A new, actively deployable trailing edge flap system is introduced and an experimental investigation is undertaken to determine its effects on the disturbances created during blade–disturbance interactions (BDI), with blade–vortex interaction (BVI) alleviation being the ultimate objective. Experimental tests were conducted using a two-dimensional (2D) wind tunnel setup incorporating a pressure instrumented airfoil section with a deployable 20% trailing edge flap and an upstream vortex generator to produce the disturbance. Results of this study showed that the disturbances, caused by BDI events, to the pressure distribution over the airfoil occur mostly at the leading edge. Carefully synchronized deployment of the trailing edge flap during BDI events resulted in a reduction of this pressure disturbance. The aeroelastic response of the active flap was modeled via unsteady linear theory and the model was validated experimentally. The aeroelastic model shows good agreement with experimental results, which supports its use as a preliminary design tool for the actuation parameters of the active flap system.

1.
George
,
A. R.
,
1978
, “
Helicopter Noise: State-of-the-Art
,”
J. Aircr.
,
15
, No. 11,
November
, pp.
707
714
.
2.
Widnall
,
S. E.
,
1971
, “
Helicopter Noise due to Blade-Vortex Interaction
,”
J. Acoust. Soc. Am.
,
50
, No.
1
, Pt. 2, pp.
354
365
.
3.
Widnall
,
S. E.
, and
Martinez
,
R.
,
1983
, “
An Aeroacoustic Model for High-Speed, Unsteady, Blade–Vortex Interaction
,”
AIAA J.
,
21
, No. 9,
September
, pp.
1225
1231
.
4.
Hardin
,
J. C.
, and
Mason
,
J. P.
,
1985
, “
A New Look at Sound Generation by Blade–Vortex Interaction
,”
Trans. ASME, J. Vib., Acoust., Stress, Reliab. Des.
,
107
, No. 2,
April
, pp.
224
229
.
5.
Hardin, J. C., and Lamkin, S. L., “Aeroacoustic Interaction of a Distributed Vortex With a Lifting Joukwoski Airfoil,” AIAA Paper 84-2287, October 1984.
6.
Hardin
,
J. C.
, and
Lamkin
,
S. L.
,
1987
, “
An Euler Code Calculation of Blade–Vortex Interaction Noise
,”
Trans. ASME, J. Vib., Acoust., Stress, Reliab. Des.
,
109
, No. 1,
January
, pp.
29
35
.
7.
Hardin
,
J. C.
, and
Lamkin
,
S. L.
,
1987
, “
Concepts for Reduction of Blade–Vortex Interaction Noise
,”
J. Aircr.
,
24
, No. 2,
February
, pp.
120
125
.
8.
Lee
,
Soogab
,
1994
, “
Reduction of Blade–Vortex Interaction Noise Through Porous Leading Edge
,”
AIAA J.
,
32
, No. 3,
March
, pp.
480
488
.
9.
Hassan
,
Ahmed A.
,
Sankar
,
L. N.
, and
Tadghighi
,
H.
,
1994
, “
Effects of Leading and Trailing Edge Flaps on the Aerodynamics of Airfoil–Vortex Interactions
,”
J. Am. Helicopter Soc.
, April, pp.
35
46
.
10.
Lorber
,
Peter F.
,
1993
, “
Blade–Vortex Interaction Data Obtained From a Pressure-Instrumented Model UH-60A Rotor at the DNW
,”
J. Am. Helicopter Soc.
, July, pp.
26
34
.
11.
Lorber
,
Peter F.
,
1991
, “
Aerodynamic Results of a Pressure-Instrumented Model Rotor Test at the DNW
,”
J. Am. Helicopter Soc.
, October, pp.
66
76
.
12.
Splettstoesser
,
W. R.
,
Schultz
,
K. J.
, and
Martin
,
R. M.
,
1990
, “
Rotor Blade–Vortex Interaction Impulsive Noise Source Localization
,”
AIAA J.
,
28
, No. 4,
April
, pp.
593
600
.
13.
Martin, R. M., Elliot, J. W., and Hoad, D. R., “Comparison of Experimental and Analytical Predictions of Rotor Blade–Vortex Interactions Using Model Scale Acoustic Data,” AIAA Paper 84-2269, October 1984.
14.
Booth
,
Earl R.
,
1990
, “
Experimental Observations of Two-Dimensional Blade–Vortex Interaction
,”
AIAA J.
,
28
, No. 8,
August
, pp.
1353
1359
.
15.
Booth, Earl R., “Surface Pressure Measurement During Low Speed Two-Dimensional Blade–Vortex Interaction,” AIAA Paper 86-1856, July 1986.
16.
Booth, E. R., and Yu, J. C., “Two-Dimensional Blade–Vortex Interaction Flow Visualization Investigation,” AIAA Paper 84-2307, October 1984.
17.
Straus
,
J.
,
Renzoni
,
P.
, and
Mayle
,
R. E.
,
1990
, “
Airfoil Pressure Measurements During a Blade Vortex Interaction and a Comparison With Theory
,”
AIAA J.
,
28
, No. 2,
February
, pp.
222
228
.
18.
