[Craze]

Hello!

My Goal is to Simulate a simple (maybe not so simple for me) Desktop - Computer water cooling circuit, especially for the dimensioning of a radiator. (for example: is a 120mm radiator enough for a given thermal power)

I've done some simulations before with the radiator alone, where I got an inlet and outer boundary case with water (and a second in and outlet on he radiator for the Air - Fan) which worked without problems.

Now i want to simulate, if (and when) the water - temperature stays constant with a given thermal power (for example 300W) on a given surface, on which a copper block is placed on it, where the water flows through it.

My problem is, that I am missing a "pump" function to keep the closed water circuit (where no in and outlets are given) at for example 100 litres per hour flowing.

I've tried with the Vx, Vy and Vz settings inside the Fluid Volume setting, that shows some very weird water flow, which stops after a few minutes calculating and leading the copper block temperature to explode.

Also I tried with the "Local Region condition" on the inner surfaces of a straight part of the water - pipe with the same weird behaviors.

Or is it possible to create an inlet, where the fluid comes from the outlet? This would help also a lot.

Does Anybody know how to cope with this?

Thanks in Advance for everyone who can help!

Best regards,
Michael

[Boris_M]

Hi Michael,

I'm not sure if I correctly understood what you need, but I think you want to have a little pump that keeps the water circulating in your water cooling unit.
You can use the fan curves as FloEFD does not care if you move water or air it works therefore also as a pump for liquids.
Simply specify your pump curve as a new fan either according to the specifications of the supplier with a real pump curve or if you want to have a constant flow rate no matter what pressure loss then you can also specify it that way. Simply select then internal fan in the boundary condition and specify the surfaces where the fluid enters the system from the pump and where it leaves the system into the pump again. If the pump is interrupting the pipe then it doesn't matter you can simply create a small lid inside the pipe and use the two faces of the lid and if the pump is separate then you probably have two ends of the pipe between the pump would sit and can use the two surfaces of the lids on each end of the pipe for in and outflow.

I hope this helps,
Boris

[Craze]

Originally Posted by Boris_M

Hi Michael,

I'm not sure if I correctly understood what you need, but I think you want to have a little pump that keeps the water circulating in your water cooling unit.
You can use the fan curves as FloEFD does not care if you move water or air it works therefore also as a pump for liquids.
Simply specify your pump curve as a new fan either according to the specifications of the supplier with a real pump curve or if you want to have a constant flow rate no matter what pressure loss then you can also specify it that way. Simply select then internal fan in the boundary condition and specify the surfaces where the fluid enters the system from the pump and where it leaves the system into the pump again. If the pump is interrupting the pipe then it doesn't matter you can simply create a small lid inside the pipe and use the two faces of the lid and if the pump is separate then you probably have two ends of the pipe between the pump would sit and can use the two surfaces of the lids on each end of the pipe for in and outflow.

I hope this helps,
Boris

Hello Boris,

thank you very very much, it worked flawlessly.

What i've done: I created a small "plug" inside the water canal, where i could define the in and outgoing areas of an internal fan (which i created with no pressure loss, only 92.4kg/h mass flow).

It seems that the solver now needs plenty more time to calculate on my i7 4700mq, but that is a good compromise for the fact that it is working

here a picture of the solver:

Best regards,
Michael