Synthetic Jet Actuators for Synthetic Jet Actuators for Aerodynamic ControlAerodynamic ControlResearch Internships in Science and EngineeringResearch Internships in Science and Engineering

University of Maryland, College Park, MDUniversity of Maryland, College Park, MD

Jeffrey D. BennettJeffrey D. Bennett Trinity UniversityTrinity University

Allison K. JonesAllison K. JonesRose-Hulman Institute of TechnologyRose-Hulman Institute of Technology

Anita W. LeungAnita W. LeungUniversity of MichiganUniversity of Michigan

Colleen E. RainboltColleen E. RainboltPurdue UniversityPurdue University

Objectives Objectives

BackgroundBackground MethodsMethods

Actuator designActuator designPressure analysisPressure analysisControl algorithmControl algorithmWind tunnel testingWind tunnel testing

ResultsResults AnalysisAnalysis ConclusionConclusion

BackgroundBackground What is a synthetic jet?What is a synthetic jet?

Previous Research

•Smith, B. L. and Glezer, A., 1997

•Lachowizc, J. T. Yao. C-S, and Wlezien, R. W., 1998

•Rathnasingham, R. and Breuer, K. S., 1996

•Hassan, A. A. and JanakiRam, R. D., 1998

BackgroundBackground What is a Micro Air Vehicle (MAV)?What is a Micro Air Vehicle (MAV)?

Project GoalsProject Goals Explore the applications of synthetic jet actuators to the control of the flow about Micro Air Vehicles with the final goal of providing improved aerodynamic performance and flight control

Study the use of synthetic jets for aerodynamic control in a range of fluid dynamic regimes

Perform flow visualization techniques to aid in understanding the interaction effects in arrays of synthetic jets.

Wing DesignWing Design

Airfoil: NACA 0012

Wing Dimensions: 3” x 6”

Shell Fabrication Method:

Sand wings

Bake in mold

Cover with fiberglass

Bake in mold

Remove core

Pressure Tap DesignPressure Tap Design

Designed taps to transfer pressure Designed taps to transfer pressure from airflow over the wing to a from airflow over the wing to a pressure reading devicepressure reading device

Pressure tap design #1 Pressure tap design #2

Actuator DesignActuator Design

Diaphragm attached to Diaphragm attached to individual airfoil sectionsindividual airfoil sections

Actuators designed to:Actuators designed to: Be smallBe small Produce ample Produce ample

displacementdisplacement

Actuator Design #1

Various exit nozzles

What is a PZT?What is a PZT?

Lead Zirconium TitanateLead Zirconium Titanate Ceramic MaterialCeramic Material Expands and contracts with applied AC voltage Expands and contracts with applied AC voltage Prior work demonstrated PZT as useful driver Prior work demonstrated PZT as useful driver

for synthetic jetsfor synthetic jets

Wing FabricationWing Fabrication

Wing sections connected Wing sections connected with threaded rodwith threaded rod

Actuators share common Actuators share common groundground

Covered in fiberglass Covered in fiberglass shell (not shown)shell (not shown)

Control System DesignControl System DesignAllow for precise data acquisition

User varies:

On/Off states

Amplitude

Frequency

Simulink algorithm

dSPACE controls

Control System BenefitsControl System Benefits

Actuators

Flow

WingSurface

Actuators

Actuators

Flow

WingSurface

Roll Control

Varied Jet Control

Locating Resonance FrequenciesLocating Resonance Frequencies

Actuator Resonance

0

1

2

3

4

5

6

1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000

Frequency (Hz)

Xfe

rDat

Actuator 1

Actuator 2

Actuator 3

Actuator 4

Actuator 5

Actuator 6

Actuator 7

Actuator 8

Flow VisualizationFlow Visualization

Using flow visualization, the bubble was observed at 14º angle of attack In theory, using synthetic jet actuators will keep flow attached at higher angles of attack

MeasurementsMeasurements

Applied force causes strain gages produce a voltage drop

Allows measurement of lift and drag

Wind Tunnel SetupWind Tunnel SetupSetup #1

Open wind tunnel

Wing mounted vertically

Setup #2

Closed test section

Wing mounted horizontally

Electronics Setup

Digital pressure sensor

Variable gain amplifiers

Digital multimeters

Function generator

ResultsResults Constructed testable Constructed testable

airfoilairfoil Collected data in wind Collected data in wind

tunnels, varying:tunnels, varying: frequenciesfrequencies angles of attackangles of attack exit nozzle diameterexit nozzle diameter

Pressure vs. Distance at 175 Hz [α=2°,6°,10°]

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0 0.5 1 1.5 2 2.5

Pressure Tap Distance, in.

Pres

sure

, Cp

α=6

α=10

α=6, piezos

α=10, piezos

a=2

a=2, piezos

a=18

a=18,piezos

a=20

a=20, piezos

Lift vs. Angle of Attack (355 Hz)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0 5 10 15 20 25 30

Angle of Attack in degrees

Lif

t in

lb

s

Without Piezos

With Piezos

Theoretical

AnalysisAnalysis

Some collected data disagreed significantly with Some collected data disagreed significantly with theoretical valuestheoretical values

Actuator effects were often indiscernible from Actuator effects were often indiscernible from signal noisesignal noise

Drag vs. Angle of Attack (175 Hz)

0.0000

0.1000

0.2000

0.3000

0.4000

0.5000

0.6000

0 5 10 15 20 25 30

Angle of Attack in Degrees

Dra

g in

lbs

Without Piezos

With Piezos

Theoretical

ConclusionsConclusions

More testing needed to determine the More testing needed to determine the effect of synthetic jet actuators effect of synthetic jet actuators

More sensitive equipment needed to test More sensitive equipment needed to test on small scaleon small scale

Gained experience in such areas as:Gained experience in such areas as: Wind tunnel testingWind tunnel testing Prototype design and constructionPrototype design and construction Modern research methods and techniquesModern research methods and techniques

Future Work Future Work

Different actuator designDifferent actuator design Multiple rows of actuatorsMultiple rows of actuators Vary exit nozzlesVary exit nozzles

ShapeShape SizeSize AngleAngle

Different pressure sensing apparatusDifferent pressure sensing apparatus Implement fuzzy logic and/or neural networks Implement fuzzy logic and/or neural networks

into the controlsinto the controls

Contact InformationContact Information

Jeffrey D. BennettJeffrey D. Bennett ---- Jeffrey.bennett@trinity.eduJeffrey.bennett@trinity.eduTrinity UniversityTrinity UniversityEngineering SciencesEngineering Sciences

Allison K. Jones -- Allison K. Jones -- Allison.k.jones@rose-hulman.eduAllison.k.jones@rose-hulman.eduRose-Hulman Institute of TechnologyRose-Hulman Institute of TechnologyPhysics and Applied Continuous MathematicsPhysics and Applied Continuous Mathematics

Anita W. Leung -- Anita W. Leung -- awleung@umich.eduawleung@umich.eduUniversity of MichiganUniversity of MichiganAerospace EngineeringAerospace Engineering

Colleen E. Rainbolt -- Colleen E. Rainbolt -- rainbolt@purdue.edurainbolt@purdue.eduPurdue UniversityPurdue UniversityAerospace EngineeringAerospace Engineering