Project 1 - Parsing NASA thermodynamic data
Aim :- Write a function that extracts the 14 co-efficients and calculates the enthalpy, entropy and specific heats for all the species in the data file.
Objective :-
- Write a function that extracts the 14 coefficients and calculates the enthalpy, entropy and specific heats for all the species in the data file.
- Calculate the molecular weight of each species.
- Plot the Cp, Enthalpy, and Entropy specific for each species, and for O2, N2 and CO2.
Formula used :-
Matlab Main code:-
% Nasa file parsing program
clear all
close all
clc
% inputs
R = 8.314;
f1 = fopen('THERMO.dat','r');
l1 = fgetl(f1);
l2 = fgetl(f1);
t = strsplit(l2);
global_min = str2double(t{2});
global_mid = str2double(t{3});
global_max = str2double(t{4});
temp = linspace(global_min,global_max,400);
for i = 1:3
fgetl(f1);
end
for i= 1:53
line_1 = fgetl(f1);
A = strsplit(line_1);
Species_name = (A{1});
tline_2 = fgetl(f1);
tline_3 = fgetl(f1);
tline_4 = fgetl(f1);
a = strfind(tline_2,'E');
b = strfind(tline_3,'E');
c = strfind(tline_4,'E');
%extraction of high temperature coefficients(a1:a7)
a1 = str2double(tline_2(1:a(1)+3));
a2 = str2double(tline_2(a(1)+4:a(2)+3));
a3 = str2double(tline_2(a(2)+4:a(3)+3));
a4 = str2double(tline_2(a(3)+4:a(4)+3));
a5 = str2double(tline_2(a(4)+4:a(5)+3));
a6 = str2double(tline_3(1:b(1)+3));
a7 = str2double(tline_3(b(1)+4: b(2)+3));
%extraction of low temperature coefficients (b1:b7)
b1 = str2double(tline_3(b(2)+4: b(3)+3));
b2 = str2double(tline_3(b(3)+4: b(4)+3));
b3 = str2double(tline_3(b(4)+4: b(5)+3));
b4 = str2double(tline_4(1:c(1)+3));
b5 = str2double(tline_4(c(1)+4: c(2)+3));
b6 = str2double(tline_4(c(2)+4: c(3)+3));
b7 = str2double(tline_4(c(3)+4: c(4)+3));
C_p = specific_heat(a1,a2,a3,a4,a5,b1,b2,b3,b4,b5,R,temp,global_mid);
h = enthalpy(a1,a2,a3,a4,a5,a6,b1,b2,b3,b4,b5,b6,R,temp,global_mid);
S = entropy(a1,a2,a3,a4,a5,a7,b1,b2,b3,b4,b5,b7,R,temp,global_mid);
% plotting
figure(1)
subplot(3,1,1)
plot(temp, C_p, 'linewidth', 4,'color', 'b');
title(Species_name)
xlabel("Temperature")
ylabel("Specific Heat")
subplot(3,1,2);
plot(temp, h, 'linewidth', 4,'color', 'r');
title(Species_name)
xlabel("Temperature")
ylabel("Enthalpy")
subplot(3,1,3);
plot(temp, S, 'linewidth', 4,'color', 'g');
title(Species_name)
xlabel("Temperature")
ylabel("Entropy")
saveas(figure1,'Nasa_data','png')
MW = molecular_weight(Species_name);
end
fclose(f1)
% program endFunction code for entropy
function [S] = entropy(a1,a2,a3,a4,a5,a7,b1,b2,b3,b4,b5,b7,R,temp, global_mid)
if temp <= global_mid
S = R.*(b1.*log(temp) + (b2.*temp)+ (b3.*(((temp).^2)./2))+ (b4.*(((temp).^3)./3)) + (b5.*(((temp).^4)./4))+ b7);
else
S = R.*(a1.*log(temp) + (a2.*temp)+ (a3.*(((temp).^2)./2))+ (a4.*(((temp).^3)./3)) + (a5.*(((temp).^4)./4))+ a7);
endFunction code for enthalpy
function [h] = enthalpy(a1,a2,a3,a4,a5,a6,b1,b2,b3,b4,b5,b6,R,temp, global_mid)
if temp <= global_mid
h = R.*temp.*(b1 + (b2.*(temp./2))+ (b3.*(temp./3))+(b4.*(temp./4)) + (b5.*(temp./5)) + (b6./temp));
else
h = R.*temp.*(a1 + (a2.*(temp./2))+ (a3.*(temp./3))+(a4.*(temp./4)) + (a5.*(temp./5)) + (a6./temp));
endFunction code for specific heat
function [C_p] = specific_heat(a1,a2,a3,a4,a5,b1,b2,b3,b4,b5,R,temp,global_mid)
if temp <= global_mid
C_p = R*(b1 + (b2*temp)+ (b3*(temp).^2)+(b4 * (temp).^3) + (b5 *(temp).^4));
else
C_p = R*(a1 + (a2*temp)+ (a3*(temp).^2)+(a4 * (temp).^3) + (a5 *(temp).^4));
end
Function code for molecular-weight
function [MW] = molecular_weight(Species_name)
element= {'H' 'C' 'N' 'O' 'Ar'};
atomic_weight = [1 12 14 16 40];
MW = 0;
for i = 1:length(Species_name)
for j = 1:length(atomic_weight);
if strcmpi(Species_name(i), element(j));
MW = MW + atomic_weight(j);
q = j;
end
end
m = str2double(Species_name(i));
if m>1
MW = MW + (atomic_weight(q)*(m-1));
end
end
fprintf('Molecular weight of %s is %d',Species_name,MW);
disp(' ')
endMatlab code explanation:-
-Programing language used matlab online
-starting the program using comments
-The value of R is provided as input in the code.
-f1 = fopen to open the file "Thermo.dat" under consideration for the data and using "r" indicating to read the command
-fgetl command is used to detect the first two lines l1 and l2.
-strsplit command is used to split the string by default delimiter and gather the corresponding temperature data points.
-using str2double is an enhanced command by the virtue of the performance criteria.
-The temperature is broken into 400 intervals using the linspace command over the min and max temperatures.
-The for loop is initiated for the 53 constituents mentioned in the data file
-t_line2, t_line3 and t_line4 are important and are assigned using fgetl, these 3 lines contains the 14 coefficients for the determination of the properties.
-strfind command is used to identify the letter E from the strings and is assigned to a,b and c for the corresponding lines.
-The values a1,a2,a3,a4,a5,a6,a7 represents the high temperature coefficients.
-The values b1,b2,b3,b4,b5,b6,b7 represents the low temperature coefficients.
-The strings are converted to values using the str2double and by identifying E in the strings accordingly.
-mkdir command is introduced to make the directory for all the values and plots determined
-C_p, h and s are calculated using them as a separate function using the formulas mentioned initially
-using the plot command to plot for cp ,h ,&s
-ending the for loop
Command window exicution/ Outpur :-
Folder Created in matlab drive :-
Result / Conclusion :-
- thus we have Written a function/ program in matlab that extracts the 14 co-efficients and calculates the enthalpy, entropy and specific heats for all the species
- also calculated the molecular weight for each species and its output is displayed in command window exicution
- also generated plots for c_p , enthalpy & entropy vs temp for O2 , N2 & CO2 . The graphs are shown below
GRAPH OF c_p , enthalpy & entropy vs temp for Oxygen
GRAPH OF c_p , enthalpy & entropy vs temp for Nitrogen
GRAPH OF c_p , enthalpy & entropy vs temp for Carbon-dioxide