Project 1 - Parsing NASA thermodynamic data

AIM OF THE PROJECT

To read 'THERMO.DAT' file and extract data about various gas species from it to plot Cp Vs T , H Vs T, S vs T graph along with calculating the molecular mass of all species

About THERMO.DAT

NASA has given some polynomials that calculate values of some thermodynamic properties such as enthalpy, specific heat and entropy. THERMO.DAT contains the following information in text format

1.Global Temperature range

2. Species name

3.Local temperature range

4. 14 co-effiecients for the polynomials , 7 for high temp, 7 for low temperature

Polynomial -

METHADOLOGY

1- fopen and fgetl

fopen - opens a file using one specifier , here f1 is the specifier

fgetl - It is a command used to read the lines of the file , its index is auto governed by the number of times it appear on the program. It is the widely used through out the logic to reasd the lines of THERMO.DAT file

2-str2num - It is used to convert the string into numbers . It is used to convert temperature and co-efficient strings to numbers .

3.mkdir - It is used to create a folder in the base MATLAB directory

4. cd - It is used to change the current directory to save the file there.

5- Finding the species name -

After reading the line containing the species name we saved it as a string and split it by using strsplit() at the ' ' (space charectar)

the 1st element of the string array was the species name

6. Finding the temperature -

After reading the temperature line it was required too find the temp

to find the temperature we searched for the '.' and saved the index position in an array

then we created a array by picking 4 charaectars to both left and right of the '.'

7-Finding the co-efficient

to find the co-efficient we searched for the 'E' and saved the index position in an array

then we created a array by picking 10 charaectars to left and 4 charectars to right of the 'E'.

8- CP , H ,S calculation

To calculate the value of H,S and CP we used 3 functions , as per the requirement the set of co-efiicients to be used was decided on the temperature range

9- Plotting the graphs

CP vs T , H vs T , S vs T all this was done using plot command with three different figures for all plots and different colours

10- Saving the results

A new folder was created inside the MATLAB root directory . Inside that new folder by the corresponding species name has been created and it contains the graphs seperately.

MAIN CODE

R=8.314;
wt=0;
%open the DAT file
f1= fopen("THERMO (1).dat");
l1= fgetl(f1);
l2=fgetl(f1);
%read the global temperature
t_range=str2num(l2);
global_Temp_low=t_range(1);
global_Temp_mid=t_range(2);
global_Temp_high=t_range(3);
%skip the next 3 lines
for i=1:3
    l=fgetl(f1);
end 

%repeating for 53 species
mkdir('NASA File Parsing')
cd("NASA File Parsing")
for i=1:53

%reading info about the species name and local temperature range  
l5=fgetl(f1);
x=findstr(l5,'.');
nmm=strsplit(l5,' ');
species_name=nmm{1};

t_low=str2num(l5(x(1)-4:x(1)+3));
t_high=str2num(l5(x(2)-4:x(2)+3));
t_modr=str2num(l5(x(3)-4:x(3)+3));

%reading 1st line of co-efficients
l6=fgetl(f1);
y=strfind(l6,'E');
%extracting 1st 5 co-eeficients
a1=str2num(l6(y(1)-11:y(1)+3));
a2=str2num(l6(y(2)-11:y(2)+3));
a3=str2num(l6(y(3)-11:y(3)+3));
a4=str2num(l6(y(4)-11:y(4)+3));
a5=str2num(l6(y(5)-11:y(5)+3));

l7=fgetl(f1);
z=strfind(l7,'E');
%extracting next 5 co-efficients
a6=str2num(l7(z(1)-11:z(1)+3));
a7=str2num(l7(z(2)-11:z(2)+3));
a8=str2num(l7(z(3)-11:z(3)+3));
a9=str2num(l7(z(4)-11:z(4)+3));
a10=str2num(l7(z(5)-11:z(5)+3));

l8=fgetl(f1);
w=strfind(l8,'E');
%extracting next 4 co-efficients
a11=str2num(l8(w(1)-11:w(1)+3));
a12=str2num(l8(w(2)-11:w(2)+3));
a13=str2num(l8(w(3)-11:w(3)+3));
a14=str2num(l8(w(4)-11:w(4)+3));


T=linspace(t_low,t_high,5000);
cp= CP(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,8.314,global_Temp_mid);
h=H(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,T,8.314,global_Temp_mid);
s=S(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,T,8.314,global_Temp_mid);
%dispalying name and molecular weight 
species_name
W=molecular_weight(species_name)
%creating a new file within the matlab folder 
mkdir('NASA File Parsing')
cd("NASA File Parsing")
mkdir(species_name);   %create the directory within 'NASA file Parshing'
cd(species_name);
figure(1)
plot(T,cp,'linewidth',3,'Color','b')
grid on
xlabel('Temperature');
ylabel('Specific heat')
saveas(figure(1),'Specific_heat.png') 
%saving 1st figure
figure(2)
plot(T,h,'linewidth',3,'Color','y')
grid on
xlabel('Temperature');
ylabel('Enthalpy')
saveas(figure(2),'enthalpy.png')
%saving 2nd figure 
figure(3)
plot(T,s,'linewidth',3,'Color','r')
grid on
xlabel('Temperature');
ylabel('Entropy')
saveas(figure(3),'entropy.png')
%saving 3rd figure 

cd('C:\Users\sukri\OneDrive\Documents\MATLAB\NASA File Parsing')
%coming back to base directory for new forlder 
end

FUNCTION FOR SPECIFIC HEAT (CP)

function [cp] = CP (a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,Temp,R,global_Temp_mid)

if(Temp<global_Temp_mid)
cp=R.*(a1+(a2.*Temp)+(a3.*Temp.^2)+(a4.*Temp.^3)+(a5.*Temp.^4));
else
 cp=R.*(a8+(a9.*Temp)+(a10.*Temp.^2)+(a11.*Temp.^3)+(a12.*Temp.^4));   
end

FUNCTION FOR ENTHALPY (H)

function [H] = H(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,Temp,R,global_Temp_mid)

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

FUNCTION FOR ENTROPY (S)

function [s] = S(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,Temp,R,global_Temp_mid)
if (Temp<global_Temp_mid)
 s= (a1.*log(Temp)+(a2.*Temp)+(a3.*Temp.^2)/2+(a4.*Temp.^3)/3+(a5.*Temp.^4)+a7)*R;
else
 s= (a8.*log(Temp)+(a9.*Temp)+(a10.*Temp.^2)/2+(a11.*Temp.^3)/3+(a12.*Temp.^4)+a14)*R;
end

FUNCTION FOR WEIGHT CALCULATION

function [W] = molecular_weight (species_name)
Element_name=['C' 'O' 'H' 'N' 'A' 'S'];
Element_mass=[12 16 1 14 40 32 ];

W=0;

for i=1:length(species_name)
    for j=1:length(Element_name)
        if(species_name(i)==Element_name(j))
            W=W+Element_mass(j);
            position=j;
        end
    end
       n=str2double(species_name(i));
       if(n>1)
          W=((Element_mass(position))*(n-1))+W;
   
       end
    end

end

FOLDER CONTAING ALL THE SPECIES WISE FOLDER

H,S , CP vs T graph for O2

H,S , CP vs T graph for CO2

H,S , CP vs T graph for N2

ERROR OCCURED

While calclating the value of the molecular weight the loop closing was placed at the wrong positon which was giving errorous results in weight calculation

Corrective measure - removing the end statement