Challenge

Project 1 - Parsing NASA thermodynamic data

SSivani Dronamraju6 Feb 2022

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.

To plot the parameters with specific local temperatures

To calculate the molecular weight of each species using the mentioned formula

Description:

specific heat: It is the quantity of heat required to raise the temperature of one gram of a substance by one degree celsius.

entropy: It is the measure of a system’s thermal energy per unit temperature that is unavailable for doing useful work.

enthalpy: It is the sum of the internal energy and the product of the pressure and volume of a thermodynamic system.

Cp= specific heat

H= enthalpy

S= entropy

R= universal gas constant

T= temperature

code:

clear all
close all
clc

f= fopen('THERMO.dat','r')
line1=fgetl(f);
line2=fgetl(f);
%comments
des_1=fgetl(f);
des_2=fgetl(f);
des_3=fgetl(f);
A= strsplit(line2,' ');

low_temperature=str2double(A{2});
med_temperature=str2double(A{3});
high_temperature=str2double(A{4});

for i=1:53
    species= fgetl(f);
    species_name= species(1:6);

    line_1=fgetl(f);
    l1=strfind(line_1,'E');
    c1=str2num(line_1(1:(l1(1)+3)));
    c2=str2num(line_1((l1(1)+4):(l1(2)+3)));
    c3=str2num(line_1((l1(2)+4):(l1(3)+3)));
    c4=str2num(line_1((l1(3)+4):(l1(4)+3)));
    c5=str2num(line_1((l1(4)+4):(l1(5)+3)));

   line_2=fgetl(f);
    l2=strfind(line_2,'E');
    c6=str2num(line_2(1:(l2(1)+3)));
    c7=str2num(line_2((l2(1)+4):(l2(2)+3)));
    c8=str2num(line_2((l2(2)+4):(l2(3)+3)));
    c9=str2num(line_2((l2(3)+4):(l2(4)+3)));
    c10=str2num(line_2((l2(4)+4):(l2(5)+3)));  

line_3=fgetl(f);
    l3=strfind(line_3,'E');
    c11=str2num(line_3(1:(l3(1)+3)));
    c12=str2num(line_3((l3(1)+4):(l3(2)+3)));
    c13=str2num(line_3((l3(2)+4):(l3(3)+3)));
    c14=str2num(line_3((l3(3)+4):(l3(4)+3)));

   
   
    temperature= linspace(300,5000,100);
    R=8.314;

    for j=1:length(temperature)
        if temperature(j)<3000
            Cp=(c1+c2.*temperature+c3.*temperature.^2+c4.*temperature.^3+c5.*temperature.^4).*R;
            H=(c1+(c2.*temperature)./2+(c3.*temperature.^2)/3+(c4.*temperature.^3)/4+(c5.*temperature.^4/5)+(c6./temperature)).*temperature.*R;
            S=(c1.*log(temperature)+c2.*temperature+(c3.*temperature.^2)/2+(c4.*temperature.^3)/3+(c5.*temperature.^4)/4+c7).*R;
        else 
            Cp=(c8+c9.*temperature+c10.*temperature.^2+c11.*temperature.^3+c12.*temperature.^4).*R;
            H=(c8+(c9.*temperature)./2+(c10.*temperature.^2)/3+(c11.*temperature.^3)/4+(c12.*temperature.^4/5)+(c13./temperature)).*temperature.*R;
            S=(c8.*log(temperature)+c9.*temperature+(c10.*temperature.^2)/2+(c11.*temperature.^3)/3+(c12.*temperature.^4)/4+c14).*R;
        end
    end
   
    %plotting temp vs entropy
    figure(1)
    plot(temperature,S,'LineWidth',4,'Color','b')
    title(species_name)
    xlabel('temperature')
    ylabel('entropy')

    %plot temp vs enthalpy
    figure(2)
    plot(temperature,H,'LineWidth',4,'Color','r')
    title(species_name)
    xlabel('temperature')
    ylabel('enthalpy')

    %plot temp vs specific heat
    figure(3)
    plot(temperature,Cp,'LineWidth',4,'Color','g')
    title(species_name)
    xlabel('temperature')
    ylabel('specific heat')

 %folder for species
  mkdir(species_name)
  cd(species_name)
   %saving
   saveas(1,'entropy.jpg');
   saveas(2,'enthalpy.jpg');
   saveas(3,'specificheat.jpg');

  
   % molecular mass calculation
   
MM = molecular_mass(species_name)
  p=sprintf('molecular weight of %s is %f',species_name,MM)
   disp(p)
end

fclose(f);

function code:

function MM= molecular_mass(species_name)
species= upper(species_name);
constituents=['H','C','N','O','A'];
atomic_weight=[1.00794 12.0107 14.006 15.9994 39.948];
MM = 0;

for i=1:length(species_name)
    for j=1:length(constituents)
        if strcmp(species(i),constituents(j))
            MM = MM +atomic_weight(j);
            u=j;
        end
    end
        n=str2num(species(i));
    if n>1
        MM = MM +atomic_weight(u)*(n-1);
    end
  
end
        end

explanation of commands used:

fgetl: this command is used to return to the next line of the specified file

strsplit: this command is used to splits str on the elements of the delimiter

strfind: this command is used to find strings in strings

mkdir:This command is used to create a new folder

cd: this command is used to change the current folder

saveas: this command is used to save the file

output:

plots for o2, N2 and co2