Project 1 - Parsing NASA thermodynamic data
AIM :
the main objectives of the project is to extract 14 coeffcient of each species and calculate the enthalpy and specific heat from the file given and to show the variation of these parameters against the corresponding temperature
FILE PARSING:
file parsing is the process of extracting the required information from a given file and implement it in program . in this program we use the nasa polynomials that can be used to evaluate thermodynamic properties
such as cp h and s and the coefficients required to evaluate these polynomials for species using that data file this programming is done using matlab
function coding for formula calculating the cp,h,s:
here temperatures vary from each species where the first 7 will be local high temperature and the rest 7 species will be the
local low temperature so here we use if and else command to calculate both tempertures
CODE:
function [cp,h,S] = input(T,R,Tm1,c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12,c13,c14)
for i = length(T)
if T(i)>Tm1
cp = (c1+c2.*T +c3.*T.^2+c4.*T.^3+c5.*T.^4)*R;
h = (c1+(c2.*T)./2+(c3.*T.^2)./2+(c4.*T.^3)./2+(c5.*T.^4)./2+(c6.*T.^5)/2).*T.*R;
S = (c1.*log(T)+(c2.*T)+(c3.*T.^2)./2+(c4.*T.^3)./3+(c5.*T.^4)./4+ c7)*R;
else
cp = (c8+c9.*T +c10.*T^.2+c11.*T^3+c12.*T^4)*R;
h = (c8+(c9.*T)./2+(c10.*T.^2)./2+(c11.*T.^3)./2+(c12.*T.^4)./2+(c13.*T.^5)/2)*T.*R;
S = (c8.*log(T)+(c9.*T)+(c10.*T.^2)./2+(c11.*T.^3)./3+(c12.*T.^4)./4+ c14)*R;
end
end
endFUNCTION CODING FOR CALCULATING THE MOLECULAR WEIGHT:
function molecular_weight_calculation = molecular_weight(sp_name)
species = (sp_name);
elements = ['H','C','O','N','A','S'];
atomic_weight = [1.0079 12.010 15.999 14.0067 39.948,32];
molecular_weight_calculation = 0;
for i = 1:length(species)
for j = 1:length(elements)
if strcmp(species(i),elements(j))
molecular_weight_calculation = molecular_weight_calculation + atomic_weight(j);
a = j;
end
end
n = str2double(species(i));
if n>1
molecular_weight_calculation = molecular_weight_calculation + atomic_weight(a)*(n-1);
end
end
endin this code the molecular weight is calculated by using function command here atomic name and atomic weight are given as input to the species
MAIN CODE
clear all
close all
clc
f1 = fopen ('THERMO.dat','r');
fgetl(f1);
tline = fgetl(f1);
a = strsplit(tline,' ');
global_low_temp = str2double(a{2});
gobal_mid_temp = str2double(a{3});
gobal_high_temp = str2double(a{4});
for i = 3:5
g = fgetl(f1);
end
for j = 1:53
species = fgetl(f1);
T = strfind(species,'.');
species(52-3:53+3)
T1 = species(52-3:T(1)+3);
Tl1 = str2double(T1);
species(T(1)+6:62+3);
Th = species(T(1)+6:T(2)+3);
Th1 = str2double(Th);
species (T(1)+6:72+3);
Tm = species(T(2)+6:T(3)+3);
Tm1 = str2double(Tm);
sp_name = species(1:6);
coeff_line_1 = fgetl(f1);
A11 = strfind(coeff_line_1,'E');
coeff_line_1(1:12+3);
%co efficients 2
a1 = coeff_line_1(1:A11(1)+3);
c1 = str2double(a1);
a2 = coeff_line_1(1:A11(1)+4:A11(2)+3);
c2 = str2double(a2);
a3 = coeff_line_1(1:A11(2)+4:A11(3)+3);
c3 = str2double(a3);
a4 = coeff_line_1(1:A11(2)+4:A11(4)+3);
c4 = str2double(a4);
a5 = coeff_line_1(1:A11(1)+4:A11(5)+3);
c5 = str2double(a5);
% co efficient 2
coeff_line_2 = fgetl(f1);
A12 = strfind(coeff_line_2,'E');
coeff_line_2(1:12+3);
a6 = coeff_line_2(1:A12(1)+3);
c6 = str2double(a6);
a7 = coeff_line_1(1:A11(1)+4:A11(2)+3);
c7 = str2double(a2);
a8 = coeff_line_1(1:A11(2)+4:A11(3)+3);
c8 = str2double(a3);
a9 = coeff_line_1(1:A11(2)+4:A11(4)+3);
c9 = str2double(a4);
a10 = coeff_line_1(1:A11(1)+4:A11(5)+3);
c10 = str2double(a5);
%co effecient 3
coeff_line_3 = fgetl(f1);
A13 = strfind(coeff_line_3,'E');
A11 = coeff_line_2(1:A13(1)+3);
c11 = str2double(A11);
A12 = coeff_line_1(1:A11(1)+4:A11(2)+3);
c12 = str2double(A12);
a13 = coeff_line_1(1:A11(2)+4:A11(3)+3);
c13 = str2double(a13);
a14 = coeff_line_1(1:A11(2)+4:A11(4)+3);
c14= str2double(a14);
T = linspace(Tl1,Th1,100);
R = 8.314;
[cp,H,S] = input(T,R,Tm1,c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12,c13,c14);
mkdir(['C:\Users\JAI RITESH KUMAR . R\Documents\MATLAB\ASSIGNMENT\NASA file parsing\species',sp_name])
molecular_weight_calculation = molecular_weight(sp_name);
%%plotting
figure(1)
plot([T,cp],'linewidth',3,'color','b');
xlabel('temp')
ylabel('specific heat')
title(sp_name);
figure(2)
plot([T,H],'linewidth',3,'color','b');
xlabel('temp')
ylabel('entropy');
title(sp_name);
figure(3)
plot([T,S],'linewidth',3,'color','b');
xlabel('temp')
ylabel('enthalpy')
title(sp_name);
program = (['C:\Users\JAI RITESH KUMAR . R\Documents\MATLAB\ASSIGNMENT\NASA file parsing\species',sp_name]);
cd(program)
saveas(1,'specific heat.jpg')
saveas(2,'entropy.jpg')
saveas(3,'enthalpy.jpg')
cd('C:\Users\JAI RITESH KUMAR . R\OneDrive\Documents\MATLAB')
end
fclose(f1)EXPLANATION OF CODE:
- clear all - remove data from the workspace and freeing up system memory
- close all -delete all the current figure or the specified memory
- clc - clear all the input and output variables
- first to read the data file fopen command is used and to get the inforamtion fget is used
- using strsplit we get the global temperatures and then using fgetl command we skip the line which are not required
- loop command is created to get the values of all the temperature and coefficients present in the file
- to get temperature and coefficients values we used strfind to specify them accurately
- so the data is in string format in order to convert it into a number str2double command used
- to make a folder mkdir command is used by specifiying the directory
- then plotting is taken place using the command plot
- for changing directory we use the command cd in order to save the plot of specific heat entropy enthalpy in each individual file of species
- and then the molecular weight is calculated by calling the molecular weight calculation function
- the file is closed using the command fclose.
RESULTS:
SCREENSHOT OF THE SAVED FILE :
PLOTS FOR O2 N2 AND CO2 SPECIES:
PLOTS FOR O2:
PLOT FOR N2
PLOT FOR CO2:
