Importing from USAF Digital DATCOM Files
by admin in Aerospace , Control Systems & Aerospace , MATLAB Family on April 3, 2019This code shows how to bring United States Air Force (USAF) Digital DATCOM files into the MATLAB® environment using the Aerospace Toolbox™ software. All the down described equations and steps are exists in the Matlab files, that you will download after the checkout.
Contents
- Example USAF Digital DATCOM File
- Import Data from DATCOM Files
- Examining Imported DATCOM Data
- Filling in Missing DATCOM Data
- Plotting Aerodynamic Coefficients
Example USAF Digital DATCOM File
Here’s a sample input file for USAF Digital DATCOM for a wing-body-horizontal tail-vertical tail configuration running over 5 alphas, 2 Mach numbers, and 2 altitudes and calculating static and dynamic derivatives:
type astdatcom.in
$FLTCON NMACH=2.0,MACH(1)=0.1,0.2$ $FLTCON NALT=2.0,ALT(1)=5000.0,8000.0$ $FLTCON NALPHA=5.,ALSCHD(1)=-2.0,0.0,2.0, ALSCHD(4)=4.0,8.0,LOOP=2.0$ $OPTINS SREF=225.8,CBARR=5.75,BLREF=41.15$ $SYNTHS XCG=7.08,ZCG=0.0,XW=6.1,ZW=-1.4,ALIW=1.1,XH=20.2, ZH=0.4,ALIH=0.0,XV=21.3,ZV=0.0,VERTUP=.TRUE.$ $BODY NX=10.0, X(1)=-4.9,0.0,3.0,6.1,9.1,13.3,20.2,23.5,25.9, R(1)=0.0,1.0,1.75,2.6,2.6,2.6,2.0,1.0,0.0$ $WGPLNF CHRDTP=4.0,SSPNE=18.7,SSPN=20.6,CHRDR=7.2,SAVSI=0.0,CHSTAT=0.25, TWISTA=-1.1,SSPNDD=0.0,DHDADI=3.0,DHDADO=3.0,TYPE=1.0$ NACA-W-6-64A412 $HTPLNF CHRDTP=2.3,SSPNE=5.7,SSPN=6.625,CHRDR=0.25,SAVSI=11.0, CHSTAT=1.0,TWISTA=0.0,TYPE=1.0$ NACA-H-4-0012 $VTPLNF CHRDTP=2.7,SSPNE=5.0,SSPN=5.2,CHRDR=5.3,SAVSI=31.3, CHSTAT=0.25,TWISTA=0.0,TYPE=1.0$ NACA-V-4-0012 CASEID SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG DAMP NEXT CASE
Here’s the output file generated by USAF Digital DATCOM for the same wing-body-horizontal tail-vertical tail configuration running over 5 alphas, 2 Mach numbers, and 2 altitudes:
type astdatcom.out
THIS SOFTWARE AND ANY ACCOMPANYING DOCUMENTATION
IS RELEASED 'AS IS'. THE U.S. GOVERNMENT MAKES NO
WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, CONCERNING
THIS SOFTWARE AND ANY ACCOMPANYING DOCUMENTATION,
INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
IN NO EVENT WILL THE U.S. GOVERNMENT BE LIABLE FOR ANY
DAMAGES, INCLUDING LOST PROFITS, LOST SAVINGS OR OTHER
INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE, OR INABILITY TO USE, THIS SOFTWARE OR ANY
ACCOMPANYING DOCUMENTATION, EVEN IF INFORMED IN ADVANCE
OF THE POSSIBILITY OF SUCH DAMAGES.
