Individual Blade Control

Transcription

Die Flugsteuerung des Hubschraubers
von den Grundlagen bis zur Einzelblattsteuerung
Dr. Oliver
Oliver Kunze
Kunze
Dr.
Produktentwicklung LX
LX-E
Produktentwicklung
-E
ZF Luftfahrttechnik
Luftfahrttechnik GmbH
GmbH
ZF
Praxis-Seminar
Luftfahrt
Praxis
-Seminar Luftfahrt
Fachhochschule Hamburg
Hamburg
Fachhochschule
Hamburg, d.
d. 28.10.2004
28.10.2004
Hamburg,
Ku LX-E 28.10.04 Slide 1
Praxis-Seminar Luftfahrt
Proprietary Information
ZFLuftfahrtechnik GmbH
Helicopter Flight Control – from primary to
individual blade control
z Overview
z History / Configuration and
Performance of a Helicopter
z Main Rotor / Main Rotor Control
Design
z Problems of the Main Rotor
z
z
z
Aerodynamics
Vibrations
Noise
z Individual Blade Control (IBC)
z
z
z
Principle of Operation
Effects in Wind Tunnel and Flight Tests
IBC System Design
z Conclusion and Outlook
z Overview
Design
z
z
z
Aerodynamics
Vibrations
Noise
z
z
z
IBC System Design
Comparison of 1930 Aircraft Maturity,
Helicopter vs. Fixed Wing
Do X giant seaplane:
MTOW:
48to
Distance:
2800km
Endurance: 14h
Helicopter by C.
d’Ascanio:
Altitude:
18m
Distance:
1078m
Endurance: 8:45min
Helicopter Standard Configuration
Lockheed AH-56A Cheyenne Compound Aircraft
Tiltrotor Aircraft Bell/Boeing V-22 Osprey
Relative Power Required vs. Forward Speed
400
Helicopter
Compound
P/m
[kW/to]
300
Tilt-Rotor
Airplane
200
100
0
0
50
100
150
200
V [m/s]
Velocity Distribution over Rotor Disk
(Advanced Ratio µ = ΩR / V)
z Overview
Design
z
z
z
Aerodynamics
Vibrations
Noise
z
z
z
IBC System Design
Rotor Blade Lift and Flap
Blade Control System Using a Conventional
Swashplate Arrangement
+ϑ
-ϑ
Angle-of-Attack Distribution in Forward Flight
Level Flight
Main Rotor Control System
Eurocopter (MBB) BO105
Pitch
Horn
Taumelscheibe
Steuerstange
Primärsteuer,
stehend
Conventional Mechanical Primary Control System
Main Rotor Sikorsky CH-53G
Main Rotor Sikorsky CH-53G
Pitch Horn
Taumelscheibe
Steuerstange
(hier IBC-Aktuator)
Primärsteuer
Booster
stehende Schere
Main Rotor Control with Spider
Westland Sea Lynx MK88
Hub
Pitch
Control
Rod
Spider
Arm
Gimbal
Joint
Spindle
Roller
Bearings
NHI NH-90
Î Erstflug: 18. Dezember 1995
Î Quadruplex fly-by-wire Steuerung
Main Rotor Design – 1950/60s
AEROSPATIALE AS 341
Sikorsky S-58
Main Rotor Design – Bell 412
Virtual Flap
Hinge
Lag Hinge
Damper and
Feather Bearing
z Overview
Design
z
z
z
Aerodynamics
Vibrations
Noise
z
z
z
IBC System Design
Limiting Phenomena Encountered by
a Helicopter Rotor in Forward Flight
Rotor Wake
Interferences
Dynamic Stall Due to
Blade Vortex Interaction
Mach Number
Effects
Yawed Flow
High Angles
of Attack
Reversed Flow
Helicopter Vibrations:
Source ⇒ Flexible Structure ⇒ Reaction
Periodic and Impulsive
Blade Loads
Flexible Blade
Coupled
Eigenmodes
Flexible Rotor/
Body Load Paths
Structural Modes
Rigid Body Motions
