Project 1 - Parsing NASA thermodynamic data
AIM: To write a function that extracts the 14 coefficients and calculates the enthalpy, entropy, and specific heats for all the species in the data file.
Here R is the universal gas constant, T is the temperature
PROCEDURE:
FILE PARSING:
Parsing, syntax analysis, or syntactic analysis is the process of analyzing a string of symbols either in natural language, computer languages, or data structures, conforming to the rules of formal grammar. The term parsing comes from Latin pars,
The term has slightly different meanings in different branches of linguistics and computer science. Traditional sentence parsing is often performed as a method of understanding the exact meaning of a sentence or word, sometimes with the aid of devices such as sentence diagrams. It usually emphasizes the importance of grammatical divisions such as subject and predicate.Within computational linguistics the term is used to refer to the formal analysis by a computer of a sentence or other string of words into its constituents, resulting in a parse tree showing their syntactic relation to each other, which may also contain semantic and other information . Some parsing algorithms may generate a parse forest or list of parse trees for a synthetically ambigious input.
THEORY OF THERMODYAMICS:
ENTROPY:
Entropy is the loss of energy available to do work. Another form of the second law of thermodynamics states that the total entropy of a system either increases or remains constant; it never decreases. Entropy is zero in a reversible process; it increases in an irreversible process.
FORMULA:
S = R*(a1.*log(T) + (a2*T) + ((a3*(T).^2)/2) + ((a4*(T).^3)/3) + ((a5*(T).^4)/4) + a7)
ENTHALPY:
The sum of the internal energy and the product of the pressure and volume of a thermodynamic system. ... According to the law of energy conservation, the change in internal energy is equal to the heat transferred to, less the work done by, the system.
FORMULA:
H = R*T.*(a1 + ((a2*T)/2) + ((a3*(T).^2)/3) + ((a4*(T).^3)/4) + ((a5*(T).^4)/5) + ((a6./T)))
SPECIFIC HEAT:
In thermodynamics, the specific heat capacity (symbol cp) of a substance is the heat capacity of a sample of the substance divided by the mass of the sample. Specific heat is also sometimes referred to as massic heat capacity. ... The SI unit of specific heat capacity is joule per kelvin per kilogram, J⋅kg−1⋅K−1.
FORMULA:
Cp = R*(a1 + (a2*T) + (a3*(T).^2) + (a4*(T).^3) + (a5*(T).^4))
MOLECULAR WEIGHT:
- The molecular weight ( molar mass ) of any gas is the mass of one particle of that gas multiplied by Avogadro’s number (6.02 x 1023).
- Knowing the molar mass of an element or compound can help us stoichiometrically balance a reaction equation.
- The average molar mass of a mixture of gases is equal to the sum of the mole fractions of each gas (xi) multiplied by the molar mass (Mi) of that particular gas: ¯M=∑ixiMiM¯=∑ixiMi.
THE CODE:
SPECIFIC HEAT:
function Cp = Specific_heat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,tempmid)
% calculating specific heat
% calculating specific heat for higher and lower temperature repectively.
if (T <= tempmid)
Cp = R*(a8 + (a9*T) + (a10*(T).^2) + (a11*(T).^3) + (a12*(T).^4));
else
Cp = R*(a1 + (a2*T) + (a3*(T).^2) + (a4*(T).^3) + (a5*(T).^4));
end
endSTEPS:
- we will find the Specific heat by creating Specific heat function and assigning its relted formula coefficent from 14 coefficients, Gas constant,
Temperature and mid temperature.
- we will creatre an condition using if loop and make the temperature less than and equal to mid temperature to specify lower temperature coefficent in the formula.
- we will use else condition to specify coefficient of Higher temperature coefficent in the formula.
- End the loop and function to calculate Specific Heat.
ENTROPY:
function S = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,T,R,tempmid)
% calculating entropy
% calculating entropy for higher and lower temperature repectively.
if (T <= tempmid)
S = R*(a8.*log(T) + (a9*T) + ((a10*(T).^2)/2) + ((a11*(T).^3)/3) + ((a12*(T).^4)/4) + a14);
else
S = R*(a1.*log(T) + (a2*T) + ((a3*(T).^2)/2) + ((a4*(T).^3)/3) + ((a5*(T).^4)/4) + a7);
endSTEPS:
- Now we will find the Entropy by creating Entropy function and assigning its relted formula coefficent from 14 coefficients, Gas constant, Temperature
and mid temperature.
- Now we will creatre an condition using if loop and make the temperature less than and equal to mid temperature to specify lower temperature coefficent
in the formula.
- Then we will use else condition to specify coefficient of Higher temperature coefficent in the formula.
- Then end the loop and function to calculate Entropy.
