2014 intercooling

[dren]

Strange that Giorgio clearly knows it's a charge cooler (air-liquid-air) http://translate.google.com/translate?s ... edit-text=

But then talks about it as an Intercooler in the F1.com piece...

Anyways I discussed all of this over a week ago when I did my piece comparing the powerunits and taking a swipe at Sky http://somersf1.blogspot.co.uk/2014/04/ ... nding.html

The Somers read is the best. The F1 website has the flow confused...

[trinidefender]

Strange that Giorgio clearly knows it's a charge cooler (air-liquid-air) [...]

But then talks about it as an Intercooler in the F1.com piece...

Well technically they're both charge coolers - they both work to reduce the temperature of the air going in to the engine.

You could inject a suitable fluid (alcohol, water) in to the charge before it enters the engine and that would also be charge cooling.

And the intercooler isn't really an intercooler, it's an aftercooler because it's placed after the supercharging stages. If the engine had two supercharging stages with a cooler between the stages then that would be an intercooler.

The problem is that the terms have been messed around with over the years - usually by the media - and actually aren't used in their correct ways. Charge cooling was developed in the aero industry in the 20s-40s as a way of extracting performance from the piston engines of the time.

This is not restricted to F1, of course - for example, just look at the use of the word "theory" where the word "hypothesis" should be used.

(Sorry mods, a bit OT )

Intercooler is also correct because you are cooling the air between two stages of compression. The turbocharger compression section and the piston compression section. Therefore it is and inter-stage-cooler.

[flyboy2160]

Bump for new posts from Mercedes Thread.

[Just_a_fan]

Intercooler is also correct because you are cooling the air between two stages of compression. The turbocharger compression section and the piston compression section. Therefore it is and inter-stage-cooler.

Reductio ad absurdum?

Charge cooling layouts:
Direct charge-cooling by injection of fluid e.g. water -> engine
Supercharger -> aftercooler -> engine (this is the method usually refered to as "intercooling" in modern parlance)
Supercharger -> intercooler -> supercharger -> engine
Supercharger -> intercooler -> supercharger -> aftercooler -> engine
Pre-cooler (e.g. actively chilled surface over which the air passes) -> supercharger -> intercooler -> supercharger -> aftercooler -> engine. I wonder if this has ever been used...

The term "intercooler" has a specific meaning. Or at least it did until marketing and media types got hold of it.

[trinidefender]

Intercooler is also correct because you are cooling the air between two stages of compression. The turbocharger compression section and the piston compression section. Therefore it is and inter-stage-cooler.

Reductio ad absurdum?

Charge cooling layouts:
Direct charge-cooling by injection of fluid e.g. water -> engine
Supercharger -> aftercooler -> engine (this is the method usually refered to as "intercooling" in modern parlance)
Supercharger -> intercooler -> supercharger -> engine
Supercharger -> intercooler -> supercharger -> aftercooler -> engine
Pre-cooler (e.g. actively chilled surface over which the air passes) -> supercharger -> intercooler -> supercharger -> aftercooler -> engine. I wonder if this has ever been used...

The term "intercooler" has a specific meaning. Or at least it did until marketing and media types got hold of it.

"a device for cooling a fluid (as air) between successive heat-generating processes"
http://www.merriam-webster.com/dictionary/intercooler

So yes, two heat generating processes. The turbocharger compresses that gas creating an increase in heat. The piston engine then compresses the gas further before ignition, therefore another heat generating process. The intercooler is cooling the air between these successive stages of heat generation. Hence an intercooler.

You are thinking of the turbocharger as an engine on its own but it is not. It cannot work without the piston engine part. Hence there are two stages of compression in this one engine.

[Just_a_fan]

I can live with that

[PlatinumZealot]

Everybody knows by now that Mercedes engines use air to air intercooling right?

[Powershift]

Everybody knows by now that Mercedes engines use air to air intercooling right?

proof? or are you being sarcastic?

I too thought there was no advantage to air-water-air(except packaging) but that seems to be the route they have chosen, at least that is what the pics seem to reveal.

[riff_raff]

This is actually quite an interesting subject from an academic standpoint. There are many trade-offs to consider with charge air cooling. There is trade between the intake flow and pressure losses produced in the system versus the benefits from increased charge air density and lower charge air temperatures. There are also the aero drag and weight penalties resulting from an air-air heat exchanger installation. If the boost pressure ratios are high, then a liquid-air heat exchanger might work best. However, with the boost levels and compressor efficiencies existing in a current F1 engine, I can't see how the additional complexity and mass of a liquid-air charge air cooler system would make sense.

[Owen.C93]

Speaking to an F1 engine designer he said they used to also use the water to air intercooler to cool the oil on the same loop. I wonder if anyone else has done that this year since the oil tank and air intake/ouput are very close together on the Mercedes engine.

