Thermo of flow processes

Question 1

Define a polytropic process

Answer 1

PVT are changing

=>Break process into steps - enthalpy function of state Ht=Ha+Hb
=> A can be calculated isothermally, B calculated isobarically

Question 2

Turbine/expanders

Answer 2

W= deltaH

isentropic (s=0)

Question 3

Throttling

Answer 3

Produces no work => Delta H=0

• Fluid moves through restriction (e.g. orifice) - result is pressure drop => Ek at inlet = Ek at outlet, Ep changes neglected

Question 4

Diffuser/ Nozzle

Answer 4

delta H= -Ek