Project 1 - Parsing NASA thermodynamic data

clear all
close all 
clc

% Open the the THERMO.dat file 
f1=fopen('THERMO.dat', 'r')

% skip the first line of the file
fgetl(f1);

% Reading the tempersture values distingushed as local, average and high temperatures 
line=fgetl(f1);
a=strsplit(line,' '); 
global_low_temp=str2num(a{2}); 
global_average_temp=str2num(a{3});
global_high_temp=str2num(a{4});
fgetl(f1);
fgetl(f1);
fgetl(f1);

% extracting data for each gas
for k=1:53
    %step7
    line=fgetl(f1);
    a=strsplit(line,' '); 
    Gas=a(1);
    b=findstr(line,'.'); 
    local_low_temp=str2num(line(b(1)-4:b(1)+4));
    local_high_temp=str2num(line(b(2)-4:b(2)+4));
    local_average_temp=str2num(line(b(3)-4:b(3)+4)); 

% extracting all 14 coefficients
ct=1;
for j=1:3
    line=fgetl(f1);
    b=strfind(line, 'E'); 
    for i=1:length(b)
        if ct<=7
            Ha(ct)=str2num(line(b(i)-11:b(i)+3)); 
            ct=ct+1;
        else
            La(ct-7)=str2num(line(b(i)-11:b(i)+3));
            ct=ct+1;
        end
    end
end

% initializing specific heat, entropy and enthalpy values to zero 
cp=0;
H=0;
S=0;

% calling the function where cp,H and S are calculated
[CP,H,S]=coefficient(local_low_temp,local_average_temp,local_high_temp,La,Ha);

% molecular weight calculating function 
M=Weight(Gas)

%plotting
GAS=char(Gas);
T=local_low_temp:local_high_temp; 
current=pwd;
mkdir(GAS);
cd(GAS)

figure(1); 
plot(T,CP, 'color', 'g', 'linewidth', 2); 
legend(Gas);
txt1=['Molecular weight:' num2str(M)]; 
text(500,max(CP)*0.98,txt1,'color','r'); 
grid on
xlabel('temperature(K)');
ylabel('Specific heat(KJ/mol)');
title('specific heat vs temperrature');

figure (2);
plot(T,H, 'color', 'r', 'linewidth', 2);
legend(Gas);
txt1=['molecular weight:' num2str(M)]; 
text(500,max(H)*0.98,txt1,'color','b');
grid on
xlabel('temperrature(K)');
ylabel('enthalpy(kj/mol)'); 
title('enthalpy vs temperature');

figure(3);
plot(T,S, 'color', 'b', 'linewidth', 2);
legend(Gas);
txt1=['Molecular weight:' num2str(M)]; 
text(500,max(S)*0.98,txt1,'color','b');
grid on
xlabel('temperrature(K)');
ylabel('entropy(kj/mol)'); 
title('entropy vs temperature');


saveas(figure(1), 'CP.jpg'); 
saveas(figure(2), 'H.jpg'); 
saveas(figure(3), 'S.jpg');

cd(current);
end

% function to calculate molecular weight

function Mo = Weight(Gas)

Weight=[1 12 14 16 32 0 40]; 
Gas1=['H' 'C' 'N' 'O' 'S' 'A' 'R']; 
number=[1 2 3 4];

M=0;
GAS=char(Gas);
for i=1:length(GAS)
    for j=1:length(Gas1) 
        if GAS(i)==Gas1(j)
            M(i)= Weight(j);
        end
        for j=1:length(number)
            if str2double(GAS(i))==number(j)
                M(i)=M(i-1)*(number(j)-1); 
            end
        end
    end
end

Mo=sum(M);
end


% function to calculate the Cp, H, S.

function [Cp,H,S] =coefficient(local_low_temp,local_average_temp,local_high_temp,La,Ha)
for i=1:local_high_temp-local_low_temp+1
    R=8.34;
    T=i+local_low_temp-1;
    % for lower temperature values
    if T<=local_average_temp
        Cp(i)=R*(La(1)+La(2)*T+La(3)*T^2+La(4)*T^3+La(5)*T^4);
        H(i)=R*T*(La(1)+(La(2)*T)/2+(La(3)*T^2)/3+(La(4)*T^3)/4+(La(5)*T^4)/5+La(6)/T);
        S(i)=R*(La(1)*log(T)+(La(2)*T)+(La(3)*T^2)/2+(La(4)*T^3)/3+(La(5)*T^4)/4+(La(7)));
       
        % for higher temperature values
    else
        Cp(i)=R*(Ha(1)+Ha(2)*T+Ha(3)*T^2+Ha(4)*T^3+Ha(5)*T^4);
        H(i)=R*T*(Ha(1)+((Ha(2)*T)/2)+(Ha(3)*T^2)/3+(Ha(4)*T^3)/4+(Ha(5)*T^4)/5+(Ha(6)/T));
        S(i)=R*(Ha(1)*log(T)+(Ha(2)*T)+(Ha(3)*T^2)/2+(Ha(4)*T^3)/3+(Ha(5)*T^4)/4+(Ha(7)));
    end
end
end

• Initially, the value of 'R' is defined.
• Then we use a command to open the file 'THERMO.dat'.
• Further, we use the 'fgetl' to start reading the lines and after reading the first two lines, from the second line convert the strings to numbers and assign global (low, mid, and high) temperatures.
• Then we have written a command to get the temperature range for calculation and plotting purposes.
• Then again use the 'fgetl' command to go to the next 3 lines and skip it.
• Then we use a for loop to get 53 species and their temperatures (low, mid, high) and the 14 coefficients.
• In the for loop we again use the fgetl command and then the next line is read and from that line, the species name, and the three local temperatures are read and stored.
• Then we use the fgetl command to go to a further line and get the first 7 coefficients and store them. Similarly using the fgetl command we move to the next two lines and get the remaining coefficients.
• Then after getting the 14 coefficients, we use these coefficients and by calling the functions we calculate cp, H, S.
• Further, we use the Molecular weight function and calculate the molecular weight for that species.
• Further, I have used a command to change the directory so that I can save the files at a particular location. After changing the directory have used 'mkdir' to create a new folder with the name of the current species and then a 'cd' command to make mkdir as the current directory.
• Then further we use the plot command to plot temperature vs (cp, enthalpy, entropy).
• In this plotting, we use the figure command to get the three different plots and save as a command to save the figures in the
• Then again we change our directory to again start the loop. So the loop continues to function till we get all the 53 species and then gets terminated.

• I have found some errors and solutions were found during execution.
• Use of the semi-colon(;) in coding results in no output in the command window.
• Here I made a mistake that is instead of a semicolon I used a colon so after changing it I was able to solve the problem
•