Center for Acoustics and Vibration

1
Center for Acoustics and Vibration
Rotorcraft Acoustics and Dynamics Group
Activities
Edward C. Smith, Professor Director, Penn State
Vertical Lift Research Center
2007 CAV Workshop
2
Presentation Outline

• Group Highlights
• Individual Project Highlights
• Ultrasonic Shear Wave Anti-Icing

3
Vertical Lift Research Center Goals

• 1) Focus research personnel and facilities on
• timely solution of 21st century technical
• barrier problems
• 2) Provide an exciting and effective educational
• environment to train the next generation
• of rotorcraft engineers
• Collaborate with industry and government
  agencies
• stimulate vertical lift development comm.
  acceptance
• Form partnerships with outstanding universities
• around the country to strengthen our
  technical
• scope and germinate

4
Research Thrusts
PSU Team Technology Strengths
Advanced materials for improved rotor and
drivetrain systems
VLRCOE Thrust Areas
Parallel computations for coupled aeroacoustics
aeromechanics
Aeromechanics Material Strength Fatigue
Adverse Weather/Environment Rotor/Flight
Controls Vibration and Noise Control
Prognostics Diagnostics Propulsion
Affordability
Innovative and effective educational initiatives
Active sound and vibration control techniques
quieter and safer
Health and Usage Monitoring Systems
Guided waves and ultrasonics
Advanced flight controls for improved safety and
pilot workload
5
Vertical Lift Center Tech Base
25 Faculty
40 ContinuingEducationStudents(Short course)
40GraduateStudents
100 UndergraduateStudents(Freshman Sem, AHS
Chapter,Senior Class, Design projects)
6
Interaction with Other PSU Research Centers
ARL
Condition Based Maintenance Dept.
ARL
Vertical Lift Research Center of Excellence
ARL iMAST
7
2007 Group Highlights

• - New US Army VLRCOE Award
• - New (Expanded) US Navy Research Grant
• - New NASA Projects

8
New VLRCOE Research Projects
Interactional Aerodynamics for Noise Prediction
of Heavy Lift Configurations (Brentner,
Rajagopalan, Long)
Prediction of Acoustic Scattering and Nonlinear
Propagation for Heavy Lift Rotorcraft (Brentner,
Morris)
Overset Grid/Gridless Methods for Fuselage and
Rotor Wakes (Duque)
Aero Improvements in Tip/Casing of Ducted Fans
for UAVs and Vertical Lift Systems (Camci)
9
New VLRCOE Research Projects
Structures and Materials Concepts for
Lightweight, Composite Rotor Blades (Bakis,
Koudela, Smith)
Next Generation Carbon-Nanotube Composites for
Mechanical Properties Enhancement and Real-Time
Structural Health Monitoring (Koratkar,
Schadler)
10
New VLRCOE Research Projects
Rotor Blade Anti-Icing and Erosion Protection
Systems (Smith, Rose, Camci)
Flight Control Design for Rotorcraft with
Variable Rotor Speed (Horn)
Miniature Trailing-Edge Effectors (Active
Gurneys) for Rotor Performance and Aeromechanics
(Gandhi, Maughmer, Lesieutre)
11
New VLRCOE Research Projects
Advanced Dynamic Modeling and Analysis of
Rotorcraft Planetary Gears (Parker, Bill)
Software Engineering for Reduced Cost Avionics
(Leach)
Life Cycle Cost Models
12
Naval Vertical Lift Research Center
Naval research priorities will include -
Enhanced performance of maritime based
rotorcraft lower deck footprint safer
more robust shipboard DI operations advanced
tiltrotor technologies - Enhanced Safety and
Survivability through basic science
advances reduced exposure to threats (sea
based and urban USMC operations)
crash protection systems (land and sea)
active control systems for reduced pilot
workload
13
Naval Vertical Lift Research Center

