Project 1 - Parsing NASA thermodynamic data

AIM:- Write a function that extracts the 14 co-efficients and calculates the enthalpy, entropy and specific heats for all the species in the data file. You will be reading this file NASA thermodynamic data

THEORY:- NASA  came up with polynomials that can be used to evaluate thermodynamic properties such as Cp, H and S. They have also documented the co-efficients that are required to evaluate these polynomials for 1000+ species.

OBJECTIVE:-

1. Writing a function that extracts the 14 co-efficients and calculates the enthalpy, entropy and specific heats for all the species in the data file
2. Calculating the molecular weight of each species and display it in the command window.
3. Plotting the Cp, Enthalpy and Entropy for the local temperature range (low temperature : high temperature) specific for each species.
4. Saving the plots as images with appropriate names and dumping them in separate folders for each species with suitable name.
5. The main program will just take the "THERMO.dat" file as an input and generate Cp, H and S plots.

EQUATIONS:-

Specific heat at constant pressure

`C_p/R = a_1 + a_2*T + a_3*T^2 + a_4*T^3 + a_5*T^4`

Enthalpy (H)

`H/(R*T) = a_1 + (a_2*T)/2 + (a_3*T^2)/3 + (a_4*T^3)/4 + (a_5*T^4)/5 + a_6*T`

Entropy (S)

`S/R = a_1*log(T) + a_2*T + (a_3*(T)^2)/2 + (a_4*(T)^3)/3 + (a_5*(T)^4)/4 + a_7`

Where

R= Universal gas constant(J/mol*K)

T= Temperature (Kelvin)

H= Enthalpy (J)

S= Entropy (J/K)

PROGRAM:-

%loading the data
F1=fopen('THERMO.dat','r');

%defining the global temp
Title=fgetl(F1);
string_temp=fgetl(F1);
strsplit(string_temp,' ');
A=str2num(string_temp);
global_low_temp=A(1);
global_mid_temp=A(2);
global_high_temp=A(3);

%Ignoring the comments
for i=1:3
    ignore=fgetl(F1);
end

for j=1:53
%Defining local temp renge
string_local1=fgetl(F1);
A1=strsplit(string_local1);
Species_name=A1{1};

local_low_temp=str2double(A1(end-3));
local_mid_temp=str2double(A1(end-1));
local_high_temp=str2double(A1(end-2));

%local temperature range of the species
local_temp_range=linspace(local_low_temp,local_high_temp,300);

%Extracting the coefficients as string
A4=fgetl(F1);
A5=findstr(A4,'E');

a1=A4(A5(1)-10:A5(1)+3);
a2=A4(A5(2)-10:A5(2)+3);
a3=A4(A5(3)-10:A5(3)+3);
a4=A4(A5(4)-10:A5(4)+3);
a5=A4(A5(5)-10:A5(5)+3);

A4=fgetl(F1);
A5=findstr(A4,'E');

a6=A4(A5(1)-10:A5(1)+3);
a7=A4(A5(2)-10:A5(2)+3);
a8=A4(A5(3)-10:A5(3)+3);
a9=A4(A5(4)-10:A5(4)+3);
a10=A4(A5(5)-10:A5(5)+3);

A4=fgetl(F1);
A5=findstr(A4,'E');

a11=A4(A5(1)-10:A5(1)+3);
a12=A4(A5(2)-10:A5(2)+3);
a13=A4(A5(3)-10:A5(3)+3);
a14=A4(A5(4)-10:A5(4)+3);

%converting the string coefficients into number
a1=str2num(a1);
a2=str2num(a2);
a3=str2num(a3);
a4=str2num(a4);
a5=str2num(a5);
a6=str2num(a6);
a7=str2num(a7);
a8=str2num(a8);
a9=str2num(a9);
a10=str2num(a10);
a11=str2num(a11);
a12=str2num(a12);
a13=str2num(a13);
a14=str2num(a14);

%calling the function of C_p,H,S
[C_p,H,S]=Nasa(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,local_low_temp,local_mid_temp,local_high_temp,local_temp_range);

%Creating individual folder for all the species and storing it
Data=sprintf('%s',Species_name);
c_d=pwd;

