INSTITUTE OF SPACE TECHNOLOGY
Flight Dynamics and Stability
Assignment No. 5
Assignment: Problems 4.3 to 4.6, 4.9 to 4.16, 4.18 to 4.21
Submitted to: Dr Jamshed Riaz
Dated: 17/12/20
Batch/Section: Aero 17A
Submitted by:
Name of student Registration No. Marks offered
Muhammad Salman Sajid 180101042
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
1 ASSIGNMENT QUESTIONS
1.1 Note:
• All relevant MATLAB codes and Graphs are given in the APPENDIX at the end of this
assignment.
• In questions 4.12, 4.18 and 4.21 you might find that my answers deviate from those by
which you are comparing. This is because I took u0 = 283.47 ft/s using L = W and
assuming it was steady-level flight, whereas it was 220 ft/s found by the formula M = V/a
where a = 1100 ft/s and M was given in Appendix B as M = 0.2 which I didn’t notice
originally when I started solving question 4.12 and until I was done with question 4.20.
So, you’re welcome to deduct any marks from these questions :)
2
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
3
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
4
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
5
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
6
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
7
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
8
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
9
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
10
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
11
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
12
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
13
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
14
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
15
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
16
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
17
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
18
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
19
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
20
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
21
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
22
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
23
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
2 APPENDEX
2.1 Q)4.5
2.1.1 Code:
%4.15
B = [2 -3 1;3 1 2;-5 2 -4]
eig(B)
[V,D] = eig(B)
2.2 Q)4.11
2.2.1 Code:
A = [ -2 1 ; -10 0 ];
B = [ 0 -5 ]';
C = [ 1 0 ; 0 1 ];
D = 0;
eigenvalues = eig(A)
sys = ss(A,B,C,D);
step(sys)
2.2.2 Unit Step Response Graph
24
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
2.3 Q)4.18
2.3.1 Code:
%4.18 Eigenvalues Function
%Taking values of flight conditions and aircraft data
rho = input('Enter value of density(rho):');
uo = input('Enter value of velocity(uo):');
c = input('Enter value of chord(c):');
S = input('Enter wing area (S):');
W = input('Enter weight of the aircraft(W):');
g = input('Enter value of acceleration due to gravity(g):');
m = W/g;
Q = 0.5*rho*(uo^2);
%Taking values of stability derivative coefficents
Cdu = input('Enter value of Cdu:');
Cdo = input('Enter value of Cdo:');
Clu = input('Enter value of Clu:');
Clo = input('Enter value of Clo:');
Cda = input('Enter value of Cda:');
Cmu = input('Enter value of Cmu:');
Cma = input('Enter value of Cma:');
Iy = input('Enter value of moment of inertia about y(Iy):');
25
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
Cmadot = input('Enter value of Cmadot:');
Cmq = input('Enter value of Cmq:');
Cla = input('Enter value of Cla:');
%Defining stability derivatives
Xu = (-(Cdu+(2*Cdo))*Q*S)/(m*uo);
Xw = ((-(Cda-Clo))*Q*S)/(m*uo);
Zu = (-(Clu+(2*Clo))*Q*S)/(m*uo);
Zw = ((-(Cla-Cdo))*Q*S)/(m*uo);
Mu = (Cmu*(Q*S*c))/(uo*Iy);
Mw = (Cma*(Q*S*c))/(uo*Iy);
Mwdot = Cmadot*(c/(2*uo))*((Q*S*c)/(uo*Iy));
Mq = Cmq*(c/(2*uo))*((Q*S*c)/Iy);
A = [ Xu Xw 0 -g ; Zu Zw uo 0 ; Mu+(Mwdot*Zu) Mw+(Mwdot*Zw) Mq+(Mwdot*uo) 0 ;
0 0 1 0 ];
eigenvalues = eig(A)
2.3.2 Relevant inputs and output
26
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
2.4 Q)4.19
2.4.1 Code:
%4.19 Eigenvalues Function
