# What is (Subject: Thermodynamics)

1. Sep 22, 2008

### dcs23

What is the interpretation of enthalpy in an isothermic system?

I ask as I am trying to understand what $$\int p d\left(\frac{1}{\rho}\right)$$ means in the context of a Lagrangian fluid.

2. Sep 22, 2008

### Mapes

Enthalpy is the total energy in the system, plus the work required to move the surrounding environment out of the way: H=U+PV.