cstr.m

linear equation routines in matlab

function varargout = cstr(x)
%
% 
%
%  [F]     = cstr(x)  returns the function value in F
%  [F,Jac] = cstr(x)  returns the function value in F and 
%                    the Jacobian in Jac
%
%  Matthias Heinkenschloss
%  Department of Computational and Applied Mathematics
%  Rice University
%  March 9, 2004
%

% Problem parameters
V      = 10;
Fa     = 3.0;
F      = 3.0;
Fh     = 0.1;
R      = 8.3144;
E      = 50000;
CAo    = 5.0;
cp     = 6.0;
cp_h   = 6.0;
k0     = 1.e9;
Ta     = 300;
Th     = 375;
Vh     = 1;
rho    = 600;
rho_h  = 600;
deltaH = 20000;
eps    = 0.144;
UA     = rho*cp/eps;

% return the function value
 
reac_rate = k0*exp(-E/(R*x(3))) * x(1);

varargout{1} = [ Fa*(CAo-x(1))/V - reac_rate;
                 -F*x(2)/V + reac_rate;
                 Fa*(Ta-x(3))/V - reac_rate * deltaH/(rho*cp) ...
                      + (x(4)-x(3))*UA/(rho*cp*V);
                 Fh*(Th-x(4))/Vh - (x(4)-x(3))*UA/(rho_h*cp_h*Vh)];
if( nargout > 1 )
  % return the Jacobian as the second argument
  error('Jacobian is not yet implemented')
end