On-blade control of rotor vibration, noise, and performance: Just around the corner? The 33rd Alexander Nikolsky honorary lecture

Journal of the American Helicopter Society

Volumn 59, Issue 4, 2014, Pages

  Friedmann, Peretz P ^a  

^a UNIVERSITY OF MICHIGAN   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CONTROL SURFACES; NOISE ABATEMENT;

ACTIVE TWIST ROTOR; ACTIVE VIBRATION; ACTIVELY CONTROLLED FLAPS; AEROELASTIC RESPONSE; HIGHER HARMONIC CONTROL; INDIVIDUAL BLADE CONTROL; VIBRATION REDUCTIONS; WIND TUNNEL MODEL TESTS;

WIND TUNNELS;

EID: 84911191300     PISSN: 00028711     EISSN: None     Source Type: Journal    
DOI: 10.4050/JAHS.59.041001     Document Type: Review

References (182)

1. Reichert, G., "Helicopter Vibration Control - A Survey," Vertica, Vol. 5, (1), 1981, pp. 1-20.
2. Loewy, R. G., "Helicopter Vibrations: A Technological Perspective," Journal of the American Helicopter Society, Vol. 29, (4), October 1984, pp. 4-30.
3. Celi, R., "Recent Applications of Design Optimization to Rotorcraft - A Survey," Journal of Aircraft, Vol. 36, (1), January-February 1999, pp. 176-189.
4. Ganguli, R., "Survey of Recent Developments in Rotorcraft Design Optimization," Journal of Aircraft, Vol. 41, (3), May-June 2004, pp. 493-510.
5. Friedmann, P. P., "The Renaissance of Aeroelasticity and Its Future," Journal of Aircraft, Vol. 36, (1), 1999, pp. 105-121.
6. Bisplinghoff, R. L., Ashley, H., and Halfman, R., Aeroelasticity, Addison-Wesley, Cambridge, MA, 1955.
7. Bernhard, A. P. F., and Chopra, I., "Hover Testing of Active Rotor Blade-Tips Using Piezo-Induced Bending Torsion Coupled Beam," Journal of Intelligent Material Systems and Structures, Vol. 9, (12), 1998, pp. 963-974.
8. Cribbs, R., Friedmann, P. P., and Chiu, T., "Coupled Rotor/Flexible Fuselage Aeroelastic Model for Control of Structural Response," AIAA Journal, Vol. 38, (10), October 2000, pp. 1777-1788.
9. King, S. P., and Staple, A. E., "Minimization of Helicopter Vibration through Active Control of Structural Response," Rotorcraft Design Operations, CP-423, AGARD, October 1986.
10. Staple, A. E., "Evaluation of Active Control of Structural Response as a Means of Reducing Helicopter Vibration," American Helicopter Society 46th Annual Forum Proceedings, Washington, DC, May 21-23, 1990, pp. 3-17.
11. Staple, A. E., and Wells, D. M., "Development and Testing of an Active Control of Structural Response System for the EH101 Helicopter," Proceedings of the 16th European Rotorcraft Forum, Glasgow, UK, September 1990.
12. Welsh, W. A., von Hardenberg, P. C., von Hardenberg, P. W., and Staple, A. E., "Test and Evaluation of Fuselage Vibration Utilizing Active Control of Structural Response (ACSR) Optimized to ADS-27," American Helicopter Society 46th Annual Forum Proceedings, Washington, DC, May 21-23, 1990.
13. Millott, T. A., and Welsh, W. A., "Helicopter Active Noise and Vibration Reduction," Proceedings of the 25th European Rotorcraft Forum, Rome, Italy, September 14-16, 1999.
14. Kessler, C., "Active Rotor Control for Helicopters: Motivation and Survey on Higher Harmonic Control," CEAS Aeronautical Journal, Vol. 1, (1-4), September 2011, pp. 23-54.
15. McHugh, F. J., and Shaw, J., "Helicopter Vibration Reduction with Higher Harmonic Blade Pitch," Journal of the American Helicopter Society, Vol. 23, (4), October 1978, pp. 26-35.
16. Shaw, J., and Albion, N., "Active Control of the Helicopter Rotor for Vibration Reduction," Journal of the American Helicopter Society, Vol. 26, (3), July 1981, pp. 32-39.
17. Hammond, C. E., "Wind Tunnel Results Showing Rotor Vibratory Loads Reduction Using Higher Harmonic Blade Pitch," Journal of the American Helicopter Society, Vol. 28, (1), January 1983, pp. 10-15.
18. Molusis, J. A., Hammond, C. E., and Cline, J. H., "A Unified Approach to the Optimal Design of Adaptive and Gain Scheduled Controllers to Achieve Minimum Helicopter Rotor Vibration," Journal of the American Helicopter Society, Vol. 28, (2), April 1983, pp. 9-18.
19. Johnson, W., "Self-Tuning Regulators for Multicyclic Control of Helicopter Vibrations," NASA Technical Paper 1996, 1982.
20. Wood, E. R., Powers, R.W., Cline, J. H., and Hammond, C. E., "On Developing and Flight Testing a Higher Harmonic Control System," Journal of the American Helicopter Society, Vol. 30, (1), January 1985, pp. 3-20.
21. Achache, M., and Polychroniadis, M., "Higher Harmonic Control: Flight Tests of an Experimental System on a SA-349 Research Gazelle," American Helicopter Society 42nd Annual Forum Proceedings, Washington, DC, June 2-5, 1986.
22. Robinson, L. H., and Friedmann, P. P., "A Study of Fundamental Issues in Higher Harmonic Control Using Aeroelastic Simulation," Journal of the American Helicopter Society, Vol. 36, (2), April 1991, pp. 32-43.
23. McCloud, J. L., and Kretz, M., "Multicyclic Jet-Flap Control for Alleviation of Helicopter Blade Stresses and Fuselage Vibration," Rotorcraft Dynamics, NASA SP-352, Proceedings of Specialists Meeting on Rotorcraft Dynamics, NASA Ames Research Center, February 13-15, 1974.
24. Kretz, M., Aubrun, J. N., and Larche, M., "Wind Tunnel Tests of the Dorand DH 2011 Jet Flap Rotor," NASA CR114693 and CR114694, June 1973.
25. Kretz, M., "Research in Multicyclic and Active Control of Rotary Wings," Vertica, Vol. 1, (1-2), 1976, pp. 95-105.
26. Ham, N. D., "A Simple System for Helicopter Individual-Blade-Control Using Modal Decomposition," Vertica, Vol. 4, 1980, pp. 23-28.
27. Ham, N. D., "Helicopter Individual-Blade-Control Research at MIT 1977-1985," Vertica, Vol. 11, 1987, pp. 109-122.
28. Jacklin, S. A., Nguyen, K. Q., Blaas, A., and Richter, P., "Full-Scale Wind Tunnel Test of a Helicopter Individual Blade Control System," American Helicopter Society 50th Annual Forum Proceedings, Washington, DC, May 11-13 1994.
29. Swanson, S. M., Jacklin, S. A., Blaas, A., Kube, R., and Niesl, G., "Individual Blade Control Effects on Blade-Vortex Interaction noise," American Helicopter Society 50th Annual Forum Proceedings, Washington, DC, May 11-13 1994.
30. Jacklin, S. A., Blaas, A., Teves, D., and Kube, R., "Reduction of Helicopter BVI Noise, Vibration, and Power Consumption through Individual Blade Control," American Helicopter Society 51st Annual Forum Proceedings, Fort Worth, TX, May 9-11, 1995.
31. Swanson, S. M., Jacklin, S. A., Blaas, A., Niesl, G., and Kube, R., "Acoustic Results from a Full-Scale Wind Tunnel Test Evaluating Individual Blade Control," American Helicopter Society 51st Annual Forum Proceedings, Fort Worth, TX, May 9-11, 1995.
32. Schimke, D., Arnold, U., and Kube, R., "Individual Blade Root Control Demonstration Evaluation of Recent Flight Tests," American Helicopter Society 45th Annual Forum Proceedings, Washington, DC, May 20-22, 1998.
33. Bebesel, M., Roth, D., and Pongratz, K., "Reduction of BVI Noise on the Ground - In-Flight Evaluation of Closed-Loop Controller," Proceedings of the 28th European Rotorcraft Forum, Bristol, UK, September 17-20, 2002, pp. 19.1-19.9.
34. Roth, D., "Advanced Vibration Reduction by IBC Technology," Proceedings of the 30th European Rotorcraft Forum, Marseilles, France, September 14-16, 2004.
35. Furst, D., Kessler, C., Auspitzer, T., Muller, M., Hausberg, A., and Witte, H., "Closed Loop IBC-System and Flight Test Results on the CH-53G Helicopter," American Helicopter Society 60th Annual Forum Proceedings, Baltimore, MD, June 7-10, 2004.
36. Arnold, U. T. P., Muller, M., and Richter, P., "Theoretical and Experimental Prediction of Individual Blade Control Benefits," Proceedings of the 23rd Europen Rotorcraft Forum, Dresden, Germany, September 16-18, 1997.
37. Arnold, U. T. P., and Hausberg, A., "Development and Testing of an Electrical Swashplate," Proceedings of the 39th European Rotorcraft Forum, Moscow, Russia, September 3-6, 2013.
38. Glaz, B., Friedmann, P. P., Liu, L., Kumar, D., and Cesnik, C. E. S., "The AVINOR Aeroelastic Simulation Code and Its Application to Reduced Vibration Composite Rotor Blade Design," AIAA 2009-2601, Proceedings of 50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Palm Springs, CA, May 4-7, 2009.
39. Yuan, K. A., and Friedmann, P. P., "Structural Optimization for Vibratory Loads Reduction of Composite Helicopter Rotor Blades with Advanced Geometry Tips," Journal of the American Helicopter Society, Vol. 43, (3), July 1998, pp. 246-256.
40. Yuan, K. A., and Friedmann, P. P., "Aeroelasticity and Structural Optimization of Composite Helicopter Rotor Blades with Swept Tips," NASA CR 4665, June 1995.
41. Cesnik, C. E. S., and Hodges, D. H., "VABS: A New Concept for Composite Rotor Blade Cross-Sectional Modeling," Journal of the American Helicopter Society, Vol. 42, (1), January 1997, pp. 27-38.
42. Palacios, R., and Cesnik, C. E. S., "Cross-Sectional Analysis of Non-Homogeneous Anisotropic Active Slender Structures," AIAA Journal, Vol. 43, (12), December 2005, pp. 2624-2638.
43. Friedmann, P. P., Glaz, B., and Palacios, R., "A Moderate Deflection Composite Helicopter Rotor Blade Model with an Improved Cross-Sectional Analysis," International Journal of Solids and Structures, Vol. 46, (10), 2009, pp. 2186-2200.
44. Yu, W., Volovoi, V. V., Hodges, D. H., and Hong, X., "Validation of the Variational Asymptotic Beam Sectional Analysis," AIAA Journal, Vol. 40, (10), October 2002, pp. 2105-2112.
45. Myrtle, T. F., and Friedmann, P. P., "Application of a New Compressible Time Domain Aerodynamic Model to Vibration Reduction in Helicopters Using an Actively Controlled Flap," Journal of the American Helicopter Society, Vol. 46, (1), January 2001, pp. 32-43.
46. Rogers, K. L., "Airplane Math Modeling Methods for Active Control Design," AGARD-CP-228, August 1977.
47. Liu, L., Padthe, A., Friedmann, P. P., Quon, E., and Smith, M., "Unsteady Aerodynamics of an Airfoil/Flap Combination on a Helicopter Rotor Using CFD and Approximate Methods," Journal of the American Helicopter Society, 56, 032003 (2011).
