Let's suppose I have a gravity-fed stream of a non-compressible fluid. A vertical pipeline from the bottom of a tank, with a valve inside (controlled to get constant flow), and then after a while (half meter?) i have the ending of the pipe.
Imagine now that i may have some troubles of coherence of the free-flow after the lower end of the pipe: instead of having the flow in the shape of a perfect, laminar trumpet (starting diam equal to the pipe internal diam, then shrinking parabolically), i have formation of droplets out of the main stream.
Question 1) Would I improve the coherence of the flow if i make the ending of the pipe with an angled cut (e.g. 45dgr), rather than a plain, 90dgr. pipe ending? Why? Would this result in a deflection of the free-fall stream direction?
Question 2) What if, from the valve to the open end of my pipe, the internal diameter of the line is tapered rather than cylindrical? (I mean with diameter decreasing towards the end, therefore the angled 45dgr cut being done in a conical pipe, which reduces its diam in the direction of the gravity-fed flow)
In my country we call a 45dgr cut as the "salami cut" so, google will not help me much, other than suggesting me how to fill my next sandwich... I know it's a easy technique to silent any compressible-fluid outlet line, or to improve open-air flow of water, but i lack some analytical explanation about.
Thanks so much for any hint and/or reference to literature
Regards
EF