Project 1 - Parsing NASA thermodynamic data

AIM:- Write a code in Matlab to parse the NASA thermodynamic data file and then calculate thermodynamic properties of various species.

OBJECTIVE:

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. Calculate the molecular weight of each species and display it in the command window.
3. Plot the Cp, Enthalpy and Entropy for the local temperature range (low temperature: high temperature) specific for each species.
4. 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.
5. The main program that you will submit will just take the "THERMO.dat" file as an input and generate Cp, H and S plots.
6. Screenshot of the window where all the folders are saved.
7. Plots for 02, N2 and Co2 species.

THEORY:

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 constituents, resulting in a parse tree showing their syntactic relation to each 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.

Parsing a file means reading in a data stream of some sort and building an in memory model of the semantic content of that data. This aims at facilitating perfoming some kind of transformation on the data.

NASA Thermodynamic File: NASA thermodynamics 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 formula as:

where,

R = Universal Gas constant

T = Temperature

Cp = Specific heat (KJ)

H = Enthalpy (KJ/mol)

S = Entropy(KJ/mol-K)

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

Specific Heat:

The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius. The relationship between heat and temperature change is usually expressed in the form shown below where c is the specific heat.

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

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.

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

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.

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

PROGRAM

FUNCTION FOR SPECIFIC HEAT(Cp)

% FUNCTION FOR SPECIFIC HEAT(Cp)

function Cp = specificheat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,t2)

% Comparing with global temperature
% If lesss than local temperature 't2' - minimum coeddicients are taken
if T <= t2
    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

STEPS :

• To find the Specific heat create Specific heat function and assigning its relted formula coefficent from 14 coefficients, Gas constant, Temperature and mid temperature.
• Create an condition using if loop and make the temperature less than and equal to mid temperature to specify lower temperature coefficent in the formula.
• Use else condition to specify coefficient of Higher temperature coefficent in the formula.
• Then end the loop and function to calculate Specific Heat.

FUNCTION FOR ENTHALPY(H)

% FUNCTION FOR ENTHALPY(H)

function H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,T,R,t2)

% Comparing with global temperature
% If less than Loocal temperature 't2' - minimum coefficients are taken

if T <= t2
    H = R*T.*(a8+((a9*T)/2)+((a10*(T).^2)/3)+((a11*(T).^3)/4)+((a12*(T).^4)/5)+((a13./T)));
else
    % Else maximum coefficients are taken
    H = R*T.*(a1+((a2*T)/2)+((a3*(T).^2)/3)+((a4*(T).^3)/4)+((a5*(T).^4)/5)+((a6./T)));
end
end

STEPS:

• To find the Enthalpy create Enthalpy function and assigning its relted formula coefficent from 14 coefficients, Gas constant, Temperature and mid temperature.
• Creatre an condition using if loop and make the temperature less than and equal to mid temperature to specify lower temperature coefficent in the formula.
• Use else condition to specify coefficient of Higher temperature coefficent in the formula.
• Then end the loop and function to calculate Enthalpy.

FUNCTION FOR ENTROPY(S)

% FUNCTION FOR ENTROPY(S)

function S = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,T,R,t2)

% Comparing with Local temperature
% If less than local temperature 't2' - minimum coefficients are taken

if (T <= t2)
    S = R.*(a8.*log(T)+(a9.*T)+(a10*((T).^2)/2)+(a11*((T).^3)/3)+(a12*((T).^4)/4)+a14);
else
    % Else - maximum coefficients are taken
    S = R.*(a1.*log(T)+(a2.*T)+(a3*((T).^2)/2)+(a4*((T).^3)/3)+(a5*((T).^4)/4)+a7);
end
end

STEPS :

• To find the Entropy create Entropy function and assigning its relted formula coefficent from 14 coefficients, Gas constant, Temperature and mid temperature.
• Creatre an condition using if loop and make the temperature less than and equal to mid temperature to specify lower temperature coefficent in the formula.
• Use else condition to specify coefficient of Higher temperature coefficent in the formula.
• Then end the loop and function to calculate Entropy.

