2014-2020 Formula One 1.6l V6 turbo engine formula

[Edis]

Okay didnt think of that. But i know that direct injection can have problems keeping up in high revs. Remember reading a article on the Porsche Spyder LMP2 car a few years back where the biggest challenge was getting the direct injection system to work at 12.000 rpm.

But i believe that will be one of the areas that can be developed in F1. A few years and they should be able to run max revs on direct injection alone.

Ilmor ran direct injected F1 engines up to about 17,000 rpm years ago without a loss in power and a 5% gain in fuel efficiency, and this was with a fuel pressure of only 150 bar. Back then it was difficult to find suitable injectors for the purpose, since then a lot have happened in that area.

I'm just disapointed that they didn't allow ceramic components. This engine design is all about thermodynamic efficiency and ceramics are likely one way to gain it.

Ceramics are in general a bad idea unless we talk about small wear or heat resistant parts like turbine wheels, balls for bearings, plungers for high pressure fuel pumps and such.

Trying to insulate the combustion chamber is a bad idea, it just increase exhaust temperature, knocking and reduce volumetric efficiency.

Ceramics have very high compressive strengths but their tensile strength is low. In tension a ceramic part fail by fast fracture and there is no way to tell when that is going to happen with a certain part (unlike with metals were fatigue can be predicted). Also, the larger the part, the greater the chance that there is a material defect in the ceramic part that can initiate the failure.

I am pretty convinced that the cooling effect of the fuel injection will be more efficient the more upstream you can do it?

Normally you get a greater cooling effect by injecting the fuel directly into the cylinder. That is one reason why direct injected engine are less prone to knock.

Mixture preparation can however suffer due to the short time availible for mixing.

I think it will be worth it.
Intercooling is the key word in turbo efficiency. If they don't have it, then it would be a complete gimmick to have electric pit lane running in the name of saving energy.

Intercooling is useful in keeping the engine cool and improving volumetric efficiency, but it doesn't have to have a positive effect on engine efficiency.

Ceramics are used for thermal insulation, like the bottom of the space-shuttle, but they don't "absorb" anything.

The tiles used on the bottom of the space shuttle insulate well because they are 90% air. Think of them like plastic foam but instead of plastic they are made from silica with a black borosilicate coating.

Since ceramics with poor heat conduction tend to crack when they are heated (or cooled) the heat shield is "precracked" by using several small tiles instead of one large heat shield.

[xpensive]

Someone is either a live walking oracle or xtremely proficient with Wikipedia?

However, regardless of the space shuttle heat shield's cracking tendencies, I believe that making said shield in one single piece would have been xtremely impractical to xpress it mildly.

[PlatinumZealot]

Intercooling is useful in keeping the engine cool and improving volumetric efficiency, but it doesn't have to have a positive effect on engine efficiency.

Hooooold on!
This is totally wrong. .

The PRIMARY reason why the air charge is cooled is because of engine efficiency not because of knocking. Inter-cooling reduces the energy needed to compress the air in the combustion chamber

A naturally aspirated engine has ONE stage of compression - the pistons compressing the intake air.

A turbo engine has TWO stages of compression. Turbo + pistons.

Thermodynamics state that when air is compressed its temperature rises.

In real life when air is compressed it also diverts from IDEAL COMPRESSION.
Ideal compression is "Isentropic compression." This means the irreversibility (the inefficiencies of the natural fabric) of the air itself causes it to be even harder to compress as energy is wasted (friction etc finite temp differences etc) the more you compress it.
And, the hotter the air you compress the more and more it diverts from ideal compression and the more energy you need to compress it. In other words cold gasses are easier to compress.

It follows that, with two stages of compression it is only common sense to cool the gas while you have the chance - so that the machine that is doing the second stage of compression has an easier job. (the pistons in this case).

So Inter-cooled engines are more mechanically efficient because they cool the gas in between each compression stage - (hence the "inter" in inter-cooler) and by so doing less energy is used (and lost) to compress the air in the combustion chamber.

I am not good at explanation but that is the gist of it.


BTW... did you know that in the ideal engine you want the air and fuel to be as hot as possible? The only reason why we have to cool our fuel and air is because of these "pesky" things like detonation, knocking, metals melting points, compressing the air, emission standards and coolant boiling points? Every year millions of dollars are spent on making internal combustion engines run hotter- ceramic parts, super alloys, refractory coatings, EDM machined cooling veins, steam/water injection,

- simply because IC engines are heat engines and the more heat you put into them the more power you get!

[ringo]

That's about it.
Edis, gotta read up on your cycles man.

No intercoolers would be a joke. It's free efficiency, compared to a silly pit lane electric rule.

