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

Colletti, Christopher

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

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

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 𝐶𝜇 when embedded in the SNLF S414 airfoil. The SNLF S414 airfoil was tested at 𝑅𝑒𝑐 = 1.8𝑥10^6 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 𝐶𝜇. 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

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

Copyright and License Information

Copyright 2019 Christopher Colletti

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