1. TASK 1.2b MINIATURE TRAILING EDGE EFFECTORS FOR ROTORCRAFT APPLICATIONS PRINCIPAL INVESTIGATORS GEORGE LESIEUTRE MARK MAUGHMER MICHAEL KINZEL MICHAEL THIEL GRADUATE RESEARCH ASSISTANTS GARY KOOPMANN EARL DUQUE

2. BACKGROUND: “REAL” GURNEY FLAPS

3. BACKGROUND MINIATURE TRAILING-EDGE EFFECTORS (MiTEs) - MOVABLE TABS, PARTIAL SPAN - CONSIDERED BY VanDam, Eaton, others MiTEs HAVE POTENTIAL TO IMPROVE - ROTOR PERFORMANCE INCREASE MAX LIFT TO REDUCE RETREATING-BLADE STALL REDUCE COMPRESSIBILITY EFFECTS ON ADVANCING SIDE - VIBRATION CONTROL SPANWISE & AZIMUTHAL LIFT DISTRIBUTIONS TECHNICAL BARRIERS ACTUATION (4/REV => 20 Hz FREQ.) DYNAMIC PERFORMANCE NOT UNDERSTOOD ROTOR PERFORMANCE EFFECTS

4. OBJECTIVES EXPLORE UTILITY OF ACTIVE GURNEY FLAPS APPROACHES: AERODYNAMIC UNDERSTANDING: EXPERIMENTAL: 2D STATIC / DYNAMIC NUMERICAL: 2D STATIC / DYNAMIC POTENTIAL FOR ROTORCRAFT: FLIGHT PERFORMANCE – IMPROVED PREDICTION METHODS IMPLEMENTATION: ACTUATION EXPECTED RESEARCH RESULTS: AERODYNAMIC EFFECTS OF SIZE AND LOCATION BETTER UNDERSTANDING OF GURNEY FLAP PHYSICS DETERMINE EFFECTS ON ROTOR PERFORMANCE DEVELOP VIABLE ACTUATION METHODS OBTAIN DYNAMIC WIND-TUNNEL DATA

5. EXPERIMENT: TRANSITION FIXED AT 5%c

6. EXPERIMENT: GURNEY LOCATION AND SIZE GF HEIGHT 0.005c 0.01c 0.02c

7. NUMERICAL INVESTIGATION: CFD STREAKLINES

9. AERODYNAMIC MODELING OF MiTES: MACH NUMBER AERO. EFFECTS FOR A GURNEY FLAP CONSISTENT WHEN CONSIDERING  ’

10. AERODYNAMIC MODELING OF MiTES: INDICIAL RESPONSE AND HARIHARAN-LEISHMAN UNSTEADY FLAPPED AIRFOIL MODEL AVERAGED INDICIAL RESPONSE IS SIMILAR TO PLAIN FLAP ALLOW THE INVESTIGATION OF UNSTEADY PLAIN- FLAPPED AIRFOIL THEORIES

11. AERODYNAMIC MODELING OF MiTES: UNSTEADY FLAPPED AIRFOIL MODEL APPLIED TO MiTES k=0.14, M=0.1,  =0deg k=0.5, M=0.6,  =0deg

12. AERODYNAMIC MODELING OF MiTES: UNSTEADY FLAPPED AIRFOIL - DYNAMIC STALL MODEL DYNAMIC STALL MODEL UNSTEADY FLAPPED AIRFOIL MODEL CFD – OVERFLOW2

13. EFFECT OF MiTE POSITION: VORTEX STREET FORMS CREATES HIGH FREQ. OSCILLATIONS TRAILING EDGE PLACEMENT AGREES WELL WITH THEODORSEN CIRCULATORY THEORY UPSTREAM PLACEMENT HAS LARGE DYNAMIC LOADS AND INCREASED LAGS (a) (b)

14. PERFORMANCE ANALYSIS: OPTIMAL DEPLOYMENT STRATEGY REASONABLE FOR STEADY ASSUMPTIONS, BUT NOT WHEN UNSTEADY AERO. AND DYN. STALL ARE CONSIDERED

15. PERFORMANCE ANALYSIS: FORWARD FLIGHT

16. PERFORMANCE ANALYSIS: MiTE DEPLOYMENT

17. PERFORMANCE ANALYSIS: FORWARD FLIGHT WITH VARIATIONS IN AIRFOIL TRANSITION RADIUS

18. NOTE: DEPLOYMENT IS SCHEDULED TO MINIMIZE PITCHING MOMENT PERFORMANCE ANALYSIS: EFFECT OF MiTE DRAG TO PERFORMANCE ENHANCEMENT

19. ACTUATOR DESIGN DESIGN FOR AERODYNAMIC BENEFITS –OPERATING FREQUENCIES OF 4 – 5 Hz APPLY TO A VR-12 AIRFOIL –HEIGHT: 0.01c –LOCATION: 0.9c Fig. from Johnson, W., Helicopter Theory