48. Liu, L., Padthe, A. K., and Friedmann, P. P., "Computational Study of Microflaps with Application to Vibration Reduction in Helicopter Rotors," AIAA Journal, Vol. 49, (7), July 2011, pp. 1450-1465.
49. Peroomian, O., Chakravarthy, S., Palaniswamy, S., and Goldberg, U., "Convergence Acceleration for Unified-Grid Formulation Using Preconditioned Implicit Relaxation," AIAA 98-0116, Proceedings of the 36th Aerospace Sciences Meeting and Exhibit, Reno, NV, January 12-15, 1998.
50. Peroomian, O., Chakravarthy, S., and Goldberg, U., "A 'Grid- Transparent' Methodology for CFD," AIAA 97-0724, Proceedings of the 35th Aerospace Sciences Meeting and Exhibit, Reno, NV, January 6-10, 1997.
51. Leishman, J. G., Principles of Helicopter Aerodynamics, 2nd edn., Cambridge University Press, Cambridge, UK, 2006.
52. Petot, D., "Differential Equation Modeling of Dynamic Stall," La Recherche Aérospatiale, Vol. 5, 1989, pp. 59-71.
53. Glaz, B., Liu, L., and Friedmann, P. P., "Reduced-Order Nonlinear Unsteady Aerodynamic Modeling Using a Surrogate Based Recurrence Framework," AIAA Journal, Vol. 48, (10), October 2010, pp. 2418-2429.
54. Glaz, B., Liu, L., Friedmann, P. P., Bain, J., and Sankar, L., "A Surrogate-Based Approach to Reduced-Order Dynamic Stall Modeling," Journal of the American Helicopter Society, 57, 022002 (2012).
55. Glaz, B., Friedmann, P. P., Liu, L., Cajigas, J. G., Bain, J., and Sankar, L., "Reduced-Order Dynamic Stall Modeling with Swept Flow Effects Using a Surrogate-Based Recurrence Framework," AIAA Journal, Vol. 51, (4), April 2013, pp. 910-921.
56. Johnson, W., CAMRAD/JA - A Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics, Vol. I: Theory Manual, Johnson Aeronautics, Palo Alto, CA, 1988.
57. Johnson, W., CAMRAD/JA - A Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics, Vol. II: Users' Manual, Johnson Aeronautics, Palo Alto, CA, 1988.
58. Patt, D., Liu, L., and Friedmann, P. P., "Rotorcraft Vibration Reduction and Noise Prediction Using a Unified Aeroelastic Response Simulation," Journal of the American Helicopter Society, Vol. 50, (1), January 2005, pp. 95-106.
59. Patt, D., Liu, L., and Friedmann, P. P., "Simultaneous Vibration and Noise Reduction in Rotorcraft Using Aeroelastic Simulation," Journal of the American Helicopter Society, Vol. 51, (2), April 2006, pp. 127-140.
60. Ffowcs Williams, J. E., and Hawkings, D. L., "Sound Generation by Turbulence and Surfaces in Arbitrary Motion," Philosophical Transactions of Royal Society London, Series A, Vol. 264, (1151), May 1969, pp. 321-342.
61. Farassat, F., and Succi, G. P., "The Prediction of Helicopter Rotor Discrete Frequency Noise," Vertica, Vol. 7, (4), May 1983, pp. 309-320.
62. Brentner, K., "A Computer Program Incorporating Realistic Blade Motions and Advanced Acoustic Formulation," NASA Technical Memorandum 87721, 1986.
63. Brentner, K. S., and Farassat, F., "Modeling Aerodynamically Generated Sound of Helicopter Rotors," Progress in Aerospace Sciences, Vol. 39, (2-3), February-April 2003, pp. 83-120.
64. Splettstoesser, W. R., Kube, R., Wagner, W., Seelhorst, U., Boutier, A., Micheli, F., Mercker, E., and Pengel, K., "Key Results from a Higher Harmonic Control Aeroacoustic Rotor Test (HART)," Journal of the American Helicopter Society, Vol. 42, 1997, pp. 58-78.
65. Shampine, L. F., Numerical Solution of Ordinary Differential Equations, Chapman and Hall, New York, 1994.
66. Millott, T. A., and Friedmann, P. P., "Vibration Reduction in Helicopter Rotors Using an Actively Controlled Partial Span Trailing Edge Flap Located on the Blade," NASA CR 4611, June 1994.
67. Liu, L., "BVI Induced Vibration and Noise Alleviation by Active and Passive Approaches," Ph.D. Dissertation, University of Michigan, Ann Arbor, MI, 2005.
68. Patt, D., Liu, L., Chandrasekar, J., Bernstein, D. S., and Friedmann, P. P., "Higher-Harmonic-Control Algorithm for Helicopter Vibration Reduction Revisited," Journal of Guidance, Control, and Dynamics, Vol. 28, (5), September-October 2005, pp. 918-930.
69. Hong, J., and Bernstein, D. S., "Bode Integral Constants, Collocation, and Spillover in Active Noise and Vibration Control," IEEE Transactions on Control System Technology, Vol. 6, (1), January 1998, pp. 111-120.
70. Hall, S. R., and Wereley, N. M., "Linear Control Issues in the Higher Harmonic Control of Helicopter Vibrations," American Helicopter Society 45th Annual Forum Proceedings, Boston, MA, May 22-24, 1989.
71. Hall, S. R., and Wereley, N. M., "Performance of Higher Harmonic Control Algorithms for Helicopter Vibration Reduction," Journal of Guidance, Control, and Dynamics, Vol. 16, (4), October 1993, pp. 193-797.
