Challenge

Project 1 - Parsing NASA thermodynamic data

KKiran Suryawanshi6 Feb 2022

AIM :

To write a code in Matlab to parse the NASA thermodynamics data file and then calculated the thermodynamic properties of various gas species.

OBJECTIVE :

1. Write a function that extracts the 14 coefficients and calculates the enthalpy, entropy and specific heats for all the species in the data file.

2. Calculate the molecular weight of each species and display it in the command window.

3. Plot the Cp, Enthalpy and Entropy for the local temperature range (low temperature : high temperature) specific for each species.

4. Save the plots as images with appropriate names and dump them in separate folders for each species with suitable name. All these should be generated automatically.

5.The main program that you will submit will just take the “THERMO.dat” file as an input and generate Cp,H and S plots.

6.Screenshot of the window where all folders are saved.

7.Plots for O2,N2 and Co2 species

FILE PARCING :

Different organisations comes up with polynomials, that can be used to evaluate different properties for different environments for Ex.In case of thermodynamics such as CP, H and S. They also create a document file for the coefficients that are required to evaluate these polynomials, for n no. of species

So, file parsing is method that helps us in decoding that data or in other words helps reading that data and use it in calculation of several parameters that defines the state that environment. and analyse behaviour of different species changing with some varying inputs.

To do file parsing first we need to check whether the data is broken down into meaningful bits or not. If not then we should first break it down the standard form so that reading for each species becomes similar.

NASA THERMODYNAMICS DATA :

NASA came up with polynomials that can be used to evaluate thermodynamic properties such as Cp, H and S. They have also documented the coefficients that are required to evaluate these polynomials for 1000+ species.

Using find parsing we need to write the function that extracts the 14 coefficients by reading data file and calculate the enthalpy(H), entropy(S) and specific heat (Cp) for all the species.We can also make plots for better understanding and the behaviour of gas w.r.t to temperature.

Formula :

Where,

R = universal gas constant

T = temperature

Cp = specific heat(KJ)

S = entropy (KJ/mol-K)

H = enthalpy (KJ/mol)

a(i) = coefficients where, i = 1 to 14

Write a function that extracts the 14 coefficients and calculates the enthalpy, entropy and specific heats for all the species in the data file

Specific Heat :

The specific heat is the amount of heat unit mass required to raise the temperature by 1° celsius. The relationship between heat and temperature change it is usually expressed in the form shown below where C is the specific heat

Cp = R*(a1+(a2*T)+(a3*(T).^2)+(a4*(T).^3)+(a5*(T).^4))

Function for 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 & lower temperature respectively

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

Entropy :

Entropy, the measure of system’s thermal energy per unit temperature that is unavailable for doing useful work. Because work is obtained from ordered molecular motion, the amount of entropy is also a measure of the molecular disorder, or randomness of system.

S = R*(a1.*log(T)+(a2*T)+((a3*(T).^2)/2)+((a4*(T).^3)/3)+((a5*(T).^4)/4)+a7)

Function for Entropy

function [S]=Entropy(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,tempmid)

%calculating Entropy

%calculating Entropy for higher & lower temperature respectively

if (T<=tempmid)

S = R*(a8*log(T)+(a9*T)+((a10*(T).^2)/2)+((a11*(T).^3)/3)+((a12*(T).^4)/4));

else

S = R*(a1*log(T)+(a2*T)+((a3*(T).^2)/2)+((a4*(T).^3)/3)+((a5*(T).^4)/4));

end

Enthalpy :

Enthalpy, a property of thermodynamic systems equal to the system’s internal energy plus the product of its pressure and volume.IN a system contained so as to prevent mass transferor processes at constant pressure, the heat absorbed or released equals the change in enthalpy.

H = R*T.*((a1+(a2*T)/2)+((a3*(T).^2)/3)+((a4*(T).^3)/4)+((a5*(T).^4)/5)+((a6./T)))

Function for Enthalpy

function [H]=Enthalpy(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,tempmid)

%calculating Enthalpy

%calculating Enthalpy for higher & lower temperature respectively

if (T<=tempmid)

H = R*T.*((a8+(a9*T)/2)+((a10*(T).^2)/3)+((a11*(T).^3)/4)+((a12*(T).^4)/5));

else

H = R*T.*((a1+(a2*T)/2)+((a3*(T).^2)/3)+((a4*(T).^3)/4)+((a5*(T).^4)/5));

end

Calculate the molecular weight of each species and display it in the command window.

