Project 1 - Parsing NASA thermodynamic data

Project Title: Parsing NASA thermodynamic data

Objective: Read .dat file in MatLab

2. Create the code for calculating the specific heat enthalpy and entropy etc.

code 

clear all
close all
clc
f = fopen('thermo.dat','r') %ll thermo,dat file
l1 = fgetl(f); % give name to 1st line of file
l2 = fgetl(f); % give name to 2nd line of file
l3 = fgetl(f); % give name to 3rd line of file
l4 = fgetl(f); % give name to 4th line of file
l5 = fgetl(f); % give name to 5th line of file
tr = strsplit(l2,' '); % Splite the line at space
glt = str2double(tr{2}); % Extract globle lower temp
gmt = str2double(tr{3}); % Extract globle middle temp
ght = str2double(tr{4}); % Extract globle high temp
for i = 1:53 % for different spacies
    l6 = fgetl(f); %give name to 6th line of file
    s = strsplit(l6,' '); % Splite the line at space
    species_name = s(1); % Extract spacies name
    z = length(s); % Find out size of s
    
    llt = str2double(s{z-3}); % Extract local lower temp
    lht = str2double(s{z-2}); % Extract local high temp
    lmt = str2double(s{z-1}); % Extract local middle temp
    
    T = linspace(llt,lht,500); % Temp range
    R = 8.314; % Universal gas constant
     line1 = fgetl(f); 
     line2 = fgetl(f); 
     line3 = fgetl(f);
     
     A = strfind(line1,'E'); % Separating the coefifirnt fron each other
     B = strfind(line1,'E'); % Separating the coefifirnt fron each other
     C = strfind(line1,'E'); % Separating the coefifirnt fron each other
     
     a1 = str2double(line1(1:A(1)+3)); % giving the name to the coefficients
     a2 = str2double(line1(A(1)+4:A(2)+3)); % giving the name to the coefficients
     a3 = str2double(line1(A(2)+4:A(3)+3));  % giving the name to the coefficients
     a4 = str2double(line1(A(3)+4:A(4)+3)); % giving the name to the coefficients
     a5 = str2double(line1(A(4)+4:A(5)+3)); % giving the name to the coefficients
     a6 = str2double(line2(1:B(1)+3)); % giving the name to the coefficients
     a7 = str2double(line2(B(1)+4:B(2)+3)); % giving the name to the coefficients
     b1 = str2double(line2(B(2)+4:B(3)+3)); % giving the name to the coefficients
     b2 = str2double(line2(B(3)+4:B(4)+3)); % giving the name to the coefficients
     b3 = str2double(line2(B(4)+4:B(5)+3));  % giving the name to the coefficients
     b4 = str2double(line2(1:C(1)+3)); % giving the name to the coefficients
     b5 = str2double(line2(C(1)+4:C(2)+3)); % giving the name to the coefficients
     b6 = str2double(line2(C(2)+4:C(3)+3)); % giving the name to the coefficients
     b7 = str2double(line2(C(3)+4:C(4)+3)); % giving the name to the coefficients
     
     cp = specific_heat(a1,a2,a3,a4,a5,a6,a7,b1,b2,b3,b4,b5,b6,b7,T,R,lmt); % clculating specific heat
     h = enthalpy(a1,a2,a3,a4,a5,a6,a7,b1,b2,b3,b4,b5,b6,b7,T,R,lmt); %lculating enthalphy
     s = entropy(a1,a2,a3,a4,a5,a6,a7,b1,b2,b3,b4,b5,b6,b7,T,R,lmt); %lculating entropy
    
     % ploting command
     figure(1)
     plot(T,h,'linewidth',3,'color','b')
     title(species_name)
     xlabel('temperature')
     ylabel('enthalpy')
     
     figure(2)
     plot(T,cp,'linewidth',3,'color','r')
     title(species_name)
     xlabel('temperature')
     ylabel('specific_heat')
     
     figure(3)
     plot(T,s,'linewidth',3,'color','g')
     title(species_name)
     xlabel('temperature')
     ylabel('entropy')
end

the code calculates entropy enthalpy and specific heat for different species available in thermo.dat file.

Code explanation mention in programme with % sign in front of code

this is the formula I used to calculate the variable.

Specific heat function

function cp=specific_heat(a1,a2,a3,a4,a5,~,~,b1,b2,b3,b4,b5,~,~,T,R,lmt)
for i = 1:length(T)
if T(i) >lmt
    cp = R.*(a1+a2.^T+a3.*T.^2+a4.*T.^3+a5.*T.^4);
else
    cp = R.*(b1+b2.^T+b3.*T.^2+b4.*T.^3+b5.*T.^4);
end
end
end

this function is used to calculate the Specific heat values for various gas species

in this if a temp is less than lmt then first cp formula is used and if not then use the second formula.

Enthalpy function

function h=enthalpy(a1,a2,a3,a4,a5,a6,~,b1,b2,b3,b4,b5,b6,~,T,R,lmt)
for i = 1:length(T)
if T(i) >=lmt
    h=R.*(a1.*T+(a2.*T.^2)./2+(a3.*T.^3)./3+(a4.*T.^4)./4+(a5.*T.^5)./5+a6);
else
    h=R.*(b1.*T+(b2.*T.^2)./2+(b3.*T.^3)./3+(b4.*T.^4)./4+(b5.*T.^5)./5+b6);
end
end
end

this function is used to calculate the enthalpy values for various gas species

Entropy function

function s=entropy(a1,a2,a3,a4,a5,~,a7,b1,b2,b3,b4,b5,~,b7,T,R,lmt)
for i = 1:length(T)
if T(i)>=lmt
    s = R.*(a1.*log(T)+(a2.*T)+(a3.*T.^2)/2+(a4.*T.^3)/3+(a5.*T.^4)/4+a7);
else
    s = R.*(b1.*log(T)+(b2.*T)+(b3.*T.^2)/2+(b4.*T.^3)/3+(b5.*T.^4)/4+b7);
    
end
end
end

This function calculates entropy for various gas species

Output 

Enthalpy vs temperature plot for CH2CHO gas species

Specific Heat vs temperature plot for CH2CHO gas species

Entropy vs temperature plot for CH2CHO gas species

Enthalpy vs temperature plot for O gas species

Entropy vs temperature plot for O gas species