Futuristic Right Angle Radiator

Mohonri said:
There will be some amount of pressure drop through any length of pipe, no matter the size. Granted, the larger the pipe, the lower the pressure drop. It's a not-so simple equation that takes into account the viscosity of the fluid, the diameter of the pipe, the smoothness of the pipe (Reynolds number), and the flow rate, among other things. A quick google shows me that an elbow produces the same pressure drop as a piece of straight pip with length = 30 * inside diameter. That means that (assuming the piping is all 1/2") each elbow is the equivalent of 15 inches of copper pipe. That gives a total of 7500ish inches of 1/2" pipe, or 625 feet.

A reference indicates that at 1gpm flow, such a system would give you .01psi pressure loss per foot. So 625*.01 = 6.25 PSI or about 14 feet of head. I don't know how much pressure a typical WC pump gives.
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The relationship between the pressure drop of an elbow is nothing as nice as you describe it. It is going to be highly related to the inductance of the water in the pipe. In this case it will be small due to the low velocity and turbulent flow, so the preasure loss in the elbows won't be that much. The picture also showed the elbows about twice as large as the lines running to it, so you can expect the velocity to be roughly 1/4th of that of the input lines.

Also, the link you refrence to is for 1/2" copper pipe elbows, they really look more like 3/4 or 1" (assuming it is a 1/2" feed line) and extrapolating from the table, your looking at .00045psi/ft or only 0.5psi head loss. Again though, I'm pretty sure your mentioned link on elbows is for residental lines which run 50-100PSI at much higher inductances (higher velocity or flow rate and very laminar flow.)

If that's 1" pipe corners, there won't be any problems, if it is 1/16" pipes there will be a major problem. The head loss is going to be porportional to something like the cube or the 4th power of the diamater of that pipe, all else being constant. So just doubling the size of the angles used is going to drastically change the loss.

Does it say anywhere what size those pipes are?
 
You obviously know a lot more about fluid dynamics than I do (though I don't know much). I thought I had put a disclaimer about my lack of knowledge, but must have deleted it while I was revising my comment.

Yeah, if the diameter of the tubing is 3/4" or 1", then the head loss will be a lot less since the velocity will be much lower. I've never heard the term "inductance" used in reference to fluid flow, only in reference to electricity (I'm an EE, not a chemical or mechanical engineer, so this is out of my field of expertise).
 
I think the pictures are actually computer generated. They look like 1/2 inch elbows, but the inside edge of the bend does not quite look shallow enough to be a real elbow. The only reference point we have for scale is the hoses, which are probably 1/2 inch hoses, since 3/4 inch hoses like that are not your common household hose.

Either way, if one were to build this as a water cooling radiator, you would need to use 1/2 inch elbows anyway to get a good surface area to volume ratio. (And to make the size reasonable).
 
Mohonri said:
You obviously know a lot more about fluid dynamics than I do (though I don't know much). I thought I had put a disclaimer about my lack of knowledge, but must have deleted it while I was revising my comment.

Yeah, if the diameter of the tubing is 3/4" or 1", then the head loss will be a lot less since the velocity will be much lower. I've never heard the term "inductance" used in reference to fluid flow, only in reference to electricity (I'm an EE, not a chemical or mechanical engineer, so this is out of my field of expertise).
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I wasn't trying to call you out as being a fake expert or anything, by no means. Please dont' take it that way.

I am a ME and lots of systems are second order differntial equations. Incompressible fluid flow can be represented fairly well in this mannor. If you want to call the diffrent terms resistors, capacitors, and inductors, or if you want to call them springs, masses, dampers it really makes no diffrence the mathamatics are the same. There are a lot of schools that get Civil students through thier EE classes by telling them electricity is like water flowing through a pipe, and conversly some EE students get through they're fluids class by being told water is just electricity.

Inductance is the inertia of the water in the pipe.
Capacitacance is the pressure,
Resistance is of course friction with the wall or flow through an orifice.

You'll hear those terms used more often when talking about fluid power (hydralics pumps/actuators/etc) than with commerical water lines though for sure. Mostly because no one cares if the pressure at the end of the pipe is 50 psi or 100 psi in your home, but that would be a much different story in a hydralic system.
 
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