Function for molecular weight

function W= Molecular_weight(species)

atomic_name = ['H','C','O','N','Ar'];

atomic_weight = [1.008 12.011 15.999 14.007 39.948];

W = 0;

for i = 1:length(species)

for j = 1:length(atomic_name)

if strcmp(species(i),atomic_name(j))

W = W + atomic_weight(j)

position = j

end

n = str2num(species)

if n>1

W = W + atomic_weight(position)*(n-1)

end

fprintf('molecular Weight of %S :-',species)

fprintf('%f',W)

disp(' ')

end

Result -

molecular weight of O :- 15.999000

molecular weight of O2 :- 15.999000

molecular weight of H :- 1.008000

molecular weight of H2 :- 1.008000

molecular weight of OH :- 17.007000

molecular weight of H2O :- 17.007000

molecular weight of HO2 :- 17.007000

molecular weight of H2O2 :- 17.007000

molecular weight of C :- 12.011000

molecular weight of CH :- 13.019000

molecular weight of CH2 :- 13.019000

molecular weight of CH2(S) :- 13.019000

molecular weight of CH3 :- 13.019000

molecular weight of CH4 :- 13.019000

molecular weight of CO :- 28.010000

molecular weight of CO2 :- 28.010000

molecular weight of HCO :- 29.018000

molecular weight of CH2O :- 29.018000

molecular weight of CH2OH :- 30.026000

molecular weight of CH3O :- 29.018000

molecular weight of CH3OH :- 30.026000

molecular weight of C2H :- 13.019000

molecular weight of C2H2 :- 13.019000

molecular weight of C2H3 :- 13.019000

molecular weight of C2H4 :- 13.019000

molecular weight of C2H5 :- 13.019000

molecular weight of C2H6 :- 13.019000

molecular weight of CH2CO :- 41.029000

molecular weight of HCCO :- 41.029000

molecular weight of HCCOH :- 42.037000

molecular weight of H2CN :- 27.026000

molecular weight of HCN :- 27.026000

molecular weight of HNO :- 31.014000

molecular weight of N :- 14.007000

molecular weight of NNH :- 29.022000

molecular weight of N2O :- 30.006000

molecular weight of NH :- 15.015000

molecular weight of NH2 :- 15.015000

molecular weight of NH3 :- 15.015000

molecular weight of NO :- 30.006000

molecular weight of NO2 :- 30.006000

molecular weight of HCNO :- 43.025000

molecular weight of HOCN :- 43.025000

molecular weight of HNCO :- 43.025000

molecular weight of NCO :- 42.017000

molecular weight of CN :- 26.018000

molecular weight of HCNN :- 41.033000

molecular weight of N2 :- 14.007000

molecular weight of AR :- 39.948000

molecular weight of C3H8 :- 13.019000

molecular weight of C3H7 :- 13.019000

molecular weight of CH3CHO :- 42.037000

molecular weight of CH2CHO :- 42.037000

The main program that you will submit will just take the “THERMO.dat” file as an input and generate Cp,H and S plots

Main code -

clear all

close all

clc

cd('/Users/kiran/Desktop/File parcing')

% Reading data file

% Open file and reading THERMO.dat file

f1 = fopen('THERMO.dat','r')

get = fgetl(f1);

R = 8.314

% 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,' ');

species = (A{1});

%converting string to number

lowtemp = str2num(A{end-3});

midtemp = str2num(A{end-2});

hightemp = str2num(A{end-1});

% Getting next line

tline1 = fgetl(f1);

a = strfind(tline1,'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);

%plotting Cp,H and S with Temperature

%saving in a folder

mkdir(species)

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 1 Cp vs T

%plot 2 S vs T

figure(2)

plot(T,S,'LineWidth',2,'Color','r')

xlabel('Temperature');

ylabel('Specific Heat(KJ/mol-K)');

title(sprintf('Entropy vs Temperature range of %s',species))

grid on

saveas(figure(2),'Entropy.jpg')

%plot 3 H 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 ..

%Molecular Weight

W = Molecular_weight(species)

end

Plot the Cp, Enthalpy and Entropy for the local temperature range (low temperature : high temperature) specific for each species. Save the plots as images with appropriate names and dump them in separate folders for each species with suitable name. All these should be generated automatically. Screen shot of the window where all folders are saved.