Project 1 - Parsing NASA thermodynamic data

• function c_p = specific_heat(x1,x2,x3,x4,x5,y1,y2,y3,y4,y5,R,temp,global_mid)  The statement that together to perform a task that to make acode to implement . 
• First, x coefficients are high temperature and y coefficients are low temperature
• if temp<=global_mid - comparing the matrix value of the temperature generated from the line space command with global medium temperature.
• The following line indicates the calculation of the entropy written to the equation.
• else statement to perform the task if the 'if' statement fails
• The following line indicates the calculation of the entropy written to the equation.
•  To end the function using the end command

MOLECULAR WEIGHT

CODE FOR MOLECULAR WEIGHT FUNCTION

% Function to calculate Molecular Weight
function mw = molecular_weight(sp_name)
% Storing value
    compound_name = (sp_name)
    % Creating an array of an element
    key_at = ['C','H','O','N','A'];
    % Storing atomic mss value in the array 
    value_at = [12.015 1.015 15.995 14.045 39.924];
    % Assigning molecular mass as 0
    mw = 0;
    % Creating for loop to perform the task
    for i = 1:length(compound_name)
        for j = 1:length(key_at)
            % Comparing  the string value
            if strcmp(compound_name(i),key_at(j))
                mw = mw + value_at(j);
                % Storing the position for further use
                pos = j;
            end
        end
        % Converting the string to a number
        k = str2num(compound_name(i));  
        if (k>1)
            % Molecular mass calculation
            mw = mw + value_at(pos)*(k-1);
        end
    end
    % Command to print Molecular mass  of the molecule
    fprintf('Molecular Weight of the species %s is %f' , compound_name,mw)
end

EXPLANATION

• % Function to calculate Molecular Weight - comments to make user friendly
• function mw = molecular_weight(sp_name)
• compound_name = (sp_name)-storing a value
• key_at = ['C','H','O','N','A']; - creating an array element
• value_at = [12.015 1.015 15.995 14.045 39.924]; - storing an atomic mass value in an array
• mw = 0; - assigning molecular mass as 0
• for i = 1:length(compound_name) - creating a for loop to execute till the element length
• for j = 1:length(key_at) - creating a for loop to execute till the key at array length
• if strcmp(compound_name(i),key_at(j)) - comparing the string value of the species name and the element in the array at key
• mw = mw + value_at(j); - molecular mass calculation
• pos = j; - storing the statement
• end - to terminate the if statement
• end - to terminate the inner for loop
• k = str2num(compound_name(I)); - converting string to a number
• if (k>1) - comment
• mw = mw + value_at(pos)*(k-1); - molecular mass calculation
• end - to terminate the if statement
• end - to terminate the outer for loop
• fprintf('Molecular Weight of the species %s is %f' , compound_name,mw) - to print species name and value
• end - to terminate the function

MAIN CODE - NASA FILE PARSING  and  PLOT 

% File Parsing for a file
close all
clear all
clc

f1 = fopen('THERMO.dat','r');
first_line = fgetl(f1);
 
% R is a universal gas  constant J/(mol-k)
R = 8.314;
temp = fgetl(f1);

% Reading a text from a header file
% Reading the global temperature from the next line

A = strsplit(temp,' ');

% Cell array is generated 1*4 cell array
global_low = str2double(A{2});
global_mid = str2double(A{3});
global_max = str2double(A{4});
 
% Temperature range 
temp = linspace(global_low , global_max , 1000);
 
% Skipping the three comment lines
for i = 1:3
    k = fgetl(f1);
end

% Running for loop for 53 times for 53 species
for i = 1:53
    % Parsing for species block
    tline = fgetl(f1);
    S = strsplit(tline,' ');
    species_name = S{1};
 
    % Extracting coefficient from line 1
    line2 = fgetl(f1);
    x = strfind(line2,'E');

    % Finding the 5 coefficients
    x1 = line2(1:x(1)+3);
    x1 = str2double(x1);

    x2 = line2(x(1)+4:x(2)+3);
    x2 = str2double(x2);

    x3 = line2(x(2)+4:x(3)+3);
    x3 = str2double(x3);

    x4 = line2(x(3)+4:x(4)+3);
    x4 = str2double(x4);

    x5 = line2(x(4)+4:x(5)+3);
    x5 = str2double(x5);
    
    % Line3 coefficient
    line3 = fgetl(f1);
    x = strfind(line3,'E');

    x6 = line3(1:x(1)+3);
    x6 = str2double(x6);

    x7 = line3(x(1)+4:x(2)+3);
    x7 = str2double(x7);

    y1 = line3(x(2)+4:x(3)+3);
    y1 = str2double(y1);

    y2 = line3(x(3)+4:x(4)+3);
    y2 = str2double(y2);

    y3 = line3(x(4)+4:x(5)+3);
    y3 = str2double(y3);

    % Line 4 coefficients
    line4 = fgetl(f1);
    x = strfind(line4,'E');

    y4 = line4(1:x(1)+3);
    y4 = str2double(y4);

    y5 = line4(x(1)+4:x(2)+3);
    y5 = str2double(y5);

    y6 = line4(x(2)+4:x(3)+3);
    y6 = str2double(y6);

    y7 = line4(x(3)+4:x(4)+3);
    y7 = str2double(y7);

    % Entropy Calculation
    S = entropy(x1,x2,x3,x4,x5,x7,y1,y2,y3,y4,y5,y7,R,temp,global_mid);

    % Specific Heat Calculation
    c_p = specific_heat(x1,x2,x3,x4,x5,y1,y2,y3,y4,y5,R,temp,global_mid);

    % Enthalpy calculation
    H = enthalpy(x1,x2,x3,x4,x5,x6,y1,y2,y3,y4,y5,y6,R,temp,global_mid);

    % Molecular Weight Calculation
    mw(i) = molecular_weight(species_name); 

    % Reading and return of molecular weight
    Moll_wt = fopen('Molecular Weight.txt','w');
    fprintf(Moll_wt,'Molecular Weight of species %s is %f',species_name,mw);
    fprintf(Moll_wt,'/n');
    fclose(Moll_wt);

    % Plotting on the graph for species for the temperature and specific
    % heat

    directory_curr = pwd;
   

    % Plotting the graph in different plotting windows
    % Plot 1 for temperature and enthalpy
    % Plot 2 for temperature and entropy
    % Plot 3 for temperature and specific heat

    % Plot 1 for Temperature and Enthalpy

    figure(1)
    plot(temp,H,'LineWidth',3,'Color','g');
    xlabel('Temperature [K]');
    ylabel('Enthalpy [KJ/mol]');
    grid on
    title (sprintf('Variation in Enthalpy wrt Temperature %s',species_name));

    saveas(figure(1),'Enthalpy.jpg');

    % Plot 2 for Temperature and Entropy

    figure(2)
    plot(temp,S,'LineWidth',3,'Color','b');
    xlabel('Temperature [K]');
    ylabel('Entropy [KJ/mol-k]');
    grid on
    title (sprintf('Variation in Entropy wrt Temperature %s',species_name));

    saveas(figure(2),'Entropy.jpg');

    % Plot 3 for Temperature and Specific Heat

    figure(3)
    plot(temp,c_p,'LineWidth',3,'Color','y');
    xlabel('Temperature [K]');
    ylabel('Specific Heat [KJ]');
    grid on
    title (sprintf('Variation in Specific Heat wrt Temperature %s',species_name));

    saveas(figure(3),'Specific Heat.jpg');

    cd(directory_curr);
end

EXPLANATION