ENTHALPY:
function H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,T,R,tempmid)
% calculating enthalpy
% calculating enthalpy for higher and lower temperature repectively.
if (T <= tempmid)
H = R*T.*(a8 + ((a9*T)/2) + ((a10*(T).^2)/3) + ((a11*(T).^3)/4) + ((a12*(T).^4)/5) + ((a13./T)));
else
H = R*T.*(a1 + ((a2*T)/2) + ((a3*(T).^2)/3) + ((a4*(T).^3)/4) + ((a5*(T).^4)/5) + ((a6./T)));
end
endSTEPS:
- Now we will find the Enthalpy by creating Enthalpy function and assigning its relted formula coefficent from 14 coefficients, Gas constant, Temperature
and mid temperature.
- Now we will creatre an condition using if loop and make the temperature less than and equal to mid temperature to specify lower temperature coefficent
in the formula.
- Then we will use else condition to specify coefficient of Higher temperature coefficent in the formula.
- Then end the loop and function to calculate Enthalpy.
MOLECULAR WEIGHT:
function W = Molecular_weight(species)
% Defining Atomic name of the species
atomic_name = ['H','C','O','N','Ar'];
% Defining Atomic masses of main species
atomic_weight = [1.008 12.011 15.999 14.007 39.948];
W=0; % Molecular weight starting range
for i=1:length(species) % Loop runs to the length of the species
for j=1:length(atomic_name) % Loop runs to the length of the atomic names
if strcmp(species(i), atomic_name(j)) %function to compare 2 strings
W = W + atomic_weight(j);
position = j;
end
end
n = str2num(species); % Now we will find if there is more element in the species then incrementing atomic weight of the species
if n>1
W = W + atomic_weight(position)*(n-1);
end
end
fprintf('Molecular Weight of %s :- ',species);
fprintf('%f',W);
disp(' ')
end
STEPS:
- Firstly we create an Molecular_weight functionW and assigning species input to that.
- Then define the main element of all 53 species in an array atomic_name that are :- 'H','C','O','N','Ar'.
- Taking above main elements we will create there atomic_wieght array from any source like internet that are :- 1.008 12.011 15.999 14.007
39.948.
- we will create an condition using if condition and use strcmp command to compare the species and atomic_name strings to calculate molecular
masses if by comparison both string found same then we will assign its molecular weight.
- we will string to the number using str2num command assign to n. Then we run an condition of if loop to find weather the species contains more
than one element if there are more then 1 elements that is n>1 then we will increment the atomic weight by the multiplication of position and n-1 to the
atomic_weight array.
- we will print the Molecular weight using fprintf command and display it using disp command.
PLOTTING CODE :
%Create plotting function
function plotting(cp,h,s,T,name)
cd(pwd)
dir_name = name;
mkdir(dir_name)
figure(1)
plot(T,cp,'linewidth',2,'color','b')
title(sprintf('Specific heat Vs Temperature for %s',name))
xlabel('TEMPERATURE')
ylabel('SPECIFIC HEAT')
figure(2)
plot(T,h,'linewidth',2,'color','r')
title(sprintf('Enthalpy Vs Temperature for %s',name))
xlabel('TEMPERATURE')
ylabel('ENTHALPY')
figure(3)
plot(T,s,'linewidth',2,'color','g')
title(sprintf('Entropy Vs Temperature for %s',name))
xlabel('TEMPERATURE')
ylabel('ENTROPY')
cd(dir_name)
saveas(1,'cp_vs_t.png')
saveas(2,'h_vs_t.png')
saveas(3,'s_vs_t.png')
end
STEPS:
- Enter all the values to plot the line.
