Project 1 - Parsing NASA thermodynamic data

Report

Aim:

To write a code in MATLAB to parse NASA thermodynamic data file and then calculate thermodynamic properties of various gas species.

Objectives of the project:

1. To parse the given NASA thermodynamic data and find following data from the file.
2. Write a function that extracts the 14 co-efficient and calculates the enthalpy, entropy and specific heats for all the species in the data file
3. Calculate the molecular weight of each species and display it in the command window.
4. Plot the Cp, Enthalpy and Entropy for the local temperature range (low temperature : high temperature) specific for each species
5. 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.
6. The main program that you will submit will just take the "THERMO.dat" file as an input and generate Cp, H and S plots.
7. Please write a detailed report to describe your logic.

Body of the content:

File Parsing:

File parsing is a string or symbol either in natural language computer language or data structure confirming to the rules of the former grammar.

MATHEMATICAL EQUATION:

Specific heat:

The quantity of heat required to raise the temperature of one gram of a substance by one Celsius degree. The units of specific heat are usually calories or joules per gram per Celsius degree.

The formulae are shown below:

Cp/R=b1+b2⋅T+b3⋅T2+b4⋅T3+b5⋅T4cpR=b1+b2⋅T+b3⋅T2+b4⋅T3+b5⋅T4

Enthalpy :

Is the measurement of energy in a thermodynamic system. The quantity of enthalpy equals to the total content of heat of a system, equivalent to the system’s internal energy plus the product of volume and pressure.

The formulae are shown below:

H/RT=b1+b2T2+b3T23+b4⋅T34+b5⋅T45+b6THRT=b1+b2T2+b3T23+b4⋅T34+b5⋅T45+b6T

Entropy:

The measure of a system's thermal energy per unit temperature that is unavailable for doing useful work.

S/R=b1⋅log(T)+b2⋅T+b3⋅T22+b4⋅T33+b5⋅T44+b7SR=b1⋅log(T)+b2⋅T+b3⋅T22+b4⋅T33+b5⋅T44+b7

where

T= local temprature

b1-b7 =high temperature coefficient

b8-b14 =low temprature coefficient

R=Gas constant=8.314

Main Program:

clear all
close all
clc

% Open file
f1=fopen('THERMO.dat','r');

% Reading Header Information
fgetl(f1);

% Global Temperature
t_line= fgetl(f1) ;

a=strsplit(t_line,' ');

global_low_temp=str2double(a{2});
global_mid_temp=str2double(a{3});
global_high_temp=str2double(a{4});


% Neglecting the 3 lines
fgetl(f1);
fgetl(f1);
fgetl(f1);

% Reading species block
% line 1
for i=1:53
    t_line2=fgetl(f1);
    s=strsplit(t_line2,' ');
    species_name=s{1};
    A=strfind(t_line2,'G');
    temp_values=t_line2(A+4:length(t_line2));
    B=strsplit(temp_values,' ');
    
    local_low_temp=str2double(B{1});
    local_mid_temp=str2double(B{2});
    local_high_temp=str2double(B{3});

t_line= fgetl(f1);
b=findstr(t_line,'E');
%1st coefficient
b1=t_line(1:b(1)+3);
b1=str2num(b1);
%2nd coefficient
b2=t_line(b(1)+4:b(2)+3);
b2=str2num(b2);
%3rd coefficient
b3=t_line(b(2)+4:b(3)+3);
b3=str2num(b3);
%4th coefficient
b4=t_line(b(3)+4:b(4)+3);
b4=str2num(b4);
%5th coefficient
b5=t_line(b(4)+4:b(5)+3);
b5=str2num(b5);

% Line 2
line2=fgetl(f1);
%6th coefficient
b6=line2(1:b(1)+3);
b6=str2num(b6);
%7th coefficient
b7=line2(b(1)+4:b(2)+3);
b7=str2num(b7);
%8th coefficient
b8=line2(b(2)+4:b(3)+3);
b8=str2num(b8);
%9th coefficient
b9=line2(b(3)+4:b(4)+3);
b9=str2num(b9);
%10th coefficient
b10=line2(b(4)+4:b(5)+3);
b10=str2num(b10);

%line 3
line3=fgetl(f1);
%11th coefficient
b11=line3(1:b(1)+3);
b11=str2num(b11);
%12th coefficient
b12=line3(b(1)+4:b(2)+3);
b12=str2num(b12);
%13th coefficient
b13=line3(b(2)+4:b(3)+3);
b13=str2num(b13);
%14th coefficient
b14=line3(b(3)+4:b(4)+3);
b14=str2num(b14);

% Universal Gas Constant
R=8.314;

t=linspace(local_low_temp,local_high_temp,100);

% To Calculate 
% Specific Heat by creating function
[c_p]=specific_heat(b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,local_low_temp,local_mid_temp,local_high_temp,t,R);

% Enthalpy by creating function
H=enthalpy(b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,local_low_temp,local_mid_temp,local_high_temp,t,R);

% Entropy by creating function
S=entropy(b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,local_low_temp,local_mid_temp,local_high_temp,t,R);


% Creating a folder
    
mkdir(species_name)
cd(species_name)

    
% Plotting for

% temperature vs specific heat

figure(1)
plot(t,c_p)
xlabel('temperature')
ylabel('specific heat')
title('temperature vs specific heat')
image=getframe(gcf);
imwrite(image.cdata,'t vs cp.png')
saveas(1,'specific heat','jpg')

%temperature vs enthalpy
figure(2)
plot(t,H)
xlabel('temperature')
ylabel('enthalpy')
title('temperature vs enthalpy')
image=getframe(gcf);
imwrite(image.cdata,'t vs H.png')
saveas(2,'enthalpy','jpg')

%temperature vs entropy
figure(3)
plot(t,S)
xlabel('temperature')
ylabel('entropy')
title('temperature vs entropy')
image=getframe(gcf);
imwrite(image.cdata,'t vs S.png')
saveas(3,'entropy','jpg')

cd ..

%calculating molecular mass
[M]=molecular_wt(species_name);
K=sprintf('%s mol_wt=%f',species_name,M);
disp(K)
end

FUNCTION

1. For Specific Heat function

   function [c_p]=specific_heat(b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,local_low_temp,local_mid_temp,local_high_temp,t,R)
   
   if (t>local_mid_temp)
       c_p=R*(b1+(b2.*t)+(b3.*(t.^2))+(b4.*(t.^3))+(b5.*(t.^4)));
   else
       
       c_p=R*(b8+(b9.*t)+(b10.*(t.^2))+(b11.*(t.^3))+(b12.*(t.^4)));
       
   end
   

2. For Enthalpy Function:

   function [H]=enthalpy(b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,local_low_temp,local_mid_temp,local_high_temp,t,R)
   
   if (t>local_mid_temp)
      
       H=(b1+((b2.*t)/2)+((b3.*(t.^2))/3)+((b4.*(t.^3))/4)+((b5.*(t.^4))/5)+(b6./t)).*t*R;
   else
       H=(b8+((b9.*t)/2)+((b10.*(t.^2))/3)+((b11.*(t.^3))/4)+((b12.*(t.^4))/5)+(b13./t)).*t*R;
       
   end
   

3. For Entropy Function:

function [S]=entropy(b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,local_low_temp,local_mid_temp,local_high_temp,t,R)

if (t>local_mid_temp)
    S=((b1.*logt)+(b2.*t)+((b3.*(t.^2))/2)+((b4.*(t.^3))/3)+(b5.*(t.^4))+b7);
    
else
    S=((b8.*log(t))+(b9.*t)+((b10.*(t.^2))/2)+((b11.*(t.^3))/3)+(b12.*(t.^4))+b14)*R;
end

4.For molecular_wt Function:

function [M]=molecular_wt(species_name)


atomic_mass=[15.999,1.008,12.011,14.007,39.948];
elements=['O','H','C','N','A'];

mol_wt=0;
for i=1:length(species_name)
    for j=1:length(elements)
        if strcmpi(species_name(i),elements(j))
            mol_wt=mol_wt+atomic_mass(j);
            z=j;
        end
         
    end
   t=str2double(species_name(i));
    if (t>1)
        mol_wt=mol_wt+(atomic_mass(z)*(t-1));
    end
end
M=mol_wt
   end

Screenshot of the window where all the folders are saved.

Plots For O2:

Plots For N2:

Plots For CO2:

Conclusion : With the help of Matlab we can easily parse the data file for various purpose .