University of Illinois Urbana-Champaign

Investigating the frequency behavior of fluidic oscillators and their application as active flow control for an SNLF airfoil

Colletti, Christopher

Content Files
COLLETTI-THESIS-2019.pdf

Permalink

https://hdl.handle.net/2142/104907

Description

Title
Investigating the frequency behavior of fluidic oscillators and their application as active flow control for an SNLF airfoil
Author(s)
Colletti, Christopher
Issue Date
2019-04-24
Director of Research (if dissertation) or Advisor (if thesis)
Ansell, Phillip J.
Department of Study
Aerospace Engineering
Discipline
Aerospace Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Date of Ingest
2019-08-23T20:01:13Z
Keyword(s)
  • Fluidic Oscillator
  • S414
  • Active Flow Control
  • Aerodynamics
  • Natural Laminar Flow
  • Multi Element Airfoil
Abstract
This current study was performed to investigate the effect of geometric variation on the frequency behavior of fluidic oscillators. Fluidic oscillators are able to passively generate a self-induced, self-sustained sweeping planar jet that is highly dependent on internal geometries and inlet conditions. Frequency data was collected for 78 parametric variations of fluidic oscillators under different inlet conditions. A multi-variate non-linear regression procedure was used to build a model to predict the frequency behavior of a fluidic oscillator given a set of internal geometries and inlet conditions. The SNLF S414 airfoil is a multi-element airfoil with an open slot to promote a laminar boundary layer across the entire fore element and large portions of the aft element. Active unsteady flow control using embedded fluidic oscillators was identified as a potential source to improve the flow field and maximize the lift of a multi-element system like the SNLF S414. The predictive model was used to design a set of fluidic oscillators to reach desired non-dimensional frequencies and š¶šœ‡ when embedded in the SNLF S414 airfoil. The SNLF S414 airfoil was tested at š‘…š‘’š‘ = 1.8š‘„10^6 in a 3-ft x 4-ft low-speed, low-turbulence wind tunnel with fluidic oscillators embedded in the aft element at x/c = 0.7 and x/c = 0.8 and applied actuation at various š¶šœ‡. Two different configurations of the SNLF S414 airfoil were tested with and without the applied actuation at both locations. This data will be used to inform additional studies investigating multi-element SNLF style airfoils with unsteady active flow control.
Graduation Semester
2019-05
Type of Resource
text
Permalink
http://hdl.handle.net/2142/104907
Copyright and License Information
Copyright 2019 Christopher Colletti

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Graduate Dissertations and Theses at Illinois PRIMARY
Graduate Theses and Dissertations at Illinois
Dissertations and Theses - Aerospace Engineering