This chapter is under heavy construction.
Please ignore. If you want to contribute and add any results of
experiments, to this chapter, please do so.
You can help especially if you have photos showing these effects.
In the previous chapters a simple model describing the flow in nozzle
was explained.
In cases where more refined calculations have to carried the gravity
or other forces have to be taken into account.
Flow in a vertical or horizontal nozzle are different because the
gravity.
The simplified models that suggests them-self are: friction and
adiabatic, isothermal, seem the most applicable.
These models can served as limiting cases for more realistic flow.
The effects of the gravity of the nozzle flow in two models
isentropic and isothermal is analyzed here.
The isothermal nozzle model is suitable in cases where the flow
is relatively slow (small Eckert numbers)
while as the isentropic model is more suitable for large Eckert
numbers.
The two models produces slightly different equations.
The equations results in slightly different conditions for the
chocking and different chocking speed.
Moreover, the working equations are also different
and this author isn't aware of material in the literature which
provides any working table for the gravity effect.
