How to write a code for iteration?

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Felipe Gonzalez
Felipe Gonzalez 2017-4-3
评论： Diyaa Khalifa 2018-12-16
Hello. I'm new using Matlab. I have to programming the below diagram in Matlab. I think I'm doing well, so far. But I've got a doubt, that is how to write a code for iteration (the step in the third block)? I guess I have to use a 'while' but I didn't know how. Hope you can help me. I let what I've done so far, in case you need it in order to answer my question. I'm writing this code with the purpose of plotting a x-y diagram and a T-x-y diagram. Thanks.
clear all; clc; close all
% Bubble temperature for P = 101.33 kPa
P = 101.33 %kPa
X = linspace (0,1,100)
phi = 1.0
x1 = X(1); x2 = X(2);
% Wilson
%PARAMETERS - System dependent
a12 = 437.98; %cal/mol
a21 = 1238.00; %cal/mol
R = 1.9872; %cal/mol?K
V1 = 76.92; %cm3/mol
V2 = 18.07; %cm3/mol
comp = 2;
% Constants for Antoine equation for 2-propane(1), water(2)
A1 = 16.6780; B1 = 3640.20; C1 = 53.54;
A2 = 16.2887; B2 = 3816.44; C2 = 46.13;
% Saturate temperature
T1sat = (B1/(A1-(log(P)))-C1);
T2sat = (B2/(A2-(log(P)))-C2);
%Temperature
T1 = sum(X*T1sat)
T2 = sum(X*T2sat)
% Activities
A12 = (V2/V1)*exp(-a12/(R*T1));
A21 = (V1/V2)*exp(-a21/(R*T2));
% Vapour pressure
P1sat = exp((A1-B1)/((T1)+C1));
P2sat = exp((A2-B2)/((T2)+C2));
for i=1:size(X,2)-1;
x1 = X(i); x2 = X(i+1);
% Calc for Gammas
ft1 = -log(x1 + 1-*A12);
st1 = x2*((A12/(x1 + x2*A12))-(A21/(x2 + x1*A21)));
gamma_1 = exp(ft1 + st1);
ft2 = -log(x2 + x1*A21);
st2 = x1*((A12/(x1 + x2*A12))-(A21/(x2 + x1*A21)));
gamma_2 = exp(ft2 - st2);
% j = Water
% Vapour pressure (Pj), kPa
Pjsat (i)= P/sum(((x2*gamma_2(i))/phi)*(P2sat/P2sat))
% Temperature, K
Tj(i) = (A2/(B2 -(log(Pjsat (i))))-C2);
% Vapour pressure, Pi_sat
Pi_sat = exp((A2-B2)/((Tj(i))+C2));
% Total pressure, P = 101.33 kPa
Ptotal = P1sat*gamma_1(i)*x1 + P2sat*gamma_2(i)*x2;
error = abs((101.33-Ptotal)/101.33);
counter = 0;
% Calc for y
y (i) = ((x2*gamma_2(i)*Pi_sat)/phi*Ptotal);
% Vapour pressure (Pj), kPa
Pj_sat = P/sum(((x2*gamma_2(i))/phi)*(Pjsat/Pjsat))
% Temperature, K
Tj=(A2/(B2 -(log(Pj_sat)))-C2);
% Iteration
if i>1
while abs(Tj(i)-Tj(i-1))<1e-10
break
end
else
end;

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采纳的回答

Thorsten
Thorsten 2017-4-4
After the first box, you write
deltaT = epsilon + 1; % so that the while loop is entered
while deltaT >= epsilon
% put code of the second box here
deltaT = % add equation for new updated value of deltaT
end
  1 个评论
Diyaa Khalifa
Diyaa Khalifa 2018-12-16
Do you have codes for
Bulbble P calculations and Dew T calculations and Dew P calculations ??

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