Low-Reynolds-Number Aerodynamic Characteristics of ...
LOW-REYNOLDS-NUMBER AERODYNAMIC CHARACTERISTICS OF NACA 0012 AIRFOIL SECTION AT ANGLE OF ATTACK FROM 0° TO 180° CHENGWEI DAI (NAVAL ARCHITECTURE AND MARINE ENGINEERING, UNIVERSITY OF MICHIGAN) 12/10/2013
BACKGROUND Commonly used in Rotary-wing
Aircraft Large angle of attack Decreasing in Reynolds Number, eg.
Quadrotor
http://www.sikorskyarchives.com/S+56%20HR2S-1H-37.php
Use CFD simulation to investigate the
aerodynamic characteristics of NA0012 airfoil section http://www.aviationnews.eu/2012/08/06/lockheed-martin-procerus-technologies-unveils-new-unmannedquad-rotor-vertical-take-off-and-landing-system/
TEST MATRIX Reynolds Number
360000
Inflow Velocity, U(m/s)
5.26
y+
5
First cell Thickness, Δy(m)
0.0006
Model before Separation
k-kl-omega
Model after Separation
k-epsilon
Angle of Attacks α(degrees)
0,5,10,15,20,30,50,90,130,160,170,180
MESH AND BOUNDARY CONDITIONS Cmesh
Omesh
Better mesh for the wake
Inlet U, P = 0
Airfoil Wall
Outlet P=0
Inlet U, P = 0
Airfoil Wall
Better numerical stability
Outlet P=0
RESULT
alpha = 0
alpha = 90
alpha = 15
alpha = 170
RESULT 1.5 1
0 0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
-0.5 -1 -1.5
alpha (degrees)
2.5 2
CD
CL
0.5
1.5 1 0.5 0 0
10
20
30
40
50
60
70
80
90
100
Alpha (degrees)
110
120
130
140
150
160
170
180
190
RESULT 1 0.9 0.8 0.7 0.6 0.5 2000
0.7
0.4
2200
2400
2600
2800
3000
3200
3400
0.3 0.2 0.1 0 -0.1
CL with error bar
0.5
CL/CD
CL
1
0 10
alpha (degrees)
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Alpha (degrees)
CL/CD vs alpha
1.5
-0.5
0.6515
0.5
Integration Points
0
CM vs alpha
0.6
CM
CL
CL for alpha = 15 degrees
20
40 36.3219 35 30 25 20 15 10 5 0 -5 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 -10
alpha
CONCLUSION
Maximum CL/CD ratio is 36.32 at 10 degrees of angle of attack (optimization)
Maximum CM is 0.6515 at 130 degrees of angle of attack (most damaging) Recommendation •
Better mesh (large fluid field, more gird, better orthonomalitiy)
•
Use Large Eddy Simulation (LES) Model for turbulence
•
Test more angles of attack
THANK YOU/Q&A
BACKGROUND Commonly used in Rotary-wing
Aircraft Large angle of attack Decreasing in Reynolds Number, eg.
Quadrotor
http://www.sikorskyarchives.com/S+56%20HR2S-1H-37.php
Use CFD simulation to investigate the
aerodynamic characteristics of NA0012 airfoil section http://www.aviationnews.eu/2012/08/06/lockheed-martin-procerus-technologies-unveils-new-unmannedquad-rotor-vertical-take-off-and-landing-system/
TEST MATRIX Reynolds Number
360000
Inflow Velocity, U(m/s)
5.26
y+
5
First cell Thickness, Δy(m)
0.0006
Model before Separation
k-kl-omega
Model after Separation
k-epsilon
Angle of Attacks α(degrees)
0,5,10,15,20,30,50,90,130,160,170,180
MESH AND BOUNDARY CONDITIONS Cmesh
Omesh
Better mesh for the wake
Inlet U, P = 0
Airfoil Wall
Outlet P=0
Inlet U, P = 0
Airfoil Wall
Better numerical stability
Outlet P=0
RESULT
alpha = 0
alpha = 90
alpha = 15
alpha = 170
RESULT 1.5 1
0 0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
-0.5 -1 -1.5
alpha (degrees)
2.5 2
CD
CL
0.5
1.5 1 0.5 0 0
10
20
30
40
50
60
70
80
90
100
Alpha (degrees)
110
120
130
140
150
160
170
180
190
RESULT 1 0.9 0.8 0.7 0.6 0.5 2000
0.7
0.4
2200
2400
2600
2800
3000
3200
3400
0.3 0.2 0.1 0 -0.1
CL with error bar
0.5
CL/CD
CL
1
0 10
alpha (degrees)
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Alpha (degrees)
CL/CD vs alpha
1.5
-0.5
0.6515
0.5
Integration Points
0
CM vs alpha
0.6
CM
CL
CL for alpha = 15 degrees
20
40 36.3219 35 30 25 20 15 10 5 0 -5 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 -10
alpha
CONCLUSION
Maximum CL/CD ratio is 36.32 at 10 degrees of angle of attack (optimization)
Maximum CM is 0.6515 at 130 degrees of angle of attack (most damaging) Recommendation •
Better mesh (large fluid field, more gird, better orthonomalitiy)
•
Use Large Eddy Simulation (LES) Model for turbulence
•
Test more angles of attack
THANK YOU/Q&A
