Entropy when one uses JWL EOS
 

Entropy is usually given as S=P/rho**gamma when one uses the ideal-gas law family.

However, when one uses different forms of EOS like the Gruneisen or JWL EOS, one does not have such a gamma.

Please teach me how to find the entropy if I do use the JWL equation.

It is to be used in the construction of a limiter and in the ghost fluid method(GFM).