****************************************************
* USAF STABILITY AND CONTROL DIGITAL DATCOM *
* PROGRAM REV. JAN 96 DIRECT INQUIRIES TO: *
* WRIGHT LABORATORY (WL/FIGC) ATTN: W. BLAKE *
* WRIGHT PATTERSON AFB, OHIO 45433 *
* PHONE (513) 255-6764, FAX (513) 258-4054 *
****************************************************
1 CONERR - INPUT ERROR CHECKING
0 ERROR CODES - N* DENOTES THE NUMBER OF OCCURENCES OF EACH ERROR
0 A - UNKNOWN VARIABLE NAME
0 B - MISSING EQUAL SIGN FOLLOWING VARIABLE NAME
0 C - NON-ARRAY VARIABLE HAS AN ARRAY ELEMENT DESIGNATION - (N)
0 D - NON-ARRAY VARIABLE HAS MULTIPLE VALUES ASSIGNED
0 E - ASSIGNED VALUES EXCEED ARRAY DIMENSION
0 F - SYNTAX ERROR
0****************************** INPUT DATA CARDS ******************************
$FLTCON NMACH=2.0,MACH(1)=0.1,0.2$
$FLTCON NALT=2.0,ALT(1)=5000.0,8000.0$
$FLTCON NALPHA=5.,ALSCHD(1)=-2.0,0.0,2.0,
ALSCHD(4)=4.0,8.0,LOOP=2.0$
$OPTINS SREF=225.8,CBARR=5.75,BLREF=41.15$
$SYNTHS XCG=7.08,ZCG=0.0,XW=6.1,ZW=-1.4,ALIW=1.1,XH=20.2,
ZH=0.4,ALIH=0.0,XV=21.3,ZV=0.0,VERTUP=.TRUE.$
$BODY NX=10.0,
X(1)=-4.9,0.0,3.0,6.1,9.1,13.3,20.2,23.5,25.9,
R(1)=0.0,1.0,1.75,2.6,2.6,2.6,2.0,1.0,0.0$
$WGPLNF CHRDTP=4.0,SSPNE=18.7,SSPN=20.6,CHRDR=7.2,SAVSI=0.0,CHSTAT=0.25,
TWISTA=-1.1,SSPNDD=0.0,DHDADI=3.0,DHDADO=3.0,TYPE=1.0$
NACA-W-6-64A412
$HTPLNF CHRDTP=2.3,SSPNE=5.7,SSPN=6.625,CHRDR=0.25,SAVSI=11.0,
CHSTAT=1.0,TWISTA=0.0,TYPE=1.0$
NACA-H-4-0012
$VTPLNF CHRDTP=2.7,SSPNE=5.0,SSPN=5.2,CHRDR=5.3,SAVSI=31.3,
CHSTAT=0.25,TWISTA=0.0,TYPE=1.0$
NACA-V-4-0012
CASEID SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
DAMP
NEXT CASE
1 THE FOLLOWING IS A LIST OF ALL INPUT CARDS FOR THIS CASE.
0
$FLTCON NMACH=2.0,MACH(1)=0.1,0.2$
$FLTCON NALT=2.0,ALT(1)=5000.0,8000.0$
$FLTCON NALPHA=5.,ALSCHD(1)=-2.0,0.0,2.0,
ALSCHD(4)=4.0,8.0,LOOP=2.0$
$OPTINS SREF=225.8,CBARR=5.75,BLREF=41.15$
$SYNTHS XCG=7.08,ZCG=0.0,XW=6.1,ZW=-1.4,ALIW=1.1,XH=20.2,
ZH=0.4,ALIH=0.0,XV=21.3,ZV=0.0,VERTUP=.TRUE.$
$BODY NX=10.0,
X(1)=-4.9,0.0,3.0,6.1,9.1,13.3,20.2,23.5,25.9,
R(1)=0.0,1.0,1.75,2.6,2.6,2.6,2.0,1.0,0.0$
$WGPLNF CHRDTP=4.0,SSPNE=18.7,SSPN=20.6,CHRDR=7.2,SAVSI=0.0,CHSTAT=0.25,
TWISTA=-1.1,SSPNDD=0.0,DHDADI=3.0,DHDADO=3.0,TYPE=1.0$
NACA-W-6-64A412
$HTPLNF CHRDTP=2.3,SSPNE=5.7,SSPN=6.625,CHRDR=0.25,SAVSI=11.0,
CHSTAT=1.0,TWISTA=0.0,TYPE=1.0$
NACA-H-4-0012
$VTPLNF CHRDTP=2.7,SSPNE=5.0,SSPN=5.2,CHRDR=5.3,SAVSI=31.3,
CHSTAT=0.25,TWISTA=0.0,TYPE=1.0$
NACA-V-4-0012
CASEID SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
DAMP
NEXT CASE
0 INPUT DIMENSIONS ARE IN FT, SCALE FACTOR IS 1.0000
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
WING SECTION DEFINITION
0 IDEAL ANGLE OF ATTACK = 0.00000 DEG.
ZERO LIFT ANGLE OF ATTACK = -3.09292 DEG.