%Taking values of flight conditions and aircraft data
rho = input('Enter value of density(rho):');
uo = input('Enter value of velocity(uo):');
c = input('Enter value of chord(c):');
S = input('Enter wing area (S):');
W = input('Enter weight of the aircraft(W):');
g = input('Enter value of acceleration due to gravity(g):');
m = W/g;
Q = 0.5*rho*(uo^2);
%Taking values of stability derivative coefficents
Cdu = input('Enter value of Cdu:');
Cdo = input('Enter value of Cdo:');
Clu = input('Enter value of Clu:');
Clo = input('Enter value of Clo:');
Cda = input('Enter value of Cda:');
Cmu = input('Enter value of Cmu:');
Cma = input('Enter value of Cma:');
Iy = input('Enter value of moment of inertia about y(Iy):');
Cmadot = input('Enter value of Cmadot:');
Cmq = input('Enter value of Cmq:');
Cla = input('Enter value of Cla:');
%Defining stability derivatives
Xu = (-(Cdu+(2*Cdo))*Q*S)/(m*uo);
Xw = ((-(Cda-Clo))*Q*S)/(m*uo);
Zu = (-(Clu+(2*Clo))*Q*S)/(m*uo);
Zw = ((-(Cla-Cdo))*Q*S)/(m*uo);
Mu = (Cmu*(Q*S*c))/(uo*Iy);
Mw = (Cma*(Q*S*c))/(uo*Iy);
Mwdot = Cmadot*(c/(2*uo))*((Q*S*c)/(uo*Iy));
Mq = Cmq*(c/(2*uo))*((Q*S*c)/Iy);
A = [ Xu Xw 0 -g ; Zu Zw uo 0 ; Mu+(Mwdot*Zu) Mw+(Mwdot*Zw) Mq+(Mwdot*uo) 0 ;
0 0 1 0 ];
eigenvalues = eig(A)
27
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
2.4.2 Relevant Inputs and output
2.5 Q)4.20
2.5.1 Code:
%4.20 For STOL Aircraft in Appendix B
%Taking values of flight conditions and aircraft data
rho = 0.002378;
uo = 154.0556159;
c = 10.1;
S = 945;
W = 40000;
g = 32.174;
m = W/g;
Q = 0.5*rho*(uo^2);
28
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
%Taking values of stability derivative coefficents
Cdu = 0;
Cdo = 0.127;
Clu = 0;
Clo = 1.5;
Cda = 0.67;
Cmu = 0;
Cma = -0.78;
Iy = 215000;
Cmadot = -6.05;
Cmq = -35.6;
Cmdele = -2.12;
Czdele = -0.465; %As Czdele = -Cldele
Cla = 5.24;
%Defining stability derivatives
Xu = (-(Cdu+(2*Cdo))*Q*S)/(m*uo);
Xw = ((-(Cda-Clo))*Q*S)/(m*uo);
Xdele = 0;
Zu = (-(Clu+(2*Clo))*Q*S)/(m*uo);
Zw = ((-(Cla-Cdo))*Q*S)/(m*uo);
Zdele = (Q*S*Czdele)/m;
Mu = (Cmu*(Q*S*c))/(uo*Iy);
Mw = (Cma*(Q*S*c))/(uo*Iy);
Mwdot = Cmadot*(c/(2*uo))*((Q*S*c)/(uo*Iy));
Mq = Cmq*(c/(2*uo))*((Q*S*c)/Iy);
Mdele = (Q*S*c*Cmdele)/Iy;
A = [ Xu Xw 0 -g ; Zu Zw uo 0 ; Mu+(Mwdot*Zu) Mw+(Mwdot*Zw) Mq+(Mwdot*uo) 0 ;
0 0 1 0 ]
B = [ Xdele ; Zdele ; Mdele+(Mwdot*Zdele) ; 0 ]
C = [ 1 0 0 0; 0 1 0 0; 0 0 1 0; 0 0 0 1 ];
D = 0;
sys = ss(A,B,C,D);
eigenvalues = eig(A)
step(-0.1*sys);
2.5.2 Output
29
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
2.5.3 -0.1 Step Input Graph
30
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
2.6 Q)4.21
2.6.1 Code:
%4.21 Pzmaps for Executive business jet
%Taking values of flight conditions and aircraft data
rho = 0.002378;
uo = 283.47;
c = 10.93;
S = 542.5;
W = 38200;
g = 32.174;
m = W/g;
Q = 0.5*rho*(uo^2);
%Taking values of stability derivative coefficents
Cdu = 0; %Changing value to 1 %Variable 4 to change Cxu
Cdo = 0.095;
Clu = 0;
Clo = 0.737;
Cda = 0.75;
Cmu = 0;
Cma = -0.8; %Changing value to -1 %Variable 1
Iy = 135869;
Cmadot = -3;
Cmq = -8; %Changing value to -30 %Variable 2
Cmdele = -0.81;
Czdele = -0.4; %As Czdele = -Cldele
Cla = 5; %Changing value to 6 %Variable 3 to change Cza
%Defining stability derivatives
Xu = (-(Cdu+(2*Cdo))*Q*S)/(m*uo);
Xw = ((-(Cda-Clo))*Q*S)/(m*uo);
Xdele = 0;
Zu = (-(Clu+(2*Clo))*Q*S)/(m*uo);
Zw = ((-(Cla-Cdo))*Q*S)/(m*uo);
Zdele = (Q*S*Czdele)/m;
Mu = (Cmu*(Q*S*c))/(uo*Iy);
Mw = (Cma*(Q*S*c))/(uo*Iy);
Mwdot = Cmadot*(c/(2*uo))*((Q*S*c)/(uo*Iy));
Mq = Cmq*(c/(2*uo))*((Q*S*c)/Iy);
Mdele = (Q*S*c*Cmdele)/Iy;
A = [ Xu Xw 0 -g ; Zu Zw uo 0 ; Mu+(Mwdot*Zu) Mw+(Mwdot*Zw) Mq+(Mwdot*uo) 0 ;
0 0 1 0 ]
B = [ Xdele ; Zdele ; Mdele+(Mwdot*Zdele) ; 0 ]
C = [ 1 0 0 0; 0 1 0 0; 0 0 1 0; 0 0 0 1 ];
D = 0;
sys = ss(A,B,C,D);
pzmap(sys)
31
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
2.6.2 Pole-zero Graphs
32
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
33
Department of Aeronautics and Astronautics
INSTITUTE OF SPACE TECHNOLOGY
34
Department of Aeronautics and Astronautics