72. Straub, F. K., Anand, V., Birchette, T. S., and Lau, B. H., "Wind Tunnel Test of the SMART Active Flap Rotor," American Helicopter Society 65th Annual Forum Proceedings, Grapevine, TX, May 27-29, 2009.
73. Rabourdin, A., Maurice, J., Dieterich, O., and Konstanzer, P., "Blue Pulse Active Rotor Control at Airbus Helicopters - New EC145 Demonstrator and Flight Test Results," American Helicopter Society 70th Annual Forum Proceedings, Montreal, Canada, May 20-22, 2014.
74. ∞ Technique for Improved Higher Harmonic Control," American Helicopter Society 68th Annual Forum Proceedings, Fort Worth, TX, May 1-3, 2012.
75. Fan, F. H., and Hall, S. R., "Gain-Scheduled Higher Harmonic Control for Full Flight Envelope Vibration Reduction," American Helicopter Society 70th Annual Forum Proceedings, Montreal, Canada, May 20-22, 2014.
76. Padthe, A. K., Friedmann, P. P., and Bernstein, D. S., "Actuator Saturation in Individual Blade Control of Rotorcraft," AIAA 2012-1477, Proceedings of the 53rd AIAA/ASME/ASCE/AHS/ACS Structures, Structural Dynamics, and Materials Conference, Honolulu, HI, April 23-26, 2012.
77. Roget, B., and Chopra, I., "Wind Tunnel Testing of Rotor with Individually Controlled Trailing-Edge Flaps for Vibration Reduction," Journal of Aircraft, Vol. 45, (3), May-June 2008, pp. 868-879.
78. Lemnios, A. Z., and Smith, A. F., "An Analytical Evaluation of the Controllable Twist Rotor Performance and Dynamic Behavior," Kaman Report R-794, 1972.
79. McCloud, J. L., and Weisbrich, A. L., "Wind Tunnel Test Results of a Full-scale Multicyclic Controllable Twist Rotor," American Helicopter Society 34th Annual Forum Proceedings, Washington DC, May 15-17, 1978.
80. Shaw, J., "Higher Harmonic Blade Pitch Control: ASystem for Helicopter VIbration Reduction," Ph.D. Dissertation, Massachusetts Institute of Technology, Cambridge, MA, 1980.
81. Millott, T. A., and Friedmann, P. P., "Vibration Reduction in Helicopter Rotors Using an Active Control Surface Located on the Blade," AIAA 92-2451, Proceedings of the 33rd AIAA/ASME/ASCE/AHS Structures, Structural Dynamics, and Materials Conference, Dallas, TX, April 13-15, 1992.
82. Millott, T., and Friedmann, P. P., "The Practical Implementation of an Actively Controlled Flap to Reduce Vibrations in Helicopter Rotors," American Helicopter Society 49th Annual Forum Proceedings, St. Louis, MO, May 19-21 1993, pp. 1079-1092.
83. Millott, T. A., and Friedmann, P. P., "Vibration Reduction in Hingeless Rotors Using and Actively Controlled Trailing Edge Flap: Implementation and Time Domain Simulation," AIAA 94-1306, Proceedings of the AIAA/ASME/ASCE/AHS/ASC 35th Structures, Structural Dynamics, and Materials Conference, Hilton Head, SC, April 18-20, 1994.
84. Friedmann, P. P., and Millott, T. A., "Vibration Reduction in Rotorcraft Using Active Control: A Comparison of Various Approaches," Journal of Guidance, Control, and Dynamics, Vol. 18, (4), July-August 1995, pp. 664-673.
85. Spangler, R. L., and Hall, S. R., "Piezoelectric Actuators for Helicopter Rotor Control," AIAA 90-1076, Proceedings of the 31st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Long Beach, CA, April 2-4, 1990, pp. 1589-1599.
86. Dawson, S., and Straub, F. K., "Design, Validation and Test of a Model Rotor with Tip Mounted Active Flaps," American Helicopter Society 50th Annual Forum Proceedings, Washington, DC, May 11-13, 1994.
87. Dawson, S., Marcolin, M., Booth, E., Straub, F. K., Hassan, A., Tagdhighi, H., and Kelly, H., "Wind Tunnel Test of an Active Flap Rotor: BVI Noise and Vibration Reduction," American Helicopter Society 51st Annual Forum Proceedings, Fort Worth, TX, May 9-11, 1995, pp. 381-392.
88. Straub, F. K., "Active Flap Control for Vibration Reduction and Performance Improvement," American Helicopter Society 51st Annual Forum Proceedings, Fort Worth, TX, May 9-11, 1995, pp. 381-392.
89. Myrtle, T. F., and Friedmann, P. P., "New Comprehensive Time Domain Unsteady Aerodynamics for Flapped Airfoils and Its Application to Rotor Vibration Reduction Using Active Control," American Helicopter Society 53rd Annual Forum Proceedings, Virginia Beach, VA, April 29-May 1, 1997.
90. Myrtle, T. F., and Friedmann, P. P., "Vibration Reduction in Rotorcraft Using the Actively Controlled Trailing Edge Flap and Issues Related to Practical Implementation," American Helicopter Society 54th Annual Forum Proceedings, Washington, DC, May 20-22, 1998.
91. de Terlizzi, M., and Friedmann, P. P., "Aeroelastic Response of Swept Tip Rotors Including the Effects of BVI," American Helicopter Society 54th Annual Forum Proceedings, Washington, DC, May 20-22, 1998, pp. 644-663.
92. de Terlizzi, M., and Friedmann, P. P., "Active Control of BVI Induced Vibrations Using a Refined Aerodynamic Model and Experimental Correlation," American Helicopter Society 55th Annual Forum Proceedings, Montreal, Canada, May 25-27 1999, pp. 599-615.
93. Milgram, J. H., and Chopra, I., "Helicopter Vibration Reduction with Trailing Edge Flaps," AIAA 95-1227, Proceedings of the 36th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, New Orleans, LA, April 10-12, 1995.
