Project 1 - Parsing NASA thermodynamic data

Main Code:-

clear all
close all
clc

% Make directory
mkdir 'D:\Anurag\Courses\Programing\MATLAB\Programs\NASA'

% Reading Data file - NASA Thermodynamic
% Open a file & 'r' Open the file for reading
f1=fopen('THERMO.dat','r')
gt=fgetl(f1);

% Obtaing Temperatures - by Reading Header Information
global_temp=fgetl(f1);

% Spliting
t=strsplit(global_temp);

% Converting string cells to numbers using str2num,
global_low_temp=str2num(t{2});
global_medium_temp=str2num(t{3});
global_high_temp=str2num(t{4});

% Temperature range & Gas Constant
% Temperature Range assumed
Temp=linspace(global_low_temp,global_high_temp,1000);
% Universal Gas Constant J/(mol-K)
R = 8.314;

% skipping three comment lines in the file
for i = 1:3
gt=fgetl(f1);
end

for i = 1:53
gt=fgetl(f1);
A=strsplit(gt,' ');
Species_SP=(A{1})

line_1=fgetl(f1) ;
a=strfind(line_1,'E');

% Extracting higher and lower temperature coefficients

% % Extracting FIRST 7 coefficients i.e HIGH-temperature coefficients
a1=line_1(1:a(1)+3);
a1=str2num(a1); %1
a2=line_1(a(1)+4:a(2)+3);
a2=str2num(a2) ; %2
a3=line_1(a(2)+4:a(3)+3);
a3=str2num(a3) ; %3
a4=line_1(a(3)+4:a(4)+3);
a4=str2num(a4); %4
a5=line_1(a(4)+4:a(5)+3);
a5=str2num(a5) ; %5

line_2=fgetl(f1);
b=strfind(line_1,'E');;
a6=line_2(1:b(1)+3);
a6=str2num(a6) ; %6
a7=line_2(a(1)+4:b(2)+3);
a7=str2num(a7); %7

% Extracting SECOND 7 coefficients - LOW-temperature coefficients
a8=line_2(b(2)+4:b(3)+3);
a8=str2num(a8); %8
a9=line_2(b(3)+4:b(4)+3);
a9=str2num(a9) ; %9
a10=line_2(b(4)+4:b(5)+3);
a10=str2num(a10) ; %10

line_3=fgetl(f1);
c=strfind(line_1,'E');

a11=line_3(1:c(1)+3);
a11=str2num(a11); %11
a12=line_3(c(1)+4:c(2)+3);
a12=str2num(a12); %12
a13=line_3(c(2)+4:c(3)+3);
a13=str2num(a13); %13
a14=line_3(c(3)+4:c(4)+3);
a14=str2num(a14); %14

% Specific heat calculation
Cp = Specificheat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,Temp,R,global_medium_temp);

% Enthalpy calculation
H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,Temp,R,global_medium_temp);

% Entropy calculation
S = Entropy_calc(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,Temp,R,global_medium_temp);

% Calculating molecular weight of species
Molecularweight(i) = Molecular_weight(Species_SP);

% Read & Write Molecular list
Molecular_list = fopen('Molecular weight.txt','a+');
fprintf( Molecular_list,'Molecular weight of %s is %d n',Species_SP,Molecularweight);
fclose(Molecular_list);

% plotting(CP,H,S,Temp,Species_SP)
% Saving as a folder

cur_dir=pwd;
mkdir(Species_SP);
cd(Species_SP);

% Plot 1, Specific heat (CP) vs Temperature Range (Temp)

figure(1)
plot(Temp,Cp,'linewidth',2,'color','r');
xlabel('Temperature [K]');
ylabel('Specific Heat [kJ]');
title(sprintf('Varying Specific Heat with Temperature Range of %s',Species_SP));
grid on
saveas(figure(1),'Specific Heat.jpg');

% Plot 2, Enthalpy (H) vs Temperature Range (Temp)

figure(2)
plot(Temp,H,'linewidth',2,'color','g');
xlabel('Temperature [K]');
ylabel('Enthalpy in [kJ/(mol)]');
title(sprintf('Varying Enthalpy with Temperature Range of %s',Species_SP));
grid on
saveas(figure(2),'Ethalpy.jpg');

% Plot 3, Entropy (S) vs Temperature Range (Temp)

figure(3)
plot(Temp,S,'linewidth',2,'color','b');
xlabel('Temperature [K]');
ylabel('Entropy in [kJ/(mol-K)]');
title(sprintf('Varying Entropy with Temperature Range of %s',Species_SP));
grid on
saveas(figure(3),'Entropy.jpg');

cd(cur_dir);

% Molecular weight

M = Molecular_weight(Species_SP)
f2 = fopen('molecular mass','w');
fprintf('%s n %s n %f n','species','Molecular mass',M)
fclose(f2)
end

Function Codes:-

1.Specific heat calculation function

% Specific heat calculation function

function Cp = Specificheat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,Temp,R,global_medium_temp)
% Comparing with global temperature
% If less than global temperature - minimum coefficients are taken
if Temp <= global_medium_temp
Cp = R*(a8 + (a9*Temp) + (a10*(Temp).^2) + (a11*(Temp).^3) + (a12*(Temp).^4));
else
Cp = R*(a1 + (a2*Temp) + (a3*(Temp).^2) + (a4*(Temp).^3) + (a5*(Temp).^4));
% Else maximum coefficients are taken
end