IDEAL LIFT COEFFICIENT = 0.40000
ZERO LIFT PITCHING MOMENT COEFFICIENT = -0.08719
MACH ZERO LIFT-CURVE-SLOPE = 0.09654 /DEG.
LEADING EDGE RADIUS = 0.00993 FRACTION CHORD
MAXIMUM AIRFOIL THICKNESS = 0.12000 FRACTION CHORD
DELTA-Y = 2.46808 PERCENT CHORD
0 MACH= 0.1000 LIFT-CURVE-SLOPE = 0.09693 /DEG. XAC = 0.26404
0 MACH= 0.2000 LIFT-CURVE-SLOPE = 0.09811 /DEG. XAC = 0.26457
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
HORIZONTAL TAIL SECTION DEFINITION
0 IDEAL ANGLE OF ATTACK = 0.00000 DEG.
ZERO LIFT ANGLE OF ATTACK = 0.00000 DEG.
IDEAL LIFT COEFFICIENT = 0.00000
ZERO LIFT PITCHING MOMENT COEFFICIENT = 0.00000
MACH ZERO LIFT-CURVE-SLOPE = 0.09596 /DEG.
LEADING EDGE RADIUS = 0.01587 FRACTION CHORD
MAXIMUM AIRFOIL THICKNESS = 0.12000 FRACTION CHORD
DELTA-Y = 3.16898 PERCENT CHORD
0 MACH= 0.1000 LIFT-CURVE-SLOPE = 0.09636 /DEG. XAC = 0.25854
0 MACH= 0.2000 LIFT-CURVE-SLOPE = 0.09761 /DEG. XAC = 0.25881
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
VERTICAL TAIL SECTION DEFINITION
0 IDEAL ANGLE OF ATTACK = 0.00000 DEG.
ZERO LIFT ANGLE OF ATTACK = 0.00000 DEG.
IDEAL LIFT COEFFICIENT = 0.00000
ZERO LIFT PITCHING MOMENT COEFFICIENT = 0.00000
MACH ZERO LIFT-CURVE-SLOPE = 0.09596 /DEG.
LEADING EDGE RADIUS = 0.01587 FRACTION CHORD
MAXIMUM AIRFOIL THICKNESS = 0.12000 FRACTION CHORD
DELTA-Y = 3.16898 PERCENT CHORD
0 MACH= 0.1000 LIFT-CURVE-SLOPE = 0.09636 /DEG. XAC = 0.25854
0 MACH= 0.2000 LIFT-CURVE-SLOPE = 0.09761 /DEG. XAC = 0.25881
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
CHARACTERISTICS AT ANGLE OF ATTACK AND IN SIDESLIP
WING-BODY-VERTICAL TAIL-HORIZONTAL TAIL CONFIGURATION
SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
----------------------- FLIGHT CONDITIONS ------------------------ -------------- REFERENCE DIMENSIONS ------------
MACH ALTITUDE VELOCITY PRESSURE TEMPERATURE REYNOLDS REF. REFERENCE LENGTH MOMENT REF. CENTER
NUMBER NUMBER AREA LONG. LAT. HORIZ VERT
FT FT/SEC LB/FT**2 DEG R 1/FT FT**2 FT FT FT FT
0 0.100 5000.00 109.70 1.7609E+03 500.843 6.1507E+05 225.800 5.750 41.150 7.080 0.000
0 -------------------DERIVATIVE (PER DEGREE)-------------------
0 ALPHA CD CL CM CN CA XCP CLA CMA CYB CNB CLB
0
-2.0 0.032 0.113 -0.0340 0.112 0.035 -0.304 8.926E-02 -2.105E-02 -3.458E-03 9.142E-04 -6.161E-04
0.0 0.035 0.296 -0.0752 0.296 0.035 -0.254 9.350E-02 -2.034E-02 -6.205E-04
2.0 0.042 0.487 -0.1153 0.488 0.025 -0.236 9.732E-02 -1.971E-02 -6.268E-04
4.0 0.052 0.685 -0.1541 0.687 0.004 -0.224 1.005E-01 -1.927E-02 -6.349E-04
8.0 0.084 1.098 -0.2304 1.099 -0.069 -0.210 1.059E-01 -1.890E-02 -6.554E-04
