can it be possible to use odeVectorField

syms f(x) g(x) h(x) Pr Nb Nt Le
[V] = odeToVectorField( diff(f,3) - diff(f)^2 + f * diff(f,2) == 0,diff(g,2) + Pr * ( f * diff(g) + Nb * diff(g)* diff(h)+ Nt * diff(g)^2) == 0,...
diff(h,2) + Le * f * diff(h) + ( Nt/Nb ) * Pr * ( f * diff(g) + Nb * diff(g)* diff(h)+ Nt * diff(g)^2)== 0)
%% I want to incorporate the expression of [V] into below code, but I am getting wrong expression (not as dydx below)
%%% can it be used in bvp 4c code and in which style
function main
Pr=10; Le=10; Nt=.1;Nb=.1;
xa=0;xb=6;solinit=bvpinit(linspace(xa,xb,1000),[0 1 1 1 0 0 0]);options=[];
sol=bvp4c(@ode,@bc,solinit,options);xint=linspace(xa,xb,100);S=deval(sol,xint);
function res=bc(ya,yb)
res=[ya(1); ya(2)-1; ya(4)-1; ya(6)-1; yb(2); yb(4); yb(6)];
end
function dydx=ode(x,y)
dydx=[y(2); y(3); y(2)^2 - y(3)*y(1); y(5); - Pr*(y(1)*y(5) + Nb*y(5)*y(7) + Nt*y(5)^2);
y(7); - Le*y(7)*y(1) + (Nt/Nb)*Pr*(y(1)*y(5) + Nb*y(5)*y(7) + Nt*y(5)^2)];
end
end

3 comentarios

darova
darova el 22 de Mayo de 2020
Please see help: LINK
MINATI PATRA
MINATI PATRA el 23 de Mayo de 2020
Dear Darova that M gives wrong code as you can compare and another question is how to include in bvp 4c code
MINATI
MINATI el 24 de Mayo de 2020
Please anybody invest some time here to help me.

Iniciar sesión para comentar.

Respuestas (1)

darova
darova el 24 de Mayo de 2020
Try this
clc,clear
syms f(x) g(x) h(x) x Y
Pr=10;
Le=10;
Nt=.1;
Nb=.1;
[V,y1] = odeToVectorField( diff(f,3) - diff(f)^2 + f * diff(f,2) == 0,...
diff(g,2) + Pr * ( f * diff(g) + Nb * diff(g)* diff(h)+ Nt * diff(g)^2) == 0,...
diff(h,2) + Le * f * diff(h) + ( Nt/Nb ) * Pr * ( f * diff(g) + Nb * diff(g)* diff(h)+ Nt * diff(g)^2)== 0)
F = matlabFunction(V,'vars', [x Y]);
bc = @(ya,yb) [ya(1) % g
ya(2)-1 % Dg
ya(4)-1 % f
ya(6)-1 % Df
yb(2) % D2f
yb(4) % h
yb(6)]; % dh
xa=0;
xb=6;
solinit = bvpinit(linspace(xa,xb,1000),[0 1 1 1 0 0 0]);
options = [];
sol = bvp4c(F,bc,solinit,options);
plot(sol.x,sol.y)
Change boundary conditions if needed

1 comentario

MINATI
MINATI el 25 de Mayo de 2020
No dear Darova, its not matching. You can compare also

Iniciar sesión para comentar.

Categorías

Preguntada:

el 22 de Mayo de 2020

Comentada:

el 25 de Mayo de 2020

Community Treasure Hunt

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

Start Hunting!

Translated by