Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
Transcript of Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
1/117
8 th AIAA Multidisciplinary Design Optimization Specialist Conference
Jia Xu, Ilan KrooAircraft Design Group
Stanford University
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
2/117
Boeing Sugar Volt (Bradley and Droney, 2011)
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
3/117
Structural EnablersActive load alleviation
Strut-braced wings
Aerodynamic FeaturesVery high span
Natural laminar flow
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
4/117
15-25% wing weight reductionfrom active load alleviation
Assumed transition Reynoldsnumber: 15-17 million
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
5/117
Incorporate active load alleviation andnatural laminar flow into conceptual design
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
6/117
Motivation
Use active control to increaseeffective structural efficiency
Invest structural savings to
enable natural laminar flow
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
7/117
Design Studies
Conclusion
Active Load Alleviation
Design Optimization
Natural Laminar Flow
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
8/117
NLF can produce 5-12% fuel burn savings(Joslin 1998, Green 2008, Allison 2010)Performance subject to multidisciplinary
tradeoffsWing sweep is a critical trade at transonic speed
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
9/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
10/117 Adopted from Rajnarayan and Sturdza (2011)
0
5
10
15
20
25
3035
40
0 10 20 30 40
S w e e p (
D e g
)
Transition Reynolds Number (Million)
NLF Region
Active LFC
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
11/117
0
5
10
15
20
25
3035
40
0 10 20 30 40
S w e e p (
D e g
)
Transition Reynolds Number (Million)
NLF Region
Active LFC
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
12/117
0
5
10
15
20
25
30
35
40
0 10 20 30 40
S w e e p (
D e g
)
Transition Reynolds Number (Million)
NLF Region
Active LFC
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
13/117
0
5
10
15
20
25
30
35
40
0 10 20 30 40
S w e e p (
D e g
)
Transition Reynolds Number (Million)
NLF Region
Active LFC
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
14/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
15/117
Slow downPotentially increased direct operating cost (DOC)Challenge for air traffic control (ATC)
Increase structural efficiencyStrut/truss braced wing (Gur et al., 2010) Active load alleviation
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
16/117
Design Studies
Conclusion
Design Optimization
Natural Laminar Flow
Active Load Alleviation
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
17/117
Reduce wing stresses under limit conditionsManeuver Load Alleviation (MLA)
Respond to commanded pseudo-static maneuvers
Gust Load Alleviation (GLA)Respond to unanticipated atmospheric turbulencePerformance limited by sensor and actuatorbandwidths
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
18/117
Maneuver lift
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
19/117
Maneuver lift with MLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
20/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
21/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
22/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
23/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
24/117
1-Cosine gust (FAR Part 25)
3 gust encounter flight conditions
8 gust gradient lengths from 35 to 600 ft
Simulations include both aircraft and wing structural dynamics
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
25/117
GLA system use control surface deflections to reducedynamic stresses in gust encountersDynamic control problem
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
26/117
Design Studies
Conclusion
Natural Laminar Flow
Design Optimization
Active Load Alleviation
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
27/117
Program for Aircraft Synthesis Studies (Kroo,1992)
Extended for aeroservoelastic design
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
28/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
29/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
30/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
31/117
W i i l th d ith
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
32/117
Inverse wing design module withboundary layer solver andtransition model
Linear hexagonal wing boxmodel for stress and load-bearing weight calculations
Aircraft dynamic simulation andFEM/modal solution of structuredynamic response
Weissinger panel method withcompressibility corrections tomodel loads and stabilityderivatives
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
33/117
Inverse wing design with integralboundary layer and transition model
Linear hexagonal wing box forstress and load-bearing weightcalculations
Aircraft dynamic simulation andmodal solution of dynamic structuralresponse
Weissinger method withcompressibility corrections to modelloads
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
34/117
Inverse wing design with integralboundary layer and transition model
Linear hexagonal wing box forstress and load-bearing weightcalculations
Aircraft dynamic simulation andmodal solution of dynamic structuralresponse
Weissinger method withcompressibility corrections to modelloads
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
35/117
Inverse wing design with integralboundary layer and transition model
Linear hexagonal wing box forstress and load-bearing weightcalculations
Aircraft dynamic simulation andmodal solution of dynamic structuralresponse
Weissinger method withcompressibility corrections to modelloads
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
36/117
Inverse wing design with integralboundary layer and transition model
Linear hexagonal wing box forstress and load-bearing weightcalculations
Aircraft dynamic simulation andmodal solution of dynamic structuralresponse
Weissinger method withcompressibility corrections to modelloads
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
37/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
38/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
39/117
30 aerodynamic controlpoints along the semi-spanStatic stress constraints:
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
40/117
Lumped mass FEM withlinear modal decompositionDynamic stress constraints:
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
41/117
MLA flap deflections arevariables:
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
42/117
Proportional-derivative GLAcontrol law
Control gains are variables:
Deflection and rate bounds
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
43/117
Method of critical sectionsMaximum lift constraints atcontrol point span stations:
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
44/117
Thin, high span wing is proneto aileron reversal
Aileron effectiveness
constraint:
Strip method to integrateaileron-induced wing torsion
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
45/117
Define C p distributions atexposed sectionsExposed root section is
forced to be turbulentUse sweep/taper theory torelate 2D to 3D pressureSimilar to Campbell (1990)
and Allison et al. (2010)
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
46/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
47/117
Cdc correlated to peak Machnumber (Allison et al., 2010)
l f l f
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
48/117
Solve airfoil geometry from C p distribution
Apply geometry constraints:
l b d l i h
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
49/117
Integral boundary layer withcompressibility correctionsTransition location is posed
as a design variablePredict transition using HR-xcriteria (Wazzan, 1986)Cdp from the Squire-Young
equation (Smith, 1980)
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
50/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
51/117
Gradient-based optimizationMotivated by the large number of design variables
Objective
Cost estimated using an extended ATA method(Thomas, 1966; Liebeck et al. 1995 )
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
52/117
Aircraft and Mission ( 11 )Takeoff weight, engine thrust, tail areaInitial and final cruise altitudes
Takeoff and landing flapWing Geometry ( 33 )
Trapezoidal wing area, sweep, AR, taper and root positionTwist and wing box geometry at breakpoints
Wing Inverse Design ( 40 )Pressure distribution and x-transition at breakpoints
MLA (8)MLA control surface deflections
GLA ( 8)GLA control channel gains
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
53/117
Aircraft and Mission ( 31 )RangeBalanced takeoff and landing field performance2nd segment climb gradientThrust margin for operational climbTrim, tail maximum lift
Stability at all flight conditionsWeight and load factor compatibilityLanding gear geometry and load compatibility
Aileron effectivenessWing fuel volume
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
54/117
Stress and Maximum Lift ( ~50,000 )
Wing maximum lift for all flight conditionsWing stresses in cruise, maneuver and gust
Inverse Design ( 40 )Wing box geometry compatibilitySection C l compatibilityRecovery Mach number limitsTransition location compatibility
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
55/117
Conclusion
Design Optimization
Natural Laminar Flow
Design Studies
Active Load Alleviation
Boeing 737 type aircraft
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
56/117
Boeing 737-type aircraft162 passengers (3-Class)Mach 0.78
2000-nm range Aluminum constructionCFM56-7B class turbofanField length (7800/5600 ft)
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
57/117
T u r b u
l e n
t
L a m
i n a r
Wing sweep of up to 40 degreesForced transition at 5% chord
Wing sweep restricted to less than 10degreesFree transition on upper surfaceForced transition on lower surface at 5%chord
Top surface produce most of the viscous dragContaminants and slat gaps
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
58/117
No Alleviation MLA+GLAMLA GLA
T u r b u
l e n
t
L a m
i n a r
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
59/117
No Alleviation MLA+GLAMLA GLA
T u r b u
l e n
t
L a m
i n a r
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
60/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a
t i v e
C o s t
Turbulent
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
61/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a
t i v e
C o s t
Turbulent
Reference design
at Mach 0.78
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
62/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a
t i v e
C o s t
TurbulentTurbulent MLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
63/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a
t i v e
C o s t
TurbulentTurbulent MLATurbulent GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
64/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a
t i v e
C o s t
TurbulentTurbulent MLATurbulent GLA
Turbulent MLA+GLA
t
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
65/117
No Alleviation MLA+GLAMLA GLA
T u r b u
l e n
t
L a m
i n a r
t
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
66/117
No Alleviation MLA+GLAMLA GLA
T u r b u
l e n
t
L a m
i n a r
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
67/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a t i v e
C o s t
LaminarLaminar MLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
68/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a t i v e
C o s t
LaminarLaminar MLALaminar GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
69/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a t i v e
C o s t
LaminarLaminar MLALaminar GLA
Laminar MLA+GLA
t
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
70/117
No Alleviation MLA+GLAMLA GLA
T u r b u
l e n
t
L a m
i n a r
t
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
71/117
No Alleviation MLA+GLAMLA GLA
T u r b u
l e n
t
L a m
i n a r
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
72/117
Wing Weight Fuel Weight Sea Level Thrust L/ D Cost0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
R e l a
t i v e
V a
l u e
TurbulentTurbulent MLA+GLALaminar MLA+GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
73/117
Wing Weight Fuel Weight Sea Level Thrust L/ D Cost0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
R e l a
t i v e
V a
l u e
TurbulentTurbulent MLA+GLALaminar MLA+GLA
-5%-15%
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
