I need your opinion for this thought:)

hello everyone!I read the hole article about the flow rate and i found it very intersting.I combined your ideas and came up with a new one.I can't say if it works so i need your help How about using a 1/2" ID tube to connect the w/b with the pump and the radiator and a 2/3" ID tubing to connect the pump,the radiator and the reservoir?
system: pump - w/b - radiator - reservoir - pump

Think about it.(smaller ID more speed, larger ID reduced speed)

Hmm I don't think I have ever seen 2/3" barbs, or 2/3" ID tubing.

Going 100% over 1/2" would be kinda insane but for this short part it could work.

My pump & rad have both over 1/2", so maybe I'll try the same - so THX for idea.

PS
Don't use >1/2" inside comp, it's rather for external solutions as so big tubes won't bend nice in so small place like comp case.

cycle would be better if it was:
pump -> radiator -> block(s) -> reservoir -> pump

(pump produces heat too)

Thank you all! The thought was to use larger ID tubing for the connection of the pump radiator and the reservoir because in this way the water goes faster in the waterblock and slower at the radiator.So it stays more time in the radiator.What is your opinion of that?
As for you venom its better to have the pump before the w/b because the water has more speed.Or i may be wrong

apomak88 said:

The thought was to use larger ID tubing for the connection of the pump radiator and the reservoir because in this way the water goes faster in the waterblock and slower at the radiator.So it stays more time in the radiator.What is your opinion of that?

Click to expand...

For any given flowrate, the average speed of the water through the radiator will be the same, regardless of the size of the tubing connected to the radiator.

Increasing the tubing ID of any substantial part of the tubing will increase the flowrate, which will in turn increase the velocity of the water through both the waterblock and the radiator.

Since87 said:

Increasing the tubing ID of any substantial part of the tubing will increase the flowrate, which will in turn increase the velocity of the water through both the waterblock and the radiator.

Click to expand...

You have that backwards, restricting the diameter will increase velocity.

gone_fishin said:

You have that backwards, restricting the diameter will increase velocity.

Click to expand...

I may not have been clear, but it's not backwards.

Increasing the ID of the tubing will reduce the velocity through the tubing, but increase flowrate. (Assuming the pump is a centrifugal pump and everything but the tubing remains the same.) The flowrate will increase because of the reduced flow resistance of the total cooling loop. (Operating point moves down and to the right on the PQ curve of the pump.)

The increased flowrate will result in higher velocities in both the waterblock and the radiator.

Since87 said:

I may not have been clear, but it's not backwards.

Increasing the ID of the tubing will reduce the velocity through the tubing, but increase flowrate. (Assuming the pump is a centrifugal pump and everything but the tubing remains the same.) The flowrate will increase because of the reduced flow resistance of the total cooling loop. (Operating point moves down and to the right on the PQ curve of the pump.)

The increased flowrate will result in higher velocities in both the waterblock and the radiator.

Click to expand...

Increasing the diameter of the tube will not increase the velocity. But you contradict yourself by saying the same thing at the beginning of your post then at the end claiming it will increase velocity.

You clearly do not have a clear understanding of the principles involved.

you are right gone_fishin what will happen if you put a smaller ID tube on the entering hose of the radiator and you put a bigger ID tube at the exit? the hoses have the same size. what will happen if the exit hose has has a bigger ID?The size of the tubing will be as it was explained before.

In tubes of smaller diameter, water runs faster, and resistance will be higher.
I like your idea with using high diameter tube on pump -> rad part, as it will increase flow much for me (my pump has higher output diameter than 1/2", similiar rad).
Any diameter change will add flow restrictions - both if we increase or decrease diameter - there's water turbulence what takes flow energy.
The worst possible diameter changes are limiting flow surface just after pump & changing flow surface on small distances.

gone_fishin said:

Increasing the diameter of the tube will not increase the velocity. But you contradict yourself by saying the same thing at the beginning of your post then at the end claiming it will increase velocity.

Click to expand...

I will try one more time.

Assuming a typical watercooling setup with a centrifugal pump...

Increasing the diameter of the tubing will:

1. DECREASE the VELOCITY of the water through the TUBING. The decreased velocity of the water through the tubing will result in a lower pressure drop for the tubing relative to the rest of the system. The decreased pressure drop for the tubing will result in an increase in the FLOWRATE, otherwise the system would be operating at a point that is not on the PQ curve of the pump.

