Project 1 - Parsing NASA thermodynamic data

AIM : To obtain NASA thermodynamic data for various species,coefficients of temperature and to find specific-heat,enthalpy and entropy using MATLAB code.

INPUTS USED :

• R = 8.31446261815324 (Universal gas constant)
• Given THERMO.txt file

A detailed report to describe my logic.

1. Using thermodynamic data opening the file contents in editor window.
2. Calling the command 'fgetl' to read out each line of the THERMO.txt file and naming as 'tlines' where it can save.
3. Converting my string to number to perform ease way of calculations for each tline operation.
4. Using formula given calculations for enthalpy, entropy and specific heat of low to high temperatures are done.
5. Calling my function to run the code to calculate molecular weight as well as atomic weight for every species mentioned.
6. Making plots for each and every species .
7. Defined my file directory where to save.
8. finally when is code excicuted required data is printed.

FORMULA :

MAIN PROGRAM :

clear all
close all
clc

%getting data 
f1=fopen('NASA.txt','r');%opening the saved file

for i = 1:5              %skipping the first five lines
    tline1 = fgetl(f1);  %getting the first line after skiped
end

 ct=1;                  %counter for loops
 ct1=54;                %counter for loops
 ct2=108;               %counter for loops
for i=1:53 
%Extracting the temperature values
tline2=fgetl(f1);
c = strsplit(tline2,' '); % spliting tline2 
species=char(c(1));       %defining charecter
a = findstr(tline2,'.');   %find string
Local_Low_temp=str2num(tline2(a(1)-3:a(1)-1));
Local_high_temp=str2num(tline2(a(2)-4:a(2)-1));
Local_mid_temp=str2num(tline2(a(3)-4:a(3)-1));
    
%Extracting the coeff values
tline3 = fgetl(f1);
b = findstr(tline3,'E');
a1 = str2num(tline3(1:b(1)+3));
a2 = str2num(tline3(b(1)+4:b(2)+3));
a3 = str2num(tline3(b(2)+4:b(3)+3));
a4 = str2num(tline3(b(3)+4:b(4)+3));
a5 = str2num(tline3(b(4)+4:b(5)+3));

tline4 = fgetl(f1);
b = findstr(tline4,'E');
a6 = str2num(tline4(1:b(1)+3));
a7 = str2num(tline4(b(1)+4:b(2)+3));
a8 = str2num(tline4(b(2)+4:b(3)+3));
a9 = str2num(tline4(b(3)+4:b(4)+3));
a10 = str2num(tline4(b(4)+4:b(5)+3));


tline5 = fgetl(f1);
b = findstr(tline5,'E');
a11 = str2num(tline5(1:b(1)+3));
a12 = str2num(tline5(b(1)+4:b(2)+3));
a13 = str2num(tline5(b(2)+4:b(3)+3));
a14 = str2num(tline5(b(3)+4:b(4)+3));
 R = 8.31446261815324;
T  = (Local_Low_temp:Local_high_temp);

if (T>Local_mid_temp);

    %formula to caluculate Specific heat,enthalpy,entropy
   cp = (a1 + a2.*T + a3.*T.^2 + a4.*T.^3 + a5.*T.^4)*R;
   H  = (a1 + a2*T + a3*T.^2 + a4*T.^3/4 + a5*T.^4/5 + a6/T)*R.*T;
   S  = (a1*(log(T))+a2*T + a3*T.^2/2 + a4*T.^3/3 + a5*T.^4/4 + a7)*R;
else
    cp = (a8 + a9*(T) + a10*(T.^2) + a11*(T.^3) + a12*(T.^4));
    H  = (a8 + a9*T + a10*T.^2 + a11*T.^3/4 + a12*T.^4./5 + a13./T)*R.*T;
    S  = (a8*(log(T))+a9*T + a10*T.^2./2 + a11*T.^3./3 + a12*T.^4./4 + a14)*R;
    
end

molecular_weight=m_wt(species) %calling the function
sprintf('molecular_weight of %s =%d',species,molecular_weight)
 %Plot the Cp, Enthalpy and Entropy for the local temperature range
 t = sprintf('%s',species);
 t=mkdir(['E:',species]) %making directory 
 
 cd(['E:',species])%current directory

 figure(1)
 plot(cp,T,'linewidth',2,'color','k')
 title(sprintf('cp vs T for %s',species))
 xlabel('specific heat')
 ylabel('temperature')
 grid on
 saveas(gcf,'CP.png')
 
 figure(2)
 plot(H,T,'linewidth',2,'color','magenta')
 title(sprintf('H vs T for %s',species))
 xlabel('Enthalpy')
 ylabel('temperature')
 grid on
 saveas(gcf,'H.png')
 
 figure(3)
 plot(S,T,'linewidth',2,'color','cyan')
 title(sprintf('S vs T for %s',species))
 xlabel('Entropy')
 ylabel('temperature')
 grid on
 saveas(gcf,'S.png') %saving as png file
 
 cd .. 
 end
​

FUNCTION :

function [out] = m_wt(species)

%Defining the elements
elements=['H','C','N','O','R']; 

%Atomic weights of each element
Atomic_Weight = [1 12 14 16 40]; 
out=0; 

%Looping for each element inside each species and finding the atomic weight
for i=1:length(species) 
    for j=1:length(elements) 
        if strcmp(species(i),elements(j)) 
            out= out + Atomic_Weight(j); 
            p=j; 
        end
    end
    
    %loop to multiply the coefficients of the elements if greater than 1.
    n=str2double(species(i)); 
    if n>1 
        out = out + (Atomic_Weight(p))*(n-1); 
    end
end

end

PLOT FOR O2 :

Specific heat vs temperature of O2

Enthalpy vs temperature of O2

Entropy vs temperature of O2

PLOT FOR N2 :

Specific heat vs temperature of N2

Enthalpy vs temperature of N2

Entropy vs temperature of N2

PLOTS FOR CO2 :

Specific heat vs temperature of Co2

Enthalpy vs temperature of Co2

Entropy vs temperature of Co2

RESULTS :

SCREENSHOTS OF SAVED FILES

SCREENSHOT OF MOLECULAR WEIGHT :