Nu and Sh value should be non-zero

4 views (last 30 days)
MINATI PATRA
MINATI PATRA on 1 Nov 2020
Commented: MINATI PATRA on 1 Nov 2020
function main
x = linspace(0,1,101); t = x; m = 0; sol = pdepe(m,@pde,@ic,@bc,x,t,[]);
U = sol(:,:,1); T = sol(:,:,2); C = sol(:,:,3);
xq = x; xq(1:end - 1) = xq(1:end - 1) + diff(xq)./2;
[u,dudx] = pdeval(m,x, A1*U(2,:,1),xq); Sk = dudx(1); %% Derivative of U at x = 0
[v,dvdx] = pdeval(m,x, - A7*T(2,:,1),xq); Nu = dvdx(1); %% Derivative of T at x = 0 (with negative)
[w,dwdx] = pdeval(m,x, - C(2,:,1),xq); Sh = dwdx(1); %% Derivative of C at x = 0 (with negative)
disp([Sk Nu Sh])
function [c,f,s] = pde(x,t,u,dudx)
Re = 1; p = 0.01; L0 = 1; L = 0.1; eps = 1; w = 0.2; M = 1; Kp = 0.5;
Gr = 0.5; Gc = 0.5; Pe = 1; N = 2; Sr = 0.5; Le = 1; G = 1; Pr = 01;
rhos = 19300; cps = 129; ks = 301; betaTs = 42*10 ^(-6); betaCs = 1.25*10^(-5); sigmas = 4.11*10^6;
rhof = 997.1; cpf = 4179; kf = 0.613; betaTf = 21*10^(-5); betaCf = 298*10^(-5); sigmaf = 0.05;
a = 13.5; b = 904.4; n = 3/0.62; sigma = sigmas/sigmaf; % n = 4.8387;
A1 = 1 - p + p * (rhos/rhof); A2 = 1 + a*p + b*p^2; A3 = (1 + (3*p*(sigma-1)/((sigma+2)-p*(sigma-1))))/A1;
A4 = 1 - p + p * ((rhos*betaTs)/(rhof*betaTf)); A5 = 1 - p + p * ((rhos*betaCs)/(rhof*betaCf));
A6 = 1 - p + p * ((rhos*cps)/(rhof*cpf)); A7 = (ks + (n-1)*kf + (n-1)*p*(kf-ks))/(ks + (n-1)*kf - p*(kf-ks));
c = [Re*A1; Pe*A6; Re;]; f = [A2.*dudx(1); A7.*dudx(2); (1/(Le*Pr)).*dudx(3) + Sr*dudx(2)];
s = [L0 + L*eps*abs(exp(i*w*t)) + A4*Gr*u(2) + A5*Gc*u(3) - (A3*M^2 + (A2/Kp))* u(1); N^2*u(2); - G*u(3)];
end
function u0 = ic(x)
u0 = [0; 0; 0];
end
function [pL,qL,pR,qR] = bc(xL,uL,xR,uR,t)
pL = [uL(1); uL(2); uL(3)]; qL = [0; 0; 0]; pR = [uR(1); uR(2)-1; uR(3)-1]; qR = [0; 0; 0];
end
end
%%%%%%%%
I want some non-zero value of Nu and Sh but '0' is coming (which is wrong). Please correct me where I am wrong.
  2 Comments
MINATI PATRA
MINATI PATRA on 1 Nov 2020
@ Dear Walter Roberson
Thanks for your concern
I corrected myself, it was in B.C.
But still my last conversation with you was unsolved. If you have time to rearrange the FULL CODE following:
https://in.mathworks.com/matlabcentral/answers/607426-generalization-needed-in-dsolve-code?s_tid=mlc_ans_email_view#comment_1082988

Sign in to comment.

Answers (0)

Categories

Find more on Exponents and Logarithms in Help Center and File Exchange

Community Treasure Hunt

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

Start Hunting!