I can give you an example with these same 1.6 turbo engines (from the trusty engine calculator).

The temperature leaving the compresor is 87 degrees C on my engine.

The intercooler cools it to about 45 degrees, this temp i take from the Honda turbo v6 from back in the day. However a proper analysis could be used.

the power output is 559 bhp.

If it is not intercooled and 87 degree air goes to the engine the power output would be.... 474 bhp!!!

a 42 degree rise in temperature effects the mass of air going to the engine drastically.
And this is all about temperature and entropy, not engine knocking etc.

Intercooling will be very important, and whoever makes the better plumbing will have a slight advantage, even though they may be using the same engine as another team.

What will be very interesting, is the plumbing.

[marekk]

I'm wondering what do the rules say about this hypothetical scenario:

State of the art (ceramics, nanotechnology, foil bearings...) turbochargers, waste gate closed all the time or not existent, very small capacity MGUH if any, disconected from turbine shaft under breaking and in corners anyway, any excess of air beyond 0,8bar escapes through blow off valves, accidentaly positioned in the direction of diffuser/wings ?

Not relevant to road cars and not fuel efficient by any means, just F1 as i like it

[Edis]

Intercooling is useful in keeping the engine cool and improving volumetric efficiency, but it doesn't have to have a positive effect on engine efficiency.

Hooooold on!
This is totally wrong. .

The PRIMARY reason why the air charge is cooled is because of engine efficiency not because of knocking. Inter-cooling reduces the energy needed to compress the air in the combustion chamber

A naturally aspirated engine has ONE stage of compression - the pistons compressing the intake air.

A turbo engine has TWO stages of compression. Turbo + pistons.

Thermodynamics state that when air is compressed its temperature rises.

In real life when air is compressed it also diverts from IDEAL COMPRESSION.
Ideal compression is "Isentropic compression." This means the irreversibility (the inefficiencies of the natural fabric) of the air itself causes it to be even harder to compress as energy is wasted (friction etc finite temp differences etc) the more you compress it.
And, the hotter the air you compress the more and more it diverts from ideal compression and the more energy you need to compress it. In other words cold gasses are easier to compress.

It follows that, with two stages of compression it is only common sense to cool the gas while you have the chance - so that the machine that is doing the second stage of compression has an easier job. (the pistons in this case).

So Inter-cooled engines are more mechanically efficient because they cool the gas in between each compression stage - (hence the "inter" in inter-cooler) and by so doing less energy is used (and lost) to compress the air in the combustion chamber.

I am not good at explanation but that is the gist of it.


BTW... did you know that in the ideal engine you want the air and fuel to be as hot as possible? The only reason why we have to cool our fuel and air is because of these "pesky" things like detonation, knocking, metals melting points, compressing the air, emission standards and coolant boiling points? Every year millions of dollars are spent on making internal combustion engines run hotter- ceramic parts, super alloys, refractory coatings, EDM machined cooling veins, steam/water injection,

- simply because IC engines are heat engines and the more heat you put into them the more power you get!

What I wrote is correct.

Charge cooling doesn't automatically mean higher engine efficiency, infact, better intercooling can lead to a lower engine efficiency. That have been shown in the past. For instance, Hondas RA168E had a 4% higher BSFC at an air inlet temperature of 40 degC than at 80 degC. It did however lose power with increased temperature, and going beyond 70 degC didn't really offered any advantages.

As for increased temperature and its effect on compression work, yes, increased temperature will cause compression to require more work, but in theory you get that back during expansion. In pratice you don't get it all back since compression and expansion aren't isentropic but polytropic.

In the ideal engine we would want the incoming charge to be as cool as possible, but in practice such an engine can have trouble vaporising its's fuel, leading to a lower efficiency. We would also want our engine to compress and expand the gas while at constant temperature, but that is usually not practical.

As for spending a lot of money on making internal combustion engines run hotter, I don't fully agree with that statement. Yes, some money is spent on dealing with higher temperatures, but a lot of money is actually spent on the opposite; making engines run cooler. In the case of a gasoline engine, it is useful if the engine can withstand higher exhaust temperatures since that allows the high load enrichment to be reduced. But reduced temperatures have advantages as well, mainly with reduced NOx formation but also smaller heat losses. A few technologies which reduce combustion temperatures: EGR, lean burn, stratified charge combustion, homogeneous charge compression ignition and partially premixed combustion; some of which are common in production cars.

In terms of handling higher temperatures the piston engine have one significant advantage compared to other engines like the gas turbine and the stirling engine: combustion is not continuous and no parts of the engine have to operate near the maximum temperature. That's why a piston engine can have peak temperatures above 2000 degC, yet few parts have to run hotter than a few hundred degrees.

