Parsing NASA thermodynamic data using matlab

Code:

Program used to calculate all the desired ouput values and make the required plots.

clear all 
close all
clc


% Inputs
R = 8.314; %Universal gas constant 

%Reading First line of the program i.e., header
f1 = fopen('THERMO.dat','r');
Header= fgetl(f1);

%Reading Global Temperature second line of the data file

temp = fgetl(f1);
%splitting the readed whole string into three individual strings
C = strsplit(temp,' ');
%Converting the obtained global low temp string into double 
global_low_temp =str2double(C{2});
%Converting the obtained global medium temp string into double 
global_mid_temp =str2double(C{3});
%Converting the obtained global high temp string into double 
global_high_temp =str2double(C{4});
%skipping 3 lines
fgetl(f1);
fgetl(f1);
fgetl(f1);
% For loop is used to caluculate desired values for each species

for i = 1:53
line= fgetl(f1); %Reading the 6th line of the data file
A=strsplit(line,' '); %Seperating strings
species=A(1); %Naming First Variable 
Q = strfind(line,'G'); 
local_low_temp = line(Q+3:Q+10); 
local_high_temp = line(Q+13:Q+21);
local_mid_temp = line(Q+23:Q+31); 
lt = str2double(local_low_temp); %Local Low Temperature
ht = str2double(local_high_temp); %Local Mid Temperature 
mt = str2double(local_mid_temp); %Local High Temperature


%line 1-Reading the first 5 coefficient data in a line

cfline1= fgetl(f1);
X = strfind(cfline1,'E');
a1 = cfline1(1:X(1)+3); 
a1 = str2double(a1); %storing 1st coefficient 
a2 = cfline1(X(1)+4:X(2)+3);
a2 = str2double(a2); %storing 2nd coefficient 
a3 = cfline1(X(2)+4:X(3)+3);
a3 = str2double(a3); %storing 3rd coefficient 
a4 = cfline1(X(3)+4:X(4)+3);
a4 = str2double(a4); %storing 4th coefficient 
a5 = cfline1(X(4)+4:X(5)+3);
a5 = str2double(a5); %storing 5th coefficient
 
%line 2-Reading the next 5 coefficient data of 2nd line

cfline2 = fgetl(f1);
G = strfind(cfline2,'E');
a6 = cfline2(1:G(1)+3);
a6 = str2double(a6); %storing 6th coefficient 
a7 = cfline2(G(1)+4:G(2)+3);
a7 = str2double(a7); %storing 7th coefficient 
a8 = cfline2(G(2)+4:G(3)+3);
a8 = str2double(a8); %storing 8th coefficient 
a9 = cfline2(G(3)+4:G(4)+3);
a9 = str2double(a9); %storing 9th coefficient 
a10 = cfline2(G(4)+4:G(5)+3);
a10 = str2double(a10); %storing 10th coefficient 

%line 3-Reading the last 4 coefficient data of 3rd line

cfline3 = fgetl(f1);
I = strfind(cfline3,'E');
a11 = cfline3(1:I(1)+3);
a11 = str2double(a11); %storing 11th coefficient 
a12 = cfline3(I(1)+4:I(2)+3);
a12 = str2double(a12); %storing 12th coefficient 
a13 = cfline3(I(2)+4:I(3)+3);
a13 = str2double(a13); %storing 13th coefficient 
a14 = cfline3(I(3)+4:I(4)+3);
a14=str2double(a14); %storing 14th coefficient 



%Ranging the temperature low temperature to high temperature

T=linspace(lt,ht,500);

%Find the Specific Heat value by calling the funtion

Cp=specific_heat(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,T,R,lt,ht,mt);

%Finding the Entropy value by calling the entropy function

S=entropy(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,T,R,lt,ht,mt);

%Finding the Enthaphy value by calling the enthalpy function

H=enthalpy(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,T,R,lt,ht,mt);

%Creating new folder for each species
spec=char(species); 
fd = sprintf('%s',spec);
cur_dir=pwd;
mkdir(spec);
cd(spec);
  
  
%Plot 1, Specific heat (Cp) vs Temperature (T)

figure(1);
plot(T,Cp,'linewidth',2,'color','r');
xlabel('Temperature in K');
ylabel('Specific heat in kJ');
title('Specific heat vs Temperature');
  
%Plot 2, Enthalpy (H) vs Temperature (T)
  
figure(2);
plot(T,H,'linewidth',2,'color','b');
xlabel('Temperature in K');
ylabel('Enthalpy in kJ/(mol)');
title('Enthalpy vs Temperature');
  
%Plot 3, Entropy (S) vs Temperature (T)

figure(3);
plot(T,S,'linewidth',2,'color','g');
xlabel('Temperature in K');
ylabel('Entropy in kJ/(mol K)');
title('Entropy vs Temperature');

