I have to do a 3D plot for rotating disk but i am not getting a 3D plot

this is what i was trying to get but all i am getting are multiple circle using the Plot3 command

% for 3D plot i was using the follwoing code 
sol = nanowithrotation1;
F=sol.y;
f=F(1,:);
g=F(4,:);
%%theta=linspace(0,360,360/2.608695);
r=linspace(0,10,10/0.07246);
syms t
Ut=r.*f.*cos(t)-r.*g.*sin(t);
 Vt=r.*f.*sin(t)+r.*g.*cos(t);
size(Ut)
size(Vt)
fplot3(Ut, Vt, t, [0 2*pi], 'LineWidth', 0.5)


%the function " nanowithrotation1" called in the above code is as follows



function [sol_6]=nanowithrotation1
format long g
global Q w0 exi M Ma omega_w gamma_inf Nrd Pr phi rho_s rho_f k_f k_s cp_f cp_s sigma_s sigma_f A1 A2 A3 s a b beta
etaMin = 0;
inf_1 =5;
etaMax1=inf_1;
stepsize1=etaMax1;

tol=1e-6;
% defining parameters

Q=0.5;
w0= 0.5;     % suction parameter
Nrd=0.5;
% omega_w= 0.3;       % rotation at z=0 
% gamma_inf=1;          % rotation at z=inf 
exi= 1;   % ratio of rotations
Ma = 1.5;       % marangoni number
Pr=6.2;        %prandtl number
rho_s= 8933  ;    % density of nanoparticle
rho_f= 997.1  ;     % density of base fluid
phi= 0.1;         % concentration of nanofluid
k_f= 0.613  ; % thermal conductivity of base fluid 
k_s= 400     ; % thermal conductivity of nanoparticle
cp_f= 4179   ;
cp_s = 385;
sigma_f= 0.05;      % electric conductivity of base fluid 
sigma_s= 5.96*10^7;     % electric conductivity of nanoparticle

% beta= ((k_s+2*k_f)-2*phi*(k_f-k_s))/((k_s+2*k_f)+phi*(k_f-k_s)); % ratio of thermal conductivity of nanoparticle to that of nanofluid

% alpha= 1+64.7*phi^(0.7460) *((d_f/d_p)^0.3690)*((k_s/k_f)^0.7476)*((mu*cp_f/k_f)^0.9955)*(rho_f*B_c*T/(3*pi*mu^2*l_bf))



% a= (1-phi)+(phi*(rho_s/rho_f));
% A1= ((1-phi)^2.5)*a;
% s=sigma_s/sigma_f;
% b= 1+((3*phi*(s-1))/((s+2)-(phi*(s-1))));
% A2=b/a;
% A3= (1-phi)+(phi*(rho_s*cp_s)/(rho_f*cp_f));
% A4=(beta*(3+(4*Nrd)))/(3*A3);
%   SOLUTION 
beta=1;
 A1=1;A2=1;A3=1;A4=1;
 s=1;a=1; b=1;
 phi=0;
 
 
%  options = bvpset('stats','on');
      

options = bvpset('stats','off','RelTol',tol);
solinit = bvpinit(linspace(etaMin,etaMax1,stepsize1),zeros(7,1)); 
sol_6 = bvp4c(@OdeBVP,@OdeBC,solinit,options);
eta=linspace(etaMin,etaMax1,stepsize1);
xsol = sol_6.x;
ysol = sol_6.y;

ysol(:,1)
%y = deval(sol_1,eta);

% plot for first solution 

    figure(1); 

plot(sol_6.x,sol_6.y(1,:),'g-','LineWidth',1)   % y(1)= F
xlabel('\eta') 
ylabel('F(\eta)')                          % label for y axis
box on
hold on

figure(2); 

plot(sol_6.x,sol_6.y(2,:),'c-','LineWidth',1)   % y(2)= F'
xlabel('\eta') 
ylabel('dF(\eta)')                          % label for y axis
box on
hold on

figure(3);

plot(sol_6.x,sol_6.y(4,:),'b-','LineWidth',1)   %y(4)= G
xlabel('\eta') 
ylabel('G(\eta)')                         % label for y axis
box on
hold on

figure(4);

plot(sol_6.x,sol_6.y(6,:),'r','LineWidth',1)   % y(6) = theta 
xlabel('\eta')
ylabel('\theta(\eta)')                           % label for y axis
box on
hold on;

figure(5);
 plot(xsol,ysol(1,:), 'g', xsol,ysol(4,:), 'b', xsol,ysol(6,:), 'r','LineWidth',1)
 hold all
             % saving output in text file for first solution 

descris =[sol_6.x; sol_6.y];
save 'slip_upper.txt' descris -ascii;
  
fprintf('\nFirst solution:\n');
fprintf('\nFirst solution:\n');

fprintf('\n');
  
function fff = OdeBVP(~,y)

 Eq1=A1* ((y(2)^2)-(2*y(1)*y(3))-(y(4)^2)+(exi^2));
 Eq2=A1 *((2*y(2)*y(4))-(2*y(1)*y(5)));
 Eq3= (Pr/A3)*(2*y(2)*y(6)-(2*y(1)*y(7))-((Q*y(6))/(2*A2)));



fff=[y(2);
    y(3);  
    Eq1;
    y(5);
    Eq2;
    y(7);
   Eq3]; 
end
%%   RESIDUAL FOR BOUNDARY CONDITIONS 
    function  res = OdeBC(y0, yinf)

      res = [
              y0(1)-w0;
              y0(3)+2*Ma*((1-phi)^2.5);
              y0(4)-1;
              y0(6)-1;
             yinf(2);
            yinf(4)-exi;
            yinf(6)];

    end
end  

[Divyajyoti Nayak]

Hi @Noor, it would be easier for others to help if you could put all the lines of code into the code block.

Answer 1

[Divyajyoti Nayak]

Hey @Noor,

I ran your code and the final plot obtained is actually a 3d plot but looks 2d because it’s a top down perspective. This is caused due to the ‘hold on’ command used before a 3d plotting function which defaults the axis to 2d.

To make the default axis 3d, consider changing the code to use the ‘fplot3’ function first and then use ‘hold on’.

To view the 3d plot without changing the code, you can use the ‘Rotate 3D’ tool to change the perspective.