is turbulence good or bad?

chewyboy · 12-31-2002, 02:49 PM

OK, I’ve been reading a lot of people doing things to cause different types of turbulence inside their waterblocks. This is a bit confusing to me for a couple different reasons. First I kayak and from time to time do work on customizing engine intake manifolds and knowing what eddies do on a river i can not see any type of turbulence inside a waterblock as anything good, your now thinking what do engine manifolds have to do with any of this. Well with turbulence inside the manifold we have a special dye that shows where the turbulence and eddies are inside there. This leaves a dyed mark on the inside of the manifold and helps us figure out what we need to do to get greater flow. Secondly with turbulence you will get those eddies and have well settling coolant isn't ever a good idea. Anyway i always thought that more was better and with turbulence you don’t get more, you get stagnant

LiquidRulez · 12-31-2002, 11:09 PM

Ok. While Im no expert in this arena, Im going to give it a shot.
While flow rate in a waterblock is important, turbulance is of more importance.Without turbulance, the flow becomes laminar nearly as soon as it enters the block.
Which (as far as I know) creates a very large boundary layer where the water touching the surface area of the block doesnt move and creates a boundary in between the two elements, and traps the heat resulting in higher core temps becuase heat is not being carried away with the flowing water because of the boundary layer acting as an insulator.
I dont think that water flow that has velocity and turbulance in a waterblock will have any problems with stagnant water, as apposed to one with plenty of flow but flow that is laminar becuase of lack of turbulance.
.......If I make a block that has a 1/2" channel with no sort of design to introduce alot of turbulance throughout,using a pump that pumps 5 gallons per minute through it, I guarentee that a block with 2--- 1/8th " channels that are well turbulated with only 3 gallons per minute flowing through it will win out everytime.
THIS IS JUST MY UNEDUCATED OPINION KEEP IN MIND.

bigben2k · 01-02-2003, 09:22 AM

http://www.overclockers.com/articles511/

gmat · 01-02-2003, 10:13 AM

As for the engine manifold, its purpose is not the same. There you want as much air as you can to go through in a given time frame, and yes turbulence is not good for that application.
The purpose of a waterblock is to transfer as much heat as possible in a given time frame. Refer to laminar vs tubulent article posted above.

chewyboy · 01-02-2003, 01:37 PM

bigben2k, thanks for that link I would have thought the complete opposite about turbulence. Anyway I’m curious about one more thing, if turbulence is wanted in one form or another with blocks like cothars wouldn't he want to do something like this between his "fins" that are in there? Note the following picture is way exaggerated.

bigben2k · 01-02-2003, 01:40 PM

Possibly, but the block had already reached the limits of what CNC machining can do.

Alternatively, one could drill the bottom of the channels (opposite of pic).

chewyboy · 01-02-2003, 02:31 PM

Limits of milling? I don’t mean to question that but are you sure you are looking at my picture the way I thought it out. That picture would be perpendicular to his fins. this could be done fairly easy with a cnc as I’ve done it before, you just have to program your gcode correctly. So basically those would be inbetween the current fins he has.

bigben2k · 01-02-2003, 02:35 PM

Yes.

The channels are a result of a 1.0 mm endmill pass, so the bottom is (mostly) flat.

In order for the bottom NOT to be flat, the endmill would have to have a point (like a drill bit).

To get what you propose, the channels would have to be cut using sawblades, with the cone shape built into the sawblade.

chewyboy · 01-02-2003, 02:46 PM

yeah they are called center cutting bits, i use em all the time. so why can't this be done again?

bigben2k · 01-02-2003, 02:54 PM

Oh, that's a sideways shot! I thought it was a cross-section....

