Which grill is more aerodynamic?

[freebeard]

I got hung up on 'edterior'. Theory would say 25-250MPH, but there may be some effect from the interference drag through the engine compartment.

[Piotrsko]

Once again, sorry. Freaking keyboard induced dyslexia

[freebeard]

People say 'sorry' too much. Try 'Excuse me'.

[aerohead]

Originally Posted by Piotrsko

Would the extractors be somewhat limited to a specific speed range for optimum flow or can you make edterior mods to regulate that flow?

Professor Morelli 'tuned' them such that, at all velocities, air leaving the extractors emerge at a velocity equal to the flow they're entering. No pressure spike one way or the other. Laminar flow always.
There's no moving parts, it's purely passive in design.
I'm pretty sure BEECHCRAFT did the same on the 'Doctor killer.' The exit ducts leaving the big Lycoming seemed to have undergone serious thinking.

[aerohead]

Originally Posted by freebeard

I got hung up on 'edterior'. Theory would say 25-250MPH, but there may be some effect from the interference drag through the engine compartment.

For their 1987, Cd 0.186, VESTA-2, Renault achieved a cooling system of Cd 0.004 / CdA 0.007. 2.3% of overall drag.
There only concern was the Delta-P across the heat exchanger matrix, and the radiator was sized accordingly.
As heat flux varied up to top-speed, air velocity would march in step, to carry off the Btus.
As with Cd, the cooling system Cd is also fixed, once critical Rn is achieved.

[Piotrsko]

Originally Posted by aerohead

Professor Morelli 'tuned' them such that, at all velocities, air leaving the extractors emerge at a velocity equal to the flow they're entering. No pressure spike one way or the other. Laminar flow always.
There's no moving parts, it's purely passive in design.
I'm pretty sure BEECHCRAFT did the same on the 'Doctor killer.' The exit ducts leaving the big Lycoming seemed to have undergone serious thinking.

Cool, thanks.

The doctor killer cowl was an incremental process as opposed to mooneys got it right the first time

[Taylor95]

Originally Posted by aerohead

Professor Morelli 'tuned' them such that, at all velocities, air leaving the extractors emerge at a velocity equal to the flow they're entering. No pressure spike one way or the other. Laminar flow always.
There's no moving parts, it's purely passive in design.
I'm pretty sure BEECHCRAFT did the same on the 'Doctor killer.' The exit ducts leaving the big Lycoming seemed to have undergone serious thinking.

Can you post pictures of the "extractors"?

[freebeard]

assets.newatlas.com/dims4/default/4e7c6fc/2147483647/strip/true/crop/1992x990+0+0/resize/1440x716!/quality/90/?url=http:%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Farchive%2F1960-pininfarina-x-concept-auction-13.png

Not much to see, that's one above the wheelwell arch.

[aerohead]

It was probably Popular Science which showed an additional photo from under the 'banana' car, illustrating the lower two extractors which made up the remainder of the system.
Mercedes-Benz's current Cd 0.1719, EQXX uses semi-similar extractors up top.
I included them on SPIRIT's hood blister. ( I've had explosive radiator failures, and I made mine more 'outboard' so any glycol coolant would not make it to the windscreen and blind me in the event of a breach ). Safety first!