94. Bir, G., Chopra, I., and Nguyen, K., "Development of UMARC (University of Maryland Advanced Rotor Code)," American Helicopter Society 46th Annual Forum Proceedings, Washington, DC, May 21-23, 1990.
95. Hariharan, N., and Leishman, J. G., "Unsteady Aerodynamics of a Flapped Airfoil in Subsonic Flow by Indicial Concepts," Journal of Aircraft, Vol. 33, (5), September-October 1996, pp. 855-868.
96. Milgram, J. H., and Chopra, I., "A Parametric Design Study for Actively Controlled Trailing Edge Flaps," Journal of the American Helicopter Society, Vol. 43, (2), April 1998, pp. 110-119.
97. Straub, F. K., and Hassan, A. A., "Aeromechanic Considerations in the Design of a Rotor with Smart Material Actuated Trailing Edge Flaps," American Helicopter Society 52nd Annual Forum Proceedings, Washington, DC, June 4-6, 1996, pp. 704-714.
98. Straub, F. K., and Charles, B. D., "Comprehensive Modeling of Rotors with Trailing Edge Flaps," American Helicopter Society 55th Annual Forum Proceedings, Montreal, Canada, May 25-27, 1999.
99. Straub, F. K., and Charles, B. D., "Aeroelastic Analysis of Rotors with Trailing Edge Flaps Using Comprehensive Codes," Journal of the American Helicopter Society, Vol. 46, (3), 2001, pp. 192-199.
100. Johnson, W., "Rotorcraft Dynamics Models for a Comprehensive Analysis," American Helicopter Society 54th Annual Forum Proceedings, Washington, DC, May 20-22, 1998.
101. Johnson, W., "CAMRAD II Nonlinear Substructure Aeromechanics Analysis," Johnson Aeronautics, Palo Alto, CA, Version 3.1, 1998.
102. Schimke, D., Janker, P., Blaas, A., Kube, R., and Kessler, C., "Individual Blade Control by Servo-Flap and Blade Root Control A Collaborative Research and Development Programme," 23rd European Rotorcraft Forum, Dresden, Germany, September 16-18, 1997.
103. Schimke, D., Jänker, P., Wendt, V., and Junker, B., "Wind Tunnel Evaluation of a Full Scale Piezoelectric Flap Control Unit," Proceedings of the 24th European Rotorcraft Forum, Marseille, France, September 15-17, 1998.
104. Prechtl, E. F., and Hall, S. R., "Design of a High Efficiency, Large Stroke, Electromechanical Actuator," Smart Materials and Structures, Vol. 8, (1), 1999, pp. 13-30.
105. Leconte, P., Rapin, M., and van der Wall, B. G., "Main Rotor Active Flaps: Numerical Assessment of VIbration Reduction," American Helicopter Society 57th Annual Forum Proceedings, Washington, DC, May 9-11, 2001.
106. Enenkl, B., Klöppel, V., Preissler, D., and Jänker, P., "Full Scale Rotor with Piezoelectric Actuated Blade Flaps," Proceedings of the 28th European Rotorcraft Forum, Bristol, UK, September 17-19, 2002.
107. Chopra, I., "Status of Application of Smart Structures Technology to Rotorcraft Systems," Journal of the American Helicopter Society, Vol. 45, (4), October 2000, pp. 228-252.
108. Chopra, I., "Review of the State of the Art of Smart Structures and Integrated Systems," AIAA Journal, Vol. 40, (11), November 2002, pp. 2145-2187.
109. Depailler, G., and Friedmann, P. P., "Reduction of Vibrations Due to Dynamic Stall in Helicopters Using an Actively Controlled Flap," AIAA 2002-1431, Proceedings of the 43rd AIAA/ASME/ASCE/AHS/ACS Structures, Structural Dynamics, and Materials Conference, Denver, CO, April 22-25, 2002.
110. Depailler, G., and Friedmann, P. P., "Alleviation of Rotor Vibrations Induced by Dynamic Stall Using Actively Controlled Flaps with Freeplay," Proceedings of the 28th European Rotorcraft Forum, Bristol, UK, September 17-20, 2002.
111. Shen, J., and Chopra, I., "Aeroelastic Stability of Trailing-Edge Flap Helicopter Rotors," Journal of the American Helicopter Society, Vol. 48, (4), October 2003, pp. 236-243.
112. Shen, J., and Chopra, I., "Aeroelastic Modeling of Trailing-Edge-Flap Helicopter Rotors Including Actuator Dynamics," Journal of Aircraft, Vol. 41, (6), November-December 2004, pp. 1465-1472.
113. Cribbs, R., and Friedmann, P. P., "Actuator Saturation and Its influence on Vibration Reduction by Actively Controlled Flaps," AIAA 2001-1467, Proceedings of the 42nd AIAA/ASME/ASCE/AHS/ACS Structures, Structural Dynamics, and Materials Conference, Seattle, WA, April 16-19, 2001.
114. Roget, B., and Chopra, I., "Individual Blade Control Methodology for a Rotor with Dissimilar Blades," Journal of the American Helicopter Society, Vol. 48, (3), July 2003, pp. 176-185.
115. Liu, L., Friedmann, P. P., Kim, I., and Bernstein, D. S., "Rotor Performance Enhancement and VIbration Reduction in Presence of Dynamic Stall," Journal of the American Helicopter Society, Vol. 53, (4), October 2008, pp. 338-350.
116. Glaz, B., Friedmann, P. P., and Liu, L., "Active/Passive Vibration Reduction and Performance Enhancement of Helicopter Rotors at High Advance Ratios," American Helicopter Society 64th Annual Forum Proceedings, Montreal, Canada, April 29-May 1, 2008.
