MATLAB Answers

The following code is not working

4 views (last 30 days)
MINATI
MINATI on 2 Jan 2019
Answered: madhan ravi on 4 Jan 2019
function [x,h] = Transient()
%% Initialization
theta = 50; % degrees - angle of repose of material
n = 8; % r.p.m. - rotation speed of tube
rho = 660; % kg/m3 - bulk density of material
R = 0.075; % m - inner radius of tube
beta = 3; % degrees - inclination angle of kiln
L_tube = 2; % m,lenght of the kiln
mass_flow_rate = 0.5; % kg/min - mass flow of material
x_points=100;
t_points=100;
%% Solving initial condition
xspan_1=[0 L_tube];
h0 = 0.000001; % initial condition (bed height at the discharge end - average of particle diameter)
sol = ode45( @saeman_bed ,xspan_1 ,h0); % solver for unsteady nonliner ode
x = linspace(0,L_tube,x_points);
u0 = deval(sol,x)
%% Solving with pdepe
m = 0;
x = linspace(0,1,x_points);
t = linspace(0,2,t_points);
sol = pdepe(m,@pdex1pde,@(x0)pdex1ic(x0,x,u0),@pdex1bc,x,t);
% Extract the first solution component as u.
u = sol(:,:,1)
function [c,f,s] = pdex1pde(x,t,u,DuDx)
f_H=power((2*u/R)-power(u,2)/power(R,2),0.5);
u_T=2*pi*n*R;
c = f_H;
f = (u_T*R*cotd(theta))*power(f_H,1.5).*DuDx;
s = u_T*tand(beta)/sind(theta)*f_H.*power(1-f_H,0.5).*DuDx;
end
% --------------------------------------------------------------
function u0 = pdex1ic(x0,x,u)
u0 = interp1(x,u,x0);
% -------------------------------
end
function [pl,ql,pr,qr] = pdex1bc(xl,ul,xr,ur,t)
pl = ul+0.000001 % exit
ql = 0;
pr =(3*tan(deg2rad(theta))* mass_flow_rate/rho) / (4*pi*n*power(R,3)) * power((2*ul/R) - power((ul/R),2),(-3/2)) -tan(deg2rad(beta))/cos(deg2rad(theta));
qr = -1;
end
%% function for initial condition
function [dhdx,h] = saeman_bed (z,h);
dhdx = (3*tan(deg2rad(theta))* mass_flow_rate/rho) / (4*pi*n*power(R,3)) * power((2*h/R) - power((h/R),2),(-3/2)) -tan(deg2rad(beta))/cos(deg2rad(theta));
end
end

  8 Comments

Show 5 older comments
MINATI
MINATI on 3 Jan 2019
While run, error is
Error: bcfun=@pdex1bc,x,t);
Unbalanced or unexpected parenthesis or bracket.
After removing last bracket
bcfun =
function_handle with value:
@Transient/pdex1bc
x = (DISPLAYS SOME VALUES)
Error using pdepe
Too many input arguments.
Error in (line 27)
sol = pdepe(m,pdefun,icfun,bcfun,x,t);
>> What to do now?
Rik
Rik on 3 Jan 2019
I see I made a copy-paste error, so indeed you should fix that line to
bcfun=@pdex1bc;
But your error seems to be a bit deeper. Can you show the output of
which pdepe -all
I'm suspecting somehing is shadowing the correct function, because your input looks like it should be valid, but it still returns this error.
MINATI
MINATI on 4 Jan 2019
By running
which pdepe -all
The following output came:
C:\Users\HP\pdepe.m
C:\Program Files\MATLAB\R2016b\toolbox\matlab\funfun\pdepe.m % Shadowed

Sign in to comment.

Answers (1)

madhan ravi
madhan ravi on 4 Jan 2019
You have file named pdepe please rename it or delete it becuase it‘s shadowing the inbuilt function pdepe()

  0 Comments

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!