Page 498 - Design and Operation of Heat Exchangers and their Networks

Appendix 481

case-16 % BA_1,6
% analytical
nu_1 = special_function_nu_(aA, bA);
nu_2 = special_function_nu_(aB, bB);
K1 = special_function_K(bA);
K2 = special_function_K(bB);
if (phi == 1)
epsilon_h = 1 - nu_1 ^ 2/(1 - aA ∗ bA ∗ K1 ^ 2 ∗ nu_1);
else
epsilon_h = 1 - nu_1 ∗ nu_2 / (1 - bB ∗ K1 ∗ K2 ...
∗ (nu_2 - nu_1) / (K1 - phi ∗ K2));
end

% numerical
t1(:, :, :) = 1;
t2(:, :, :) = 0;
smax = 100;
n=0;
while (abs(smax) > eps && n < 100)
smax = 0;
ntuh = NTUh(1);
ntuc = NTUc(1);
th(:, :) = t1(1, :, :);
tc(:, :) = t2(1, :, :);

[th, tc, thm, tcm] = crossflow_mixed_unmixed ...
(ntuh, ntuc, nx, ny, th, tc, A, T, D);
for i=1:1:nx1
for j=1 :1:ny1
s = th(i, j) - t1(1, i, j);
if (abs(s) > abs(smax))
smax = s;
end
t1(1, i, j) = t1(1, i, j) + e ∗ s;
s = tc(i, j) - t2(1, i, j);
if (abs(s) > abs(smax))
smax = s;
end
t2(1, i, j) = t2(1, i, j) + e ∗ s;
end
end