• - Innovative concept exploration Concept
  feasibility
• simulation, enabling technologies
• Variable diameter rotors
• Variable speed rotors
• Shrouded rotor configurations
• Etc. (evolving concepts )
• - Complement and leverage Army VLRCOE, NASA
• NRA, and industry investments

Propulsion and Drive systems
Aeromechanics Vibration Control Diagnostics
and CBM
14
2006 ONR Program
15
2007 ONR Program
Additional projects based on Mid and Far term
Navy ST needs (e.g. Roadmap, personnel, fill
DoD gaps) Students -
Crashworthy systems SMA mounts 1 -
Rotor Loads Control Forward flight 1 -
Variable speed/geometry rotor perf 1 -
Fancraft Wind Tunnel Test CFD 2 -
Fancraft Rotor Analysis Design 1 -
Fancraft Aeroacoustics Simulation 1 Will
trigger additional PSU cost share on graduate
students Total US Navy ONR Program 800K / year
16
Penn State 6.1 Contributions to Ducted
Fan/FANCRAFT RD

• 1. Flight Dynamics and Simulation
• Aerodynamics tests and CFD Models
• Noise prediction control
• Rotor system design and tailoring
• 5. Aeroacoustic Simulation

ONR 6.1 Funds ONR Cong. Mark
17
2006 NASA RFA Program

• 2 selected proposals from NASA Glenn Research
  Center
• Integrated Propulsion System Modeling
• (Wang, Smith, Bill, DeSmidt _at_ Univ of Tennessee)
• Gearbox Windage Loss CFD
• (Kunz, Morris, Long)
• Approx 450K per year total x 3 years
• (5-6 graduate students)
• - January 2007 starts

18
New Start CRI and Industry Programs

• Damper Modeling (Bell, LORD Corp)
• Drive Systems (PURDY Corp)
• Rotor Blade Anti-Icing (Bell)
• Flexible Composite Driveshafts (Bell, Boeing,
  CRI)
• Rotor System Damage Detection x 3 (CRI)
• Shipboard Flight Simulation and Controls
  (Sikorsky, CRI)

19
Presentation Outline

• Group Highlights
• Individual Project Highlights
• Ultrasonic Shear Wave Anti-Icing

20
Rotor Blade Anti-Icing
Protection Systems
Project Task PS 1.6

• PIs Edward Smith
• Joseph Rose
• [phone], ecs5_at_engr.psu.edu
• Graduate Students
• Jose Palacios (started Dec 2006 PhD)
• Yun Zhu (started Dec 2006 PhD)
• CAV WORKSHOP
• May, 2007

Palacios, Smith, Zhu, Dept. of Aerospace
Engineering
21
Background/Problem Statement

• Rotorcraft Icing Characteristics
• High collection efficiency of rotor
• - Higher rotor velocity collects more water
  droplets per second
• Vibrations due to mass unbalance
• Ice shedding
• Premature transition Separation of flow around
  the blade
• Change in the profile drag over very short
  periods of time
• ? torque required increase
• Undesired vibrations changes in the
• handling of the vehicle
• ? flight conditions dangerous

Typical Rotor Blade Ice Fragments found in the
Ground
Glaze Ice Encountered During Test (Icing Research
Tunnel NASA Glenn)
22
Background/Problem Statement

• ELECTROTHERMAL DE-ICING
• Only system qualified by the FAA and the DoD
• Heavy system (4 Blades 12,000 lbs Model gt160
  lbs.)
• Does not allow for continuous application due to
  high power consumption
• Large electrical power consumption (4 Blades
  12,000 lbs Model gt20 KW)
• Allows ice accretion up to 0.3 in (10 Torque
  Increase)
• Melted ice may flow aft and refreeze further
• Difficult to integrate with polymer
  erosion-resistant materials