FUNCTION TO FIND MOLECULAR WEIGHT OF THE DIFIFFERENT SPECIES

% Function to find Molecular weight of the diffferent species

function W = Molecular_weight(Species)

% Standard - Atomic Name
% Hydrogen, Carbon, Oxygen, Nitrogen, Argon
atomic_name = ['H','C','O','N','Ar'];

% Standard Atomic Weight
atomic_weight = [1.008 12.011 15.999 14.007 39.948];

% Starting Range of Molecular weight(W)
W = 0;

% Adding Atomic number to obtain particular value
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 %s :- %f',Species,W)

STEPS:

1. Create an Molecular_weight function 'W' and assigning species input to that.
2. Define the main element of all 53 species in an array atomic_name that are : 'H', 'C', 'O', 'N', & 'Ar'.
3. Then by taking above main elements we will create there atomic_wieght array from any source like internet that are:- [1.008 12.011 15.999 14.007 39.948].
4. Then assign molecular starting range W To zero and then create an for loop condition which runs to the length of the species and an another nested for loop is created which runs to the length of the string atomic_name.
5. Then create an condition using if condition and use strcmp command to compare the species and atomic_name strings to calculate molecular masses if by comparison both string found same then we will assign its molecular weight.
6. Use str2num command assign to n. Then we run an condition of if loop to find weather the species contains more than one element if there are more then 1 elements that is n>1 then we will increment the atomic weight by the multiplication of position and n-1 to the atomic_weight array.
7. Then, print the Molecular weight using fprintf command and display it using disp command.

MAIN CODE

% Parsing of Thermodynamic data

clear all
close all
clc

% Reading Data file -Nasa Thermodynamic
% Open a file & 'r' open the file for reading
f1 = fopen('THERMO.dat','r');

% Skip the first line
get = fgetl(f1);

% Read the next line which contains the Global temperatures
Global_temp = fgetl(f1);

% Store the global temperature values in array
s = strsplit(Global_temp,' ');

% Converting string values into Numerical data
global_low_temperature = str2num(s{2});
global_mid_temperature = str2num(s{3});
global_high_temperature = str2num(s{4});

% Skip the next three lines
for i=1:3
    get = fgetl(f1);
end

% Store the coefficients of temperature and local temperatures
% Calculate the specific heat, Enthalpy and Entropy
for i=1:53

    % Read the line that contains the Species name and local temperatures
    header=fgetl(f1);

    % Split the character database into cell array
    A=strsplit(header,' ');

    % First array of 'D' is stored with the name of species
    Species=(A{1});
   
    % Values in the 'D' array is converting to numerical data and assigned
    local_low_temp=str2num(A{end-3}); % Fourth last value of 'D' containd the Local low temperature
    local_high_temp=str2num(A{end-2}); % Third last value of 'D' containd the Local High temperature
    local_mid_temp=str2num(A{end-1}); % Second last value of 'D' containd the Local Medium temperature
    
    % Assigning Temporary Variables t1,t2&t3 for the Local low, medium & high temperatures
    t1 = local_low_temp;
    t2 = local_mid_temp;
    t3 = local_high_temp;

    % Create an arrey to store the values of temperature in between local low and high temperature
    T = linspace(t1,t3,1000);

    % Extracting Higher and lower temperature coefficients
    
    % Extracting First 7 coefficients i.e., High-temperature coefficients
    % Read the first line that contain coefficients
    line_1=fgetl(f1);

    % Store the values of 5 coefficients that contains in the Line1
    a = strfind(line_1,'E');
    
    % Finding Higher Coefficients
    a1 = line_1(1:a(1)+3);
    a1 = str2num(a1);
    a2 = line_1(a(1)+4:a(2)+3);
    a2 = str2num(a2);
    a3 = line_1(a(2)+4:a(3)+3);
    a3 = str2num(a3);
    a4 = line_1(a(3)+4:a(4)+3);
    a4 = str2num(a4);
    a5 = line_1(a(4)+4:a(5)+3);
    a5 = str2num(a5);

    % Read the second line that contain coefficients
    line_2=fgetl(f1);

    % Store the values of 5 coefficients that contains in the line2
    b = strfind(line_2,'E');
    a6 = line_2(1:b(1)+3);
    a6 = str2num(a6);
    a7 = line_2(b(1)+4:b(2)+3);
    a7 = str2num(a7);

    % Extracting Second 7 coefficents - Lower-temperature coefficients
    a8 = line_2(b(2)+4:b(3)+3);
    a8 = str2num(a8);
    a9 = line_2(b(3)+4:b(4)+3);
    a9 = str2num(a9);
    a10 = line_2(b(4)+4:b(5)+3);
    a10 = str2num(a10);