117. Glaz, B., Friedmann, P. P., and Liu, L., "Helicopter Vibration Reduction throughout the Entire Flight Envelope Using Surrogate-Based Optimization," Journal of the American Helicopter Society, 54, 12007 (2009).
118. Zhang, J., "Active-Passive Hybrid Optimization of Rotor Blades With Trailing Edge Flaps," Ph.D. Dissertation, The Pennsylvania State University, State College, PA, 2001.
119. Splettstoesser, W., Schultz, K. J., Kube, R., Brooks, T. F., Booth, E. R., Niesl, G., and Streby, O., "A Higher Harmonic Control Test in the DNW to Reduce Impulsive BVI Noise," Journal of the American Helicopter Society, Vol. 39, (1), October 1994, pp. 3-13.
120. Patt, D., "Simultaneous Noise and Vibration Reduction in Rotorcraft Using Actively Controlled Flaps and Including Performance Considerations," Ph.D. Dissertation, University of Michigan, Ann Arbor, MI, 2004.
121. Khanh, N., Lauzon, D., and Anand, V., "Computation of Loads on the McDonnell Douglas Advanced Bearingless Rotor," American Helicopter Society 50th Annual Forum Proceedings, Washington, DC, May 11-13, 1994.
122. Fulton, M. V., and Ormiston, R. A., "Hover Testing of a Small-Scale Rotor with On-Blade Elevons," Journal of the American Helicopter Society, Vol. 46, (2), April 2001, pp. 96-106.
123. Fulton, M., and Ormiston, R. A., "Small-Scale Rotor Experiments with On-Blade Elevons to Reduce Blade Vibratory Loads in Forward Flight," American Helicopter Society 54th Annual Forum Proceedings, Washington, DC, May 20-22, 1998, pp. 433-451.
124. de Terlizzi, M., "Blade Vortex Interaction and Its Alleviation Using Passive and Active Control Approaches," Ph.D. Dissertation, UCLA, Los Angeles, 1999.
125. Koratkar, N. A., and Chopra, I., "Open-Loop Hover Testing of a Smart Rotor Model," AIAA Journal, Vol. 40, (2), August 2002, pp. 1495-1502.
126. Koratkar, N.A., and Chopra, I., "Wind Tunnel Testing of a Smart Rotor Model with Trailing Edge Flaps," Journal of the American Helicopter Society, Vol. 47, (4), October 2002, pp. 263-272.
127. Roget, B., and Chopra, I., "Closed-Loop Test of a Rotor with Individually Controlled Trailing-Edge Flaps for Vibration Reduction," Journal of the American Helicopter Society, 55, 012009 (2010).
128. Janaki Ram, R. D., Sim, B. W., Kitaplioglu, C., and Straub, F. K., "Blade-Vortex Interaction Noise Characteristics of an Active Flap," American Helicopter Society 65th Annual Forum Proceedings, Grapevine, TX, May 27-29, 2009.
129. Hall, S. R., Anand, V. R., Straub, F. K., and Lau, B. H., "Active Flap Control of the SMART Rotor for Vibration Reduction," American Helicopter Society 65th Annual Forum Proceedings, Grapevine, TX, May 27-29, 2009.
130. Straub, F. K., Kennedy, D. K., Stemple, A. D., Anand, V., and Birchette, T. S., "Development and Whirl Tower Test of the SMART Active Flap Rotor," Proceedings of SPIE Conference on Smart Structures and Materials, Vol. 5388, July 2004, pp. 202-212.
131. Hall, S. R., Tzianetopoulou, T., Straub, F. K., and Ngo, H., "Design and Testing of a Double X-Frame Piezoelectric Actuator," Proceedings of the SPIE Conference on Smart Structures and Materials, Newport Beach, CA, March 2000.
132. Sim, B. W., Janaki Ram, R. D., and Lau, B. H., "Reduced in-Plane Low Frequency Noise of an Active Flap Rotor," Journal of the American Helicopter Society, 59, 02002 (2014).
133. Lorber, P. F., O'Neill, J. J., Isabella, B., Andrews, J., Wong, J., Hein, B., Geiger, D., Wake, B. E., Jonsson, U., and Sun, F., "Whirl Test of a Large Scale High Authority Active Flap Rotor," American Helicopter Society 66th Annual Forum Proceedings, Phoenix, AZ, May 11-13, 2010.
134. Lorber, P., O'Neill, J., Hain, B., Isabella, B., Andrews, J., Brigley, M., Wong, J., LeMasurier, P., and Wake, B., "Whirl and Wind Tunnel Testing of the Sikorsky Active Flap Demonstration Rotor," American Helicopter Society 67th Annual Forum Proceedings, Virginia Beach, VA, May 3-5, 2011.
135. Lorber, P., Hain, B., Wong, J., and Wake, B., "Rotor Aeromechanics Results from the Sikorsky Active Flap Demonstration Rotor," American Helicopter Society 68th Annual Forum Proceedings, Fort Worth, TX, May 1-3, 2012.
136. Wong, J., Andrews, J., and Brigley, M., "Dynamics of a High Authority Active Flap Rotor," American Helicopter Society 68th Annual Forum Proceedings, Fort Worth, TX, May 1-3, 2012.
137. Sim, B. W., Potsdam, M., Kitaplioglu, C., LeMasurier, P., Lorber, P. F., and Andrews, J., "Localized, Non-Harmonic Active Flap Motions for Low Frequency In-Plane Rotor Noise Reduction," American Helicopter Society 68th Annual Forum Proceedings, Fort Worth, TX, May 1-3 2012.
138. Saberi, H., Khoshlahjeh, M., Ormiston, R. A., and Rutkowski, M. J., "Overview of RCAS and Application to Advanced Rotorcraft Problems," Proceedings of the American Helicopter Society 4th Decennial Specialist's Conference on Aeromechanics, San Francisco, CA, January 21-23, 2004.