%making new directory and creating new folders
mkdir(Data);
cd(Data);

%Calculating molecular weight
Element_name={'H','C','N','O','A'};
Atomic_weight=[1,12,14,16,40];
mol_weight=0;


for k=1:length(Species_name)
    for m=1:length(Element_name)
        if strcmp(Species_name(k),Element_name(m))==1
            mol_weight=mol_weight+Atomic_weight(m);
            d=m;
        end
    end
    p=str2double(Species_name(k));
    if p>1
        mol_weight=mol_weight+((Atomic_weight(d))*(p-1));
    end
end

%plotting
%plotting graph for C_p
figure(1)
plot(local_temp_range,C_p,'linewidth',2,'color','r');
xlabel('Local Temperature range');
ylabel('Specific Heat');
title('C_p vs Temperature');

%saving file of C_p as png
getframe(gcf);
saveas(1,'Graph of C_p.png');

%plotting graph for Enthalpy
figure(2)
plot(local_temp_range,H,'linewidth',2,'color','b');
xlabel('Local Temperature range');
ylabel('Enthalpy');
title('Enthalpy vs Temperature');

%saving file of Enthaply as png
getframe(gcf);
saveas(2,'Graph of Enthalpy.png');

%plotting graph for Entropy
figure(3)
plot(local_temp_range,S,'linewidth',2,'color','g');
xlabel('Local Temperature range');
ylabel('Entropy');
title('Entropy vs Temperature');

%saving file of Entropy as png
getframe(gcf);
saveas(3,'Graph of Entropy.png');

%setting current directory as c_d
cd(c_d);

%Displaying the molecular weight
fprintf('Molecular weight of [%s] - %du \n',Species_name,mol_weight)
end

FUNCTION PROGRAM FOR CALCULATING C_p, H, S:-

function [C_p,H,S]=Nasa(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,local_low_temp,local_mid_temp,local_high_temp,local_temp_range)
R=8.314;
%low temperature range
L_T=linspace(local_low_temp,local_mid_temp,300);

%High temperature range
H_T=linspace(local_mid_temp,local_high_temp,300);

if(local_temp_range>=local_mid_temp)
C_p = (a1 + a2.*H_T + a3.*(H_T).^2 + a4.*(H_T).^3 + a5.*(H_T).^4).*R;
H = (a1 + ((a2.*H_T)./2) + ((a3.*H_T).^2)./3 + ((a4.*H_T).^3)./4 + ((a5.*H_T).^4)./5 + a6.*H_T).*R.*H_T;
S = (a1.*log(H_T) + a2.*H_T + ((a3.*(H_T).^2)./2)+ ((a4.*(H_T).^3)./3) + ((a5.*(H_T).^4)./4) + a7).*R;
else
    C_p = (a1 + a2.*L_T + a3.*(L_T).^2 + a4.*(L_T).^3 + a5.*(L_T).^4).*R;
H = (a1 + ((a2.*L_T)./2) + ((a3.*L_T).^2)./3 + ((a4.*L_T).^3)./4 + ((a5.*L_T).^4)./5 + a6.*L_T).*R.*L_T;
S = (a1.*log(L_T) + a2.*L_T + ((a3.*(L_T).^2)./2)+ ((a4.*(L_T).^3)./3) + ((a5.*(L_T).^4)./4) + a7).*R;
end
end

OUTPUT:-

Plot of O_2:-

Plot of N_2:-

Plot of CO_2:-

SCREENSHOT OF THE FOLDERS STORED IN PC:-

MOLECULAR WEIGHT:-

ERRORS:-

There were tons of errors made. I have not taken the screenshot of the errors, but I remember all of them

Here below are the errors I faced,

1. Didn’t used the ‘.’ Dot operator in the function file i.e ‘Nasa.m’.
2. While calculating the molecular weight of ‘Ar’ it was showing an error so I fixed the name of ‘AR’ to ‘A’
3. Faced many problems while writing the code for calculating 'molecular weight' of the species.
4. Made lots of mistakes while writing the FUNCTION for calculating C_p,H,S.
5. While running the program I was not getting the GRAPH of some species because of the errors made in the FUNCTION file.
6. Faced error while creating the directory for individual species.