PIEZOELECTRIC SHEAR WAVE INDUCED ANTI-ICING SYSTEM

1、Rotorcraft Center of ExcellenceDepartment of Aerospace EngineeringPIEZOELECTRIC SHEAR WAVE INDUCED ANTI-ICING SYSTEMPIs: Dr. Edward C. Smith, Professor of Aerospace EngineeringDr. Joseph L. Rose, Professor of Engineering MechanicsGraduate Students: Jose L. PalaciosHuidong GaoRotorcraft Center of Exc

2、ellenceThe Pennsylvania State University, PA 16802April, 2005ROTORCRAFT CENTER OF EXCELLENCERotorcraft Center of ExcellenceDepartment of Aerospace EngineeringThe icing tanker provides simulated test conditions throughout the test envelope required for icing certification (Sikorsky Artificial Icing T

3、ests)Glaze Ice Encountered During Test(Icing Research Tunnel NASA Glenn)Liquid Water Content: 0.1 to 3 g/m3Temperature: = 00 C to -200 CBackgroundRotorcraft Center of ExcellenceDepartment of Aerospace EngineeringRime Ice: Low water vapor concentration (0.5 1.0 g/m3) Water droplets freeze on impact S

4、mooth 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 edgeRotor

5、craft Aerodynamics in Icing ConditionsHigh collection efficiency of rotor: Higher rotor velocity collects more water droplets per second (ice accretes under icing conditions)Vibrations due to mass unbalanceIce shedding Premature transition & Separation of flow around the bladeChange in the profi

6、le 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 Iceb) Glaze IceTemperature, airspeed or liquid water content increaseAIRFOILAIRFOILTypical Rotor Blade Ice

7、Fragments found in the GroundRotorcraft Center of ExcellenceDepartment of Aerospace EngineeringELECTROTHERMAL DE-ICINGHeavy system Large electrical power consumption Melted ice may flow aft and refreeze further Qualified by the FAA and the DodFast erosion of metallic leading-edge protections caps Su

8、bstitution by erosion resistant composite plastic leading-edgePlastic materials have low thermal conductivity Not suitable to work with thermal de-icing systems due to melting and delamination of the materialPNEUMATIC DE-ICINGLight weight Inexpensive High engine torque requirementNegligible electric

9、al power requirements Fast erosion of the blade leading edge boots ICE REMOVAL DURINGBOOT INFLATIONOther Methods Explored: FLUID ANTI-ICING ELECTRO-IMPULSE DE-ICING ELECTRO-VIBRATORY DE-ICING HIGH FREQUENCY MICROWAVE ANTI/DE-ICINGAnti/De-Icing Solutions For RotorcraftRotorcraft Center of ExcellenceD

10、epartment of Aerospace EngineeringAnti/De-Icing Solutions For RotorcraftElectro-ThermalFluidPneumaticElectro-ImpulseVibratoryApplication to DateIn ProductionFlight TestedBeing EvaluatedFeasibility StudyUnder DevelopmentWeight (lbs)16219454120120Ice AccretionYesNoYesYesYesKW Power Requirement26Neglig

11、ibleNegligible3.01.3Performance Effects10% Torque IncreaseNo Penalty10% Torque Increase10% Torque Increase10% Torque IncreaseRunback PotentialYesNoNoNoNoDetached Ice ImpactYesNoYesYesYesBell Model412 (6800 lb)Ice Thickness 0.3 in.Ref: Coffman, H.J., “Helicopter Rotor Icing Protection Methods”Limited

12、 by Fluid on BoardRotorcraft Center of ExcellenceDepartment of Aerospace EngineeringAnti-Icing Leading Edge Shear Actuator Conceptual DesignsSubstitute with Shear Piezoelectric Tube Segments poled along longitudinal direction, P2 Electric field applied in the width direction, E1aaaDead Leading Edge

13、Mass (10 20% Weight of the Blade)aaaInsert Embedded Shear Actuators12Rotorcraft Center of ExcellenceDepartment of Aerospace Engineering2 Frequency Ranges to Study:Frequency Ranges to Study1) Standing wave vibration: 0 Hz up to fifth natural frequency of the system2) Shear horizontal waves (SHW): 18