139. Dieterich, O., Enenkl, B., and Roth, D., "Trailing Edge Flaps for Active Rotor Control Aeroelastic Characteristics of the ADASYS Rotor System," American Helicopter Society 62nd Annual Forum Proceedings, Phoenix, AZ, May 9-11, 2006.
140. Roth, D., Enekl, B., and Dieterich, O., "Active Rotor Control by Flaps for Vibration Reduction - Full Scale Demonstrator and First Flight Test Results," Proceedings of 32nd European Rotorcraft Forum, Maastricht, The Netherlands, September 12-14, 2006.
141. Konstanzer, P., Enenkl, B., Aubourg, P., and Cranga, P., "Recent Advances in Eurocopter's Passive and Active Vibration Control," American Helicopter Society 64th Annual Forum Proceedings, Montreal, Canada, April 29-May 1, 2008.
142. Hohenemser, K. H., and Yin, S. Y., "Some Applications of the Method of Multiblade Coordinates," Journal of the American Helicopter Society, Vol. 17, (3), July 1972, pp. 3-12.
143. King, F. A., Maurice, J. B., and Fichter, W., "In-Flight Rotorblade Tracking Control for Helicopters Using Active Trailing-Edge Flaps," Journal of Guidance, Control, and Dynamics, Vol. 37, (2), March-April 2014, pp. 633-643.
144. King, F. A., Steinwandel, A., and Fichter, W., "Performance Characteristics of a Symmetrized In-Flight Tracking Control," American Helicopter Society 70th Annual Forum Proceedings, Montreal, Quebec, Canada, May 20-22, 2014.
145. Maurice, J. B., Farolfi, R., Saupe, F., King, F. A., and Fichter, W., "Robust Stability Analysis of a Linear Time-Periodic Active Helicopter Rotor," Journal of Guidance Control and Dynamics, Vol. 35, (5), September-October 2012, pp. 1625-1636.
146. Maurice, J. B., King, F. A., Fichter, W., Rabordin, A., and Kostanzer, P. K., "Helicopter Rotor In-Plane Stability Enhancement Using Trailing Edge Flaps," Journal of Guidance Control and Dynamics, Vol. 36, (5), 2013, pp. 1477-1489.
147. Kessler, C., "Active Rotor Control for Helicopters: Individual Blade Control and Swashplateless Rotor Designs," CEAS Aeronautical Journal, Vol. 1, (1-4), September 2011, pp. 23-54.
148. Bent, A. A., and Hagood, N. W., "Piezoelectric Fiber Composites with Interdigitated Electrodes," Journal of Intelligent Material Systems and Structures, Vol. 8, 1997, pp. 903-919.
149. Chen, P. C., and Chopra, I., "Wind Tunnel Test of a Smart Rotor Model with Individual Blade Twist Control," Journal of Intelligent Material Systems and Structures, Vol. 8, 1997, pp. 414-425.
150. Rodgers, J. P., Hagood, N. W., and Weems, D. B., "Design and Manufacture of an Integral Twist-Actuated Rotor Blade," AIAA 97-1264, Proceedings of the 38th AIAA/ASME/ASCE/AHS/ACS Structures, Structural Dynamics, and Materials Conference, Kissimmee, FL, April 7-10, 1997.
151. Rodgers, J. P., and Hagood, N. W., "Preliminary Mach-Scale Hover Testing of an Integrally Twist-Actuated Rotor Blade," Proceedings of the SPIE Conference on Smart Structures and Integrated Systems, San Diego, CA, March 8-12, 1998, SPIE Vol. 3329, pp. 291-308.
152. Rodgers, J. P., and Hagood, N. W., "Hover Testing of a 1/6 Mach-Scale CH-47D Blade with Integral Twist Actuation," Proceedings of the 9th International Conference on Adaptive Structures and Technology, Cambridge, MA, October 14-18, 1998.
153. Shin, S. J., Cesnik, C. E. S., Wilkie, W. K., and Wilbur, M. L., "Design and Manufacturing of a Model-scale Active Twist Rotor Prototype Blade," Journal of Intelligent Material Systems and Structures, Vol. 19, 2008, pp. 1443-1456.
154. Cesnik, C. E. S., and Shin, S. J., "On the Modeling of Integrally Actuated Helicopter Blades," International Journal of Solids and Structures, Vol. 38, (10-13), 2001, pp. 1765-1789.
155. Wilbur, M. L., Mirick, P. H., Yaeger, W. T., Langston, C., Cesnik, C. E. S., and Shin, S., "Vibratory loads Reduction Testing of the NAS/Army/MIT Active Twist Rotor," Journal of the American Helicopter Society, Vol. 47, (4), October 2002, pp. 123-133.
156. Shin, S. J., Cesnik, C. E. S., and Hall, S. R., "Closed-Loop Control Test of the NASA/Army/MIT Active Twist Rotor for Vibration Reduction," Journal of the American Helicopter Society, Vol. 50, (4), October 2005, pp. 178-194.
157. Hoffmann, F., Opitz, S., and Riemenschneider, J., "Validation of Active Twist Modeling Based on Whirl Tower Tests," American Helicopter Society 65th Annual Forum Proceedings, Grapevine, TX, May 27-29, 2009.
158. Monner, H. P., Riemenschneider, J., Opitz, S., and Schultz, M., "Development of Active Twist Rotors at the German Aerospace Center (DLR)," AIAA 2011-1824, Proceedings of 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Denver, CO, April 4-7, 2011.
159. Kumar, D., and Cesnik, C. E. S., "Optimization Framework for the Dynamic Analysis and Design of Active Twist Rotors," American Helicopter Society 68th Annual Forum Proceedings, Fort Worth, TX, May 1-3, 2012.
160. Liebeck, R. H., "Design of Subsonic Airfoils for High Lift," Journal of Aircraft, Vol. 15, (9), September 1978, pp. 547-561.
