Challenge

Project 1 - Parsing NASA thermodynamic data

SSethu Raman9 Mar 2022

AIM :

To write a code in Matlab to parsing the NASA thermodynamics data file and to calculate the thermodynamic properties of various gas species .

OBJECTIVES :

To write a program that extracts the 14 co -efficienets and to calculate the enthaply, entropy and specific heats for all the species in the data file .
To calculate the molecular weight of each species and display in the command window .
To plot the Cp,Enthaply and Entropy for the local temperature range (low temperature : high temperature ) specific for the each species .
Save the plots as images with appropriate names and dump them in separate folders for each species with suitable name. All these should be generated automatically.
The main program that you will submit will just take the "THERMO.dat" file as an input and generate Cp, H and S plots
To plot for o2, N2, and Co2 species .

FILE PARSING : DEFINITION

Parsing , syntax analysis or syntactic analysis is the process of analyzing a string of symbols , either in natural language, computer languages or data structures , conforming to the rules of a formal grammar .
The term parsing comrs from the latin pars (orationis), meaning part (of speech ) .
within the computional linguistics the term is used to refer the formal analysis by a computer of a sentence or the string of words into the constituents , resulting in a prase tree showing their syntactic relation to each other , which may also contain semantic and other information ( p - values ).
Some parsing alogrithms may generate a parse forest or list of pars trees for a syntactically ambiguous input .

DIAGRAM :

NASA Thermodynamic File :

NASA thermodynamic file which is THERMO.dat file in which temperature range and species are given in these data and each species contains 14 co - efficients and temperature ranges .we have to parse these 14 co - effeicients to find the Specific heat , Entropy , Enthalpy using equation as follows ,

where,

R = Universal Gas Constant .
T = Temperature .
Cp = Specific heat (KJ) .
S = Entropy (KJ/mol-K) .
H = Enthaply (kJ/mol) .
a(i) = Cofficients where i = 1 to 14 .

SPECIFIC HEAT :

Specific heat can be define as 'the quantity of heat required to raise the temperature of one gram of a substance by one celsius degree.

The unit of specific heat is calories or joules per gram per celsius degree .

EXPRESSION OF SPECIFIC HEAT (Cp) :

`Cp = R*(a1 +(a2*T) +(a3*(T).^2)+(a4*(T).^3+(a5*(T).^4)

ENTHAPLY :

Enthaply is defined as a property of a thermodynamic system , is the sum of system's internal energy and the product of its pressure and volume .

The unit of enthalpy is joule per kilogram .

EXPRESSION OF ENTHALPY :

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

ENTROPY :

Entropy is defined as , the measure of a system's thermal energy per unit temperature that is unavaible for doing useful work .

The unit of entropy is joule per kelvin .

EXPRESSION OF ENTROPY (S) :

`S = R*(a1.*log(T) +(a2*T) +((a3*(T).^2)/2)+((a4*(T).^3)/3)+((a5*(T).^4)/4)+a7)`

MAIN PROGRAM :

% A program to calculate NASA parasing 

clear  all 
close all 
clc

% Inputs 
% Universal gas constant 
R = 8.314 ;

% Reading the file data 
% Open file and reading THERMO.dat file 
f1 = fopen('THERMO.dat','r')
get = fgetl(f1);

% Now reading the temperature from this file 
temp = fgetl(f1);

% splitting 
s = strsplit(temp);

% Coverting strings cells into numbers 
templow  = str2num(s{2});
tempmid  = str2num(s{3});
temphigh = str2num(s{4});

% Temperature range 
T = linspace(templow,temphigh,1000);

% skipping comment lines 
for i = 1:3
    get = fgetl(f1);
end  

% Reading the species 
 for  j = 1:53 
    tline = fgetl(f1);

% Splitting into cell array 
 A = strsplit(tline,' ')

% To read the name of the species 
 species = (A{1});

% Converting strings to number 
lowtemp  = str2num(A{end-3});
midtemp  = str2num(A{end-2});
hightemp = str2num(A{end-1});

% Getting next lines 
tline1 = fgetl(f1);

% Finding the string E 
a = findstr(tline1,'E');

% Finding Higher coefficents and lower coefficients
% Finding first 7 higher coefficients 

a1 = tline1(1:a(1)+3);
a1 =str2num(a1);
a2 = tline1(a(1)+4:a(2)+3);
a2 = str2num(a2);
a3 = tline1(a(2)+4:a(3)+3);
a3 = str2num(a3);
a4 = tline1(a(3)+4:a(4)+3);
a4 = str2num(a4);
a5 = tline1(a(4)+4:a(5)+3);
a5 = str2num(a5);
 
tline2 = fgetl(f1);
b  = findstr(tline2,'E');
a6 = tline2(1:b(1)+3);
a6 = str2num(a6);
a7 = tline2(b(1)+4:b(2)+3);
a7 = str2num(a7);

% Next finding the second 7 coefficents which is lower order
a8  = tline2(b(2)+4:b(3)+3);
a8  = str2num(a8);
a9  = tline2(b(3)+4:b(4)+3);
a9  = str2num(a9);
a10 = tline2(b(4)+4:b(5)+3);
a10 = str2num(a10);

tline3 =fgetl(f1);
c   = findstr(tline3,'E');
a11 = tline3(1:c(1)+3);
a11 = str2num(a11);
a12 = tline3(c(1)+4:c(2)+3);
a12 = str2num(a12);
a13 = tline3(c(2)+4:c(3)+3);
a13 = str2num(a13);
a14 = tline3(c(3)+4:c(4)+3);
a14 = str2num(a14);

