Project 1 - Parsing NASA thermodynamic data

AIM
NASA came up with polynomials that can be used to evaluate thermodynamic properties such as Cp, H, and S. They have also documented the coefficients that are required to evaluate these polynomials for 1000+ species. In this project, we are going to Parsing this data file for 53 species. Our aim is to extract necessary information from this file and evaluate them to plot the properties of these species. The process of extracting information from any file is known as
File Parsing.
GOVERNING EQUATIONS:
In this Project, we are going to calculate Specific Heat(Cp ), Enthalpy(H ), Entropy( S) of the 53 species recorded on the file.
~ The equation for Specific Heat (Cp )
~ The equation for Enthalpy (H )
~ The equation for Entropy (S )

Where, R is Universal Gas Constant , T is Temperature and a1, a2, .......a7 are coefficients.
OBJECTIVE:
In this project, we are going to Parsing the NASA Thermodynamic Data & calculate the Properties of the species in the data file. The objectives are

1) To write a function that extracts the 14 coefficients and calculates the enthalpy, entropy, and specific heats for all the species in the data file.
2) To calculate the molecular weight of each species and display it in the command window.
3) To plot the Cp, Enthalpy, and Entropy for the local temperature range (low temperature: high temperature) specific for each species.
4) To save the plots as images with appropriate names and dump them in separate folders for each species with a suitable name. All of these should be generated automatically.

Evaluation Of Program:
The program of this project is divided into three parts, one is to write a program to calculate Cp,H,S , 2nd is to calculate Molecular Weight Of the species and 3rd is to extract all the coefficients from the file and to plot Cp,H S, with temperature ranges. The 3rd part is the Main program that includes the evaluation of plots with making folders and saves individual plots within these folders.

Fistly to create function to calculate Cp , H , S -

% Function To Calculate Cp,Enthalpy and Entropy
% for the local temperature range, specific for each species.

function [ Cp H S ]=property(A1,A2,A3,A4,A5,A6,A7,a1,a2,a3,a4,a5,a6,a7,T,G_mid_T)
% Cp = Specific Heat of species at constant Pressure
% H = Enthalpy
% S = Entropy
% T = Temperature Range
% G_mid_T = Global Mid Temperature
R = 8.314 ; % R = Universal Gas Constant
for q = 1: length(T)

if T(q) >= G_mid_T

Cp = (A1+ (A2.*T) + (A3.*T.^2) + (A4.*T.^3) + (A5.*T.^4)) * R ;
H = (A1+(A2.*(T./2))+(A3.*(T.^2)./3)+(A4.*(T.^3)./4)+(A5.*(T.^4)./5)+(A6./T)).*(T.*R);
S = ((A1.* log(T))+(A2.*T)+(A3.*T.^2)+(A4.*T.^3)+(A5.*T.^4)+A7)* R ;

else
Cp =(a1+ (a2.*T) + (a3.*T.^2) + (a4.*T.^3) + (a5.*T.^4)) * R ;
H = (a1+(a2.*(T./2))+(a3.*(T.^2)./3)+(a4.*(T.^3)./4)+(a5.*(T.^4)./5)+(a6./T)).*(T.*R);
S = ((a1.*log(T))+(a2.*T)+(a3.*T.^2)+(a4.*T.^3)+(a5.*T.^4)+a7)* R ;
end
end

After that to create a function to calculate molecular weight of the species -

% Function To Calculate Molecular Weight
function MW= Molecular_Weight(species)
atoms={'H','C','N','O','A'};
% H=HYDROGEN(1), C=CARBON(12), N=NITROGEN(14), O=OXYGEN(16), A=ARGON(40)
atomic_weight=[1 12 14 16 40];

MW=0;

for i=1:length(species)
for j=1:length(atomic_weight)
if (strcmp(species(i),atoms(j))==1) % for comparing atoms of the species with atoms
MW = MW + atomic_weight(j);
rank=j; % to find the position of atoms in the species
end
end

% For the weights of the repeating atoms
m=str2num(species(i));
if m>1
n=m-1;
MW=MW+atomic_weight(rank)*(n);
end

end
end

Main program -

clc
clear all
close all
% Program for Parsing NASA thermodynamic data
file = fopen('THERMO.dat','r'); % To open the data file & set to read mode
file_name = fgetl(file) ; % To read the Header line(file name)
first_line = fgetl(file) ; % To read the 1st line after Header
Global_Temp_Range=strsplit(first_line,' ') ;% To extract temp from 1st line
G_low_T = str2num(Global_Temp_Range{2}); % To get the Global low temperature
G_mid_T = str2num(Global_Temp_Range{3}) ; % To get the Global mid temperature
G_high_T = str2num(Global_Temp_Range{4}) ;% To get the Global high temperature
for i= 1:3
a= fgetl(file) ; % To read the next 3 lines after first line
end
for j= 1:53
line_1 = fgetl(file); %To read 1st line of species,as ranked 1 on RHS of data file
L1 = strsplit(line_1,' '); % To split 1st line
species = (L1{1}); % To extract Species from 1st line
G = strfind(line_1,'G '); % To find the position of G in 1st line