2.Entropy Calculation function

%Entropy Calculation function

function S = Entropy_calc(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,Temp,R,global_medium_temp)
% Comparing with global temperature
% If less than global temperature - minimum coefficients are taken

if Temp <= global_medium_temp
S = R.*(a8.*log(Temp) + (a9.*Temp) + (a10*((Temp).^2)/2) + (a11*((Temp).^3)/3) + (a12*((Temp).^4)/4) + a14);
else

% Else - maximum coefficients are taken
S = R.*(a1.*log(Temp) + (a2.*Temp) + (a3*((Temp).^2)/2) + (a4*((Temp).^3)/3) + (a5*((Temp).^4)/4) + a7);
end

3.Enthalpy Calculation function

% Enthalpy Calculation function

function H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,Temp,R,global_medium_temp)
% Comparing with global temperature
% If less than global temperature - minimum coefficients are taken

if Temp <= global_medium_temp
H = R*Temp.*(a8 + ((a9*Temp)/2) + ((a10*(Temp).^2)/3) + ((a11*(Temp).^3)/4) + ((a12*(Temp).^4)/5) +((a13./Temp)));
else
% Else maximum coefficients are taken

H = R*Temp.*(a1 + ((a2*Temp)/2) + ((a3*(Temp).^2)/3) + ((a4*(Temp).^3)/4) + ((a5*(Temp).^4)/5) +((a6./Temp)));
end

4.Molecular Weight Calculation function

% Molecular Weight Calculation function

function Molecularweight = Molecular_weight(Species_SP)
% Standard - Atomic Name
atomic_name = ['H','C','O','N','A'];
% Hydrogen, Carbon, Oxygen, Nitrogen, Argon

fprintf('Molecular Weight of ');
fprintf(Species_SP);
fprintf(' : ');
% Standard Atomic Number
Atomic_Weight = [1.008 12.011 15.999 14.007 39.948];
% Starting Range of Molecule
Molecularweight = 0;

% Adding Atomic number to obtain particular value
for i = 1:length(Species_SP)
for j = 1:length(atomic_name)
if strcmpi(Species_SP(i),atomic_name(j))
Molecularweight = Molecularweight +Atomic_Weight(j);
position = j;
end
end
n = str2num(Species_SP(i));

if n>1

Molecularweight = Molecularweight + Atomic_Weight(position)*(n-1);

end
end
fprintf('molecular weight %s :',Species_SP);
fprintf('%d',Molecularweight);
disp(' ');
end

Step-wise Explanation of Code:-

Code Explanation:

1. 'clear all' - clear all the variables in the workspace,

   'close all' - closes all the plots and figures and

   'clc' - clears the command window.

2. Making a directory using 'mkdir' with location address.
3. After that, reading the text file 'Thermo.dat' file and opening it by using ‘fopen’ and 'r' as the reading command.
4. For reading the line in a text file using ‘fgetl’.
5. To obtain the temperature range from the Thermo.dat file, using ‘strsplit’ to split the temperature into a particular string cell.
6. Used ‘str2num’ for converting string cells to numbers.
7. Divided the temperature into a string and then converted it to a number to use temperature values separately to solve the NASA thermodynamics.
8. Using ‘for & end’ loops to skip the next three comment lines in the text file.
9. Reading all the 53 species to plot specific heat(cp), enthalpy(H), and entropy(S), with temperature values, and to find the molecular weights.
10. Used ‘for’ loop to read 53 species.
11. Used ‘strfind’ to find string.
12. Using 'linspace' specified the temperature range from low to high.
13. Adding universal gas constant value ‘R’.
14. Extracted higher and lower temperature coefficients by reading line by line from the species.
15. Calling specific heat, enthalpy, entropy function codes.
16. Calculating Molecular weight.

Syntax Used during Coding

fopen :	Open a file or obtain information about open files
‘r’ :	Open the file for reading
fgetl	Read line from file
strsplit	Split string or character vector at the specified delimiter
str2num	Convert character array or string to numeric array
strfind	Find one string within another
linspace	Generate linearly spaced vectors
fprintf	Write formatted data to file
pwd	Identify current directory
mkdir	Make new directory
cd	Change working directory

References:-

https://in.mathworks.com/help/matlab/ref/mkdir.html

https://in.mathworks.com/matlabcentral/answers/317006-create-new-folders-by-mkdir

https://in.mathworks.com/help/matlab/ref/saveas.html

https://in.mathworks.com/matlabcentral/answers/17580-how-to-define-a-path-in-saveas-command

https://in.mathworks.com/help/matlab/referencelist.html?type=function&category=printing-and-exporting

https://in.mathworks.com/help/matlab/ref/msgbox.html

https://in.mathworks.com/matlabcentral/answers/151692-display-value-in-message-box

https://in.mathworks.com/help/matlab/ref/fprintf.html

https://in.mathworks.com/help/matlab/ref/sprintf.html

http://combustion.berkeley.edu/gri-mech/data/nasa_plnm.html

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940013151.pdf

https://link.springer.com/chapter/10.1007/978-1-4684-0186-8_8