Project 1 - Parsing NASA thermodynamic data

• Now we calculate the molecular weight of all the species as per reqiuirement by defining the function molecular_weight with input values as species.

function [mol_weight] = molecular_weight(species)
%defining elements
element = ['O','C','H','N','A'];
fprintf('Molecular Weight of ')
fprintf(species)
fprintf(' : ' )
%atomic weight of the elements
atomic_weight =  [16,12,1,14,39];
mol_weight = 0;
for i =1:length(species)
    for j = 1:length(element)

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

   mol_weight = mol_weight+atomic_weight(j);
        p = j;
    end
   
    end
     n = str2num(species(i));
   
if n>1
    mol_weight = mol_weight+atomic_weight(p)*(n-1);
end
end
fprintf('Molecular Weight of %s :',species)
fprintf('%d',mol_weight)
disp(' ')
end

Here first we define the elements which are the basic elements of the species present and store it in an array called 'element'.

Then we print the lines 'Molecular Weight of' species ':' using the fprintf command where the species are all the species whose molecular weight is to be found.

The next step is to define the atomic weight of the elements defined, for that cerate an array called atomic_weight and store the atomic weights of respective elements.

Then we put initial molecular weight of the species as 0 and this is done to initiate the process of calculation of molecular weight

After that we create two for loops i and j of which i varies from 0 to the length of species i.e. 53 and j loop varies from 0 to length of elements which is 5. This is done to compare the species with elements and also calculate the molecular weight using the equation mol_weight = mol_weight+atomic_weight(j);

We store the value of j into a variable p then we end both the commands and calculate 'n' which is the number of species present in a molecule for eg. in co2 there is one mole of carbon and 2 moles of oxygen thus to calculate the molecular weight we have to add these 2 moles of oxygen which makes it 16*2= 32 . Here 2 is the 'n'. Similarly for other species the molecular weight is calculated using the n whose value is always greater than 1. For those species we calculate the molecular weight using the below equation

In the above equation the molecular weight of co2 will turn out to be (12+16)+16*(2-1) = 44

similarly for CH4 (12+1)+1*(4-1) = 16

Now we end the if command and the loop using the end command and write the command to print 'Molecular weight of ' species ':' and to print the molecular weight using the fprintf command. Here %s is to show it is a string and %d is used to show that molecular weight is a double. Then we need to display the molecular weights of all the species thus we use the disp command.

• Now we call the functions of Enthalpy, Entropy, Specific Heat and Molecular weight so that we could calculate them.

%Calculating specific heat Cp
Cp = specific_heat_func(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,t,R,mid_temp) ;
%Calculating enthalpy H
H = enthalpy_func(a1,a2,a3,a4,a5,a6,a8,a9,a10,a11,a12,a13,t,R,mid_temp);
%Calculating Entropy S
S =  entropy_func(a1,a2,a3,a4,a5,a7,a8,a9,a10,a11,a12,a14,mid_temp,R,t);
%calculating molecular weight
[mol_weight] = molecular_weight(species)

• Now we have to plot and save the program for that we craeate a program as shown below

• %plotting Cp vs t
  mkdir(['/Users/aadarshr/Documents/Aadarsh/',species])
  figure(1)
  plot(t,Cp,'linewidth',3,'color','r')
  title('Cp vs t')
  xlabel('Temperature')
  ylabel('Specific Heat')
  %plotting S vs t
  figure(2)
  plot(t,S,'linewidth',3,'color','y')
  xlabel('Temperature')
  ylabel('Entropy')
  title('S vs t')
  %plotting H vs t
  figure(3)
  plot(t,H,'linewidth',3,'color','b')
  xlabel('Temperature')
  ylabel('Enthalpy')
  title('H vs t')
  cd(['/Users/aadarshr/Documents/Aadarsh/',species])
  saveas(1,'Cp vs t','jpg')
  saveas(2,'H vs t','jpg')
  saveas(3,'S vs t','jpg')
  cd(['/Users/aadarshr/Documents/'])
  
  end

• In the above program at first we create a directory named '/Users/aadarshr/Documents/Aadarsh/' using mkdir command, this command makes a directory with plots of all the species and assigns the address that is given by us.
• Then we plot Specific heat vs temperature using plot command with x axis as temperature and y axis labelled as Specific heat. We also plot the Enthalpy vs Temperature and Entropy vs Temperature in the similar manner. Exception is that the y axis will be labelled as H and S respectively.
• Then we change the directory using cd command and save the plots of the species in jpg format using the saveas command
• At last we end the j loop using END command

OUTPUT

Output showing the molecular weight of each species is as follows

Screenshot of the window were all folders are saved

Plots of o2

Plots of N2

Plots of Co2

ERRORS OCCURED

Forgot to use the dot product while multiplying a matrix i.e here 't' in the specific heat function ,thus the following error message popped up.

it is done because the matrix is square and the power is a scalar quatity , for scalar multiplicaation/division dot product is necessary.

Thus we put the dot and after putting the dot the function got defined and it is called in the main program and the program got executed.

• Forgot to put END command at the last of the main program which resulted in the popping of the following message.

After putting END command the program got executed

RESULT

The molecular weight of o2 = 32

molecular weight of Co2 = 44

molecular weight of N2 = 28

The rest of the molecular weights are displayed on the command window

CONCLUSION

The program to parse the NASA Thermodynamic data and to calculate the molecular weight of the species present inside the data and also to display it in the command window is successfully carried out and the results are noted down along with the plots.

REFERENCES

MATHWORKS, Google, Wikipedia,