Red Bull RB6

[747heavy]

agree
I would say delta T of ~5°C would be a very good radiator

not sure we see the full plumbing of the rad in the photo, the entry could be on
the other side of the core.
Maybe they use top and bottom core seperate for LHS/RHS bank of the engine and
combine with the Y-piece for the return to the sucktion side of the WP (water pump)
Maybe the have different radiator sections for the heads and the block of the engine.
In some other applications people use different radiators for the head and the block of the engine, using two WP´s to control temp indepentend in heads (as cool as possible to avoid knock) and block (hotter for less friction)
Just some random thoughts - not sure if this is done or even permitted in F1

[marcush.]

agree
I would say delta T of ~5°C would be a very good radiator

not sure we see the full plumbing of the rad in the photo, the entry could be on
the other side of the core.
Maybe they use top and bottom core seperate for LHS/RHS bank of the engine and
combine with the Y-piece for the return to the sucktion side of the WP (water pump)
Maybe the have different radiator sections for the heads and the block of the engine.
In same applications people use different radiators for the head and the block of a engine, using two WP to control temp indepentend in heads (as cool as possible to avoid knock) and block (hotter for less friction)
Just some random thoughts - not sure if this is done or even permitted in F1

that radiator looks quite elaborate ,compared to the Renault `Works` layout..thats for sure..one would not think that a customer team does indeed do a much more elaborate system than the original layout.But then it´s not clear what information Renault is giving to a customer team.

[timbo]

Can different tube size correspond to different liquid velocity?
Optimizing hot/cold flow?

[lotus7]

Can different tube size correspond to different liquid velocity?
Optimizing hot/cold flow?

Ingoing to radiator is under pressure , outgoing is under suction.
Even my little race car is set up like that.

[marcush.]

Can different tube size correspond to different liquid velocity?
Optimizing hot/cold flow?

Ingoing to radiator is under pressure , outgoing is under suction.
Even my little race car is set up like that.

hm ... the water is sucked into the water pump and pushed out of it ... that is the real split in the system ,correct?Normally its an impeller pump .in need of a certain speed to even work decently but you get horrible cavitation if you exceed the maximum speed the unit is designed for..

what you get is a pressure drop across the core ,influenced also by the in and outgoing geometries no question....

Bu my thought is that this should be a reverse flow application where cold water enters the heads first and will be sucked through the rest of the engine .this will increase the delta t available at the parts that get hottest ,the cylinderheads and thus it will be able to increase cooling capability .If flowing the other way round preheated water will reach the heads and less delta t and less cooling capacity is available to cool the parts that need it most....at leas thats the way its done in modern cars.
quite often the reverse flow principle is also used in radiators .. in our case with the multiple in and outlets its difficult for me to see if this could be anything reverse in the radiator itself..

it´s amazing how little knowledge about water plumbing is available ...

[aral]

Can different tube size correspond to different liquid velocity?
Optimizing hot/cold flow?

Ingoing to radiator is under pressure , outgoing is under suction.
Even my little race car is set up like that.

If the input is under pressure, then the output will also be under pressure, that is unless there is considerable water loss as it passes through the rad. If the impeller is downstream of the outlet, then water could well be under suction but then the inlet would also be under suction. You cannot ave two different effects in a water system, and cars generally operate in a pressurised basis.

[PlatinumZealot]

Water pressure will not vary significantly before and after the radiator.

What I posted earlier; the temperature could be the reason.

A pipe with a smaller diameter is much stronger.

Hoop stress = Pressure x Diameter / (4 *thickness).

The pressure is similar but the stress in the pipe is less. I think this helps alleviate the addition of thermal tress.

So I think the hot water pipe is the smaller diameter.

[lotus7]

Can different tube size correspond to different liquid velocity?
Optimizing hot/cold flow?

Ingoing to radiator is under pressure , outgoing is under suction.
Even my little race car is set up like that.

If the input is under pressure, then the output will also be under pressure, that is unless there is considerable water loss as it passes through the rad. If the impeller is downstream of the outlet, then water could well be under suction but then the inlet would also be under suction. You cannot ave two different effects in a water system, and cars generally operate in a pressurised basis.

My understanding is that with the much larger surface area in the radiator , there will be a potential pressure drop in the radiator . The pressure after the pump is there to overcome the potential pressure drop .
Big agricultural irrigation impellor pumps work the same, although not in closed loop. The suction pipe normally has a restrictor( thinner) pipe before the pump , then a larger dia pipe after the pump Much more physics to this than meets the eye!

[aral]

Optimizing hot/cold flow?

Ingoing to radiator is under pressure , outgoing is under suction.
Even my little race car is set up like that.[/quote]
If the input is under pressure, then the output will also be under pressure, that is unless there is considerable water loss as it passes through the rad. If the impeller is downstream of the outlet, then water could well be under suction but then the inlet would also be under suction. You cannot ave two different effects in a water system, and cars generally operate in a pressurised basis.[/quote]
My understanding is that with the much larger surface area in the radiator , there will be a potential pressure drop in the radiator . The pressure after the pump is there to overcome the potential pressure drop .
Big agricural irrigation impellor pumps work the same, although not in closed loop. The suction pipe normally has a restrictor( thinner) pipe before the pump , then a larger dia pipe after the pump (in this case the sprnklers provide the restrictor ) Much more physics to this than meets the eye![/quote

The size of the rad has no effect on the flow, due to the fact that the entire system is charged with fluid. The rad consists of a number of microbore tubes which, to ensure even flow, would have the same flow rate as the inlet and outlet pipes. There is nothing in the system to impede flow, otherwise there would be overheating problems.

[bjpower]

maybe the pipes are the same size internally.
could the outlet/cool pipe have insulation on it?

[mep]

The cooling system is a closed loop of non compressible medium.
So when you put it under static pressure the pressure is everywhere.
You do so to increase the boiling point of water to run temperatures over 100°C.
When you start to push the water trough the pipes it will cause a instant reaction in the whole system. So the pump doesn't need to suck water in. The water gets pushed in.
The work of the pump is minimal even when your piping goes up a hill and down on the other side. You only need to overcome friction loses. Nothing else.
Friction loses for a radiator are "quite big" because all the little tubes cause more friction than a single big tube would do even when cross area is the same.


Edit: added quite

[lotus7]

Friction loses for a radiator are big because all the little tubes cause more friction than a single big tube would do even when cross area is the same.

Quite.

[PlatinumZealot]

Yes, but the pressure drop of the radiator is not the determining factor in answering the question of why one set pipe is of a larger diameter. Especially when you expect an F1 to be well designed to reduce pressure drop as much as possible, I don't think it is significant, it should be very low.

Either way, making the outlet pipe bigger won't change the pressure drop across the radiator.

[mep]

Thats true n-smikle.
In fact I still don't know the reason and start to wonder more and more.
We don't even know is the big tube inlet our outlet.

I asked a car mechanic today who knows very much about cars but also couldn't explain. The only explanation he had is that the tube is bigger than needed because the thermostat valve is build into its end.
What I don't like is that the big tube is filled with water without any reason and adding useless weight to the car. Remember water is also weight. So it would be bad designed.


I sought marcus would come up with a good explanation he should be well informed about cooling and radiators.
Maybe we should do separate treat about radiators and cooling?

[marcush.]

@mep
I´m working close to this environment in my profession ,but not directly .So I get good information about cooler core capabilities and air flows and efficiencies ,but the water plumbing side is something I can only ask for randomly but I will try to fill the voids in the next weeks ,promised.
we should definitetively start a thread about cooling efficiency.