14、KHz up to 20 MHzFrequency (Hz)Amplitude Response (Deg.)300 Volts inputAnalytical Model and Experimental Results 144 in. AL. TubeAnalytical EOMExperimentalDispersion Curves for a 1mm. Think ice layer on an Aluminum PlateTheoretical calculations (Rose et al): SHW create interface shear stresses of 0.5

15、GPa. Chu et al: typical adhesive shear strength of glaze ice is 0.4MPa Rotorcraft Center of ExcellenceDepartment of Aerospace EngineeringInitial Approach Standing Wave VibrationaaPZT ActuatorAluminum TubeRotorcraft Center of ExcellenceDepartment of Aerospace Engineering20 Psi Pressurized Air Liquid

16、Nitrogen Bath Cooper Coil Super Cooled Air Radiator PZT Shear Actuator Aluminum TubeMotivation Icing Static TestRotorcraft Center of ExcellenceDepartment of Aerospace EngineeringPiezoelectric ActuatorMotivation Icing Static TestFrequency (Hz)Amplitude (Deg.)FRF: W1 = 436 HzRotorcraft Center of Excel

17、lenceDepartment of Aerospace EngineeringMotivation Icing Static TestGenerate a model to efficiently experimentally test the prototype under icing conditions in future workRotorcraft Center of ExcellenceDepartment of Aerospace EngineeringIntroduction of a new shear induced rotorcraft anti-icing conce

18、ptual design Low weight penaltyNo heat degradation of plastic/composite materialsConduction of icing environment motivation experiments (Vibration Range):6 Aluminum tube actuated by Shear TubeTemperature: - 250 CIce accretion was prevented by actuator (System 1st natural frequency, standing wave ran

19、ge)Input voltage of 300 VoltsStrains generated up to 90 -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% errorsElectrical mecha

20、nical coupled EOM accurately predict the behavior of the actuatorDevelopment of analytical tools for SHW ultrasonic rangesSummary of Preliminary StudiesRotorcraft Center of ExcellenceDepartment of Aerospace EngineeringExperimental validation of predicted ultrasonic shear horizontal wave (SHW) behavi

21、or 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 patchExperimentally observe the generated waves using Electromagnetic Transducers (EMAT) Experimental selection of optimum fre

22、quency and phase velocity for anti-icing purposesTheoretical 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 boundingObjective:Form accreted ice to a substrate plate using th

23、e liquid nitrogen cooling radiatorObserve 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 interfaceImplementation of presented ultrasonic anti-icing sy

24、stem to composite and plastic protection leading edge capsCold wind tunnel and hover stand icing testing on proposed ultrasonic induced shear anti-icing systemCold Chamber with rotor stand at Penn StateFatigue integrity testsDelamination of composite rotorsDepoling of shear actuators at larger numbe

25、r of cycles (greater than 2 x 108 cycles)Proposed Future WorkRotorcraft Center of ExcellenceDepartment of Aerospace EngineeringShear horizontal ultrasonic waves in a solid isotropic elastic media formal solution X1X2X3IceFeoWave propagation21)(231kctxxikkkeBua21)(3231)(kctxxikkkkeikBamasUltrasonic S

26、HW Theory2u32kDisplacement FieldStress FieldEigen values obtained from Christoffels Equation kBUndetermined Coefficients for the Partial Waves K Wave number along the x1 direction Corresponding Phase Velocity of the Wave cSolved from BcsRotorcraft Center of ExcellenceDepartment of Aerospace Engineer

27、ingICEd15 Shear Motion+-THERMOMETERSUPERCOOLED AIR FROM LIQUID NITROGEN RADIATORProposed Initial Approach Shear Horizontal WavesPoling DirectionWidth Applied VoltageEMAT SENSORRotorcraft Center of ExcellenceDepartment of Aerospace EngineeringContact: Edward C. SmithECS5PSU.EDU Rotorcraft Center of ExcellenceDepartment of Aerospace EngineeringCoffman, 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 Candsda