Design verification... Need your help folks!

MMZ_TimeLord · 09-18-2003, 02:25 AM

Okay... for Ben2k, Cathar, Jaydee and many others who have WAY more knowledge about this stuff than I do.

Below is the design. It shows 3 sizes of copper tube to use for the jets. The drawing shows the largest (1/8") used. This gives 30 jets and a flow area roughly 3 times that of the inlet tube.

Will this be okay? or should I use a smaller jet tube size and get more of them in there?

This is mainly just a test of the general design to go with my radiator that's on order. I want to change the block first, then the radiator and compare.

Thanks in advance everyone!

Cathar · 09-18-2003, 06:54 AM

Hmmm, I never experimented with tubes much more than half as big as the smallest you show in your diagram. I could speculate for you, but someone like leejsmith might be better able to help since I believe he directly experimented with jets as large as you're contemplating.

trit187 · 09-18-2003, 07:15 AM

wen't there issues with base being flat where the the inlet tubes are? you'd have to look in the past discussions but they had some great modles showing the flow difference depending on the cup shape, might be something to look back on

MMZ_TimeLord · 09-18-2003, 08:44 AM

trit187,

Yeah, I went through that ENTIRE thread and it was determined from the flow simulations that the square bottomed hole was indeed the best. It created the MOST turbulance.

Cathar,

Thanks for the reply. I'm just concerned that the effect won't be as pronounced as the flow through all of the jets combined is roughly 3 times that of the inlet tube. Will probably make for great flow but what will happen to my turbluance? Will it be more or less pronounced.

We may just have to see... :shrug:

winewood · 09-18-2003, 09:04 AM

I would like to see this thing milled out and tried! Please tell us what kind of flow rate etc. I bet that design will require a pretty high flow with those bigger tubes. Were you attempting to get a TEC cooling block?

MMZ_TimeLord · 09-18-2003, 09:33 AM

Winewood,

No TEC for me... (oooooo ... a rhyme!

)

I have a P4 (yeah, yeah... I know

) and that is what the jet arrangement is designed to cover... completely.

1.5 inches on a side for the area it covers. This is to allow for block placement in the retention mechanism. The drawing has no measurements on it other than the tube size, so it's almost double or more the size of the real thing.

bigben2k · 09-18-2003, 10:54 AM

You're on the right track, but it still needs a little more tweaking.

#1-Use smaller jet tubes

#2-Flow area is irrelevant. Flow restriction is. You need to keep the jet tube OD to less than half of the diameter of the dimple.

Build it, then try it at different height.

Too bad for the TEC: this thing would be perfect for it, as is.

MMZ_TimeLord · 09-18-2003, 11:22 AM

BigBen2k,

On #1: The next jet size down, with an ID of 3/32" and OD of 1/8", that I have in the drawing would yield 72 jets packed in that space with a hole size of 5/32"... again the flow area of the ID on the combined jets is going to be even more than three times that of the ID of the inlet tube. This would yield a larger surface area within the holes to transfer heat and create turbulance.

On #2: I thought that's what I had done... the ID of the jets in the above design are 1/8" which means the OD is 5/32".

Is that not enough of a difference? Do I need to make the dimples smaller diameter for this jet size?

I'm thinking I may just build this first version as-is and then have it as a benchmark reference. :shrug:

bigben2k · 09-18-2003, 01:29 PM

5/32" is more than half of 1/4.

Go ahead and build it. Then tweak it for optimal jet tube heights, and carry it to your next revision, with smaller tubes.

MMZ_TimeLord · 09-18-2003, 02:25 PM

DOH!

Missed that "HALF" part... my bad.

Yeah... I'm gonna start on it today and see how it works.

Thanks to everyone for your help.

Cathar · 09-18-2003, 06:19 PM

Quote:

Originally posted by bigben2k
#2-Flow area is irrelevant. Flow restriction is. You need to keep the jet tube OD to less than half of the diameter of the dimple.

Hmmm, not quite.

A = ðr²

You can have the OD of the jet tube be as large as the orifice area of the cup - the OD of the jet tube being equal to the orifice area of the inner diameter of the jet tube

So if the cup was 6.35mm OD (1/4") and the jet tube had a 3.175mm ID (1/8"), then the OD of the tube tube may be as large as:

3.175² - x² = 1.5875²

x = 2.75

Now x is the radius, so the OD of the jet tube may be as large as 5.5mm, (or ~7/32" converting everything back to imperial)

bigben2k · 09-18-2003, 08:19 PM

Yeah, that's a basic area comparison, but for flow, it's going to behave differently.

Check out www.lmnoeng.com and look up the calculation for this type of flow. Oh heck... (searching)

Here's a link to it:
http://www.lmnoeng.com/PipeDuct.htm

As Dave pointed out, there's a point where the opening is so narrow, that it doesn't matter how far it extends.

