Challenge

Project 1 - Parsing NASA thermodynamic data

SSantosh Dudhabhate17 Oct 2021

%FUNCTION OF THERMAL PROPERTISE.....
function [c_p,h,s]=thermal_properties(a1,a2,a3,a4,a5,a6,a7,T)
R=8.314

c_p=(a1+(a2*T)+(a3*T.^2)+(a4*T.^3)+(a5*T.^4))*R
h=(a1*T+(a2*(T.^2/2))+(a3*(T.^3/3))+(a4*(T.^4/4))+(a5*(T.^5/5))+a6./T)*R.*T
s=(a1*log(T)+(a2*T)+(a3*(T.^2/2))+(a4*(T.^3/3))+(a5*(T.^4/4))+a7)*R
end
% END OF FUNCTION CODE FOR THERMAL PROPERTIES
%function of calculation of molecular weight....
function [M]=molecular_weight(species_name)
atomic_mass=[15.999,1.008,12.011,14.007,39.948];
elements=['O','H','C','N','A'];
mol_wt=0
for i=1:length(species_name)
    for j=1:length(elements)
        if strcmpi(species_name(i),elements(j));
            mol_wt=mol_wt+atomic_mass(j);
            z=j;
        end
    end
    var=str2double(species_name(i));
    if (var>1)
        mol_wt=mol_wt+(atomic_mass(z)*(var-1));
    end
end
M=mol_wt
end

% END OF FUNCTION CODE FOR MOLECULAR WEIGHT

% FILE PARSING MAIN CODE



% main code to extract 14 coefficients from file

clear all
close all
clc
%opening file saved
b=fopen('THERMO.dat','r');
line1=fgetl(b)


%reading line where  global temperature available
line2=fgetl(b)
%spliting line into 'strings '
a=strsplit(line2,' ')
%converting string to numbers
global_low_temp=str2num(a{2});
global_mid_temp=str2num(a{3});
global_high_temp=str2num(a{4});

%skipping 3 lines 
fgetl(b);
fgetl(b);
fgetl(b);

%finding coeff values
%using for loop to limit the file
for i=1:inf
    line3=fgetl(b);
    B=strsplit(line3,' ')
%giving breat in the end of data
    if strcmp(line3,'END')
        break
    end
% finding species location
    species_name=(B{1});

%finding local temprature values
    local_low_temp=str2num(B{end-3});
    local_mid_temp=str2num(B{end-1});
    local_high_temp=str2num(B{end-2});
   %reading line 4 
    line4=fgetl(b);

%finding location of E
    C=strfind(line4,'E');
%finding coeff. according to the E locations
    
    a1=str2num(line4(1:C(1)+3))
    a2=str2num(line4((C(1)+4):(C(2)+3)));
    a3=str2num(line4((C(2)+4):(C(3)+3)));
    a4=str2num(line4((C(3)+4):(C(4)+3)));
    a5=str2num(line4((C(4)+4):(C(5)+3)));
  % repeating same for next 2 lines  
    line5=fgetl(b);
    D=strfind(line5,'E')
    a6=str2num(line5(1:D(1)+3))
    a7=str2num(line5((D(1)+4):(D(2)+3)));
    a8=str2num(line5((D(2)+4):(D(3)+3)));
    a9=str2num(line5((D(3)+4):(D(4)+3)));
    a10=str2num(line5((D(4)+4):(D(5)+3)));
    
    line6=fgetl(b);
    D=strfind(line6,'E')
    a11=str2num(line6(1:D(1)+3))
    a12=str2num(line6((D(1)+4):(D(2)+3)));
    a13=str2num(line6((D(2)+4):(D(3)+3)));
    a14=str2num(line6((D(3)+4):(D(4)+3)));


    
    T_low=linspace(local_low_temp,local_mid_temp,100);%low temp    T_high=linspace(local_mid_temp,local_high_temp,100);% high temp 
    % calling function and putting with low & high temperature values
    [c_ph,hh,sh]=thermal_properties(a1,a2,a3,a4,a5,a6,a7,T_high)% high temp coeffs
    [c_pl,hl,sl] =thermal_properties(a8,a9,a10,a11,a12,a13,a14,T_low)%low temp. coeffs
    %plotting 
    figure(1)
    plot(T_low,c_pl)
    hold on
    plot(T_high,c_ph)
    title('temperature vs specific heat ')
    xlabel('temperature')
    ylabel('specific heat')
    
    figure(2)
    plot(T_low,sl)
    hold on
    plot(T_high,sh)
    title('temperature vs entropy')
    xlabel('temperature')
    ylabel('entropy')
    
    figure(3)
    plot(T_low,hl)
    hold on
    plot(T_high,hh)
    title('temperature vs enthalpy')
    xlabel('temperature')
    ylabel('enthalpy')
    % creating file
    mkdir('species')
    cd('species')
%changing file directory
    mkdir(species_name)
    cd(species_name)
%saving files below
    saveas(1,'specific_heaT.jpg');
    saveas(3,'enthalpy.jpg');
    saveas(2,'entropy.jpg');
    close all
    cd ..
    cd ..
     % calculating molecular weight
    [M]=molecular_weight(species_name)
    k=sprintf('molecular weight of%s=%fu',species_name,M)
    disp(k)
end

AIM:

To write a code in MATLAB to parse nasa thermodynamic data file and then calculate thermodynamic properties of various gas species.

OBJECTIVE:

Write a function that extracts the 14 coefficients and calculates the enthalpy.entropy and specific heats for all the species
Calculating molecular weight of each species
Plotting the specific heat, enthalpy and entropy for the local temperature range.
Saving the plots as images with appropriate names and dumping them in seperate folders for each species.

THEORY:

File Parsing File parsing is a string or symbol either in natural language computer language or data structure conferming to the rules of the former grammer,

RESULT: