Hi
On what you term the first question, you are correct but it is generally not necessary to delve into the tensors of Reynolds and normal stresses when control volumes are considered. I am quite familiar with the dissipation term in the differential energy equation, actually spent quite a while...
Chestermiller,
forgot to add the problem I am looking at has 300 to 8000W of viscous heating, hence hard to ignore it.
Microchannels with high speed flows.
Thanks, the above was close to my thinking also but could not find a textbook that explains it in detail. I will look up the one that you suggested. I am also not sure what you propose is fully correct.
My thoughts are that the Enthalpy in must equal Enthalpy out based on steady flow energy...
Thanks for answer, but nothing to do with question. You do not have to solve the Navier Stokes equation for this, there are plenty of correlations for pressure drops across all types of throttles including channels that are reasonable.
The Bernoulli equation has nothing to do with this, it is...
Some great answer by Q_Goest, if still online can you explain the following. Has me a bit stumpted.
For flow of an ideal gas across a throttle the enthalpy is constant and hence since enthalpy, Cp(DT), is constant there can be no temperature change across a throttle for a gas flow.
However...