Turbocharger assisted Aerodynamics in 2014 and beyond

[riff_raff]

IMO even in recent years the throttles have been far from closed during braking
and in 2014 the amount of airflow from the exhaust can continue to be rather large during braking (maybe larger than before)
enough airflow to run the engine at or near max rpm unloaded ie equivalent to a 10500-13000 rpm idle
(because it is allowed to produce 'over-run push' (zero torque rather than engine braking) when the driver is 'off accelerator')
and added to this enough airflow to run the engine to generate 120 kW from the MGU-K (still counting as zero torque)
and FWIW here it can run on eg 3 cylinders

so rather a lot of gas can pass through and emerge from the engine in the braking phase if this is desired
also in any low-torque activity after braking
given that at many (less fuel-hungry) tracks a 100 kg fuel fill will leave scope for this running via the fuel rate limits
surely this available fuel will be used, as in 2013, 2012 etc, not left in the pits ?

The engine is basically a positive displacement pump, and assuming that the engine is coupled to the rear wheels thru the transmission, the volume of air pumped thru the engine at WOT and no load will vary based on wheel speed and gear ratio.

[Tommy Cookers]

agreed, the amount (in mass terms) of gas passed by a given engine is rather independent of the power produced
but the amount (in exhaust energy/pressure/velocity terms) is strongly power-related, even under 'cold-blowing' rules

AFAIK the rules allow the engine to run 'accelerator lifted' about 200 hp higher power than normal idle (170 hp to generator)
so eg 3 cyl running would allow in effect WOT

that's quite a lot of gas energy for something, ie usefully passing somewhere/somehow more/more energetic air than otherwise
the turbo shaft is also motorised

[hollus]

Well the compressed air could be directed from the intake plenum and fed into the exhaust before the turbo. The fuel is injected into the cylinders but not fired. Perhaps 3 cylinders could do this and the remaining 3 could fire just to create hot enough exhaust to burn the rest of the fuel.

Though as stated I don't see any gain in this. The MGU-H could only direct 120 kw to the MGU-H and the total ES is 4MJ.

If I follow you correctly something similar is done in some motorsports where turbos are used, WRC is the most well known. The fuel will auto ignite in the turbo (it is done to help keep the turbo spooled). It is very damaging to the turbo and I suspect a turbo wouldn't survive a race weekend if this was done.

I have the theory that the monkey seats will provide a beautiful lower surface for interaction with a high exhaust pipe for some extra downforce. If you then hot burn (or cold burn and just overspool the turbo with battery energy), you would get more air from the exhausts for more downforce, with negligible extra thrust. This can be useful under braking, also in that this extra downforce is at the rear, where tires are most unloaded.
Bad for reliability and wasteful? Surely, but maybe it can be used only at some times, say once per lap, or as a push-to-pass-under-braking (PTPUB) button. Or, come to think of it, in quali, which only lasts a lap, and where the fuel burnt is almost irrelevant. In quali you could also use it for cornering then. You qualify 2-3 rows ahead of your natural position plus you get the extra PTPUB (or to defend) button if you need it in the race.

[marcush.]

one silly question here-
wouldn´t it make for a worthwhile gain in Aero to use inlet air demand of the engine to enhance laminar flow in critical areas of the bodywork -eg stop separation ? This could be slots in the top of the sidepods (for ease of application) or a bit more elaborate the underside of front and rear wings or underfloor..
I confess this would be a disaster for wet races but then ..there must be something in this .

[wuzak]

one silly question here-
wouldn´t it make for a worthwhile gain in Aero to use inlet air demand of the engine to enhance laminar flow in critical areas of the bodywork -eg stop separation ? This could be slots in the top of the sidepods (for ease of application) or a bit more elaborate the underside of front and rear wings or underfloor..
I confess this would be a disaster for wet races but then ..there must be something in this .

Rules preclude slots in many areas - icluding teh tops of the sidepods and, especially, on the floor.

Also, I don't think they can have slots in the wings any more.

