Contents

Aircraft takeoff demo.

The aircraft starts on the runway in takeoff mode. When it is moving at the takeoff speed it climbs. You can also try banked turns.

The parameters are for the F-35 fighter. They are only approximate.

This demo uses ACPointMassControl.

Things to try: 1. Switch the mode to turn 2. Determine the ceiling for the aircraft 3. Determine the maximum speed for the aircraft

References: http://en.wikipedia.org/wiki/Pratt_%26_Whitney_F135
            http://en.wikipedia.org/wiki/F-35_Lightning_II

%--------------------------------------------------------------------------

%--------------------------------------------------------------------------
%   Copyright (c) 2013-2014 Princeton Satellite Systems, Inc.
%   All rights reserved.
%--------------------------------------------------------------------------

% Time step
%----------
dT                      = 0.2;
tEnd                    = 200;
n                       = ceil(tEnd/dT);

% Constants
%----------
g                       = 9.806;
vTakeoff                = 100;
radToDeg                = 180/pi;

F-35 Aircraft model

%--------------------

% Aircraft
%---------
massDry                 = 13300;
massFuel                =  8382;
wingArea                = 42.7;

d                       = struct;
d.lDData.l              = 15.67;        % Aircraft length (m)
d.lDData.b              = 10.7;         % Span (m)
d.lDData.s              = 204;          % Surface area (m^2)
d.lDData.v              = 10*pi*0.6^2;
d.lDData.sL             = wingArea;     % Lifting surface  (m^2)

% Lift and drag model
%--------------------
d.cDCL                  = @LiftAndDragJonesSearsHaack;
cLAlpha                 = 2*pi;

d.lDData.cL             = cLAlpha;
d.lDData.alpha          = 0;

d.mass                  = massDry;          % Dry mass of aircraft (kg)
d.atmData               = load('AtmData.txt');

% Turbojet engine data
%---------------------
d.thrustData.kM         = -0.3;
d.thrustData.tStatic	  = 2*191.3e3; % 2 F135 engines
d.thrustData.kI         = -1/2;
d.thrustData.iSp0       = 10000;
d.thrust                = @JetEngine;

Control system data structure

%-------------------------------
dC.gammaSet             = 3*pi/180;
dC.bankAngle	          = 0;
dC.vSet                 = 400;
dC.gainGamma	          = 0.5;
dC.gainThrust	          = 0.2;
dC.throttle             = 1;
dC.mode                 = 'takeoff';
dC.vTakeoff             = vTakeoff;
dC.alpha                = 0;

Simulate

%----------
fprintf(1,'Demo          %s\n','F-35 Simulation');
fprintf(1,'Dry Mass      %12.2f (kg)\n', d.mass);
fprintf(1,'Volume        %12.2f (m^3)\n',d.lDData.v);
fprintf(1,'Surface Area  %12.2f (m^2)\n',d.lDData.s);
fprintf(1,'Static Thrust %12.2f (kN\n',d.thrustData.tStatic/1000);

% Initial conditions
%-------------------
x   = [0;0;0;0;0;0;massFuel];
t   = (0:(n-1))*dT;

xP  = zeros(16,n);

for k = 1:n

  % Standard atmosphere
  %--------------------
	p               = StdAtm(x(6));

  % Control system
  %---------------
  dC              = ACPointMassControl( x, p, d, dC );

  % Pass data to the dynamics data structure
  %-----------------------------------------
	d.lDData.p      = p;
	d.lDData.alpha	= dC.alpha;
	d.phi           = dC.bankAngle;
	d.throttle      = dC.throttle;
  d.alpha         = dC.alpha;

	% Get D, L and rho for plotting
	%------------------------------
	[xDot, D, L, rho, thrust, mach, q] = RHS3DPointAircraft( x, t(k), d );
	xP(:,k)                            = [x;D;L;rho;d.alpha*radToDeg;d.phi*radToDeg;thrust;mach;q;d.throttle];

	% Update state
	%-------------
	x = RK4(@RHS3DPointAircraft, x, dT, t(k), d );

	% Break if we run out of jet fuel
	%--------------------------------
	if( x(7) <= 0  )
    disp('Breaking due to lack of jet fuel')
    break
  end
end

Demo          F-35 Simulation
Dry Mass          13300.00 (kg)
Volume               11.31 (m^3)
Surface Area        204.00 (m^2)
Static Thrust       382.60 (kN

Plot

%------

% Limit the plot arrays if it the plane ran out of fuel
%------------------------------------------------------
xP              = xP(:,1:k-1);
t               =  t(:,1:k-1);

[t,tL]          = TimeLabl( t );

% Convert to km
%--------------
xP(4:6,:)       = xP(4:6,:)/1000;

% Convert to degrees
%-------------------
xP(2:3,:)       = xP(2:3,:)*180/pi;

% Convert to kN
%--------------
xP([8 9 13],:)  = xP([8 9 13],:)/1000;

yL              = {'V (m/s)' 'x (km)' 'h (km)' 'Mach'  'q'};

k               = [1 4 6 14 15];
Plot2D(t,xP(k,:),tL,yL,'Summary',[],{},{},1,[],1)

k               = [4 5 6];
Plot3D(xP(k,:),'x (km)','y (km)','h (km)','Aircraft Track',[],1)

k               = [9 8 11 12 13 16];
yL              = {'L (kN)' 'D (kN)' '\alpha (deg)', '\phi (deg)', 'Thrust (kN)' 'Throttle'};
Plot2D(t,xP(k,:),tL,yL,'Lift and Drag',[],{},{},1,[],1)

%--------------------------------------

Published with MATLAB® R2019a