error in the matrix

hey guys when i try to run the program it tell me excced number of matrix in line 41 i want to draw p in y axis with V in x axis thank you

clc;clear;
B=79.21  
a=30.835
L=83.919
j=0
k=0
n=0
f=0
i=0
P_i=6
RPM=300
d_time=(5/360)*(60/RPM)
p(k+1)=.99*(P_i)
p(k+2)=.9*p(1)
T(f+1)=290  
R=.287
V(1)=27*1000
c_d=.6
h=8
Tw=290
cp=1.005
m(n+1)=p(1)*V(1)/(R*T(1))
for Theta=0:5:360
   i=i+1
   j=j+1
   x(i)=a*cos(Theta)+sqrt((((L*L)-(a*a)*(sin(Theta))^2)))
   V(j)=(pi/4)*(B^2)*(x(i))+(27*1000)
end

for Theta=0:5:360
   n=n+1

     k=k+1
     f=f+1
     rho=(p(k)+p(k+1))./(2*R*T(f))

if (Theta <=120)
d_Mi=c_d*(pi/4)*((.3)^2)*sqrt(2*rho.*(p(k)-p(k+1)))
m(n+1)=m(n)+d_Mi
T(f+1)=(d_time*h*pi*B*x(i).*(2*Tw-T(f))-(p(k)+p(k+1)).*(V(j+1)-V(j))+2*m(n)*cp*T(f))./(2*m(n+1).*cp+(d_time*h*pi*B.*x(i)))
p(k+1)=m(n+1).*R*T(f+1)./(v(j+1))
end
if (Theta >=160) && (Theta <=300)
   d_Me=c_d*(pi/4)*((.28)^2)*sqrt(2*rho*(p(k)-p(k+1)))
   m(n+1)=m(n)-d_Me
T(f+1)=(d_time*h*pi*B*x(i)*(2*Tw-T(f))-(p(k)+p(k+1))*(V(j+1)-V(j))+2*m(n)*cp*T(f))/(2*m(n+1)*cp+(d_time*h*pi*B*x(i)))
p(k+1)=m(n+1)*R*T(f+1)/(v(j+1))
end
if (Theta >=300) && (Theta <=360)
   m(n+1)=m(n)
   T(f+1)=(d_time*h*pi*B*x(i)*(2*Tw-T(f))-(p(k)+p(k+1))*(V(j+1)-V(j))+2*m(n)*cp*T(f))/(2*m(n+1)*cp+(d_time*h*pi*B*x(i)))
p(k+1)=m(n+1)*R*T(f+1)/(v(j+1))
end
if (Theta >120) && (Theta <160)

m(n+1)=m(n)
   T(f+1)=(d_time*h*pi*B*x(i)*(2*Tw-T(f))-(p(k)+p(k+1))*(V(j+1)-V(j))+2*m(n)*cp*T(f))/(2*m(n+1)*cp+(d_time*h*pi*B*x(i)))
p(k+1)=m(n+1)*R*T(f+1)/(v(j+1))
end
end

[Jan]

Please mark the code and press the "{} Code" button. Currently the code is not readable.

Answer 1

[Walter Roberson]

Your code

j=0
for Theta=0:5:360
 i=i+1
 j=j+1
 x(i)=a*cos(Theta)+sqrt((((L*L)-(a*a)*(sin(Theta))^2)))
 V(j)=(pi/4)*(B^2)*(x(i))+(27*1000)
end

will leave j as 73 and V as length 73.

Your line

T(f+1)=(d_time*h*pi*B*x(i).*(2*Tw-T(f))-(p(k)+p(k+1)).*(V(j+1)-V(j))+2*m(n)*cp*T(f))./(2*m(n+1).*cp+(d_time*h*pi*B.*x(i)))

has V(j+1)-V(j) which tries to access V(73+1)-V(73) but V(74) does not exist.

[abdalrhman hassan]

thank you,what can i do to solve this problem ? i want it to start from j=1 not from 73

[Walter Roberson]

Assign

j = 0;

before

for Theta=0:5:360

and where you have k=k+1 add in j=j+1;

I suspect some of your variables are effectively duplicates of each other.

[abdalrhman hassan]

yes it should be try and error but i didn’t finsh yet i should use while loop but i can’t seem to remember how it work,thank you so much