In 1987 only 9 rotorcraft had electrothermal
blade deicing capabilities (Coffman, H.J.,
Helicopter Rotor Icing Protection Methods,
Journal of the American Helicopter Society, Vol.
32, No. 2, April 1987) Aerospatiale SA-330 Bell
UH-1H Bell 412 Bell 214st Boeing Vertol 234
Hughes Boeing AH-64 MBB BO-105 Sikorsky UH-60
Westland Wessex 5 20 Years later Still using
only electrothermal systems (e.g. V-22, EH101,
S-92 etc)
23
Project Objectives

• To develop and explore the feasibility of a novel
  non-thermal anti-icing system based on ultrasonic
  guided waves
• Challenges
• Develop and validate analytical design tools
• Experimental data of ice adhesion strength
• Light-weight, low-power actuator
• Integration of actuator in realistic rotor blades
• Testing

24
Anti-Icing Conceptual Design (2004-2006)
1
2
Leading Edge Mass (10 20 Weight of the Blade)
a
a
a
a
O
Substitute with Shear Piezoelectric Tube
a
Insert Embedded Shear Actuators
(Centolanza, Smith 2000)
Flow Control PSU Damage Detection Rose, Smith,
Wang, Conlon CRI

• Segments poled along longitudinal direction, P2
• Electric field applied in the width direction, E1

25
Local Anti-Icing (2006)
1 mm Thick Aluminum Plate with a 2 mm Ice Layer
ICE
Aluminum
Ice
THERMOMETER
Ultrasonic SH Wave Proof of Concept Design
26
Ice Adhesion Bonding Strength (2006)
70 Reduction on Ice Adhesion
Experimental and Theoretical Ultrasonic
Resonance Within 3
Shear Stress (MPa)
Actuator Generates Larger Interface Stresses at
Resonance
Test
Shear Strength Required to De-Bond 1 in2 of Ice
Accreted to Aluminum
Adhesion Strength (MPa)
Frequency (KHz)
27
Proof of Concept Global Anti-Icing (Year 1)
1.5 mm thick AL plate with 1 mm ice layer
Resonance PZT
ISCC
Plate Dimensions are wavelength multiple ensure
constructive interference
Aluminum
Ice
28
Global De-Icing (Year 1)
x10 Microscopic Amplification
Actuator Off
ACTUATOR ON
29
Proof of Concept ISCC (Year 1)
Ice Layer is completely detached
Lamb Wave Dispersion Curves for a 9mm Aluminum
Plate with 3mm Ice Layer
Lamb Wave Dispersion Curves for a 2mm Aluminum
Plate with 3mm Ice Layer
Lamb Wave Dispersion Curves for a 2mm Aluminum
Plate with 3mm Ice Layer
Lamb Wave Dispersion Curves for a 9mm Aluminum
Plate with 3mm Ice Layer
Fracture mechanics are not involved in
delaminating accreted ice
42KHz Transducer is not as effective on thicker
plates
Shear Stress Model
30
Study of ISCC Effects with Power (Year 1)

• As the Lamb wave power increases, the ice
  adhesion failure time decreases

1.5mm Ice Thickness
Ice Removal Time (Sec.)
31
ISCC Effects with Ice Thickness (Year 1)

• As the ice thickness increases, the ice adhesion
  failure time decreases
• This phenomena can be explained theoretically
  from the wave structure
• calculated for the different ice thickness
  scenarios

2 mm Ice Layer
1 mm Ice Layer
4 mm Ice Layer
1.5 mm Aluminum Plate
1.5 mm Aluminum Plate
Ice Removal Time (Sec.)

• Shear wave structure 1 and 2 mm accreted ice on a
  1.5 mm AL plate
• The ice-AL interface shear stress increases with
  ice thickness

3 mm Ice Layer
32
Summary

• Accomplishments Year 1 (2006 - 2007)
• Development of analytical tools to predict
  interface
• shear stress coefficients (ISCC) between
  accreted ice
• and a host structure
• Development of FEM to model piezoelectric
  actuators
• Proof-of-concept experiments of global anti-icing
• Proof-of-concept experiments demonstrating ISCC
  concept
• Analytical model to calculate ultrasonic
  dispersion curves for composite plates