How to Find the Spin in vy and vz in Matlab?

[starbaj12]

I know this is a programming language question, but no one seems to answer in that Forum. I'm running a program in Matlab and I'm running two loops One for the velocities in the x,y,z components and another for the magnus force (spin) vx,vy,vz. I'm holding all constant except vy and vz which I switch one at a time while holding the other constant. I need to find the spin in the vy then the vz that makes it within my constraints I have in place in my program. I try running now but it is just non-stop numbers that come out any help will be great. Thank you

clear;
Cd = .5;
Cs = .5;
p = 1.2; %Air density
r = .11303; %radius
m = .4536; %massx(1) = 0; %initial position
y(1) = 0;
z(1) = 0;

wx = 0; %initial angular velocity for x

wy = 0;

vx(1) = 14.95; %intial velocity for x
vy(1) = 14.5;
vz(1) = 7.9;
k = -300;
g = 9.81; %gravity
dt = .001;
t = 20;
n = t/dt;

for j = 1:n
   wz = j;
   for i = 1:n

      u = sqrt((vx(i))^2+(vy(i))^2+(vz(i))^2); %v for all components

      ax = (-((Cd*p*pi*r^2)*u*vx(i))/(2*m) - ((Cs*p*pi*r^3*(vz(i)*wy-wz*vy(i)))/(2*m)));
      ay = (-((Cd*p*pi*r^2)*u*vy(i))/(2*m) - ((Cs*p*pi*r^3*(wz*vx(i)))/(2*m)));
      az = ((-g)-((Cd*p*pi*r^2)*u*vz(i))/(2*m) + ((Cs*p*pi*r^3*(-wy*vx(i)))/(2*m)));

      Fx = ax*m; %Force for x-component
      Fy = ay*m;
      Fz = az*m;

      vx(i+1) = vx(i) + ((Fx/m)*dt); %Final velocity for x-component
      vy(i+1) = vy(i) + ((Fy/m)*dt);
      vz(i+1) = vz(i) + ((Fz/m)*dt);

      x(i+1) = x(i) + vx(i+1)*dt;
      y(i+1) = y(i) + vy(i+1)*dt;
      z(i+1) = z(i) + vz(i+1)*dt;

      if(x(i+1)>(11.531+ .1524))
         break
      end

      if((y(i+1)>10.9564)&(y(i+1)<11.531))&((z(i+1)>1.8288)&(z(i+1)<2.3254))&((x(i+1)>11.531)&(x(i+1)<(11.531+.1524)))
         fprintf('q')
         break
      end

      end
   fprintf('number %g',wz);
end

plot3(x,y,z)
grid on

 

[mmwave]

I understand that you are running a program in Matlab and are having trouble with the output. From the code you have provided, it seems that you are trying to simulate the motion of an object through the air and are trying to find the spin in the vy and vz components that will meet certain constraints.

I suggest breaking down your problem into smaller parts and testing each component separately. For example, you can first test the effect of changing the spin in only the vy component while keeping all other variables constant. Once you have determined the effect of this change, you can then move on to testing the vz component.

Additionally, it may be helpful to plot the output of your program to better visualize the motion of the object and see if it matches your expectations. You can also try debugging your code by adding print statements throughout the loops to see how the variables are changing.

I hope this helps and wish you success in your programming endeavors.

 

[tacman]

Thank you for your question. It seems like you are trying to find the spin values for vy and vz that will satisfy your constraints in the program. One way to approach this problem is to use a nested for loop where you vary the values of vy and vz within a certain range and then check if the constraints are satisfied. If they are, then you can store those values and break out of the loop. Here is an example code:

clear;
Cd = .5;
Cs = .5;
p = 1.2; %Air density
r = .11303; %radius
m = .4536; %mass

x(1) = 0; %initial position
y(1) = 0;
z(1) = 0;

wx = 0; %initial angular velocity for x
wy = 0;

vx(1) = 14.95; %intial velocity for x
vy(1) = 14.5;
vz(1) = 7.9;
k = -300;
g = 9.81; %gravity
dt = .001;
t = 20;
n = t/dt;

% define range for vy and vz values
vy_range = 14:0.1:15;
vz_range = 7:0.1:8;

% initialize variables to store spin values that satisfy constraints
spin_vy = 0;
spin_vz = 0;

for vy_val = vy_range
for vz_val = vz_range
% reset variables for each loop iteration
x(1) = 0; %initial position
y(1) = 0;
z(1) = 0;

vx(1) = 14.95; %intial velocity for x
vy(1) = vy_val;
vz(1) = vz_val;

for j = 1:n
wz = j;
for i = 1:n

u = sqrt((vx(i))^2+(vy(i))^2+(vz(i))^2); %v for all components

ax = (-((Cd*p*pi*r^2)*u*vx(i))/(2*m) - ((Cs*p*pi*r^3*(vz(i)*wy-wz*vy(i)))/(2*m)));
ay = (-((Cd*p*pi*r^2