    % Read the third line that contain coefficients
    line_3=fgetl(f1);

    % Store the values of 5 coefficients that contains in the line3
    c = strfind(line_3,'E');
    a11 = line_3(1:c(1)+3);
    a11 = str2num(a11);
    a12 = line_3(c(1)+4:c(2)+3);
    a12 = str2num(a12);
    a13 = line_3(c(2)+4:c(3)+3);
    a13 = str2num(a13);
    a14 = line_3(c(3)+4:c(4)+3);
    a14 = str2num(a14);

    % Universal Gas Constant
    R = 8.314;

    % Calculation of Specific heat
    Cp = specificheat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,t2);

    % Calculation of Enthalpy
    H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,T,R,t2);

    % Calculation of Entropy
    S = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,T,R,t2);

    % Calculation of Molecular weight of species
    W = Molecular_weight(Species);
    
    % Plotting Cp, H and S with Temperature
    % Saving in a folder
    cd('D:\Challenges\Parsing')
    % Creating directory
    mkdir(Species);
    cd(Species);
    
    % Plot1, Specific heat(Cp) vs Temperature Range (T)
    figure(1)
    plot(T,Cp,'linewidth',2,'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');

    % Plot2, Enthalpy(H) vs Temperature Range (T)
    figure(2)
    plot(T,H,'linewidth',2,'Color','g');
    xlabel('Temperature [K]');
    ylabel('Enthalpy [KJ/(mol)]');
    title(sprintf('Enthalpy Vs Temperature Range of %s',Species));
    grid on
    saveas(figure(2),'Enthalpy.jpg');

    % Plot3, Entropy(S) vs Temperature Range (T)
    figure(3)
    plot(T,S,'linewidth',2,'Color','b');
    xlabel('Temperature [K]');
    ylabel('Entropy [KJ/(mol-K)]');
    title(sprintf('Entropy Vs Temperature Range of %s',Species));
    grid on
    saveas(figure(3),'Entropy.jpg');

    % Changing directory to original matlab path
    cd('D:\Challenges')

   end

STEPS:

1. Start with clear all, close all, and clc commands to clear all the windows.
2. Firstly, open a file THERMO.dat file using fopen command and Input the parameter 'r' reading this file.
3. Then, using fgetl command read first line 'THERMO' then we read temperature file and split the temperatures using strsplit command to convert it into cell array and then we will convert this string to number using str2num command to find global low, high and mid temperatures.
4. Then assigning temperature range using linspace command. Then by using loop command to skip the lines of data file using 'fgetl' command inside the loop.
5. Now, again run the loop to find 53 element in the data file by assigning 'fgetl' command and then spliting into the cell array to find the species line and then find the species name and then find the number of the local temperatures in the species line.
6. In order to read the coefficient in the data file we will first find the 'E' string using strfind command to find before and after numbers of the coefficients then we will find remaining 14 coefficients and convert them to numbers from strings.
7. Out of which the first 7 Coefficients are for Local higher temperature and the Second 7 Coefficients are for Local lower temperature.
8. Now specify Specific heat (Cp), Entropy (S), Enthalpy (H) functions to find these parameters using these 14 coefficients for Lower and higher Temperature. then we will specify Molecular weight (W) function to find the Molecular weight of the different species.
9. Write the Molecular weight.txt file and fprintf all the molecular weights of the species. and then close the txt file using fclose command.
10. Changing the directory using cd command and then creating directory folder where we have to save our files using mkdir command and then we will change the directory to this created folder.
11. Now, plot Specific heat, Entropy and Enthalpy with the Temperature for different species. Using scanf command to in the title command to create different species title.
12. Use saveas command to save the plots of different species in the directory folder. Now we will change the directory to which our main code file runs in the MATLAB.

ERRORS

• After writing the functions do not provided proper 'end' function.

• Writing the text.file and fprintf commands for Molecular weight both in Function and Main code.

ERRORS SOLVED

1. By rechecking the function and provided with proper end script.
2. By removing the repeated code or command the repeating of Molecular weight ans is solved.

RESULTS

1) Output of Molecular weight of the Different Species

2) Screenshot of the Directory where different Species are saved

3) Plots of the different species

Plots of specie O2

Plots of Specie N2

Plots of Specie Co2