L_low_T = str2num(line_1(G+3:G+10)); % To extract LOCAL Low Temperature
L_high_T = str2num(line_1(G+12:G+20)); % To extract LOCAL High Temperature
L_mid_T = str2num(line_1(G+22:G+30));% To extract LOCAL Midium Temperature
T = linspace(L_low_T,L_high_T,500); % To set a range of Local Temperature

line_2 = fgetl(file); %To read 2nd line of species,as ranked 2 on RHS of data file
L2 = strfind(line_2,'E'); % To find the position of E in 2nd line
A1 = str2num(line_2(1:L2(1)+3)); % To extract 1st coefficient for High Temperature
A2 = str2num (line_2(L2(1)+4:L2(2)+3)); % To extract 2nd coefficient for High Temperature
A3 = str2num (line_2(L2(2)+4:L2(3)+3)); % To extract 3rd coefficient for High Temperature
A4 = str2num (line_2(L2(3)+4:L2(4)+3)); % To extract 4th coefficient for High Temperature
A5 = str2num (line_2(L2(4)+4:L2(5)+3)); % To extract 5th coefficient for High Temperature

line_3 = fgetl(file); %To read 3rd line of species,as ranked 3 on RHS of data file
L3 = strfind(line_3,'E'); % To find the position of E in 3rd line
A6 = str2num(line_3(1:L3(1)+3)); % To extract 6th coefficient for High Temperature
A7 = str2num (line_2(L3(1)+4:L3(2)+3)); % To extract 7th coefficient for High Temperature
a1 = str2num (line_2(L3(2)+4:L3(3)+3)); % To extract 1st coefficient for Low Temperature
a2 = str2num (line_2(L3(3)+4:L3(4)+3)); % To extract 2nd coefficient for Low Temperature
a3 = str2num (line_2(L3(4)+4:L3(5)+3)); % To extract 3rd coefficient for Low Temperature

line_4 = fgetl(file); %To read 4th line of species,as ranked 4 on RHS of data file
L4 = strfind(line_4,'E'); % To find the position of E in 4th line
a4 = str2num(line_4(1:L4(1)+3)); % To extract 4th coefficient for Low Temperature
a5 = str2num (line_4(L4(1)+4:L4(2)+3)); % To extract 5th coefficient for Low Temperature
a6 = str2num (line_4(L4(2)+4:L4(3)+3)); % To extract 6th coefficient for Low Temperature
a7 = str2num (line_4(L4(3)+4:L4(4)+3)); % To extract 7th coefficient for Low Temperature

% Function To Calculate Cp,Enthalpy and Entropy
[Cp,H,S] = property(A1,A2,A3,A4,A5,A6,A7,a1,a2,a3,a4,a5,a6,a7,T,G_mid_T);

% To creat Folders with species name
Folder_name = sprintf('%d) [%s]',j, species); % To give Folder names
current_dir = pwd ; % To specify the current directory
% All The Function Program And Thermodynamic Data file are stored in a folder,that specify current

mkdir(Folder_name); % To creat a Folder
cd(Folder_name); % To load plots in that new folder

figure (1);
plot(T,Cp,'r','linewidth',3)
grid on
xlabel(' Local Temperature');
ylabel(' Specific Heat')
title(' Specific Heat(Cp) Vs Temperature(T) ')
IMAGE1 = sprintf(" Cp Vs T of [%s].png",species); % To give a name of the file
saveas(gca,IMAGE1) % To save the image file

figure (2);
plot(T,H,'b','linewidth',3)
grid on
xlabel(' Local Temperature');
ylabel(' Enthalpy')
title(' Enthalpy(H) Vs Temperature(T) ')
IMAGE2 = sprintf(" H Vs T of [%s].png",species); % To give a name of the file
saveas(gca,IMAGE2) % To save the image file
figure (3);
plot(T,S,'g','linewidth',3)
grid on
xlabel(' Local Temperature');
ylabel(' Entropy')
title(' Entropy(S) Vs Temperature(T) ')
IMAGE3 = sprintf(" S Vs T of [%s].png",species); % To give a name of the file
saveas(gca,IMAGE3) % To save the image file

cd(current_dir); % To give a path,return to current directory

% Function To Calculate Molecular Weight
MW = Molecular_Weight(species);
fprintf(' %d) Molecular Weight of [%s] is %d.',j,species,MW) % To display as output
fprintf('n n') % To set the next output after 2 line interval
end

EXPLANATION OF CODE:

• First step is to clear all, close all, clc. The clear all command helps to clear the workspace. The close all command closes all figures and the clc command clears the command window.
• The fopen command is used in reading mode to read the THERMO.dat file.
• The temperature values are calculated by using strsplit,str2num commands.
• Then the comment lines are stored in three variables i.e., line3, line4, line5.
• The for loop is used to create an array that contains every line of the file.
• Then the co-efficients are founded by using the findstr, str2num.
• Then the directory is created to save the plots in png format with species name.
• The cp, h, s functions are called to the main program which have been created separate script.
• Then the plots are created between temperature and cp, s, h.
• The saveas is used to save the plots in png extension.
• Finally the molecular_weight function is called for calculating the molecular weight of the species.
• The fclose command is used to end the reading of the file

SCREENSHOT OF THE WINDOW WHERE ALL THE FOLDERS ARE SAVED:

SCREENSHOT OF MOLECULAR WEIGHT IN COMMAND WINDOW:

Outputs -

Polts of the O2 -

Polts of the N2 -

Polts of theCo2 -

CONCLUSION:

Thus the file parsing of NASA thermodynamic data has been done using MATLAB.