Project 1 - Parsing NASA thermodynamic data

AIM

To calculate specific heat ,enthalpy ,entropy and molecular weight for all species given in nasa thermodynamic data file using matlab.

OBJECTIVE:

1.To calculate specific heat , entropy, enthalpy and molecular weight for all species .

2.To create a directory and store all species.

3.Plot for all species and stored in a particular file .

INTRODUCTION

From the given thermodynamic file ,we need to read the external file and import all species coefficients and temperature values to the program to calculate cp, s, h by using the respective formula.The specific heat is the amount of heat per unit mass required to raise the temperature by 1 degree celsius. Enthalpy the sum of internal energy and the product of the pressure and volume of a thermodynamic system . Entropy the measure of a system's thermal energy per unit temperature that is unavailable for doing useful work . The formula for specific heat , entropy , and entthalpy are given below.

clear all

close all

clc

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

fgetl(f1)

fgetl(f1)

fgetl(f1)

fgetl(f1)

fgetl(f1)

for j = 1:53

tline = fgetl(f1)

A = strsplit(tline,' ')

sp = A{1}

llt = str2num(A{end-3})

lht= str2num(A{end-2})

lmt= str2num(A{end-1})

tline = fgetl(f1)

pos = findstr(tline,'E')

a1 = str2num(tline(1:pos(1)+3)

a2 = str2num(tline(pos(1)+4:pos(2)+3))

a3 = str2num(tline(pos(2)+4:pos(3)+3))

a4 = str2num(tline(pos(3)+4:pos(4)+3))

a5 = str2num(tline(pos(4)+4:pos(5)+3))

tline = fgetl(f1)

a6 = str2num(tline(1:pos(1)+3)

a7 = str2num(tline(pos(1)+4:pos(2)+3))

a8 = str2num(tline(pos(2)+4:pos(3)+3))

a9= str2num(tline(pos(3)+4:pos(4)+3))

a10 = str2num(tline(pos(4)+4:pos(5)+3))

tline = fgetl(f1)

a11 = str2num(tline(1:pos(1)+3)

a12 = str2num(tline(pos(1)+4:pos(2)+3))

a13 = str2num(tline(pos(2)+4:pos(3)+3))

a14= str2num(tline(pos(3)+4:pos(4)+3))

T = linspace(llt,lht,500);

R = 8.314

cp = specificheat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,lmt,T,R);

H = Enthalpy (a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,lmt,T,R);

S = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,lmt,T,R);

function[cp] = specific_heat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,lmt,T,R);

% Finding specific heat with low and high temperature variables

if T<=lmt

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

else

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

end

end

function[s] = Entropy(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,lmt,T,R);

if T<=lmt

S = (a8*log(T)+(a9*T)+(a10*log(T)+(a11*T.^3/3)+(a12*T.^4/4)+(a14)*R;

else

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

end

end

function [H] = Enthalpy (a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,lmt,T,R);

if T<= lmt

H = (a8+(a9*T/2)+(a10*T.^2/3)+(a11*T.^3/4)+(a12*T.^4/5)+(a13./T))*R.*T

else

H = (a1+(a2*T/2)+(a3*T.^2/3)+(a4*T.^3/4)+(a5T.^4/5)+(a6./T))*R.*T

end

end

figure(1)

plot(t,cp)

xlabel('Temperature')

ylabel('specific_heat')

grid on

figure(2)

plot(T,H)

xlabel('Temperature')

ylabel('Enthalpy')

grid on

figura(3)

plot(T,S)

xlabel('Temperature')

ylabel('Entropy')

mkdir(sp)

saveas(1,'specificheat','jpg')

saveas(2,'Enthalpy','jpg')

saveas(3,'Entropy','jpg')

cd..

end

% To calculate molecular weight
elements = {'H','C','O','N','A','S'};
atomic_weight = [1,12,16,14,39,32];
molecular_weight=0;

 for k=1:length(species)
     for l=1:length(elements)
         if strcmp(species(k),elements(l))
             molecular_weight = molecular_weight+atomic_weight(l);
             position=l;
         end
     end  
       n = str2double(species(k));
       if(n>1)
             molecular_weight = molecular_weight+(atomic_weight(position)*(n-1));  
 end
end

                                    CARBON SPECIES

HYDROGEN SPECIES

NITOGEN SPECIES

CONCLUSION

1. Plots are obtained for all species and stored in particular folder.

2. Specific heat ,entropy, enthalpy are calculated by using formula and by condition 1st seven coefficients are high temperature and seven coefficients are low temperature.

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