0 ALPHA Q/QINF EPSLON D(EPSLON)/D(ALPHA)
0
-2.0 1.000 0.953 0.571
0.0 1.000 2.094 0.583
2.0 1.000 3.284 0.606
4.0 1.000 4.520 0.610
8.0 1.000 6.897 0.594
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
DYNAMIC DERIVATIVES
WING-BODY-VERTICAL TAIL-HORIZONTAL TAIL CONFIGURATION
SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
----------------------- FLIGHT CONDITIONS ------------------------ -------------- REFERENCE DIMENSIONS ------------
MACH ALTITUDE VELOCITY PRESSURE TEMPERATURE REYNOLDS REF. REFERENCE LENGTH MOMENT REF. CENTER
NUMBER NUMBER AREA LONG. LAT. HORIZ VERT
FT FT/SEC LB/FT**2 DEG R 1/FT FT**2 FT FT FT FT
0 0.100 5000.00 109.70 1.7609E+03 500.843 6.1507E+05 225.800 5.750 41.150 7.080 0.000
DYNAMIC DERIVATIVES (PER DEGREE)
0 -------PITCHING------- -----ACCELERATION------ --------------ROLLING-------------- --------YAWING--------
0 ALPHA CLQ CMQ CLAD CMAD CLP CYP CNP CNR CLR
0
-2.00 9.739E-02 -8.918E-02 1.874E-02 -4.247E-02 -7.824E-03 -1.516E-03 -1.498E-04 -1.059E-03 6.334E-04
0.00 1.913E-02 -4.336E-02 -8.226E-03 -1.649E-03 -4.034E-04 -1.068E-03 1.240E-03
2.00 1.991E-02 -4.512E-02 -8.599E-03 -1.792E-03 -6.631E-04 -1.073E-03 1.878E-03
4.00 2.003E-02 -4.540E-02 -8.890E-03 -1.942E-03 -9.290E-04 -1.073E-03 2.542E-03
8.00 1.952E-02 -4.424E-02 -9.387E-03 -2.262E-03 -1.479E-03 -1.060E-03 3.926E-03
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
CHARACTERISTICS AT ANGLE OF ATTACK AND IN SIDESLIP
WING-BODY-VERTICAL TAIL-HORIZONTAL TAIL CONFIGURATION
SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
----------------------- FLIGHT CONDITIONS ------------------------ -------------- REFERENCE DIMENSIONS ------------
MACH ALTITUDE VELOCITY PRESSURE TEMPERATURE REYNOLDS REF. REFERENCE LENGTH MOMENT REF. CENTER
NUMBER NUMBER AREA LONG. LAT. HORIZ VERT
FT FT/SEC LB/FT**2 DEG R 1/FT FT**2 FT FT FT FT
0 0.200 5000.00 219.39 1.7609E+03 500.843 1.2301E+06 225.800 5.750 41.150 7.080 0.000
0 -------------------DERIVATIVE (PER DEGREE)-------------------
0 ALPHA CD CL CM CN CA XCP CLA CMA CYB CNB CLB
0
-2.0 0.028 0.114 -0.0335 0.113 0.032 -0.297 9.000E-02 -2.124E-02 -3.465E-03 8.781E-04 -6.226E-04
0.0 0.031 0.298 -0.0751 0.298 0.031 -0.252 9.421E-02 -2.051E-02 -6.270E-04
2.0 0.038 0.491 -0.1155 0.492 0.021 -0.235 9.800E-02 -1.987E-02 -6.332E-04
4.0 0.048 0.690 -0.1546 0.692 0.000 -0.223 1.011E-01 -1.943E-02 -6.413E-04
8.0 0.081 1.105 -0.2316 1.106 -0.074 -0.209 1.065E-01 -1.906E-02 -6.614E-04
0 ALPHA Q/QINF EPSLON D(EPSLON)/D(ALPHA)
0
-2.0 1.000 0.957 0.573
0.0 1.000 2.103 0.585
2.0 1.000 3.297 0.609
4.0 1.000 4.537 0.612
8.0 1.000 6.923 0.596
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
DYNAMIC DERIVATIVES
WING-BODY-VERTICAL TAIL-HORIZONTAL TAIL CONFIGURATION
SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
----------------------- FLIGHT CONDITIONS ------------------------ -------------- REFERENCE DIMENSIONS ------------
MACH ALTITUDE VELOCITY PRESSURE TEMPERATURE REYNOLDS REF. REFERENCE LENGTH MOMENT REF. CENTER
NUMBER NUMBER AREA LONG. LAT. HORIZ VERT
FT FT/SEC LB/FT**2 DEG R 1/FT FT**2 FT FT FT FT
0 0.200 5000.00 219.39 1.7609E+03 500.843 1.2301E+06 225.800 5.750 41.150 7.080 0.000
DYNAMIC DERIVATIVES (PER DEGREE)
0 -------PITCHING------- -----ACCELERATION------ --------------ROLLING-------------- --------YAWING--------
0 ALPHA CLQ CMQ CLAD CMAD CLP CYP CNP CNR CLR
0
-2.00 9.840E-02 -8.993E-02 1.900E-02 -4.307E-02 -7.877E-03 -1.525E-03 -1.499E-04 -1.057E-03 6.448E-04
0.00 1.940E-02 -4.398E-02 -8.276E-03 -1.659E-03 -4.038E-04 -1.066E-03 1.264E-03
2.00 2.018E-02 -4.574E-02 -8.646E-03 -1.802E-03 -6.637E-04 -1.070E-03 1.915E-03
4.00 2.030E-02 -4.602E-02 -8.934E-03 -1.953E-03 -9.297E-04 -1.070E-03 2.593E-03
8.00 1.978E-02 -4.483E-02 -9.423E-03 -2.273E-03 -1.479E-03 -1.057E-03 4.003E-03
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
CHARACTERISTICS AT ANGLE OF ATTACK AND IN SIDESLIP
WING-BODY-VERTICAL TAIL-HORIZONTAL TAIL CONFIGURATION
SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
----------------------- FLIGHT CONDITIONS ------------------------ -------------- REFERENCE DIMENSIONS ------------
MACH ALTITUDE VELOCITY PRESSURE TEMPERATURE REYNOLDS REF. REFERENCE LENGTH MOMENT REF. CENTER
NUMBER NUMBER AREA LONG. LAT. HORIZ VERT
FT FT/SEC LB/FT**2 DEG R 1/FT FT**2 FT FT FT FT
0 0.100 8000.00 108.52 1.5721E+03 490.151 5.6457E+05 225.800 5.750 41.150 7.080 0.000
0 -------------------DERIVATIVE (PER DEGREE)-------------------
0 ALPHA CD CL CM CN CA XCP CLA CMA CYB CNB CLB
0
-2.0 0.032 0.113 -0.0340 0.112 0.036 -0.305 8.926E-02 -2.106E-02 -3.458E-03 9.190E-04 -6.161E-04
0.0 0.035 0.296 -0.0753 0.296 0.035 -0.254 9.350E-02 -2.034E-02 -6.205E-04
2.0 0.042 0.487 -0.1154 0.488 0.025 -0.236 9.732E-02 -1.971E-02 -6.268E-04
4.0 0.052 0.685 -0.1541 0.687 0.004 -0.224 1.005E-01 -1.927E-02 -6.349E-04
8.0 0.085 1.098 -0.2304 1.099 -0.069 -0.210 1.059E-01 -1.891E-02 -6.554E-04
0 ALPHA Q/QINF EPSLON D(EPSLON)/D(ALPHA)
0
-2.0 1.000 0.953 0.571
0.0 1.000 2.094 0.583
2.0 1.000 3.284 0.606
4.0 1.000 4.520 0.610
8.0 1.000 6.897 0.594
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
DYNAMIC DERIVATIVES