2. INCREASE the VELOCITY of water through the WATERBLOCK and RAD. The velocity of the water through the waterblock must increase because the FLOWRATE is higher, even though the water is flowing at lower velocity through the tubing.

Examples:

System A

Small ID tubing
System dP - high
Flowrate - low
Velocity of water through tubing - high
Pressure drop across tubing - high
Velocity of water through waterblock and rad - low
Pressure drop across waterblock and rad - low

System B

Large ID tubing
System dP - low
Flowrate - high
Velocity of water through tubing - low
Pressure drop across tubing - low
Velocity of water throug waterblock and rad - high
Pressure drop across waterblock and rad - high

If maximizing the velocity through the tubing was the same thing as maximizing the velocity through the waterblock, we would all be using 1/4" ID tubing.

gone_fishin said:

You clearly do not have a clear understanding of the principles involved.

Click to expand...

Back at ya.



Edit: For emphasis.

What you are saying in a long winded way is the equivalent of putting a ball valve on the pump intake. Obviously closing the valve off lowers flowrate and thus all associated velocities at any given point in the system.

gone_fishin said:

What you are saying in a long winded way is the equivalent of putting a ball valve on the pump intake. Obviously closing the valve off lowers flowrate and thus all associated velocities at any given point in the system.

Click to expand...

Too many words for you to follow at one sitting huh?

That's not what I'm saying. It's not even close.

I originally posted in this thread to address the following statement:

apomak88 said:

The thought was to use larger ID tubing for the connection of the pump radiator and the reservoir because in this way the water goes faster in the waterblock and slower at the radiator.

Click to expand...

Do you, or do you not, see see that this statement is fallacious?

Using a larger tube for the pump intake straight from an open resevoir will increase the flowrate. It is as if a ball valve were placed there and the valve were opened up further. The part he posted about slower in the radiator is obviously false because system flowrate has now been increased.

Using larger tubing for any part of the system will (at least in theory) help, although it may be difficult to actually document the improvement.

Using smaller tubing to increase the velocity through a given block/component will not help- it will just reduce the overall flowrate.

*Think about the restricting effect that a smaller tube has: while velocity may be higher, there will be a reduction in flowrate.
This is also true when the coolant goes through a restrictive block, but there the increased velocity (at the cost of reducing flowrate) does some good: more turbulence and better heat exchange.

Restriction any place besides an area that transfers heat (blocks or radiators) will hurt performance. Smaller tube will hurt performance because it restricts flow rate while not transferring heat.

You are much better off using 1/2" ID tube throughout the system and letting the blocks themselves increase velocity.

gone_fishin said:

The part he posted about slower in the radiator is obviously false because system flowrate has now been increased.

Click to expand...

Thank you. That was the issue I was trying to address.

gone_fishin said:

Using a larger tube for the pump intake straight from an open resevoir will increase the flowrate. It is as if a ball valve were placed there and the valve were opened up further.

Click to expand...

Yes, minimizing the restriction at the pump inlet (insuring positive pressure at the inlet) will improve performance, but this is a separate issue.

Now i cleared it out thanks to you all. Because all the hoses will be the same size, the velosity of the water in the w/b or radiator will stay the same whatever tubing you put that has bigger ID from the hoses.

So now lets put different hoses on the waterblock. We put an enter hose for 1/2"ID tubing and an exit hose for 2/3"ID tubing.The pump has hoses for 1/2"ID tubing. Can i gain something from that? (i will not have pressure in the waterblock)

apomak88 said:

So now lets put different hoses on the waterblock. We put an enter hose for 1/2"ID tubing and an exit hose for 2/3"ID tubing.The pump has hoses for 1/2"ID tubing. Can i gain something from that? (i will not have pressure in the waterblock)

Click to expand...

By "hoses" do you mean "barbs"? (The brass fittings on waterblocks which the tubing slides over are called barbs.)

"Hose" and "tube" both mean the same thing.

Opps lol!! yes i ment barbs! sorry for that but im trying to learn english as good as i can.Im from greece and english is a foreign lunguage for me So any opinions?