MS;Terms of Use
This electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.; Attribution-NonCommercial-NoDerivs 3.0 United StatesMetadata
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This work characterizes and controls Tollmien-Schlichting (T-S) waves by means of Piezoelectrically-Driven Oscillating Surface (PDOS) actuators, using Particle Image Velocimetry (PIV). A parametric study of PDOS actuator design parameters was conducted and a 0.79 mm thick rubber surface with a 12.7 mm diameter circular dimple, a cavity height of 2 mm, and a neck height of 2 mm was selected for implementation in T-S wave control over a flat plate. Two circular PDOS actuators were used to excite and control the most amplified frequency of the T-S wave on a flat plate. The actuators were placed at the mid-span of a flat plate at two streamwise locations of x/L = 0.18 and x/L = 0.28 downstream from the leading edge, where the free-stream velocity was U = 16 m/s. The upstream actuator was used to excite and phase-lock the T-S waves at an excitation frequency of fact = 250 Hz (corresponding to the most amplified frequency of the T-S wave, based on linear stability analysis), and the downstream PDOS was used to mitigate the T-S wave by driving it at an anti-phase with the appropriate amplitude. Time- and phase-averaged flow fields were acquired at two downstream interrogation domains. The first window of data, taken in between the two PDOS actuators, explored the effect of the excitation amplitude on the magnitude of the excited T-S waves. At the second window, located downstream of both PDOS actuators, the simultaneous activation of both actuators at an appropriate phase shift and amplitudes resulted in a significant reduction or augmentation of the T-S waves, depending on the phase shift between the two actuators.;Description
August 2016; School of EngineeringDepartment
Dept. of Mechanical, Aerospace, and Nuclear Engineering;Publisher
Rensselaer Polytechnic Institute, Troy, NYRelationships
Rensselaer Theses and Dissertations Online Collection;Access
CC BY-NC-ND. Users may download and share copies with attribution in accordance with a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License. No commercial use or derivatives are permitted without the explicit approval of the author.;Collections
Except where otherwise noted, this item's license is described as CC BY-NC-ND. Users may download and share copies with attribution in accordance with a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License. No commercial use or derivatives are permitted without the explicit approval of the author.