161. Chow, R., and van Dam, C. P., "Unsteady Computational Investigations of Deploying Load Control Microtabs," Journal of Aircraft, Vol. 43, (5), September-October 2006, pp. 641-648.
162. Padthe, A. K., "Active Vibration and Noise Alleviation in Rotorcraft Using Microflaps," Ph.D. Dissertation, University of Michigan, Ann Arbor, MI, 2011.
163. Baker, J. P., Standish, K. J., and van Dam, C. P., "Two-Dimensional Wind Tunnel and Computational Investigation of a Microtab Modified Airfoil," Journal of Aircraft, Vol. 44, (2), March-April 2007, pp. 563-572.
164. Cole, J. A., Vieira, B. A. O., Coder, J. G., Premi, A., and Maughmer, M. D., "Experimental Investigation into the Effect of Gurney Flaps on Various Airfoils," Journal of Aircraft, Vol. 50, (4), July-August 2013, pp. 1287-1294.
165. Storms, B. L., and Jang, C. S., "Lift Enhancement of an Airfoil Using a Gurney Flap and Vortex Generators," Journal of Aircraft, Vol. 31, (3), May-June 1994, pp. 542-547.
166. Giguere, P., Lemay, J., and Dumas, G., "Gurney Flap Effects and Scaling for Low-speed Airfoils," Proceedings of the AIAAApplied Aerodynamics Conference, San Diego, CA, June 19-22, 1995.
167. Niu, Y., Hsu, T., Hsieh, C. T., Chang, C. C., and Chu, C. C., "How Does a Gurney Flap Enhance the Aerodynamic Forces," AIAA Journal, Vol. 48, (11), November 2010, pp. 2710-2714.
168. Li, Y., Wang, J., and Zhang, P., "Influences of Mounting Angles and Locations on the Effects of Gurney Flaps," Journal of Aircraft, Vol. 40, (3), May-June 2003, pp. 494-498.
169. Lee, H.-T., and Kroo, I. M., "Computational Investigation of Airfoils with Miniature Trailing Edge Control Surfaces," AIAA 2004-1051, Proceedings of the 42nd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, Jan 5-8 2004.
170. Coder, J. G., Maughmer, M. D., and Martin, P. B., "CFD Investigation of Unsteady Rotorcraft Airfoil Aerodynamics: MiTEs and Dynamic stall," AIAA 2011-1125, Proceedings of the 49th AIAA Aerospace Sciences Meeting and Exhibit, Orlando, FL, January 4-7, 2011.
171. Lee, H.-T., Kroo, I. M., and Bieniawski, S., "Flutter Suppression for High Aspect Ratio Flexible Wings Using Microflaps," AIAA 2002-1717, Proceedings of the 43rd AIAA/ASME/ASCE/AHS/ACS Structures, Structural Dynamics, and Materials Conference, Reno, NV, April 22-25, 2002.
172. Matalanis, C. G., and Eaton, J. K., "Wake Vortex Alleviation Using Rapidly Actuated Segmented Gurney Flaps," AIAA Journal, Vol. 45, (8), August 2007, pp. 1874-1884.
173. Cooperman, A. M., Chow, R., Johnson, S. J., and van Dam, C. P., "Experimental and Computational Analysis of a Wind Turbine Airfoil," AIAA 2011-1250, Proceedings of the 49th AIAA Aerospace Sciences Meeting and Exhibit, Orlando, FL, January 4-7, 2011.
174. Wilson, D. G., Berg, D. E., Li, D. W., and Zayas, J. R., "Optimized Active Aerodynamic Blade Control for Load Alleviation on Large Wind Turbines,"AWEA WINDPOWER 2008 Conference & Exhibition, Houston, TX, June 1-4, 2008.
175. Kentfield, J. A. C., "The Potential of Gurney Flaps for Improving the Aerodynamic Performance of Helicopter Rotors," AIAA 93-4883, Proceedings of the AIAA International Powered Lift Conference, Santa Clara, CA, December 1-3, 1993.
176. Kinzel, M. P., Maughmer, M. D., and Lesieutre, G. L., "Miniature Trailing-Edge Effectors for Rotorcraft Performance Enhancement," Journal of the American Helicopter Society, Vol. 52, (2), April 2007, pp. 146-158.
177. Padthe, A. K., Liu, L., and Friedmann, P. P., "Numerical Evaluation of Microflaps for On Blade Control of Noise and Vibration," Proceedings of the 52nd AIAA/ASME/ASCE/AHS/ACS Structures, Structural Dynamics, and Materials Conference, Denver, CO, April 4-7 2011.
178. Padthe, A. K., and Friedmann, P. P., "Simultaneous BVI Noise and Vibration Reduction in Rotorcraft Using Microflaps Including the Effect of Actuator Saturation," American Helicopter Society 68th Annual Forum Proceedings, Fort Worth, TX, May 1-3, 2012.
179. Min, B. Y., Sankar, L., and Bauchau, O. A., "A CFD-CSD Coupled Analysis of Hart II Rotor Vibration Reduction Using Gurney Flaps," American Helicopter Society 66th Annual Forum Proceedings, Phoenix, AZ, May 11-13 2010.
180. Nakafuji, D. T. Y., van Dam, C. P., Smith, R. L., and Collins, S. D., "Active Load Control for Airfoils using Microtabs," Journal of Solar Energy Engineering, Vol. 123, (4), November 2001, pp. 282-289.
181. Thiel, M. R., Lesieutre, G. A., Maughmer, M. D., and Koopmann, G. H., "Actuation of an Active Gurney Flap for Rotorcraft Applications," AIAA 2006-2181, Proceedings of 47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Newport, RI, May 1-4, 2006.
182. Brigley, M., Welsh, W., Altieri, R., and Rich, A., "Design and Testing of a New Vibration Suppression System," American Helicopter Society 67th Annual Forum Proceedings, Virginia Beach, VA, May 3-5, 2011.