20. AERODYNAMIC FORCE ON THE FLAP Re = 4x10 6 M = 0.45 HEIGHT: 0.02c PER UNIT SPAN ONLY DRAG ACCURATELY MODELED

21. ACTUATOR ISSUES DESIGN CONSIDERATIONS SIZE CONSTRAINTS TOTAL WEIGHT FREQUENCY REQUIREMENTS CENTRIFUGAL FORCES ACTUATION METHODS UNDER CONSIDERATION LINEAR DC ACTUATORS (VOICE COILS) PIEZOELECTRIC ROTARY/STEPPER MOTORS VR-12 AIRFOIL ~14” CHORD

22. FLAP ACTUATION: AMPLIFIED PIEZO BENDER FpFp MhMh Piezoelectric Bender Coupler TAPERED PIEZO BENDER LEVER AMPLIFIER REQUIREMENTS QUASISTATIC DISP. > 0.36” RESONANT FREQ > 20 Hz (4/rev) MODELS PIEZO BEAM FOR DISP. R-R FOR RESONANCE FREQ.

23. LINEAR DC ACTUATORS MOVING COIL (NCC) –MORE FORCE –HEAVIER Motion MOVING MAGNET (NCM) –LESS FORCE –LIGHTER

24. TESTING OF NCC ACTUATOR - LASER VELOCIMETER USED - BROADER FREQUENCY RANGE NEEDED

25. CURRENT CONCEPT CURRENT CONCEPT FOR NCC ACTUATOR LOCATE AS FAR AFT AS POSSIBLE SIMILAR DESIGN FOR THE NCM ACTUATOR OPTIMAL DIMENSIONS NEEDED

26. REFINE SIMULATION MODEL BUILD PROTOTYPE OF NCC ACTUATOR TEST NCM ACTUATOR DEVELOP DESIGNS FOR OTHER ACTUATOR TYPES (i.e. PIEZO) DETERMINE COMPARISON CRITERIA DETERMINE OPTIMAL INPUT SIGNAL DEVELOP METHODS TO TEST UNDER CF LOADS ACTUATION DESIGN - IMMEDIATE FUTURE

27. ACCOMPLISHMENTS WIND-TUNNEL MEASUREMENTS OF GURNEY FLAPS (2002) CFD PREDICTION OF GURNEY FLAP PERFORMANCE (2003) ACTUATION CONCEPTS EXPLORED (2002) DYNAMIC CFD CALCULATIONS (2003-2004) ROTOR PERFORMANCE ANALYSIS (2003-2004) –INCLUDE DYNAMIC STALL MODEL –CONSIDER UNSTEADY MiTE MODEL INVESTIGATE MODELING UNSTEADY AERO. OF MiTES (2004) MORE EXTENSIVE ACTUATION METHODS EXPLORED (2004-2005) –LINEAR DC ACTUATORS –PIEZOELECTRIC BUILD MODELS OF ACTUATION SYSTEMS WIND-TUNNEL VERIFICATION OF ACTUATION METHODS EXTEND ACTUATION DESIGN TO FULL-SCALE ROTOR BLADE 2005-2006 PLANS

28. PUBLICATIONS Maughmer, M., Lesieutre, G., Thepvongs, S., Anderson, W, Kinzel, M., “Miniature Trailing-Edge Effectors for Rotorcraft Applications”, AHS 59th Forum, Phoenix, AZ, May 2003. Kinzel, M., “Miniature Trailing-Edge Effectors for Rotorcraft Applications,” Mindbend 2004 Student Conference, University Park, PA, April 2004. Kinzel, M.P., “Miniature Trailing-Edge Effectors for Rotorcraft Applications,” M.S. Thesis, Dept. of Aerospace Eng., Penn State University, University Park, PA, 2004. Kinzel, M.P, Maughmer, M.D, Lesieutre, G.L, Duque, E.P.N, "Numerical Investigation of Miniature Trailing-Edge Effectors on Static and Oscillating Airfoils," AIAA Paper No. 2005-1039, 2005. Thiel, M., “Actuation of an Active Gurney Flap for Rotorcraft Applications,” Mindbend 2005 Student Conference, University Park, PA, April 2005. Maughmer, M., Lesieutre, G., Kinzel, M., “Miniature Trailing-Edge Effectors for Rotorcraft Performance Enhancement”, AHS 61th Forum, Grapevine, TX, June 2005. FUTURE RESEARCH NEEDS DEVELOPMENT OF UNSTEADY AERO. MODELS FOR THE UPSTREAM PLACEMENT OF MITES DYNAMIC WIND-TUNNEL DATA COMPREHENSIVE ROTOR PERFORMANCE / APPLICATION ANALYSES HIGH-FREQUENCY ACTUATION DESIGN MITE SPECIFIC AIRFOIL DESIGN OTHER POTENTIAL BENEFITS OF MITES FOR ROTORCRAFT

29. MiTE SCHEDULE TASKS 20012002 2004 2005 STAGE ONE WT TEST WITH FIXED GURNEY FLAP CFD SOLUTIONS (FLUENT) MODEL ACTUATOR DESIGN STAGE TWO TRANSONIC CFD SOLUTIONS ROTOR PERFORMANCE SPECAILIZED CFD (OVERFLOW) STAGE THREE DEVELOP FULL SCALE ACTUATORS DYNAMIC WT TESTING SHORT TERM LONG TERM COMPLETE 2003 2006