1. Balance equationsΒΆ
In thermodynamics, fundamental principles have been ennounced for a mass M representing a closed system. Closed thermodynamics systems are usefull for a given number of applications. This is the case for all piston/cylinder systems that are separating a given mass of fluid and applying to it different transformations (heating, compression, expansion). This is typically the case for piston compressors used in refrigerators or for reciprocal internal combustion engines of cars. Reversely, when a system is crossed continuously by a fluid, principles should be ennounced for an open system as it is the case for example in nozzles, gas turbines, heat exchangers, pumps, etc. In that case, we should obtain balance equations for a control volume as it was been done in fluid mechanics course.
The aim of this section is to recall principles of thermodynamics for a control volume crossed by a fluid. We talk about Balance equations.