Project 1 - Parsing NASA thermodynamic data

AIM -

1. 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.
2. To calculate the molecular weight of each species.
3. To plot the Cp, Enthalpy and Entropy for the local temperature range (low temperature : high temperature) specific for each species.

PRE-REQUISITE KNOWLEDGE :

FILE PARSING - It is the splitting of file into pieces of data that can be easily stored.

WHY PARSING FUNCTIONS - Because user input is always in the form of strings.

GOVERNING EQUATIONS :

`(Cp)/R=aunderset(1)()+aunderset(2)()T+aunderset(3)()T^2+aunderset(4)()T^3+aunderset(5)()T^4`

`(H)/R=aunderset(1)()+aunderset(2)()T/2+aunderset(3)()(T^2)/3+aunderset(4)()(T^3)/4+aunderset(5)()(T^4)/5+(aunderset(6)())/T`

`(S)/R=aunderset(1)()lnT+aunderset(2)()T+aunderset(3)()(T^2)/2+aunderset(4)()(T^3)/3+aunderset(5)()(T^4)/4+aunderset(7)()`

where,

R `rarr` universal gas constant

T `rarr` temprature

`aunderset(1)(), aunderset(2)(), aunderset(3)(), aunderset(4)(), aunderset(5)(), aunderset(6)(), aunderset(7)()` `rarr` high temprature coefficients

`aunderset(8)(), aunderset(9)(), aunderset(10)(), aunderset(11)(), aunderset(12)(), aunderset(13)(), aunderset(14)()` `rarr` low temprature coefficient

FUNCTIONS USED :

fopen(filename, permission) `rarr` opens the file

getl(filenameid) `rarr` returns the next line of the specified file

strsplit(str,'delimiter') `rarr` slpits the str at the delimiters specified by delimiter

str2double(chr) `rarr` converts the text in str to double precision values, str contains text that represents real or complex numeric values.

findstr(str1, str2) `rarr` searches the longer of the two input strings for any occurances of the shorter string

strcmp() `rarr` takes two input arguments and returns either true or false

mkdir('dirname') `rarr` creates the specified folder and returns a status of 1 if the operation is successfull or if the folder exists.

cd(newfolder) `rarr` changes the current folder to new folder

saveas(fig,filename) `rarr` saves the figure specified by the figure to file name

EXPLAINATION :

- Reading the file

- Skipping the first 3 lines of the text file. Because these three statements are irrelevent

- Reading the species and the global tempratures. This reamains same for the next 53 species and hence for loop is used

- Reading the first line the coefficients. In order to get the co-efficient we need to find the variable 'E' by using this as the reference. This remains same for second and third line

- Reading the second line the coefficients

- Reading the third line the coefficients

- Calling the functions

- Plotting and saving in a folder

MAIN CODE:

%main code
clear all
close all
clc

f1 = fopen('THERMO.dat','r');
fgetl(f1);
global_temp = fgetl(f1);
t = strsplit(global_temp,' ');
global_low_temp = str2num(t{2});
global_mid_temp = str2num(t{3});
global_high_temp = str2num(t{4});
temp = linspace(global_low_temp, global_high_temp,1000);
R = 8.314;

%skipping the 3 lines in the file
for i=1:3
    fgetl(f1);
end
%reading the species
for i=1:53
    header = fgetl(f1);
    x = strsplit(header,' ');
    species_name = (x{1});
    z = length(x);
    local_low_temp = str2double(x{z-3});
    local_high_temp = str2double(x{z-2});
    local_mid_temp = str2double(x{z-1});
    t1 = local_low_temp;
    t2 = local_mid_temp;
    t3 = local_high_temp;
    
    %gettting the first line of coefficients
    line_1 = fgetl(f1);
    a_1 = findstr(line_1,'E');
    a1 = str2double(line_1(1:a_1(1)+3));
    a2 = str2double(line_1(a_1(1)+4:a_1(2)+3));
    a3 = str2double(line_1(a_1(2)+4:a_1(3)+3));
    a4 = str2double(line_1(a_1(3)+4:a_1(4)+3));
    a5 = str2double(line_1(a_1(4)+4:a_1(5)+3));
    
    %gettting the second line of coefficients
    line_2 = fgetl(f1);
    a_2 = findstr(line_2,'E');
    a6 = str2double(line_2(1:a_2(1)+3));
    a7 = str2double(line_2(a_2(1)+4:a_2(2)+3));
    a8 = str2double(line_2(a_2(2)+4:a_2(3)+3));
    a9 = str2double(line_2(a_2(3)+4:a_2(4)+3));
    a10 = str2double(line_2(a_2(4)+4:a_2(5)+3));
    