09-18-2003, 08:44 AM	#4
MMZ_TimeLord Cooling Savant Join Date: Apr 2003 Location: San Mateo, CA, USA, Earth Posts: 433	trit187, Yeah, I went through that ENTIRE thread and it was determined from the flow simulations that the square bottomed hole was indeed the best. It created the MOST turbulance. Cathar, Thanks for the reply. I'm just concerned that the effect won't be as pronounced as the flow through all of the jets combined is roughly 3 times that of the inlet tube. Will probably make for great flow but what will happen to my turbluance? Will it be more or less pronounced. We may just have to see... :shrug: __________________ MMZ>TimeLord "Oooooooooh... that's gonna leave a mark!"

09-18-2003, 09:04 AM	#5
winewood Cooling Savant Join Date: Nov 2002 Location: in my chair Posts: 574	I would like to see this thing milled out and tried! Please tell us what kind of flow rate etc. I bet that design will require a pretty high flow with those bigger tubes. Were you attempting to get a TEC cooling block? __________________ -winewood-

09-18-2003, 09:33 AM	#6
MMZ_TimeLord Cooling Savant Join Date: Apr 2003 Location: San Mateo, CA, USA, Earth Posts: 433	Winewood, No TEC for me... (oooooo ... a rhyme! ) I have a P4 (yeah, yeah... I know ) and that is what the jet arrangement is designed to cover... completely. 1.5 inches on a side for the area it covers. This is to allow for block placement in the retention mechanism. The drawing has no measurements on it other than the tube size, so it's almost double or more the size of the real thing. __________________ MMZ>TimeLord "Oooooooooh... that's gonna leave a mark!"

09-18-2003, 10:54 AM	#7
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	You're on the right track, but it still needs a little more tweaking. #1-Use smaller jet tubes #2-Flow area is irrelevant. Flow restriction is. You need to keep the jet tube OD to less than half of the diameter of the dimple. Build it, then try it at different height. Too bad for the TEC: this thing would be perfect for it, as is. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

09-18-2003, 11:22 AM	#8
MMZ_TimeLord Cooling Savant Join Date: Apr 2003 Location: San Mateo, CA, USA, Earth Posts: 433	BigBen2k, On #1: The next jet size down, with an ID of 3/32" and OD of 1/8", that I have in the drawing would yield 72 jets packed in that space with a hole size of 5/32"... again the flow area of the ID on the combined jets is going to be even more than three times that of the ID of the inlet tube. This would yield a larger surface area within the holes to transfer heat and create turbulance. On #2: I thought that's what I had done... the ID of the jets in the above design are 1/8" which means the OD is 5/32". Is that not enough of a difference? Do I need to make the dimples smaller diameter for this jet size? I'm thinking I may just build this first version as-is and then have it as a benchmark reference. :shrug: __________________ MMZ>TimeLord "Oooooooooh... that's gonna leave a mark!"

09-18-2003, 02:25 AM	#1
MMZ_TimeLord Cooling Savant Join Date: Apr 2003 Location: San Mateo, CA, USA, Earth Posts: 433	Design verification... Need your help folks! Okay... for Ben2k, Cathar, Jaydee and many others who have WAY more knowledge about this stuff than I do. Below is the design. It shows 3 sizes of copper tube to use for the jets. The drawing shows the largest (1/8") used. This gives 30 jets and a flow area roughly 3 times that of the inlet tube. Will this be okay? or should I use a smaller jet tube size and get more of them in there? This is mainly just a test of the general design to go with my radiator that's on order. I want to change the block first, then the radiator and compare. Thanks in advance everyone! __________________ MMZ>TimeLord "Oooooooooh... that's gonna leave a mark!"

09-18-2003, 06:54 AM	#2
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	Hmmm, I never experimented with tubes much more than half as big as the smallest you show in your diagram. I could speculate for you, but someone like leejsmith might be better able to help since I believe he directly experimented with jets as large as you're contemplating.

09-18-2003, 07:15 AM	#3
trit187 Cooling Savant Join Date: May 2003 Location: shanghai, china Posts: 200	wen't there issues with base being flat where the the inlet tubes are? you'd have to look in the past discussions but they had some great modles showing the flow difference depending on the cup shape, might be something to look back on

09-18-2003, 01:29 PM	#9
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	5/32" is more than half of 1/4. Go ahead and build it. Then tweak it for optimal jet tube heights, and carry it to your next revision, with smaller tubes. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

09-18-2003, 02:25 PM	#10
MMZ_TimeLord Cooling Savant Join Date: Apr 2003 Location: San Mateo, CA, USA, Earth Posts: 433	DOH! Missed that "HALF" part... my bad. Yeah... I'm gonna start on it today and see how it works. Thanks to everyone for your help. __________________ MMZ>TimeLord "Oooooooooh... that's gonna leave a mark!"

09-18-2003, 08:19 PM	#12
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	Yeah, that's a basic area comparison, but for flow, it's going to behave differently. Check out www.lmnoeng.com and look up the calculation for this type of flow. Oh heck... (searching) Here's a link to it: http://www.lmnoeng.com/PipeDuct.htm As Dave pointed out, there's a point where the opening is so narrow, that it doesn't matter how far it extends. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

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