% Calculate the Specific heat
Cp = Specific_heat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,tempmid);

% Calculate the Entropy 
S = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,T,R,tempmid);

% calculate the Enthalpy
H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,T,R,tempmid);

% Calculate the Molecular weight of the species 
W = Molecular_weight(species);

% Writing molecular weight file 
MW_file = fopen('Molecular Weight.txt','w')
fprintf(MW_file,'Molecular weight of %s is %d ',species,W)
fclose(MW_file)

% Plotting Cp, H and S with temperature 
% Saving in a folder 
cd('C:/Users/SETHU RAMAN/Skill lync/Species/')
mkdir(species);
cd(species);

% Plot 1 Cp vs T 
figure(1)
plot(T,Cp,'Linewidth',2,'color','b')
xlabel('Temperature in (K)')
ylabel('Specific Heat in (KJ)')
title(sprintf('Specific heat vs Temperature range of %s',species))
grid on 
saveas(figure(1),'Specific Heat.jpg')

% plot 2 S vs T 
figure(2)
plot(T,S,'linewidth',2,'color','r')
xlabel('Temperature in (k)')
ylabel('Entropy in (KJ/mol-K)')
title(sprintf('Entropy vs Temperature range of %s',species))
grid on 
saveas(figure(2),'Entropy.jpg')

% plot 3 Cp vs T 
figure(3)
plot(T,H,'linewidth',2,'color','g')
xlabel('Temperature in (K)')
ylabel('Enthalpy in (KJ/mol)')
title(sprintf('Enthaply vs Temperature range of %s',species))
grid on 
saveas(figure(3),'Enthalpy.jpg')
cd('C:/Users/SETHU RAMAN/Skill lync/Species')

% Molecular weight
W = Molecular_weight(species)

end

CODE EXPLANATION :

The program starts with clear all, close all and clc .
clear all command is used to clear all the varaibles from the workspace .
close all command is used to close all the plots and figures .
clc command is used to clear all the txt from the comman window .
Then we need to input the universal gas constant R = 8.314 parameter and then we need to open the file of THERMO. dat after that reading this file using the fopen command .
Then fgetl command is used to read the THERMO file and temperature is been readed ,after that need to split the temperature file .
so, strsplit command is used to convert it into the cell array and then convert this string to the number by using the str2num command . so now we will able to find the high mid low temperatures respectively .
Now the linspace command is used to assign the temperature range .
Then the loop statement is used to skip the comment data from the THERMO file . and again we running the loop statement to find the 53 elements from the file respectively .
findstr command is used to find the 'E' from the species .
Molecular Weight function is used to find the differenet species of molecular weight .
Then we will plot the Specific heat , Entropy and Enthalpy with the temperatures of different species .
Then saveas command is used to save the plots of differnet species .

FUNCTION OF SPECIFIC HEAT :

function Cp = Specific_heat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,tempmid)

% Calculating specific heat 
% Calculating the specific heat for higher and lower Temperatures

if (T <=tempmid)
    Cp = R*(a8 + (a9*T) + (a10*(T).^2) + (a11*(T).^3) + (a12*(T).^4));
else
    Cp = R*(a1 + (a2*T) + (a3*(T).^2) + (a4*(T).^3) + (a5*(T).^4));
end 
end

FUNCTION OF ENTROPY :

function S = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,T,R,tempmid)

% calculate the entropy 
% calculate the entropy for higher and lower temperatures

if (T <= tempmid)
    S = R*(a8.*log(T) + (a9*T) + ((a10*(T).^2)/2) + ((a11*(T).^3)/3) + ((a12*(T).^4)/4) +a14);
else
    S = R*(a1.*log(T) + (a2*T) + ((a3*(T).^2)/2) + ((a4*(T).^3)/3) + ((a5*(T).^4)/4) + a7);
end
end

FUNCTION OF ENTHALPY :

function H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,T,R,tempmid)

% Calculate the enthalpy
% Calculating the enthaply for higher and lowerR * temperatures

if (T <= tempmid)
    H = R*T.*(a8 + ((a9*T)/2) + ((a10*(T).^2)/3) + ((a11*(T).^3)/4) + ((a12*(T).^4)/5) + ((a13./T)));
else 
    H = R*T.*(a1 + ((a2*T)/2) + ((a3*(T).^2)/3) + ((a4*(T).^3)/4) + ((a5*(T).^4)/5) + ((a6./T)));
end
end

FUNCTION OF MOLECULAR WEIGHT :

function W = Molecular_weight(species)

% Defining the Atomic name of the Species
atomic_name = ['H','C','O','N','A'];

% Defining the Atomic masses of the Main Species 
atomic_weight = [1.008 12.011 15.999 14.007 39.948 ];

% Molecular weight starting range 
W = 0; 

for i = 1:length(species)
    for j = 1:length(atomic_name)
        if strcmp(species(i), atomic_name(j))
            W = W + atomic_weight(j);
            position = j;
        end
    end
    n = str2num(species);

    if n>1
        W = W + atomic_weight(position)*(n-1);
    end
end

fprintf('Molecular Weight of %s :- ',species);
fprintf('%f',W);
disp(' ')
end

EXPLANATION :

Molecular weight function is beed initiated to assign the species , then define the main of all 53 elements in an array of atomic_name which is 'H' 'C' 'O' 'N' 'A' .
The atomic _weight array has been created which is 1.008 12.011 15.999 14.007 39.948 .
Then molecular weight range is assinged to zero .
strcmp command is used to compare the species and the atomic_name strings to calculate the molecular masses.
str2num command is used to convert strings into number .
fprintf command is used to print the molecular weight .
disp command is used to display it .