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.

1. To 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.
2. To plot the Cp, Enthalpy and Entropy for the local temperature range specific for each species.

EQUATION:

Where

R = Universal Gas Constant

T = Temperature

Cp = Specific Heat (KJ)

S = Entropy (KJ/mol-K)

H = Enthalpy (KJ/mol)

a(i) = Coefficients where, i = 1 to 14

File Parsing - 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 comes from Latin pars (orationis). meaning part (of speech), Within computational linguistics the term is used to refer to the formal analysis by a computer of a sentence or other string of words into its constituent, resulting in a parse tree showing their syntactic relation to reach other, which may also contain semantic and other information. Some parsing algorithms may generate a parse forest or list of parse trees for a syntactically ambiguous input.

NASA Thermodynamic file- NASA Thermodynamic file which is THERMO.dat file in which there are temperature range and 53 species are given in these data and each species contains 14 coefficients and temperature ranges and we have to parse these 14 coefficients to find Specific heat, Entropy and Enthalpy using formulae.

Specific Heat - The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.

Entropy - Entropy, the measure of a system’s thermal energy per unit temperature that is unavailable for doing useful work. Because work is obtained from ordered molecular motion, the amount of entropy is also a measure of the molecular disorder, or randomness, of a system.

Enthalpy - Enthalpy, a property of a thermodynamic system, is equal to the system’s internal energy plus the product of its pressure and volume. In a system contained so as to prevent mass transfer, for processes at constant pressure, the heat absorbed or released equals the change in Enthalpy.

Molecular Weight- The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.

List of 53 Elements contained in 'THERMO.dat' file:

AR C C2H C2H2 C2H3 C2H4

C2H5 C2H6 C3H7 C3H8 CH CH2

CH2(S) CH2CHO CH2CO CH2O CH2OH CH3

CH3CHO CH3O CH3OH CH4 CN CO

CO2 H H2 H2CN H2O H2O2

HCCO CCOH HCN HCNN HCNO HCO

HNCO HNO HO2 HOCN N N2

N2O NCO NH NH2 NH3 NNH

NO NO2 O O2 OH

PROGRAM

1. Specific Heat Code

% Specific Heat Calculation Function

function Cp = Specific_heat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,tempmid)
  
  % calculating specific heat for higher and lower temperature respectively.
  
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

% Molecular Weight Calculation Function

function MW = Molecular_weight(species)
  
  % Defining Atomic Name of the species
  
  atomic_name = ['H', 'C', 'O', 'N', 'Ar'];
   % Hydrogen , Carbon, Oxygen, Nitrogen, Argon
   
   
   % Defining Atomic masses of main species
   atomic_weight = [1.008 12.011 15.999 14.007 39.948];
   
   MW = 0;                           % Molecular weight starting range
   
   % Adding Atomic Number to obtain particular value
   
   for  i=1:length(species)          % Loop runs to the length of the species
       for j=1:length(atomic_name)   % Loop runs to the length of the atomic name
         if strcmp(species(i), atomic_name(j)) % function to compare 2 strings
         MW = MW + atomic_weight(j);
         position = j;
       end
     end
     n = str2num(species);           % Finding more elements in the species and incrementing  atomic weight of the species
        
   if n>1
       MW = MW + atomic_weight(position)*(n-1);
     end
   end
   fprintf('Molecular Weight of %s : ',species);
   fprintf('%f',MW);
   disp(' ');
 end

% Entropy Calculation Function

function S = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,T,R,tempmid)
  
  % calculating entropy for higher and lower temperature respectively.
  
  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

% Enthalpy Calculation function

function H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,T,R,tempmid)
  
  % calculating enthalpy for higher and lower temperature respectively.
  
  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

Main Code

clear all
close all
clc

% Input
R = 8.314; % Gas Constant (J/(mol-K))

% Reading data File
% Open and read THERMO.dat file

f1 =   fopen('THERMO.dat','r')
get = fgetl(f1);


% NOW reading Temperature from this file
temp = fgetl(f1);

% Splitting
s = strsplit(temp);

% Converting   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);
  
  
  A = strsplit(tline, ' ');   % Splitting cell into array
 
 species = (A{1});            % To read the name of the species
 
% Converting   strings cells into numbers
lowtemp = str2num(A{end-3});
midtemp = str2num(A{end-2});
hightemp = str2num(A{end-1});

tline1 = fgetl(f1);            % getting next line
a = strfind(tline1, 'E');      % Finding the string E

% Finding first 7 higher and second & lower coefficients

% Finding the 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 = strfind(tline2, 'E');
a6 = tline2(1:b(1)+3);
a6 = str2num(a6);
a7 = tline2(b(1)+4:b(2)+3);
a7 = str2num(a7);


% Finding lower coefficients
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 = strfind(tline3, 'E');
a11 = tline(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 specific heat
Cp = Specific_heat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,tempmid);

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

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

% calculate Molecular Weight of the species
MW = Molecular_weight(species);

% writing molecular weight file
MW_file = fopen('Molecular Weight.txt','w');
fprintf(MW_file,'Molecular weight of %s is %d ',species,MW);
fclose(MW_file);                           % closing the file

% Plotting Cp, H & S with temperature
% saving in a folder
cd('C:/Users/DELL/Desktop/thermodynamics')   % changing directory
mkdir(species);                            % creating directory
cd(species);

% Plot 1 | Cp vs T
figure(1)
plot(T,Cp,'linewidth',3,'color','r');
xlabel('Temperature (K)');
ylabel('Specific heat (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',3,'color','g');
xlabel('Temperature (K)');
ylabel('Entropy (KJ/mol-K)');
title(sprintf('Entropy vs Temperature range of %s', species));
grid on
saveas(figure(2),'Entropy.jpg');

% Plot 3 | H vs T
figure(3)
plot(T,H,'linewidth',3,'color','b');
xlabel('Temperature (K)');
ylabel('Enthalpy (KJ/mol)');
title(sprintf('Enthalpy vs Temperature range of %s', species));
grid on
saveas(figure(3),'Enthalpy.jpg');

cd('C:/Users/DELL')                      % Changing directory to original matlab path

% Molecular Weight
MW = Molecular_weight(species)

end

Explanation