Matlab is skipping over my while loop.
4 views (last 30 days)
Show older comments
I am trying to calculate the thurst, velocity, and displacement of an aircraft approaching takeoff. Matlab is skipping over my while loop and I do not know why. If i take the loop away there are no errors and will give me the answer "0" since that is what it would be with no iterations. If you could please help it would be greatly appreciated.
Code:
%Question 2
clc, clear
%Constants
b=36;
Sw=175;
Hw=5.7;
AR=b^2/Sw;
e=2/((2-AR)+sqrt(4+AR^2));
AReff=AR*sqrt(b/(2*5.7));
CDG=(.65*4)^2/(3.14*e*AReff);
%Part A
CD=CDG+.02+.018
%Part B
T0=765;
rho=.002377;
Wto=3500;
Pmax=270;
g=32.2;
muroll=.023;
Dprop=84/12;
Clmax=4;
CLG=.65*Clmax;
deltat=.01;
Tguess=700;
Vcr=110;
Vstall=64.8;
V=1.2*Vstall;
n=1;
t(n)=0;
x(n)=0;
V(n)=0;
a(n)=0;
T=Groundroll(T0,V);
T(n)=T;
while V(n)<V
n=n+1;
T(n)=Groundroll(T0,V(n));
t(n)=t(n-1)+deltat;
V(n)=V(n-1)+a(n-1)*deltat;
q(n)=.5*V(n)^2*rho;
Daero(n)=CDG*q(n)*Sw;
L(n)=CLG*q(n)*Sw;
Droll(n)=muroll*(Wto-L(n));
Fx(n)=T(n)-Daero(n)-Droll(n);
a(n)=g*(Fx(n)/Wto);
x(n)=x(n-1)+.5*(V(n)+V(n-1))*deltat;
x=x(n)
V=V(n)
end
0 Comments
Answers (1)
Stephen23
on 15 Feb 2020
"Matlab is skipping over my while loop and I do not know why."
Because you told it to.
Lets have a look at what values V and n have before the loop runs:
>> V
V = 0
>> n
n = 1
Now lets look at your loop condition... But first, is zero less than zero? (hint: no). We can check that using MATLAB too:
>> V(n)<V
ans = 0
Ergo your condition is not true, and the loop never runs. Because that is exactly what you told MATLAB to do.
0 Comments
See Also
Categories
Find more on Loops and Conditional Statements in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!