    %gettting the third line of coefficients
    line_3 = fgetl(f1);
    a_3 = findstr(line_3,'E');
    a11 = str2double(line_3(1:a_3(1)+3));
    a12 = str2double(line_3(a_3(1)+4:a_3(2)+3));
    a13 = str2double(line_3(a_3(2)+4:a_3(3)+3));
    a14 = str2double(line_3(a_3(3)+4:a_3(4)+3));
    
    %specific heat calculation
    Cp = specificheat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12, temp, R, global_mid_temp);
    
    %enthalpy calculation
    H = enthapy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13, temp, R, global_mid_temp);
    
    %entropy calculation
    S = entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14, temp, R, global_mid_temp);
    
    %molecular weight calculation
    molecularweight = molecular_weight(species_name);
    
    %saving as a folder
    %t=sprintf('%s',species_name)
    mkdir(species_name)
    cd(species_name)
    
    %plot 1 Specific Heat (Cp) vs Tempreture(T)
    figure(1)
    plot(temp, Cp, 'linewidth', 2, 'color', 'r')
    xlabel('Temprature [K]')
    ylabel('Specific Heat [KJ/Kg.K]')
    title(sprintf('Varying Specific Heat with Temprature Range of %s',species_name))
    grid on
    saveas(figure(1),'Specific Heat.jpg')
    
    %plot 2 enthalpy (H) vs Tempreture(T)
    figure(2)
    plot(temp, H, 'linewidth', 2, 'color', 'b')
    xlabel('Temprature [K]')
    ylabel('Enthalpy [KJ/mol]')
    title(sprintf('Varying Enthalpy with Temprature Range of %s',species_name))
    grid on
    saveas(figure(2),'Enthalpy.jpg')
    
    %plot 3 entropy (S) vs Tempreture(T)
    figure(3)
    plot(temp, S, 'linewidth', 2, 'color', 'g')
    xlabel('Temprature [K]')
    ylabel('Entropy [KJ/mol-K]')
    title(sprintf('Varying Entropy with Temprature Range of %s',species_name))
    grid on
    saveas(figure(3),'Entropy.jpg')
    cd ..        
end

FUNCTION CODE FOR SPECIFIC HEAT :

Amount of heat required to raise the temprature of a substance of 1 gram by 1 deg C.

%funtion for specific heat

function Cp = specificheat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12, temp, R, global_mid_temp)
if temp <= global_mid_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));
end

FUNCTION CODE FOR ENTHALPY :

Its the internal energy of the system plus the product of pressure and volume.

%funtion for enthalpy

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

FUNCTION CODE FOR ENTROPY :

Entropy is the measure of the disorder of a system. It is an extensive property of a thermodynamic system, which means its value changes depending on the amount of matter that is present.

%funtion for entropy

function S = entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14, temp, R, global_mid_temp)
if temp <= global_mid_temp
    S = R.*(a8*log(temp) + a9*temp + (a10*temp.^2)./2 + (a11*temp.^3)./3 + (a13*temp.^4)./4 + a14);
else
    S = R.*(a1*log(temp) + a2*temp + (a3*temp.^2)./2 + (a4*temp.^3)./3 + (a5*temp.^4)./4 + a7);
end

FUNCTION CODE FOR MOLECULAR WEIGHT :

Molecular weight, also called molecular mass, mass of a molecule of a substance, based on 12 as the atomic weight of carbon-12. It is calculated in practice by summing the atomic weights of the atoms making up the substance's molecular formula.

%function for molecular weight of the given species

function molecularweight = molecular_weight(species_name)
atomic_name = ['H','C','O','N','A'];
atomic_weight = [1.008 12.011 15.999 14.007 39.948];
molecularweight = 0;
for i=1:length(species_name)
    for j=1:length(atomic_name)
        if strcmpi(species_name(i),atomic_name(j))
            molecularweight = molecularweight + atomic_weight(j);
            position = j;
        end
    end
    n = str2double(species_name(i));
    if n>1
        molecularweight = molecularweight + atomic_weight(position)*(n-1);
    end
end
fprintf('Molecular Weight of %s : %4.5f \n', species_name, molecularweight);
end

RESULTS :

The program was written and executed.

- Screenshots of the molecualar weight of the species.

- Screenshot of the folders in which all the plots are saved.

- Plot for `Ounderset2`

- Plot for `Nunderset2`

- Plot for `COunderset2`