Vibration Levels of 6 Different Helicopter Types (BO-105 4- and
5-Bladed, CH-53G Aluminium and IRB Blades, Tiger, UH-60)
nBl/rev Vibration at Pilot Seat [g]
0.5
0.4
0.3
MIL-H-8501A
(1962)
0.2
0.1
0.0
0.00
NASA
Recommendation
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Advance Ratio
Passive Vibration Absorber and Isolation Systems
Cabin
Structure
Flapping
Mass
Flexible
Leaf
Pendulum Absorber
Cabin Absorber
Bifilar Absorber
Antiresonance
Isolation System
Nodal Beam
Isolation System
BVI-Noise Generating Mechanism
Air Flow
Modified Vortex
Strength
ψ = 90°
Reduced
Pitch during
BVI
ψ = 0°
Example of Helicopter Rotor Sound Spectrum
(l.h.s.) and Average Time History (r.h.s.)
z Overview
Design
z
z
z
Aerodynamics
Vibrations
Noise
z
z
z
IBC System Design
Individual Blade Control through Blade Root
or Trailing Edge Flap Actuation
Blade Root
Actuator
Electrically
Driven Trailing
Edge (Servo) Flap
Individual Blade Control through Blade
Twist or Trailing Edge Flap Actuation
IBC Blade Pitch Control with higher
harmonic blade pitch movements
IBC Blade Pitch
Movement
characterization:
12
10
with IBC
• frequency (2 .. 7
ΩRotor)
B la d e P itc h [°]
8
•amplitude (0..3..6°)
6
• phase (0..360°)
4
primary control
2
0
0
45
90
135
180
225
270
315
360
Rotor Head Azimuth Angle [°]
Resultant Angle of Attack αres at
Blade Radial Station r/R = 0.7 [Deg.]
Modification of Local Angle of Attack through IBC
15
x
Ω
with IBC
-
Baseline
r
ψ
10
++
y
+
5
+
-
0
0
90
180
270
360
Rotor Azimut Angle ψ [Deg.]
Principle Layout of IBC System
BLADE-ROOT IBC
PITCH ACTUATORS
HYDRAULIC
DISTRIBUTION
CONVENTIONAL
FLIGHT CONTROL
SYSTEM
FEEDBACK
SIGNALS
CONTROL
PANEL
HYDRAULIC
POWER PICK-UP
DIGITAL
COMPUTER
A
HYDRAULIC
MANIFOLD,
MONITORING
AND SHUT-OFF
B
ELEC. & HYDRAUL.
ROTARY TRANSMISSION
IBC POSITION
COMMANDS
IBC Actuator Mounted between Swashplate and
Blade Pitch Horn Replacing the Rigid Pitch Rod
Full Scale UH-60 Rotor Wind Tunnel
Tests conducted at NASA Ames
IBC Inputs and Test Conditions
Large Wind Tunnel at NASA Ames Research Center
Testbed BO-105 S1 with IBC System
IBC Testbed CH-53G 84+02 Operated by WTD 61
Dynamic Components with IBC Mock-Up
IBC Data Processing and Control Computer (ZFL)
and Data Gathering System (WTD 61)
Effect of 0.15deg 5/rev IBC on 6/rev Accelerations
at Main Gear Box and Pilot Seat @120kts
y
x
z
MGB
x
y
z
Pilot
Seat
Effect of 0.15deg 5/rev IBC on z-Vibration Spectrum
at Pilot Seat @120kts
without IBC
with IBC
C.L. Test Sequence @70kts, Single Mode 5/rev IBC
Controlled Variable: 6/rev AccPilz
CL
ref
OL
Phase
Sweep
ref
ref
ref
90%
Predicted Multi Harmonic Vibration Reduction at Main Gear Box
Based on Single Harmonic Flight Test Data (0.15deg IBC at 90kts)
G(AccHGx,AccHGy,AccHGz)
Vibration Reduction [%]
100
Numerically Predicted 6/rev Vibration
Reduction at Main Gear Box (All
Three Axes) Due to Different IBC
Frequency Combinations
