Lecture 2 Flashcards
What is the definition of enthalpy (h) and specify units
Enthalpy is an energy-like property or state. It has the dimensions of energy (and is thus measured in units of joules or ergs), and its value is determined by the systems properties. Measured in J or J/kg.
H= U + pV
h=U+pv
Give the first law of thermodynamics for open system, steady state and constant mass
flow rate.
Energy can be transformed from one form to another, but can
be neither created nor destroyed.
For closed system the only ways the energy of a closed system can be changed are through transfer of energy by work or by heat
Enter an equation for calculating work of an open system (PE and KE can be neglected) and explain what it is.
W= Wyc + Wcv. Wyc is the flow work, the work done by the different flows through the boundaries, such as mass and energy. Wcv are all the other work effects inside the CV, such as electrical, displacement of the boundary etc.
