Cooling Flow Exit

King of Spades · Post 05 Jan 2006, 18:13

Hello.

I'm designing a cooling-flow system (i.e. the intake, diffuser, ducting through the radiator, and the exit location) for a racing sidecar. It's being made by a friend-of-the-family in his garage, and intends to race it this season.

I'm currently considering the exit shape, and was wondering what the advantages/disadvantages of a chimney (as on the Ferrari F1-2005) vs "shark gills" (as on the Ferrari F2003-GA) vs an angled hole (as on the Ferrari F1-2000). Could one of you knowledgeable chaps help me out, please?

DaveKillens · Post 06 Jan 2006, 16:16

A chimney adds wetted surface, but ducts the hot air away from the bodywork and to a location more desirable. That is how they first were used. But in recent generations, they are used more as vertical wing elements, to direct the airflow. In many races, the chimney is closed off and not even used for cooling purposes.
On a GP car it's not really exposed to rough handling. But on a sidecar, the passenger moves around a lot, and this chimney may be more vunerable to damage.

manchild · Post 06 Jan 2006, 16:41

This is an old testing pic but still very strange - one shimney opened and another closed! Since radiators are symetrical (one oil and one water radiator in each sidepod) I wonder what this could mean?

Spencifer_Murphy · Post 06 Jan 2006, 17:23

I thought the renault was using asymetrical cooling in the sidepods?

manchild · Post 06 Jan 2006, 17:44

I don't think so (unless they've changed it since R24)

dumrick · Post 06 Jan 2006, 20:33

As far as I've read, this assymetry comes from the fact that turns on circuits make the air intake assymetrical. Therefore, depending on the layout of the circuit (high-speed long turns make for big assymetry in cooling for quite a few seconds), there is, or not, the need for this adjustments in cooling.

King of Spades · Post 07 Jan 2006, 15:51

DaveKillens wrote:A chimney adds wetted surface, but ducts the hot air away from the bodywork and to a location more desirable. That is how they first were used. But in recent generations, they are used more as vertical wing elements, to direct the airflow. In many races, the chimney is closed off and not even used for cooling purposes.
On a GP car it's not really exposed to rough handling. But on a sidecar, the passenger moves around a lot, and this chimney may be more vunerable to damage.

Thank you very much. I shall bear that in mind in the next design stage.

Which type of exit I eventually plump for will depend on where it is decided to vent the heated air. Apart from the sidecar's undertray, I'm not sure offhand where the low-pressure points are... but that can wait 'til I have a more accurate drawing of the sidecar.