PIEZOELECTRIC SHEAR WAVE INDUCED ANTI-ICING SYSTEM
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Transcript of PIEZOELECTRIC SHEAR WAVE INDUCED ANTI-ICING SYSTEM
Rotorcraft Center of Excellence Department of Aerospace Engineering
PIEZOELECTRIC SHEAR WAVE INDUCED ANTI-ICING SYSTEM
PIs: Dr. Edward C. Smith, Professor of Aerospace EngineeringDr. Joseph L. Rose, Professor of Engineering Mechanics
Graduate Students: Jose L. Palacios
Huidong Gao
Rotorcraft Center of ExcellenceThe Pennsylvania State University, PA 16802
April, 2005
ROTORCRAFT CENTER OF EXCELLENCE
Rotorcraft Center of Excellence Department of Aerospace Engineering
The icing tanker provides simulated test conditions throughout the test
envelope required for icing certification (Sikorsky Artificial Icing Tests)
Glaze Ice Encountered During Test(Icing Research Tunnel NASA Glenn)
•Liquid Water Content: 0.1 to 3 g/m3
•Temperature: = 00 C to -200 C
Background
Rotorcraft Center of Excellence Department of Aerospace Engineering
Rime Ice: Low water vapor concentration (0.5 – 1.0 g/m3) Water droplets freeze on impact Smooth streamlined, white opaque layers High surface roughness
Glaze Ice: High water concentrations (1.5 – 3.0 g/m3)Water droplets do not freeze upon contact: travel back in the chord direction Has a stronger influence on the lift and drag Irregular ice horns structures created on the leading edge
Rotorcraft Aerodynamics in Icing Conditions•High collection efficiency of rotor:
Higher rotor velocity collects more water droplets per second (ice accretes under icing conditions)
•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 and changes in the handling of the vehicle flight conditions critically dangerous
Rotorcraft Icing
a) Rime Ice
b) Glaze Ice
Temperature, airspeed or liquid water content
increase
AIRFOIL
AIRFOIL
Typical Rotor Blade Ice Fragments found in the
Ground
Rotorcraft Center of Excellence Department of Aerospace Engineering
ELECTROTHERMAL DE-ICING• Heavy system • Large electrical power consumption • Melted ice may flow aft and refreeze further • Qualified by the FAA and the Dod• Fast erosion of metallic leading-edge protections caps
Substitution by erosion resistant composite plastic leading-edge• Plastic materials have low thermal conductivity
Not suitable to work with thermal de-icing systems due to melting and delamination of the material
PNEUMATIC DE-ICING• Light weight • Inexpensive • High engine torque
requirement• Negligible electrical power requirements • Fast erosion of the blade
leading edge boots
ICE REMOVAL DURINGBOOT INFLATION
Other Methods Explored:• FLUID ANTI-ICING• ELECTRO-IMPULSE DE-ICING• ELECTRO-VIBRATORY DE-ICING• HIGH FREQUENCY MICROWAVE ANTI/DE-ICING
Anti/De-Icing Solutions For Rotorcraft
Rotorcraft Center of Excellence Department of Aerospace Engineering
Anti/De-Icing Solutions For Rotorcraft
Electro-Thermal Fluid Pneumatic Electro-
Impulse Vibratory
Application to Date In Production Flight Tested Being
EvaluatedFeasibility
StudyUnder
Development
Weight (lbs) 162 194 54 120 120
Ice Accretion Yes No Yes Yes Yes
KW Power Requirement 26 Negligible Negligible 3.0 1.3
Performance Effects
10% Torque Increase No Penalty
10% Torque Increase
10% Torque Increase
10% Torque Increase
Runback Potential Yes No No No No
Detached Ice Impact Yes No Yes Yes Yes
Bell Model412 (6800 lb)
Ice Thickness
0.3 in.
Ref: Coffman, H.J., “Helicopter Rotor Icing Protection Methods”
Limited by Fluid on Board
Rotorcraft Center of Excellence Department of Aerospace Engineering
Anti-Icing Leading Edge Shear Actuator Conceptual Designs
Substitute with Shear Piezoelectric Tube
• Segments poled along longitudinal direction, P2
• Electric field applied in the width direction, E1
a’
Ω a’
a’
Dead Leading Edge Mass (10 – 20% Weight of the Blade)
a a’ a
Insert Embedded Shear Actuators
1 2
Rotorcraft Center of Excellence Department of Aerospace Engineering
2 Frequency Ranges to Study:
Frequency Ranges to Study
1) Standing wave vibration: 0 Hz up to fifth natural frequency of the system
2) Shear horizontal waves (SHW): 18 KHz up to 20 MHz
Frequency (Hz)
Am
plitu
de R
espo
nse
(Deg
.)
300 Volts input
Analytical Model and Experimental Results 144 in. AL. Tube
Analytical EOMExperimental
Dispersion Curves for a 1mm. Think ice layer on an Aluminum Plate
Theoretical calculations (Rose et al): SHW create interface shear stresses of 0.5GPa.
