Project 1 - Parsing NASA thermodynamic data

%clear all the previous data or stores values

clear all

close all

clc

%Open the the THERMO.dat file f1-fopen('THERMO.dat', 'r')

%skip the first line of the file

fgetl(f1);

%reading the tempersture values distingushed as local, average and high temperatures

line=fgetl(f1);

a=strsplit(line,' ');

global_low_temp=str2num (a{2});

global_average_temp-str2num(a{3}); global_high_temp-str2num (a{4});

fgetl(f1);

fgetl(f1);

fgetl(f1);

%extracting data for each gas

for k=1:53

%step7

line=fgetl(f1);

a=strsplit(line,' ');

Gas=a(1);

b=findstr(line, '.');

local_low_temp=str2num (line (b(1)-4:b(1)+4)); local_high_temp=str2num (line (b(2)-4: b (2)+4));

local_average_temp=str2num(line (b(3)-4:b(3)+4));

%extracting all 14 coefficient

ct=1;

for j=1:3

line-fgetl(f1);

b=strfind(line, 'E');

for i=1:length(b)

if ct<=7

Ha(ct)=str2num (line (b(i)-11: b(i)+3));

ct=ct+1;

else

La(ct-7)=str2num (line (b(i)-11: b(i)+3));

ct=ct+1;

end

end

end

%initializing specific heat, entropy and enthalpy values to zero

cp=0;

H=0;

S=0;

%calling the function where cp, H and S are calculated

[Cp,H,S] = coefficient (local_low_temp, local_average_temp, local_high_temp, La,Ha);

%molecular weight calculating function M=Weight (Gas)

%plotting

GAS=char(Gas);

T=local_low_temp:local_high_temp;

current=pwd;

mkdir (GAS);

cd (GAS)

figure(1);

plot(T, Cp, 'color', 'g', 'linewidth', 2);

egend (Gas);

txt1=['Molecular weight: num2str(M)]; text (500, max(Cp)*0.98, txt1, 'color', 'r');

grid on

xlabel('temperature (K)');

ylabel('Specific heat (KJ/mol)');

title('specific heat vs temperrature');

figure(2);

plot (T,H, 'color', 'r', 'linewidth',2);

legend (Gas);

txt1=['molecular weight: num2str(M)]; text (500, max (H)*0.98, txt1, 'color', 'b');

grid on

xlabel('temperrature (K)');

ylabel('enthalpy (kj/mol)'); title('enthalpy vs temperature');

figure(3);

plot (T,S, 'color', 'b', 'linewidth',2);

legend (Gas);

txt1=['Molecular weight: num2str(M)]; text (500, max (S)*0.98, txt1, 'color', 'b');

grid on

xlabel('temperature(K)');

ylabel('entropy (KJ/mol)'); title('entropy vs temperature');

saveas (figure(1), 'Cp.jpg');

saveas (figure(2), 'H.jpg'); saveas (figure(3), 'S.jpg');

cd (current);

end

%function to calculate molecular weight function Mo-Weight (Gas)

Weight [1 12 14 16 32 0 40]; Gas1=['H' 'C' 'N' 'O' 'S' 'A' 'R'];

number=[1 2 3 4];

M=0;

GAS=char(Gas);

for i=1:length(GAS)

for j=1:length(Gas1)

if GAS (i)==Gas1(j)

M(i) Weight (j);

end

for j=1:length(number)

if str2double (GAS (i)) ==number(j) M(i)=M(i-1)* (number(j)-1);

end

end

end end

Mo=sum(M);

end

%function to calculate the Cp, H, S.

function [Cp,H,S]=coefficient (local_low_temp, local_average_temp, local_high_temp, La, Ha) for i=1:local_high_temp-local_low_temp+1

R=8.34;

T-i+local_low_temp-1;

%for lower temperature values

if T<= local_average_temp

Cp(i)=R* (La(1)+La (2) *T+La(3) *T^2+La (4) *T^3+La(5)*T^4);

H(i)=R*T* (La (1)+(La (2) T)/2+(La (3) *T^2)/3+ (La (4) *T^3)/4+ (La (5) *T^4)/5+La(6)/T); S(i)=R (La (1) *log (T)+(La (2) *T)+((La (3) *T^2)/2)+((La (4) *T^3)/3) + ((La (5) *T^4)/4)+(La(7)));

%for higher temperature values

else

Cp(i)=R* (Ha (1) +Ha (2) T+Ha (3) *T^2+Ha (4) *T^3+Ha(5)*T^4); H(i)=R*T(Ha(1)+((Ha (2) T)/2)+(Ha (3) *T^2)/3+ (Ha (4) *T^3)/4+ (Ha (5) *T^4)/5+(Ha(6)/T)); S(i)=R (Ha (1) *log(T)+(Ha (2) *T)+(Ha (3) *T^2)/2+(Ha (4) *T^3)/3+ (Ha(5)*T^4)/4+ (Ha (7)));

end

end

end

The fist step in the code clears all the previously stored data on the command window.

The 'fopen' command opens the 'THERMO.dat' file and 'r' here indicated the 'read only' command. We use 'fget!' command to read the data file line by line. The first line of the file is omitted and the next line is stores in a variable 'line' and the line is split using 'strsplit' command and stored in a variable 'a'. Different temperature values are assigned to read the 53 gases mentioned in the data file we use for loop then we further read the lines in the file using fgetl command.

When all the global and local temperatures are read we call functions which are written to calculate molecular weight, specific heat(Cp),enthalpy(H),Entropy(s).

Calculating the value of Cp,H & S for local temperature range. Initial values of Cp, H & S are defined as zero, Plotting the graphs & saving them in the folder. It is standard procedure to store in file in specific location, by using many commands (pwd, mkdir, cd, saveas) written in this program.

We are using formulae to calculate Cp, H & S. We are using for loop to calculate each value at local temperature range. We are also using if & else command to use low & high temperature coefficient as per average temperature. If Temperature is less than average temperature then use low temperature co-efficient & If Temperature is more than average temperature then use hign temperature co-efficient

Molecular weight is calculated in a different function which is later called in the main function.