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Applied Aerospace Structures

MEMS 473 Aerospace StructuresGuest Lecture

Ricky Hollenbach, Ph.D. Student6 November 2019

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❑B.S. Mechanical Engineering at the University of Pittsburgh

❑ Certificate: Applied Simulation in Design

❑Minors: Mathematics and German

❑Ph.D. Student at Duke

❑ Certificates: College Teaching, Aerospace Engineering

❑Research at:

❑ Pitt

❑ Texas A&M

❑ Duke

❑ Internships at:

❑ Hydro Instruments

❑ Naval Nuclear Laboratory

❑ Rolls-Royce

Introduction

❑Review of In Class Structures

❑ Introduction to Aeroelasticity

❑Research in Academia

❑Aerospace Structures in Industry

❑Questions and Discussion

Agenda

Pre-Class Quiz with Kahoot!

Kahoot Quiz

Introduction

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Review of In Class Structures

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What have we studied?

❑Beams

❑Plates

❑Rings

❑Configurations of multiple members

❑ Trusses

❑ Frames

Review of In Class Structures

Where are they used?

-Get out a piece of paper

-Draw an airplane

-Point out potential structures

Review of In Class Structures

Inside A Jet Engine:

Review of In Class Structures

Rotors

Stators

Shaft

Nacelle

Inlet Guide Vanes

Struts

Fan

Review of In Class Structures

How do jet engines work:

Course Recommendation: MEMS 490 Power for Mechanical Systems

Review of In Class Structures

Review of In Class Structures

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Introduction to Aeroelasticity

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Introduction to Aeroelasticity

Collar’s Triangle

Introduction to Aeroelasticity

MEMS 473: Aerospace

Structures

Course Recommendation: MEMS 544: Advanced Vibrations

Collar’s Triangle

Introduction to Aeroelasticity

MEMS 472: Aircraft

Performance

Spring Course

Dr. Hall

Course Recommendation: MEMS 571: Aerodynamics

Collar’s Triangle

Introduction to Aeroelasticity

Campbell Diagram

Separated Flow Vibrations, Forced Response,

Nonsynchronous Vibrations, Flutter

Introduction to Aeroelasticity

Aeroelasticity

Flutter

Nonsynchronous Vibrations

Forced Response

Separated Flow Vibrations

Introduction to Aeroelasticity

Aeroelasticity

Flutter

Nonsynchronous Vibrations

Forced Response

Separated Flow Vibrations

Introduction to Aeroelasticity

Aeroelasticity

Flutter

Nonsynchronous Vibrations

Forced Response

Separated Flow Vibrations

Introduction to Aeroelasticity

Aeroelasticity

Flutter

Nonsynchronous Vibrations

Forced Response

Separated Flow Vibrations

Introduction to Aeroelasticity

Aeroelasticity

Flutter

Nonsynchronous Vibrations

Forced Response

Separated Flow Vibrations

Introduction to Aeroelasticity

“The cardinal rule of mechanical

vibrations is: separate the natural

frequency and excitation frequency.” – Dr.

Robert Kielb

In engines, the excitation

frequency is usually the rotor

speed.

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Research in Academia

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Research in Academia

Research in Academia 25

Near Tip, Pressure Side,

Near Leading Edge

9% low

Compressor Blade (C1) NSV

Experimental CFD

Research in Academia 26

❑Pressure Transducer Details

❑ 10 pressure transducers

❑ Omega PX163

❑ 13.84 v/psi (note that 1 psi = 6894.76 N/m2)

❑NACA 0012 Airfoil Details

Tang, D. , Dowell, E. H. 2014. “Experimental Aerodynamic Response for An Oscillating Airfoil in

Buffeting Flow.” AIAA Journal 52(6)

Research in Academia 27

❑ International Work:

❑ Presented in Paris

❑ 3 Stage Experimental Rig in Germany

Research in Academia

How do you absorb vibrations?

• Change excitation frequency

• Increase stiffness

• Decrease mass

• Add more damping

• Introduce an absorber

Research in Academia

Research in Academia

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Aerospace Structures in Industry

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Aerospace Structures in Industry

Rolls-Royce North America

❑Headquartered in Indianapolis, Indiana

❑14 buildings across the city

❑Jet engines only

❑Manufacturing, Design, Analysis,

HR and Business

Other Locations:

❑States: Virginia, Pittsburgh, California

and more

❑ International: UK, Germany, India, Japan, Singapore

Aerospace Structures in Industry

What Did I Do?

❑Defense

❑ Structural Systems Design

❑ Aeromechanics

❑ Me

❑Unsteady Aerodynamic Simulations using an in-house code AU3D

❑ Flutter

❑ Forced Response

Aerospace Structures in Industry

Linux Excel MATLAB

Aerospace Structures in Industry

Sensitivity Studies

Experimental Vibrations

Searchable Report

Database

Aeromechanics Course

Summer Projects

Aerospace Structures in Industry

Sensitivity Studies

Aerospace Structures in Industry

Experimental Vibrations

Aerospace Structures in Industry

Experimental Vibrations

Laser Displacement

Capture System

Part

Acoustic Excitation

System

Pressure Waves

Motion

Aerospace Structures in Industry

Aeromechanics Report

Database

Aeromechanics Training Course

Aerospace Structures in Industry

Acknowledgements

❑My Rolls-Royce Manager, Katy Sontag

❑My Aeromechanics Group

❑My Advisor, Dr. Kielb

❑Dr. Virgin

Questions and Discussion

❑Questions about:

❑Research in Aeroelasticity at Duke

❑Applying to Graduate School

❑Aeromechanics at Rolls-Royce

❑Applying for jobs and internships

Aeroelasticity

Flutter

Nonsynchronous Vibrations

Forced Response

Separated Flow Vibrations

Contact Information

❑Ricky Hollenbach❑richard.Hollenbach@duke.edu

❑189 Hudson Hall

❑people.duke.edu/~rlh55

❑https://aeroelasticity.pratt.duke.edu/