399 
where oA is the molar entropy at unit pressure of the i-th constituent. 
With the equation of state 2.8, we obtain, 
BO g 3x Bx 
SU, 7) Po = WR | bog + ale -1)- wxe | (2.13) 
which can be employed for the determination of the entropy of the adia- 
batic constant volume explosion state and which then suffices for the 
construction of the adiabatic P= Per) if the composition of the ex- 
plosion products is known along the adiabatic expansion curve. In the 
construction of thiscurve, it is convenient to employ the temperature as 
the independent variable and to determine, 
p= p (TS) 
ie a (2.14) 
P 5 Pp ie Py) : 
The function @g# (p) canbe calculated by numerical methods from a tabular 
presentation of relatims 2,14. 
* Ms OK 
In the calculation of Pe > } (2, , and the construction of the 
curve ps physse ) it is necessary at each stage of the computations 
to know the composition of the fluid composed of the explosion products, 
The calculations are carried out iteratively. The state (T, p) is deter- 
mined by the appropriate relation for an approximate composition. The com- 
position (n; ) is then calculated for this state by standard thermodynamic 
methods, This composition is then employed in the determination of a 
second approximation of the state, and the process is continued to con- 
vergence. 
The composition is determined by solving the requisite 
numher of equations expressing the conservation of each kind of element 
13 