WING-BODY-VERTICAL TAIL-HORIZONTAL TAIL CONFIGURATION
SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
----------------------- FLIGHT CONDITIONS ------------------------ -------------- REFERENCE DIMENSIONS ------------
MACH ALTITUDE VELOCITY PRESSURE TEMPERATURE REYNOLDS REF. REFERENCE LENGTH MOMENT REF. CENTER
NUMBER NUMBER AREA LONG. LAT. HORIZ VERT
FT FT/SEC LB/FT**2 DEG R 1/FT FT**2 FT FT FT FT
0 0.100 8000.00 108.52 1.5721E+03 490.151 5.6457E+05 225.800 5.750 41.150 7.080 0.000
DYNAMIC DERIVATIVES (PER DEGREE)
0 -------PITCHING------- -----ACCELERATION------ --------------ROLLING-------------- --------YAWING--------
0 ALPHA CLQ CMQ CLAD CMAD CLP CYP CNP CNR CLR
0
-2.00 9.739E-02 -8.918E-02 1.874E-02 -4.247E-02 -7.824E-03 -1.516E-03 -1.498E-04 -1.060E-03 6.334E-04
0.00 1.913E-02 -4.336E-02 -8.226E-03 -1.649E-03 -4.034E-04 -1.069E-03 1.240E-03
2.00 1.991E-02 -4.512E-02 -8.599E-03 -1.792E-03 -6.631E-04 -1.073E-03 1.878E-03
4.00 2.003E-02 -4.540E-02 -8.890E-03 -1.942E-03 -9.290E-04 -1.074E-03 2.542E-03
8.00 1.952E-02 -4.424E-02 -9.387E-03 -2.262E-03 -1.479E-03 -1.061E-03 3.926E-03
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
CHARACTERISTICS AT ANGLE OF ATTACK AND IN SIDESLIP
WING-BODY-VERTICAL TAIL-HORIZONTAL TAIL CONFIGURATION
SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
----------------------- FLIGHT CONDITIONS ------------------------ -------------- REFERENCE DIMENSIONS ------------
MACH ALTITUDE VELOCITY PRESSURE TEMPERATURE REYNOLDS REF. REFERENCE LENGTH MOMENT REF. CENTER
NUMBER NUMBER AREA LONG. LAT. HORIZ VERT
FT FT/SEC LB/FT**2 DEG R 1/FT FT**2 FT FT FT FT
0 0.200 8000.00 217.04 1.5721E+03 490.151 1.1291E+06 225.800 5.750 41.150 7.080 0.000
0 -------------------DERIVATIVE (PER DEGREE)-------------------
0 ALPHA CD CL CM CN CA XCP CLA CMA CYB CNB CLB
0
-2.0 0.028 0.114 -0.0335 0.113 0.032 -0.297 9.000E-02 -2.124E-02 -3.465E-03 8.829E-04 -6.226E-04
0.0 0.031 0.298 -0.0751 0.298 0.031 -0.252 9.421E-02 -2.051E-02 -6.270E-04
2.0 0.038 0.491 -0.1156 0.492 0.021 -0.235 9.800E-02 -1.987E-02 -6.332E-04
4.0 0.049 0.690 -0.1546 0.692 0.000 -0.223 1.011E-01 -1.943E-02 -6.413E-04
8.0 0.081 1.105 -0.2316 1.106 -0.073 -0.209 1.065E-01 -1.906E-02 -6.614E-04
0 ALPHA Q/QINF EPSLON D(EPSLON)/D(ALPHA)
0
-2.0 1.000 0.957 0.573
0.0 1.000 2.103 0.585
2.0 1.000 3.297 0.609
4.0 1.000 4.537 0.612
8.0 1.000 6.923 0.596
1 AUTOMATED STABILITY AND CONTROL METHODS PER APRIL 1976 VERSION OF DATCOM
DYNAMIC DERIVATIVES
WING-BODY-VERTICAL TAIL-HORIZONTAL TAIL CONFIGURATION
SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG
----------------------- FLIGHT CONDITIONS ------------------------ -------------- REFERENCE DIMENSIONS ------------
MACH ALTITUDE VELOCITY PRESSURE TEMPERATURE REYNOLDS REF. REFERENCE LENGTH MOMENT REF. CENTER
NUMBER NUMBER AREA LONG. LAT. HORIZ VERT
FT FT/SEC LB/FT**2 DEG R 1/FT FT**2 FT FT FT FT
0 0.200 8000.00 217.04 1.5721E+03 490.151 1.1291E+06 225.800 5.750 41.150 7.080 0.000
DYNAMIC DERIVATIVES (PER DEGREE)
0 -------PITCHING------- -----ACCELERATION------ --------------ROLLING-------------- --------YAWING--------
0 ALPHA CLQ CMQ CLAD CMAD CLP CYP CNP CNR CLR
0
-2.00 9.840E-02 -8.993E-02 1.900E-02 -4.307E-02 -7.877E-03 -1.525E-03 -1.499E-04 -1.057E-03 6.448E-04
0.00 1.940E-02 -4.398E-02 -8.276E-03 -1.659E-03 -4.038E-04 -1.066E-03 1.264E-03
2.00 2.018E-02 -4.574E-02 -8.646E-03 -1.802E-03 -6.637E-04 -1.071E-03 1.915E-03
4.00 2.030E-02 -4.602E-02 -8.934E-03 -1.953E-03 -9.297E-04 -1.071E-03 2.593E-03
8.00 1.978E-02 -4.483E-02 -9.424E-03 -2.273E-03 -1.479E-03 -1.057E-03 4.003E-03
1 THE FOLLOWING IS A LIST OF ALL INPUT CARDS FOR THIS CASE.
0
1 END OF JOB.
Import Data from DATCOM Files
Use the datcomimport function to bring the Digital DATCOM data into MATLAB.
alldata = datcomimport('astdatcom.out', true, 0);
Examining Imported DATCOM Data
The datcomimport function creates a cell array of structures containing the data from the Digital DATCOM output file.
data = alldata{1}
data =
struct with fields:
case: 'SKYHOGG BODY-WING-HORIZONTAL TAIL-VERTICAL TAIL CONFIG'
mach: [0.1000 0.2000]
alt: [5000 8000]
alpha: [-2 0 2 4 8]
nmach: 2
nalt: 2
nalpha: 5
rnnub: []
hypers: 0
loop: 2
sref: 225.8000
cbar: 5.7500
blref: 41.1500
dim: 'ft'
deriv: 'deg'
stmach: 0.6000
tsmach: 1.4000
save: 0
stype: []
trim: 0
damp: 1
build: 1
part: 0
highsym: 0
highasy: 0
highcon: 0
tjet: 0
hypeff: 0
lb: 0
pwr: 0
grnd: 0
wsspn: 18.7000
hsspn: 5.7000
ndelta: 0
delta: []
deltal: []
deltar: []
ngh: 0
grndht: []
config: [1x1 struct]
version: 1976
cd: [5x2x2 double]
cl: [5x2x2 double]
cm: [5x2x2 double]
cn: [5x2x2 double]
ca: [5x2x2 double]
xcp: [5x2x2 double]
cma: [5x2x2 double]
cyb: [5x2x2 double]
cnb: [5x2x2 double]
clb: [5x2x2 double]
cla: [5x2x2 double]
qqinf: [5x2x2 double]
eps: [5x2x2 double]
depsdalp: [5x2x2 double]
clq: [5x2x2 double]
cmq: [5x2x2 double]
clad: [5x2x2 double]
cmad: [5x2x2 double]
clp: [5x2x2 double]
cyp: [5x2x2 double]
cnp: [5x2x2 double]
cnr: [5x2x2 double]
clr: [5x2x2 double]
Filling in Missing DATCOM Data
By default, missing data points are set to 99999 and data points are set to NaN where no DATCOM methods exist or where the method is not applicable.