80
60
40
20
0
6/rev
4, 6/rev
4, 6, 7/rev
4, 5, 6, 7/rev
Required Amplitudes [deg]
0.35
0.30
Corresponding Amplitudes Required
0.25
0.20
0.15
0.10
0.05
0.00
6/rev
4, 6/rev
4, 6, 7/rev
4, 5, 6, 7/rev
Non-corrected Sound Pressure Level [dB]
Noise Reduction Due to 2/rev 0.66deg IBC at Three
Microphones (65kts, -6deg, Optimum IBC Phase)
103
100
97
94
91
88
85
103
100
97
94
91
88
85
VIAS = 65kts, γ = -6°
Mic #1 (Center)
Mic #2 (Retr. Side)
103
100
Mic #3 (Adv. Side)
97
94
91
88
85
-10
-8
-6
-4
Reference, no IBC
A2 = 0.67°, ϕ2 = 30°
-2
0
2
4
6
8
10
Time [sec] (t=0 at moment of highest sound pressure level)
Flight Performance Relevant Parameters
During 2/rev IBC Phase Sweep
Altitude [ft] VIAS [kts]
Power
Q·Ω [kW]
Level Flight VIAS = 125kts, A2 = 0.67°
2600
w/o IBC
ϕ2 = 0°
= 60°
= 120°
= 180°
= 240°
= 300°
= 359°
2500
2400
2300
135
130
125
120
4500
16 Revs
≈ 5 sec
4000
3500
#1
#2
#3
#4
#5
#6
#7
#8
Data Points
Effect of 2/rev 0.66deg IBC on Power Required (125kts,
Net Effect, Corrected by Speed, Accel. and Heave Effects)
15.00
∆ P [%] (corrected)
More Power Required
10.00
5.00
0.00
-5.00
-10.00
Less Power Required
-15.00
0
60
120
180
240
300
360
IBC Phase Angle ϕ 2 [°]
Reduction of Pitch Link / Actuator Load by Application
of Optimum Phase 2/rev IBC (A2 = 0.66° ϕ2 = 270°)
z Overview
Design
z
z
z
Aerodynamics
Vibrations
Noise
z
z
z
IBC System Design
Integration of IBC-System into CH-53G Testbed
ZFL´s IBC Actuator Evolution
BO 105 WT/T
BO 105 F/T
TSS
CH-53G F/T
UH-60A WT/T
CH-53G IBC Experimental System
Actuator Design
IDS IBC DC test bench with reversed
kinematics non rotating ↔ rotating
hydraulic manifold
4 IBC actuators
IBC DC pump
pump control unit
in drive cage
torque/speed sensor
11 kW electrical drive
electrical slip ring
Adaptation of Existing IDS to Lynx Rotor Hub
InHuS: Innovative Integrated Primary and
Individual Blade Control System for Helicopters
IDS:
Integration of Both
Primary Control and
IBC into
Gearbox/Rotorhub
InHuS:
Control System in the
Rotating Frame at Blade
Root, Combining Both
Primary Control and IBC
Using One Actuation System
IBC:
Hydraulic and Electrical
Individual Blade
Control Systems with
High Bandwidth but
Low Authority
InHuS: Innovative Integrated Primary and
Individual Blade Control System for Helicopters
(preliminary design)
z Overview
Design
z
z
z
Aerodynamics
Vibrations
Noise
z
z
z
IBC System Design
Conclusion
z Helicopter versatile aircraft
z Complex aerodynamics of main rotor in
forward flight causes performance
restrictions
z advanced main rotor blade control can
reduce vibation & noise and extend flight
envelope
z extensive research work on IBC effects
has been done
z world-wide development activites of the
helicopter industry in the field of
application to production helicopters

Individual Blade Control

Transcription

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