Chu et al: typical adhesive shear strength of glaze ice is 0.4MPa
Rotorcraft Center of Excellence Department of Aerospace Engineering
Initial Approach Standing Wave Vibration
a’
Ω a’
PZT Actuator
Aluminum Tube
Rotorcraft Center of Excellence Department of Aerospace Engineering
20 Psi Pressurized Air Liquid Nitrogen Bath
Cooper Coil
Super Cooled Air Radiator
PZT Shear Actuator
Aluminum Tube
Motivation Icing Static Test
Rotorcraft Center of Excellence Department of Aerospace Engineering
Piezoelectric Actuator
Motivation Icing Static Test
Frequency (Hz)
Am
plitu
de (D
eg.) FRF: W1 = 436 Hz
Rotorcraft Center of Excellence Department of Aerospace Engineering
Motivation Icing Static Test
Generate a model to efficiently experimentally test the prototype under icing conditions in future work
Rotorcraft Center of Excellence Department of Aerospace Engineering
• Introduction of a new shear induced rotorcraft anti-icing conceptual design – Low weight penalty– No heat degradation of plastic/composite materials
• Conduction of icing environment motivation experiments (Vibration Range):– 6’’ Aluminum tube actuated by Shear Tube– Temperature: - 250 C– Ice accretion was prevented by actuator (System 1st natural frequency, standing wave
range)– Input voltage of 300 Volts– Strains generated up to 90 μ-strains (Shear Stress of 2.6 MPa)
• Formulation and experimental validation of an analytical tool to model the system (Vibration Range)
– Uncoupled EOM do not predict the actuators behavior: 1st natural frequency predicted 70% errors
– Electrical – mechanical coupled EOM accurately predict the behavior of the actuator
• Development of analytical tools for SHW ultrasonic ranges
Summary of Preliminary Studies
Rotorcraft Center of Excellence Department of Aerospace Engineering
• Experimental validation of predicted ultrasonic shear horizontal wave (SHW) behavior – SHW generate 2 orders of magnitude higher shear stress than standing waves (Vibration Range)– Objective:
• Induce horizontal shear waves on a plate using a shear piezoelectric patch• Experimentally observe the generated waves using Electromagnetic Transducers (EMAT)
• Experimental selection of optimum frequency and phase velocity for anti-icing purposes
– Theoretical calculations predicts that for ice layer thicknesses from 0.3 mm to 0.8 mm, the 2nd mode of the SHW will generate high shear stresses (0.5 GPa), sufficient to affect the ice bounding
– Objective:• Form accreted ice to a substrate plate using the liquid nitrogen cooling radiator• Observe the effects of SHW to the ice bounding strength via ice detection system (visual, infrared system, or
ultrasonic guided wave (Rose 1999))
• Measurement of generated shear stresses at the ice-substrate interface
• Implementation of presented ultrasonic anti-icing system to composite and plastic protection leading edge caps
• Cold wind tunnel and hover stand icing testing on proposed ultrasonic induced shear anti-icing system
– Cold Chamber with rotor stand at Penn State
• Fatigue integrity tests– Delamination of composite rotors– Depoling of shear actuators at larger number of cycles (greater than 2 x 108 cycles)
Proposed Future Work
Rotorcraft Center of Excellence Department of Aerospace Engineering
Shear horizontal ultrasonic waves in a solid isotropic elastic media formal solution
X1
X2 X3
Ice
Fe
o
Wave propagation
∑=
−+=2
1
)(2
31
k
ctxxikk
keBu α
∑=
−+=2
1
)(32
31)(k
ctxxikkk
keikB αμασ
Ultrasonic SHW Theory
2u
32σ
kα
Displacement Field
Stress Field
Eigen values obtained from Christoffel’s Equation
kB Undetermined Coefficients for the Partial Waves
K Wave number along the x1 direction
Corresponding Phase Velocity of the Wave
cSolved from Bc’s
Rotorcraft Center of Excellence Department of Aerospace Engineering
ICE
d15 Shear Motion
+
-THERMOMETER
SUPERCOOLED AIR FROM LIQUID NITROGEN
RADIATOR
Proposed Initial Approach Shear Horizontal Waves
Poling Direction
Width Applied Voltage
EMAT SENSOR
Rotorcraft Center of Excellence Department of Aerospace Engineering
Contact: Edward C. Smith
Rotorcraft Center of Excellence Department of Aerospace Engineering
• Coffman, H.J., “Helicopter Rotor Icing Protection Methods,” Bell Helicopter Textron Inc., Fort Worth Texas. Journal of the American Helicopter Society 1987
• Gent, R.W., Dart, N.P., and Candsdale, J.T., “Aircraft Icing,” Defense Evaluation and Research Agency, Farnborough, Hampshire GU14 OLX, UK, The royal Society, 2000
• Flemming, R.J., “The Past Twenty Years of Icing Research and Development at Sikorsky Aircraft,” 40th AIAA Aerospace Sciences Meeting, January 14th 2002
• M.C. Chu, and R.J.Scavuzzo, Adhesive Shear Strength of Impact Ice, AIAA Journal, Vol. 29, No. 11, November (1991), 1921-1926
• Bragg, M.B., Bassar, T., Perkins, W. R., Selig, M. S., Voulgaris, P. G., and Melody, J. W., “Smart Icing Systems for Aircraft Icing Safety,” AIAA Aerospace Science Meeting January 14th 2002
• J. L. Rose and Lvis E. Soley, “Ultrasonic guided wave for anomaly detection in aircraft components”, Material Evaluation, Sep. 2000, 1080-1086
• J. L. Rose, D. D. Hongerholt, G.. Williams, “Ultrasonic In-Flight Ice Detection,”
• J. L. Rose, Ultrasonic waves in solid media, Cambridge university press, Cambridge, (1999).
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