It can be seen in the Digital DATCOM output file and examining the imported data that
have data only in the first alpha value. Here are the imported data values.
data.cyb
ans(:,:,1) =
1.0e+04 *
-0.0000 -0.0000
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
ans(:,:,2) =
1.0e+04 *
-0.0000 -0.0000
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
data.cnb
ans(:,:,1) =
1.0e+04 *
0.0000 0.0000
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
ans(:,:,2) =
1.0e+04 *
0.0000 0.0000
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
data.clq
ans(:,:,1) =
1.0e+04 *
0.0000 0.0000
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
ans(:,:,2) =
1.0e+04 *
0.0000 0.0000
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
data.cmq
ans(:,:,1) =
1.0e+04 *
-0.0000 -0.0000
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
ans(:,:,2) =
1.0e+04 *
-0.0000 -0.0000
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
9.9999 9.9999
The missing data points will be filled with the values for the first alpha, since these data points are meant to be used for all alpha values.
aerotab = {'cyb' 'cnb' 'clq' 'cmq'};
for k = 1:length(aerotab)
for m = 1:data.nmach
for h = 1:data.nalt
data.(aerotab{k})(:,m,h) = data.(aerotab{k})(1,m,h);
end
end
end
Here are the updated imported data values:
data.cyb
ans(:,:,1) = -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 ans(:,:,2) = -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035 -0.0035
data.cnb
ans(:,:,1) =
1.0e-03 *
0.9142 0.8781
0.9142 0.8781
0.9142 0.8781
0.9142 0.8781
0.9142 0.8781
ans(:,:,2) =
1.0e-03 *
0.9190 0.8829
0.9190 0.8829
0.9190 0.8829
0.9190 0.8829
0.9190 0.8829
data.clq
ans(:,:,1) =
0.0974 0.0984
0.0974 0.0984
0.0974 0.0984
0.0974 0.0984
0.0974 0.0984
ans(:,:,2) =
0.0974 0.0984
0.0974 0.0984
0.0974 0.0984
0.0974 0.0984
0.0974 0.0984
data.cmq
ans(:,:,1) = -0.0892 -0.0899 -0.0892 -0.0899 -0.0892 -0.0899 -0.0892 -0.0899 -0.0892 -0.0899 ans(:,:,2) = -0.0892 -0.0899 -0.0892 -0.0899 -0.0892 -0.0899 -0.0892 -0.0899 -0.0892 -0.0899
Plotting Aerodynamic Coefficients
Plot lift curve, drag polar and pitching moments.
h1 = figure;
figtitle = {'Lift Curve' ''};
for k=1:2
subplot(2,1,k)
plot(data.alpha,permute(data.cl(:,k,:),[1 3 2]))
grid
ylabel(['Lift Coefficient (Mach =' num2str(data.mach(k)) ')'])
title(figtitle{k});
end
xlabel('Angle of Attack (deg)')
h2 = figure;
figtitle = {'Drag Polar' ''};
for k=1:2
subplot(2,1,k)
plot(permute(data.cd(:,k,:),[1 3 2]),permute(data.cl(:,k,:),[1 3 2]))
grid
ylabel(['Lift Coefficient (Mach =' num2str(data.mach(k)) ')'])
title(figtitle{k})
end
xlabel('Drag Coefficient')
h3 = figure;
figtitle = {'Pitching Moment' ''};
for k=1:2
subplot(2,1,k)
plot(permute(data.cm(:,k,:),[1 3 2]),permute(data.cl(:,k,:),[1 3 2]))
grid
ylabel(['Lift Coefficient (Mach =' num2str(data.mach(k)) ')'])
title(figtitle{k})
end
xlabel('Pitching Moment Coefficient')
close(h1,h2,h3);
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