% saving the plots that are generated above

saveas(figure(1),'cp.png');
saveas(figure(2),'h.png');
saveas(figure(3),'s.png');
cd(cur_dir);
%Finding Molecular mass of each species
M= molecular_mass(species)

f2 = fopen('molecular mass','w');
fprintf('%s n %s n %f n','species','Molecular mass',M)
fclose(f2)

 

end   
fclose(f1)

Program to calculate entropy as function:

%Program to find the entropy of the specices

function S=entropy(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,T,R,lt,ht,mt)
if T>=mt
    S=(a1.*log(T)+a2.*T+a3.*(T.^2)./2+a4.*(T.^3)./3+a5.*(T.^4)./4+a7)*R;
else
    S=(a8.*log(T)+a9.*T+a10.*(T.^2)./2+a11.*(T.^3)./3+a12.*(T.^4)./4+a14)*R;
end

Program to calculate enthalpy as function:

%Program to find the enthalpy of the species
function H=enthalpy(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,T,R,lt,ht,mt)
if T>=mt
    H=(a1.*T+a2.*(T.^2)./2+a3.*(T.^3)./3+a4.*(T.^4)./4+a5.*(T.^5)./5+a6)*R;
else
    H=(a8.*T+a9.*(T.^2)./2+a10.*(T.^3)./3+a11.*(T.^4)./4+a12.*(T.^5)./5+a13)*R;
end

Proram to calculate specific heat function:

%Program to calcuclate the specific heat of the species

function Cp=specific_heat(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,T,R,lt,ht,mt)
if T>=mt
    Cp=(a1+a2.*(T)+a3.*(T.^2)+a4.*(T.^3)+a5.*(T.^4))*R;
else
    Cp=(a8+a9.*(T)+a10.*(T.^2)+a11.*(T.^3)+a12.*(T.^4))*R;
end

Program to calulate the moecular mass as function:

%Program to calculate the molecular mass and atomic weight of the species

function M= molecular_mass(species)
        atoms={'H','C','N','O','AR'};
        AtomicWeight=[1 12 14 16 40];
               M=0;
        for i=1:length(species)
            for j=1:length(AtomicWeight)
                if (strcmp(species(i),atoms(j))==1)
                    M=M+AtomicWeight(j);
                    g=j;
                end
            end
         % repeting elements 
                n=str2double(species(i));
                if n>1
                    p=(n-1);
                    M=M+AtomicWeight(p)*(n-1);
                end
                         
      end
end

Output:

Plot for various species:

O2:

N2:

Co2:

REPORT:

Aim:

To read the data in the NASA thermodynamic data file and to calculate the enthaply, entropy, specific heat, mocular weight of all the species avaliable in the given data file.

Objective of the program:

The main objective is to parsing the NASA thermodynamic report. Need to create seprate function code to find the required values. The required values are obtained by using the below equations:

3.Body of the content:

Explannation for the main program:

Line 1-3: clears the workspace and cmd window

Line 7: assgined the value for the new variable 'R' as 8.314 which is the universal gas constant value.

Line 10: opening the "THERMO.dat" file with read permissionn and saving its data to variable f1

Line 11: Reading the first line in the data file andd saving the readed value to the variable 'Header'.

Line15: Reading the second line of the data file wherre the global temperature alues are found and these values are saved to the variable 'temp'

Line 17: seprating the obtained value in temp into seprate string values i.e, three string values are obtained.

Line 19-23: Seprated three strings values are stored into three different variables as converted into daouble value from the string value.

Line 25-27:Read and Omitting the next 3 lines as these lines are comments

Line 30: For loop begins which will ranges from 1 to 53. hence 53 type of species are found to be in the data file.

Line 31: Reading the 6the line of the data file and store its values to the v: ariable name as line.

Line32: Converting the values in the varibale line as seprate strings and save the value to variable A

Line 33: Reading the first string in the variable A as it represent the name of the species hence its storeed to variable named as species

Line34: Finding the value G in the 6th line

Line 35-37: saving the local low, mid and high temp values to new variables respectively.

Line 38-40: converting the string saved in the above lines is stored into new varaibles as double

Line 45-84: Reading the coefficient values in the each line and converting the obtiained string values into double and store them in the variable

Line 90: Using linspace cmd obatining the 500 temp values between the low and high temperature.

Line 94: Calculate the specific heat using the specific heat function.

Line 98: Calculating the entropy as function

Line 102: calculate the enthalpy value using the enthalpy function

Line 105-109: Creating ne folder name in the current direcotry for each species.

Line 114: Creating a new figure 1

Line115-118: Ploting the tempreature and specific heat values and naming the x and y axis and the title.

Line122-126: Ploting the tempreature and enthalpy values and naming the x and y axis and the title.

Line130-134: Ploting the tempreature and entropy values and naming the x and y axis and the title.

Line138-140: Saving the plots in the current directory

Line 143-146: Calculating the molecular mass of the species

Line 151: end the loop

Line 152: close the file f1

In each calling function program the desired values calculated using the given equation.

Conclusion:

Thus the required values are calculated and the desiredvalues are plotted.