74/117
Wing Weight Fuel Weight Sea Level Thrust L/ D Cost0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
R e l a
t i v e
V a
l u e
Turbulent
Turbulent MLA+GLALaminar MLA+GLA
Weight versus aerodynamics
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
75/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a
t i v e
C o s t
TurbulentTurbulent MLA+GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
76/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a
t i v e
C o s t
TurbulentTurbulent MLA+GLALaminar
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
77/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a
t i v e
C o s t
TurbulentTurbulent MLA+GLALaminar
Laminar MLA+GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
78/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
79/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
80/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
81/117
Up to 25 degrees of wing
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
82/117
sweep Assume that crossflow can be
stabilized with no adverseeffect on T-S stabilityOptimistic model for 3-D NLFwing
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
83/117
0.7 0.72 0.74 0.76 0.78 0.80.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a t i v
e C o s t
Laminar MLA+GLALaminar25 MLA+GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
84/117
Design Optimization
Natural Laminar Flow
Active Load Alleviation
Conclusion
Design Studies
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
85/117
MLA and GLA are complementaryTurbulent MLA+GLA achieves 10% fuel reduction
The combination enables low-sweep NLF wingsLaminar MLA+GLA achieves 15% fuel reduction
Low-sweep MLA+GLA designs can serve asalternatives to crossflow-dominated NLFdesigns
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
86/117
AerodynamicsUnsteady aerodynamicsFlutter and its suppression
ControlSensorsControl power and control allocation
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
87/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
88/117
Allison, Eric. Kroo , I., Aircraft Conceptual Design with LaminarFlow, 2010
Ning, S. and Kroo , I., Multidisciplinary Considerations in the Designof Wings and Wing Tip Devices, Journal of Aircraft, 2010
Rajnarayan, D. Sturdza, P., Extensible Rapid Transition Predictionfor Aircraft Conceptual Design. 29th AIAA Applied AerodynamicsConference, 2011
Wakayama, S. and Kroo , I., Subsonic Wing Planform Design UsingMultidisciplinary Optimization, Journal of Aircraft, 1995
Xu, J, Kroo. I., Aircraft Design with Maneuver and Gust Load Alleviation, 29th AIAA Applied Aerodynamics Conference, 2011
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
89/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
90/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
91/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
92/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
93/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
94/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
95/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
96/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
97/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
98/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
99/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
100/117
Laminar MLA+GLA Laminar-25 MLA+GLA DeltaMTOW (lb) 150920 149140 -1.2%
SLS Thrust (lb) 18128 18050 -0.4%L/D 21 21 0.5%Fuel Burn (lb) 22169 21915 -1.1%DOC (c/pax/nm) 4.86 4.82 -0.8%
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
101/117
Wing Weight Fuel Weight Sea Level Thrust L/ D Cost
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
R e l a t i v
e V a l u e
Laminar
Laminar25
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
102/117
Wing Weight Fuel Weight Sea Level Thrust L/ D Cost
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
R e l a t i v
e V a l u e
Laminar
Laminar25
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
103/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
104/117
Turbulent
Turbulent MLA+GLALaminar MLA+GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
105/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
106/117
Reduced t/c due towing unsweep
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
107/117
Inboard t/c constrained bycompressibility and NLF
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
108/117
Aeroelastic constraintsincrease outboard t/c
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
109/117
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
110/117
0 5 10 15
0.92
0.94
0.96
0.98
1
1.02
1.04
Allowable Load Control Deflection (Deg)
R e l a t i v e
C o s t
Turbulent MLA+GLALaminar MLA+GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
111/117
0 10 20 30 40
0.92
0.94
0.96
0.98
1
1.02
1.04
Load Control Deflection Rate (Deg/ s)
R e l a t i v e
C o s t
Turbulent MLA+GLALaminar MLA+GLA
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
112/117
0.7 0.72 0.74 0.76 0.78 0.8
0.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a t i v e
C o s t
Turbulent MLA+GLALaminar MLA+GLALaminar Bottom Surface
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
113/117
0.7 0.72 0.74 0.76 0.78 0.8
0.92
0.94
0.96
0.98
1
1.02
1.04
Cruise Mach Number
R e l a t i v e
C o s t
Laminar MLA+GLAGLA with aileron
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
114/117
Wing Weight Fuel Weight Sea Level Thrust L/ D Cost
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
R e l a t i v e
V a
l u e
Turbulent MLA+GLAGate constrained
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
115/117
Wing Weight Fuel Weight Sea Level Thrust L/ D Cost
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
R e l a t i v e
V a
l u e
Laminar MLA+GLAGateconstrained
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
116/117
Wing Weight Fuel Weight Sea Level Thrust L/ D Cost
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
R e l a t i v e
V a
l u e
TurbulentGate constrained
-
8/13/2019 Presentation: Aircraft Design with Active Load Alleviation and Natural Laminar Flow
117/117
Long wave gustsHigh amplitudes
Aircraft can rise with the gust
Short wave gusts
Low amplitudesMuch faster than typical wing natural frequencyCan rate-saturate control actuators