[Robbobnob]

Ringo is right.

The benefit of a air-water charge-cooler isn't the reduction in the size of the heat exchangers required. Yes it will be smaller than a traditional air-air charge-cooler, however it will require another water-air heat exchanger of equivalent size to the air-air charge cooler to transfer the heat energy back to the air stream in the sidepods. This arguably requires more equipment to achieve the same effect as the air - air charge cooler.

The benefit is in the reduction in the path length for the charge air inside the charge-cooler. Due to the relatively higher thermal heat capacity of water compared to air, the air - water charge cooler can reduce the charge air temperature over a shorter distance, with the benefits being less head loss due to friction.

Ferrari also lowered the COG of their engine, by placing the dense turbo charger low in the gear box casing and the air - water charge-cooler in the V.

Anyways back to topic, in order to cool the charge air to the same temperature with an air-air charge-cooler and a air-water charge-cooler, there inevitably has to be the same heat exchange with the free stream air in the side pods, which will require similarly sized heat exchangers.

[gruntguru]

This is actually quite an interesting subject from an academic standpoint. There are many trade-offs to consider with charge air cooling. There is trade between the intake flow and pressure losses produced in the system versus the benefits from increased charge air density and lower charge air temperatures. There are also the aero drag and weight penalties resulting from an air-air heat exchanger installation. If the boost pressure ratios are high, then a liquid-air heat exchanger might work best. However, with the boost levels and compressor efficiencies existing in a current F1 engine, I can't see how the additional complexity and mass of a liquid-air charge air cooler system would make sense.

Liquid to air also makes sense if the desired charge temperature is significantly higher than ambient. I believe this to be the case (as I have stated elsewhere). Honda RA128E was deliberately operated at 80*C to improve combustion and therefore thermal efficiency. Current F1 engines have no need of additional charge density. 3.5 bar boost + intercooling to ambient delivers at least 50% more air than required to burn the allocated fuel.

At 80*C charge temperature a liquid to air system could share the engine cooling system.

[wuzak]

This is actually quite an interesting subject from an academic standpoint. There are many trade-offs to consider with charge air cooling. There is trade between the intake flow and pressure losses produced in the system versus the benefits from increased charge air density and lower charge air temperatures. There are also the aero drag and weight penalties resulting from an air-air heat exchanger installation. If the boost pressure ratios are high, then a liquid-air heat exchanger might work best. However, with the boost levels and compressor efficiencies existing in a current F1 engine, I can't see how the additional complexity and mass of a liquid-air charge air cooler system would make sense.

Liquid to air also makes sense if the desired charge temperature is significantly higher than ambient. I believe this to be the case (as I have stated elsewhere). Honda RA128E was deliberately operated at 80*C to improve combustion and therefore thermal efficiency. Current F1 engines have no need of additional charge density. 3.5 bar boost + intercooling to ambient delivers at least 50% more air than required to burn the allocated fuel.

At 80*C charge temperature a liquid to air system could share the engine cooling system.

It would appear that Ferrari have gone down the liquid-to-air route, while Mercedes, and maybe Renault, have gone for a combination.

[wuzak]

At some point one of the teams will realise that they can do cooling in the surfaces of all the body work to reduce their side pod size and aerodrag even further (and increase downforce slightly in some cases if they add heat to partially stagnated air), Perhaps in the floor tray and rear wing would be most attractive as can get rid of heat through both sides.

Brabham tried this at one point several decades ago. It was not a long lived idea.

But I would bet that engine oil+coolant temps have increased greatly since then - possibly 120-130°C now, reducing the necessary areas, also budgets have increased by perhaps an order of magnitude or more, and they are looking for tiny gains to give them the edge over the competition, where in the 70's everything was still pretty crude and design mostly done on gut instinct with a lot of other low-hanging fruit available (development wise) that just doesn't exist anymore. Nowadays relatively little things like blown or double diffusers can make all the difference.

The Brabham BT46



This is the Macchi MC72 (a model).


The gold coloured bits are the surface coolers. There are several sections on the floats, a bit on the nose and most of the upper and lower surface of the wings.

That is a lot of cooling.

Also, evaporative cooling (surface radiators) was a big thing in fighter aircraft of the early 1930s, but it never quite worked out.

[gruntguru]

The surface area required for surface cooling is probably similar to the total area of conventional finned heat exchangers. One obvious difficulty is transporting and confining the working fluid over the large area required. At the very least it is going to be considerably heavier than the conventional solution - due to greater volume of working fluid and greater mass of the "pressure system" which has only about half of its total surface area exposed to the airstream. In contrast a conventional heat exchanger has most of the metal which confines the working fluid exposed to the airstream.