Yes, certainly it can be done. I'm planning on doing the same to Radius: a 1.0 mm drill bit dropped into the channel, every 2 mm.

chewyboy · 01-02-2003, 02:55 PM

hehe cool another design to impliment when i do mine

thx again for the help guys

12-31-2002, 02:49 PM	#1
chewyboy Cooling Neophyte Join Date: Dec 2002 Location: us Posts: 75	is turbulence good or bad? OK, I’ve been reading a lot of people doing things to cause different types of turbulence inside their waterblocks. This is a bit confusing to me for a couple different reasons. First I kayak and from time to time do work on customizing engine intake manifolds and knowing what eddies do on a river i can not see any type of turbulence inside a waterblock as anything good, your now thinking what do engine manifolds have to do with any of this. Well with turbulence inside the manifold we have a special dye that shows where the turbulence and eddies are inside there. This leaves a dyed mark on the inside of the manifold and helps us figure out what we need to do to get greater flow. Secondly with turbulence you will get those eddies and have well settling coolant isn't ever a good idea. Anyway i always thought that more was better and with turbulence you don’t get more, you get stagnant

01-02-2003, 09:22 AM	#3
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,301	http://www.overclockers.com/articles511/ __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

01-02-2003, 01:40 PM	#6
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,301	Possibly, but the block had already reached the limits of what CNC machining can do. Alternatively, one could drill the bottom of the channels (opposite of pic). __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

01-02-2003, 02:35 PM	#8
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,301	Yes. The channels are a result of a 1.0 mm endmill pass, so the bottom is (mostly) flat. In order for the bottom NOT to be flat, the endmill would have to have a point (like a drill bit). To get what you propose, the channels would have to be cut using sawblades, with the cone shape built into the sawblade. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

01-02-2003, 02:54 PM	#10
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,301	Oh, that's a sideways shot! I thought it was a cross-section.... Yes, certainly it can be done. I'm planning on doing the same to Radius: a 1.0 mm drill bit dropped into the channel, every 2 mm. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

12-31-2002, 11:09 PM	#2
LiquidRulez Cooling Savant Join Date: Sep 2002 Location: In Hell Posts: 322	Ok. While Im no expert in this arena, Im going to give it a shot. While flow rate in a waterblock is important, turbulance is of more importance.Without turbulance, the flow becomes laminar nearly as soon as it enters the block. Which (as far as I know) creates a very large boundary layer where the water touching the surface area of the block doesnt move and creates a boundary in between the two elements, and traps the heat resulting in higher core temps becuase heat is not being carried away with the flowing water because of the boundary layer acting as an insulator. I dont think that water flow that has velocity and turbulance in a waterblock will have any problems with stagnant water, as apposed to one with plenty of flow but flow that is laminar becuase of lack of turbulance. .......If I make a block that has a 1/2" channel with no sort of design to introduce alot of turbulance throughout,using a pump that pumps 5 gallons per minute through it, I guarentee that a block with 2--- 1/8th " channels that are well turbulated with only 3 gallons per minute flowing through it will win out everytime. THIS IS JUST MY UNEDUCATED OPINION KEEP IN MIND.

01-02-2003, 10:13 AM	#4
gmat Thermophile Join Date: Mar 2001 Location: France Posts: 1,221	As for the engine manifold, its purpose is not the same. There you want as much air as you can to go through in a given time frame, and yes turbulence is not good for that application. The purpose of a waterblock is to transfer as much heat as possible in a given time frame. Refer to laminar vs tubulent article posted above.

01-02-2003, 02:31 PM	#7
chewyboy Cooling Neophyte Join Date: Dec 2002 Location: us Posts: 75	Limits of milling? I don’t mean to question that but are you sure you are looking at my picture the way I thought it out. That picture would be perpendicular to his fins. this could be done fairly easy with a cnc as I’ve done it before, you just have to program your gcode correctly. So basically those would be inbetween the current fins he has.

01-02-2003, 02:46 PM	#9
chewyboy Cooling Neophyte Join Date: Dec 2002 Location: us Posts: 75	yeah they are called center cutting bits, i use em all the time. so why can't this be done again?

01-02-2003, 02:55 PM	#11
chewyboy Cooling Neophyte Join Date: Dec 2002 Location: us Posts: 75	hehe cool another design to impliment when i do mine thx again for the help guys

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