MAIN CODE:
clear all
close all
clc
%Input
R=8.314; % Gas Constant
% Reading data file
% open file and reading THERMO.dat file
f1 = fopen('THERMO.dat','r')
get = fgetl(f1);
% Now Reading Temperature from this file
temp = fgetl(f1);
%spliting
s = strsplit(temp);
% converting strings cells into numbers
templow = str2num(s{2});
tempmid = str2num(s{3});
temphigh = str2num(s{4});
% Temperature Range
T = linspace(templow,temphigh,1000);
%Skipping comment lines
for i=1:3
get=fgetl(f1);
end
% Reading the Species
for j=1:53
tline=fgetl(f1);
A=strsplit(tline,' '); % spliting into cell array
species = (A{1}); % To read the name of the species
% Converting string to number
lowtemp = str2num(A{end-3});
midtemp = str2num(A{end-2});
hightemp = str2num(A{end-1});
tline1 = fgetl(f1); % getting next line
a = strfind(tline1,'E'); % Finding the string E
% Finding First 7 higher and second 7 lower coefficients
%Finding Higher coefficients
a1 = tline1(1:a(1)+3);
a1 = str2num(a1);
a2 = tline1(a(1)+4:a(2)+3);
a2 = str2num(a2);
a3 = tline1(a(2)+4:a(3)+3);
a3 = str2num(a3);
a4 = tline1(a(3)+4:a(4)+3);
a4 = str2num(a4);
a5 = tline1(a(4)+4:a(5)+3);
a5 = str2num(a5);
tline2 = fgetl(f1);
b = strfind(tline2,'E');
a6 = tline2(1:b(1)+3);
a6 = str2num(a6);
a7 = tline2(b(1)+4:b(2)+3);
a7 = str2num(a7);
% Finding Lower coefficients
a8 = tline2(b(2)+4:b(3)+3);
a8 = str2num(a8);
a9 = tline2(b(3)+4:b(4)+3);
a9 = str2num(a9);
a10 = tline2(b(4)+4:b(5)+3);
a10 = str2num(a10);
tline3 = fgetl(f1);
c = strfind(tline3,'E');
a11 = tline3(1:c(1)+3);
a11 = str2num(a11);
a12 = tline3(c(1)+4:c(2)+3);
a12 = str2num(a12);
a13 = tline3(c(2)+4:c(3)+3);
a13 = str2num(a13);
a14 = tline3(c(3)+4:c(4)+3);
a14 = str2num(a14);
% calculate specific heat
Cp = Specific_heat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,tempmid);
% calculate Entropy
S = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,T,R,tempmid);
% calculate Enthalpy
H = Enthalpy(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,T,R,tempmid);
% Calculate Molecular weight of the Species
W = Molecular_weight(species);
% writing molecular weight file
MW_file = fopen('Molecular Weight.txt','w');
fprintf(MW_file,'Molecular weight of %s is %d ',species,W);
fclose(MW_file); % Closing the file
%Plotting Cp, H and S with Temperature
% Saving in a folder
% changing directory
mkdir(species); %creating directory
cd(species);
% Plot 1 Cp vs T
figure(1)
plot(T,Cp,'linewidth',2,'color','b');
xlabel('Temperature(K)');
ylabel('Specific Heat(KJ)');
title(sprintf('Specific heat vs Temperature range of %s',species));
grid on
saveas(figure(1),'Specific Heat.jpg');
% Plot 2 S vs T
figure(2)
plot(T,S,'linewidth',2,'color','r');
xlabel('Temperature');
ylabel('Entropy(KJ/mol-K)');
title(sprintf('Entropy vs Temperature range of %s',species));
grid on
saveas(figure(2),'Entropy.jpg');
% Plot 3 Cp vs T
figure(3)
plot(T,H,'linewidth',2,'color','g');
xlabel('Temperature');
ylabel('Enthalpy(KJ/mol)');
title(sprintf('Enthalpy vs Temperature range of %s',species));
grid on
saveas(figure(3),'Enthalpy.jpg');
cd ..
%Changing directory to Original matlab path
%Molecular weight
W = Molecular_weight(species)
endSTEPS:
- we will Input the parameter R and we will open a file THERMO.dat file and reading this file using fopen command.
- Then, we will read first THERMO using fgetl command and then we read temperature file and we will split the temperatures using strsplit command to
convert it into cell array and then we will convert this string to number using str2num command to find low, high and mid temperatures.
- Then we will assign temperature range using linspace command. Then we run loop to skip command lines the data file using fgetl command inside the
loop.
- we will run the loop to find 53 element in the data file by assigning fgetl command and then spliting into the cell array to find the species line and
then find the species name and then find the number of the temperatures in the species line.
- Then we read the new line. In order to read the coefficient in the data file we will first find the 'E' string using strfind command to find before and after
numbers of the coefficients then we will find remaining 14 coefficients and convert them to numbers from strings.
- we will find first 7 Coefficients which are for Higher temperature and then Second 7 Coefficients which are for Lower temperature.
- Now we will specify Specific heat Cp, Entropy S, Enthalpy H functions to find these parameters using these 14 coefficients for Lower and higher
Temperature. then we will specify molecular weight W function to find the Molecular weight of the different species.
- we will write the Molecular weight.txt file and fprintf all the molecular weights of the species. and then close the txt file using fclose command.
- we change the directory using cd command and then creating directory folder where we have to save our files using mkdir command and then we
will change the directory to this created folder.
- we will plot Specific heat, Entropy and Enthalpy with the Temperature for different species. We we will use scanf command to in the title
command to create different species title.
- Then we will use saveas command to save the plots of different species in the directory folder. Now we will change the directory to which our main code
file runs in the MATLAB
ERRORS:
- Saving location was wrongly entered
- file named as a 'Entropy_calc' but I entered ' Entropy' on that
PLOTTING RESULTS:
PLOTS OF O2 :
PLOTS OF N2:
PLOTS OF CO2 :
REFERENCES:
2) https://en.wikipedia.org/wiki/Parsing
6) https://in.mathworks.com/support/search.html?q=thermodynamics&page=1