666 jvbasha

javid basha jv

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These are questions asked by 666 jvbasha

How to apply two for loops to solve ode problem.

code:

restart; with(plots); fcns := {T(eta), f(eta)};
m := .5; bet := 1; na := 1/6; N := 5;
eq1 := (diff(f(eta), `$`(eta, 3)))*pr+m-m*(diff(f(eta), `$`(eta, 1)))+((m+1)*(1/2))*(diff(f(eta), `$`(eta, 2)))*f(eta) = 0;
eq2 := diff(T(eta), `$`(eta, 2))+((m+1)*(1/2))*(diff(T(eta), `$`(eta, 1)))*f(eta) = 0;
bc := f(0) = 0, (D(f))(0) = 0, (D(f))(N) = 1, (D(T))(0) = -bi*(1-T(0)), T(N) = 0;
bi:= [seq(1..4,0.1)];  NN := nops(bi);  
pr:=[seq(1..2,0.1)];  NN1 := nops(pr);
for i  from 1 to NN do    
for j from 1 to NN1 do  

R := dsolve(eval({bc, eq1,eq2}, bi[i],pr[j]), fcns, type = numeric, method = bvp[midrich], maxmesh=2400):  
X1||[i,j]:=rhs(-R(0)[3]):
end do:  
end do:  

Have a good day.
 

Dear friends,

Greetings.

How to get the second solution.

how to change the guess value in maple.

figure 1 plot in Matlab with two different initial guesses.

 

TWOSOLUTION.mw

 



 

Greetings,

How se the f^(IV) ode problem using the Runge metho

 

restart; with(plots);
fcns := {f(eta), gta), t(a)};
N1k1 ;b :; nt 3; pr := 5; sc := 1;
eq1 := diff(f(eta), `$`(eta, 3))+(1/2)*f(eta)*(diff(f(eta), `$`(eta, 2)))+k1*((diff(f(eta), `$`(eta, 1)))*(diff(f(eta), `$`(eta, 3)))-(1/2)*f(eta)*(diff(f(eta), `$`(eta, 4)))+(1/2)*(diff(f(eta), `$`(eta, 2)))^2) = 0; eq2 := diff(t(eta), `$`(eta, 2))+pr*nb*if`ta, 1)))*(diff(g(et`$`(eta, 1)))+pr*nt*(diff(t(eta), `$`(eta, 1^2+(1/2)*f(eta)*(diff(t(eta), `$`(eta, 1))) = 0; eq3 := diff(g(eta), `$`(eta, 2))+nt*(diff(t(eta), `$`(eta, 2)))/nb+(1/2)*f(eta)*(diff(g(eta), `$`(eta, 1)))*sc/pr = 0;
bc := f(0) = 0, (D(f))(0) = 0, (D(f))(N) = 1, ((D@@2)(f))(N) = 0, t(0) = 1, t(N) = 0, g(0) = 1, g(N) = 0;
R := dsolve(eval({bc, eq1, eq2, eq3}), fcns, type = numeric);
Error, (in dsolve/numeric/bvp) system is singular at left endpoint, use midpoint method instead
p1u := odeplot(R, [eta, (D(f))(eta)], 0 .. N, numpoints = 100, labels = ["η", "f'"], linestyle = solid, color = [blue], thickness = 1, labeldirections = [horizontal, vertical], labelfont = ['TIMES', 'BOLDOBLIQUE', 16]);
Error, (in plots/odeplot) input is not a valid dsolve/numeric solution
p1u;


bvp.mw

 

Have a good day.

Dear authors,
How to solve this ode problem.

Download link ode.mw

In this problem the boundary condition is

Note: F=g in our problem.

eta approaches N.

Thank you.

 

in this problem i used slip coundary condition.

the plot want to starts in 0.2, but the plot starts in 0

bc := f(0) = 0, (D(f))(0) = ak*((D^2)(f))(0), (D(f))(N) = 1, g(0) = -de*((D^2)(f))(0), g(N) = 0, T(0) = 1+be*(D(T))(0), T(N) = 0:

How to type double drivative in BC.

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