Seath
,
D. D.
,
Kim
,
Jai-Moo
, and
Wilson
,
D. R.
,
1989
, “
Investigation of the Parallel Blade–Vortex Interaction at Low Speed
,”
J. Aircr.
,
26
, No. 4,
April
, pp.
328
333
.
19.
Lee
,
S.
, and
Bershader
,
D.
,
1994
, “
Head-On Parallel Blade–Vortex Interaction
,”
AIAA J.
,
32
, No. 1,
January
, pp.
16
22
.
20.
Kalkhoran, I., Wilson, D., and Seath, D., “An Experimental Investigation of the Parallel Vortex–Airfoil Interaction at Transonic Speeds,” AIAA Paper 89-1833, June 1989.
21.
Smith, D., and Sigl, D., “Helicopter Rotor Tip Shapes for Reduced Blade–Vortex Interaction an Experimental Investigation,” AIAA Paper 95-0192, Reno, Nevada, Jan. 1995.
22.
Brooks
,
Thomas F.
, and
Booth
,
Earl R.
,
1993
, “
The Effects of Higher Harmonic Control on Blade–Vortex Interaction Noise and Vibration
,”
J. Am. Helicopter Soc.
, July, pp.
45
54
.
23.
Dawson, S., and Straub, F., “Design, Validation and Test of a Model Rotor With Tip Mounted Active Flaps,” AHS 50th Annual Forum, May 1994, Washington DC.
24.
Marcolini, M., Booth, E., Tadghighi, H., Hassan, A., Smith, C., and Becker, L., “Control of BVI Noise Using an Active Trailing Edge Flap,” Presented at the 1995 AHS Vertical Lift Aircraft Design Conference, San Francisco, CA, January 1995.
25.
Simonich
,
J.
,
Lavrich
,
P.
,
Sofrin
,
T.
, and
Topol
,
D.
,
1993
, “
Active Aerodynamic Control of Wake–Airfoil Interaction Noise—Experiment
,”
AIAA J.
,
31
, No. 10,
October
, pp.
1761
1768
.
26.
Nelson, C. T., “Effects of Trailing Edge Flap Dynamic Deployment on Blade–Vortex Interactions,” MS Thesis, Aerospace Engineering Department, Texas A&M University, August 97.
27.
Walz, C., and Chopra, I., “Design and Testing of a Helicopter Rotor Model With Smart Trailing Edge Flaps,” AIAA Paper 94-1767, April 1994.
28.
Webb
,
G.
,
Wilson
,
L.
,
Lagoudas
,
D. C.
, and
Rediniotis
,
O. K.
,
2000
, “
Adaptive Control of Shape Memory Alloy Actuators for Underwater Biomimetic Applications
,”
AIAA J.
,
38
, No. 2,
Feb.
, pp.
325
334
.
29.
Rediniotis
,
O.
,
Wilson
,
L.
,
Lagoudas
,
D.
, and
Khan
,
M.
,
2002
, “
Development of a Shape-Memory-Alloy Actuated Biomimetic Hydrofoil
,”
J. Intell. Mater. Syst. Struct.
,
13
, No. 1,
Jan.
, pp.
35
49
.
30.
Jun, H., “Development of a Fuel-Powered, Compact SMA Actuator System,” Ph.D. Dissertation, Aerospace Engineering Department, Texas A&M University, College Station, Texas, October 2003.
31.
Garner
,
L.
,
Wilson
,
L.
,
Lagoudas
,
D.
, and
Rediniotis
,
O.
,
2000
, “
Development of a Shape Memory Alloy Actuated Underwater Biomimetic Vehicle
,”
J. Smart Mater. Struct.
,
9
, No. 5,
Oct.
, pp.
673
683
.
32.
Lagoudas, D. C., and Miller, D. A., “Experiments of Thermomechanical Fatigue of SMAs,” Proceedings of the 1999 Conference on Smart Structures and Materials, SPIE, 1999, pp. 275–282.
33.
Rae, W. H., and Pope, A., Low-Speed Wind Tunnel Testing, John Wiley & Sons, New York, 1984.
34.
Rediniotis
,
O. K.
, and
Pathak
,
M. M.
,
1999
, “
A Simple Technique for Frequency Response Enhancement of Miniature Pressure Probes
,”
AIAA J.
,
37
, No. 7,
July
, pp.
897
899
.
35.
Abbott, I. H., and Von Doenhoff, A. E., Theory of Wing Sections, Dover Publications, Inc., New York, 1959.
36.
Fung, Y. C., An Introduction to the Theory of Aeroelasticity, Dover Publications Inc., New York, 1993.
37.
Lee, B. H. K., and Desrochers, J., “Flutter Analysis of a Two-Dimensional Airfoil Containing Structural Nonlinearities,” National Research Council Canada, LR-618, May, 1987.
38.
Houbolt
,
J. C.
,
1950
, “
A Recurrence Matrix Solution for the Dynamic Response of Elastic Aircraft
,”
J. Aeronaut. Sci.
,
17
, No.
9
, pp.
540
550
.
39.
O’Neil, Todd, and Strganac, T. W., Nonlinear Aeroelastic Response—Analyses and Experiments, AIAA Paper 95-1404, April, 1995.
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