[BorisTheBlade]

Additionally there are restrictions about where the inlets may be. Also they have to be visible entirely if you look at the car from the front and have to be vertical.
The only thing I can think of is to put a winglet right in front and above or below of the inlet. But I guess the radius rule would be in the way.

[PlatinumZealot]

The peak suction of the turbo charger is not much more than a regular engine of similar peak horsepower because it has similar peak mass flow rate, but it has a wider spread over the rpm band. I am not sure why people think there is monster suction at the inlet of the turbocharger?

[riff_raff]

one silly question here-
wouldn´t it make for a worthwhile gain in Aero to use inlet air demand of the engine to enhance laminar flow in critical areas of the bodywork -eg stop separation ? This could be slots in the top of the sidepods (for ease of application) or a bit more elaborate the underside of front and rear wings or underfloor..
I confess this would be a disaster for wet races but then ..there must be something in this .

Your fundamental question is the basis of why "cold blowing" provides any benefit. Any airflow passing thru the engine will not improve aero performance much unless some energy is imparted to the airflow mass via combustion or momentum transfer. If the airflow mass exiting the engine has less energy than the airflow mass entering the engine, then what benefit does "cold blowing" provide?

[BorisTheBlade]

I thought it was to drive the MGU-H as much as possible. Wasn't it?

[neilbah]

yes, Does it not create some kind of self feeding loop where the turbo is kept at high velocity? maintaining the spool has got to be worth something in getting up to boost quickly, rather than stalling which would put strain on the turbocharger? I still think we need to afterburn and melt the cars behind though.

[PlatinumZealot]

The turbo charger cant stall becasue it has a blow off valve and the MGUH is smart enough to reduce load when it senses the compressor rpms dropping.

[Holm86]

The turbo charger cant stall becasue it has a blow off valve and the MGUH is smart enough to reduce load when it senses the compressor rpms dropping.

Blow off is not needed. Just open the throttle bodies.

[PlatinumZealot]

No that doesn't make sense.
The throttle is modulated by the driver to deliver the right amount torque to get the car around the race track. The throttle is not just something you can use some computer to open and close just because you have a compressor stalling. That's just madness.

When the throttle is closed by the driver the compressor is working against a constant volume container. There is no where for the air to go so the compressor will at first stall and then air will flow backwards through the compressor blades because of the pressure buildup (or even destroy the compressor blades). The engines will definitely need a blow-off valve I am pretty sure of that .

[langwadt]

No that doesn't make sense.
The throttle is modulated by the driver to deliver the right amount torque to get the car around the race track. The throttle is not just something you can use some computer to open and close just because you have a compressor stalling. That's just madness.

When the throttle is closed by the driver the compressor is working against a constant volume container. There is no where for the air to go so the compressor will at first stall and then air will flow backwards through the compressor blades because of the pressure buildup (or even destroy the compressor blades). The engines will definitely need a blow-off valve I am pretty sure of that .

the _accelerator_ is modulated by the driver, there is no mechanical link to the throttles they are controlled by the ECU.

[neilbah]

smikle, i have read other posts or articles including statements by someone who works in renault (cant find the link but its on this site somewhere) that throttles on a F1 car are left pretty open these days when the throttle is lifted, probably due to the fact In the EBD situation this was put to use to seal the diffuser but it could also be useful to blow now for the benefit of the turbo which is why were having this conversation. Its already been discussed here http://www.f1technical.net/forum/viewto ... 1&start=15 I guess what were describing is a form of antilag system or ALS for short but utilising cold blowing if thats possible. Id have thought its more useful/efficient to keep recirculating the energy than just dumping it in the exhaust pipe which is the only place excess boost is allowed to go seeing as according to the rules it cannot vent to atmosphere. If your blow off valve reinserts the air into the exhaust manifild between the exhaust ports and the turbine then maybe its acceptable. Im not saying they wont have a blow off for emergency sake, just that im not sure its needed. Potentially its getting slightly off thread as id consider it pneumatics