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i was thinkin about petars wb designs.

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Lt. Max

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Jan 28, 2002
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Seattle, but im Estonian
he does cross drilled holes in the blocks so the water doesnt have a defined path through the block. how is that good? or is it just an easy way to make a block?
 

KingB

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Jan 29, 2002
Location
Calgary, Alberta
Lt. Max said:
he does cross drilled holes in the blocks so the water doesnt have a defined path through the block. how is that good? or is it just an easy way to make a block?

This got me thinking too. It must be that it is an easy way to build the block.

I would think that the water would take the path of least resistance, therefore more water would flow down a one channel over another. This, in my mind, would cool one section of the block better than another. Correct? This isn't good is it?
 

racecar12

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Feb 6, 2002
Location
mid-tn
Re: Re: i was thinkin about petars wb designs.

KingB said:


I would think that the water would take the path of least resistance, therefore more water would flow down a one channel over another. This, in my mind, would cool one section of the block better than another. Correct? This isn't good is it?
The water will flow properly through all channels and not take a least path of resistance, such as water flowing in nature, because the water is being forced through the w/b with the waterpump.

Crossdrilling to create a w/b is normally because they don't have a milling machine.
 

KingB

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Calgary, Alberta
I remember building a water pond back when I use to do landscaping for a summer job. We built a water fall with 4 different waterfall points (basically it was 4 water spouts running in a parallel closed sytem with one pump running it). There was a distinct difference in flow rates to the 4 spouts (with the closest spout having alot of flow, while the furthest spout barely had any). We ended up installing two pumps running in separate systems to even the flow to all spouts. Why would this be different? Comment would be appreciated.

Edit: I am not saying water wouldn't flow in all channels, I'm saying each channel will experience a different amount of flow as each channel loop is a different length.
 

racecar12

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mid-tn
KingB said:
I remember building a water pond back when I use to do landscaping for a summer job. We built a water fall with 4 different waterfall points (basically it was 4 water spouts running in a parallel closed sytem with one pump running it). There was a distinct difference in flow rates to the 4 spouts (with the closest spout having alot of flow, while the furthest spout barely had any). We ended up installing two pumps running in separate systems to even the flow to all spouts. Why would this be different? Comment would be appreciated.

Edit: I am not saying water wouldn't flow in all channels, I'm saying each channel will experience a different amount of flow as each channel loop is a different length.
That would be due to the head preassure of the waterpump. The higher the water has to lift upward the less flow it will have. IE: A 250 gal/hr pump rated at 4' lift will be a 210gal/hr at a 5' lift.

edit also> You may have been able to do that pond with one pump if you set up the main lifting waterline line at 1" with 4 T junctions starting with a 3/8" T to a 1/2"T to 5/8".....3/4" to offset the loss of flow rate during lift.
 
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KingB

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Calgary, Alberta
Yeah, I get the headloss component of the waterfall example. That still doesn't compute in my mind the difference in channel loop lengths. I would think to get even flow, each loop would have to occupy an equal volume (As of now they don't). This would mean cross drilling diffent diameter holes.

Does this make any sense or am I out to lunch?
 

racecar12

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mid-tn
KingB said:
Yeah, I get the headloss component of the waterfall example. That still doesn't compute in my mind the difference in channel loop lengths. I would think to get even flow, each loop would have to occupy an equal volume (As of now they don't). This would mean cross drilling diffent diameter holes.

Does this make any sense or am I out to lunch?
You are not having to deal with the head preassure loss when the lift is 1" so each passage will be really close in flow rate.
 

Aesik

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Jan 6, 2002
Actually, the difference will not be negligible depending on the design. There is no head loss due to height changes, but there are significant head losses due to longer channel lengths and especially due to 90 degree corners or other turns. It all depends on the design of the block.

Most crossed drilled blocks I've seen will have significantly different flow rates through the channels. I have seen a few that are pretty well balanced though.
 

KingB

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Calgary, Alberta
See that's what I thought. Will this adversely affect cooling or is there a method to evenly distribute flow. IE: different diameter crossdrilled holes.

I am asking because I was thinking of making my own block. This method look easiest to do.


(I new I didn't forget everything from my fluid dynamics course from 10 years ago. I am a structural engineer now so all the mechnical stuff is long forgotten. althought this new addiction is bringing alot of this knowledge back)
 

racecar12

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mid-tn
Aesik said:
There is no head loss due to height changes, but there are significant head losses due to longer channel lengths and especially due to 90 degree corners or other turns. It all depends on the design of the block.
Sorry, but I don't think that is right my friend. First of all, you do get a head preassure loss with height(or how the high the water has to make a vertical climb from the pump). And second, the loss of waterflow due to 90 degree turns or maybe a cross-drilled w/b, is caused by back preassure(restriction).

It is the restriction inside the cross-drilled block that causes the proper flow.
 

Aesik

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Jan 6, 2002
Sorry, I wrote that post wrong and you mis-read it. What I was saying is that there is little to no head loss due to height in a wb itself. There is certainly head loss in any system where there is a height differential. My bad in my previous posts wording.

"And second, the loss of waterflow due to 90 degree turns or maybe a cross-drilled w/b, is caused by back preassure(restriction). "

I'm not sure what you are trying to say here. Any loss in pressure, thus causing a reduction in flow, is termed 'head loss.'

"It is the restriction inside the cross-drilled block that causes the proper flow."

Restriction in a cross-drilled block *could* cause proper flow, but it could also cause improper flow. It all depends on the design. For fairly simple geometries it's quite easy to calculate the head loss and flow rate for every possible flow path. Armed with such knowledge, a person could easily design a cross drilled block that would have the desired flow profile.
 

racecar12

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mid-tn
Aesik said:
. Armed with such knowledge, a person could easily design a cross drilled block that would have the desired flow profile.
Correct on the head loss:D
But not only to have the knowledge but to have the tools.:cool:
 

Aesik

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Jan 6, 2002
Heh! I like how you keep track of your chuck key. I'll have to start doing that so I quit losing mine.
 

Diggrr

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Nov 29, 2001
I'd think that example 'B' would have more even flow than example 'A'. Being that the water would follow the path of least resistence, pumping the water to opposite corners like so would help to even out the flow rates between the small diameter paths. I would also believe that to increase flow in the central path (across the core) the centermost channels could be made with a larger bit than the others...say 3/8" for the main ones, 1/4" for the two central ones and 1/8" for the four outermost ones.

Just my $.02
 
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