What physics study path would help me answer my own hydraulics question?

[pvshackguy]

TL;DR

What physics study path would help me answer my own hydraulics question?

I have a water pipe in an exposed location that is allowed to drain when not in use. The vertical drop between the top and bottom of the pipe is fixed, as is the horizontal distance between the ends.

If the pipe does not drain properly after use, it will freeze and burst in winter, so any downwards dip along the run of the pipe is unacceptable.

I am wondering whether, for quick and reasonably complete drainage, a linear slope or a curved path would be optimal. However I'd prefer not to be handed the answer.

What I'd really like to know is what course of study would be needed, for a well-aged gent who took Canadian high school physics late in life by correspondence (quaint?) to know enough to answer this question for myself.

 

[.Scott]

Here are the "concepts of concern".
A thin coating of water will not readily flow, so you are looking for either a very thin coat that will readily evaporate or "beading" to form clumps of water that will descend the slope.
You're going to be dealing with surface tension and hydrophilic/hydrophobic surfaces. Of course, gravity is the main mover, but you have likely mastered that part.

When I ask Google AI "What college courses deal with surface tension and hydrophilic surfaces?", it responds with:

College courses covering surface tension and hydrophilic surfaces often focus on material science, fluid mechanics, and physical chemistry, focusing on wetting, capillary action, and surface energy. Key courses include Surface Chemistry, Advanced Fluid Mechanics, Materials Science, and Biomedical Engineering, where topics like capillary behavior, surfactant function, and contact angles are studied.

 

[pvshackguy]

So, an afternoon's casual read I take it.
Cheers, much appreciated.

 

[gmax137]

For practical problems such as this, I would recommend you look at fluid flow textbook for mechanical engineers.
EDIT: do a search on 'fluid flow pdf' to find a bunch of class notes. Scan thru them till you find one you like.


An alternative would be Crane 410, a completely practical guide. "Flow of Fluids Through Valves, Fittings, and Pipe (Technical Paper No. 410)"

Wow, scratch that, I just looked on Amazon and used copies are $120 and up. I paid $8 for mine, direct from Crane valve company (in 1987, lol). If you are near an engineering school you might find a copy in a used bookstore.

Sorry for that diversion. Your particular pipe:
is it open at both ends?
diameter?
length?

 

[kuruman]

I assume that the pipe is supposed to drain under gravity. Based on the idea that the less time the water spends in the pipe the less likely it is to freeze, I would recommend researching the brachistochrone which literally means "shortest time" in Greek. Of particular interest is that a ball released at the top of a brachistochrone track will take the same time to reach the bottom as a ball released at any point in between.

The web has lots of videos, simulations, the math background and suggestions on how to draw and construct one. Should you choose to go that route, I will be curious to hear how it played out.