[riff_raff]

CART turbo engines were not allowed to use intercoolers. In the later years of that formula the manufacturers came up with injectors that were more and more upstream. If I recall correctly they were eventually injecting (some of the fuel) just upstream of the turbo compressor itself.

bill shoe,

Mid 90's Cosworth XB turbo compressor inlet:



riff_raff

[bill shoe]

Great pic, thanks. Usually when people talk about closed-loop fuel control they mean a software algorithm. The picture shows literal closed-loop fuel hardware .

[ringo]

What I wrote is correct.

Charge cooling doesn't automatically mean higher engine efficiency, infact, better intercooling can lead to a lower engine efficiency. That have been shown in the past. For instance, Hondas RA168E had a 4% higher BSFC at an air inlet temperature of 40 degC than at 80 degC. It did however lose power with increased temperature, and going beyond 70 degC didn't really offered any advantages.

As for increased temperature and its effect on compression work, yes, increased temperature will cause compression to require more work, but in theory you get that back during expansion. In pratice you don't get it all back since compression and expansion aren't isentropic but polytropic.

In the ideal engine we would want the incoming charge to be as cool as possible, but in practice such an engine can have trouble vaporising its's fuel, leading to a lower efficiency. We would also want our engine to compress and expand the gas while at constant temperature, but that is usually not practical.

As for spending a lot of money on making internal combustion engines run hotter, I don't fully agree with that statement. Yes, some money is spent on dealing with higher temperatures, but a lot of money is actually spent on the opposite; making engines run cooler.

I'm going to cut your post short, as the rest of it isn't really a strong argument to the fundamental reasoning behind inter cooling.

It can be proven to you that charge cooling increases efficiency.
Mass flow and temperature difference is king in any engine design.
Take a while to consider what the inter-cooler does to the air, and how it affects it's mass flow and temperature going into the engine.
then consider the Carnot efficiency.
It's simple as that.

A gas turbine power plant can easily get a 20% increase in efficiency with an intercooler.
All the Nox and other little nuances in the rest of the post, can't compare to that 20% chunk of efficiency.

Even with consideration for isentropic efficiency below unity and pressure drop in the heat exchanger, intercooling is still very advantageous.

[marekk]

On the other hand both flame speed and flammability of the mixture depend positive on the pressure and temp of reactants, so there could be some limitations on how cold your compressed air is to allow for complete burning of the fuel/air mixture before exhaust vavlve opens. At 18,000 rpm time is limited, not so much with 2,000 rpm diesels or gas turbines with long combustion chambers.

[Edis]

I'm going to cut your post short, as the rest of it isn't really a strong argument to the fundamental reasoning behind inter cooling.

It can be proven to you that charge cooling increases efficiency.
Mass flow and temperature difference is king in any engine design.
Take a while to consider what the inter-cooler does to the air, and how it affects it's mass flow and temperature going into the engine.
then consider the Carnot efficiency.
It's simple as that.

A gas turbine power plant can easily get a 20% increase in efficiency with an intercooler.
All the Nox and other little nuances in the rest of the post, can't compare to that 20% chunk of efficiency.

Even with consideration for isentropic efficiency below unity and pressure drop in the heat exchanger, intercooling is still very advantageous.

I suggest you look up SAE Technical Paper 890977, Fig 10, Effect of intake air temperature on power and BSFC.

And you're wrong about Carnot:

n_carnot = 1 - (Q_removed/Q_added) = 1 - (T1/T2)
T2 = T1*cr^(k-1)

Lets assume cr=10 and T1_low = 300K, T1_high = 400K:

n_carnot_low = 1 - (T1/(T1*cr^(k-1))) = 1 - (300/(300*10^(1.4-1))) = 60.19%
n_carnot_high = 1 - (T1/(T1*cr^(k-1))) = 1 - (400/(400*10^(1.4-1))) = 60.19%

You also can't compare gas turbine intercoolers with piston engine intercoolers. The gas turbine intercooler cools the gas after/during compression while the piston engine intercooler cools the gas before compression. A major difference.

[PlatinumZealot]

What I wrote is correct.

Charge cooling doesn't automatically mean higher engine efficiency, infact, better intercooling can lead to a lower engine efficiency. That have been shown in the past. For instance, Hondas RA168E had a 4% higher BSFC at an air inlet temperature of 40 degC than at 80 degC. It did however lose power with increased temperature, and going beyond 70 degC didn't really offered any advantages.

How did the intake temperature change from 40*C to 80*C in your example? Post the article please...

[PlatinumZealot]

OK, Edis I have found the article!

http://docs.google.com/viewer?a=v&q=cac ... 2aLePNkdBg

OK first of all... at 2.5 bar boost you are not going to get 70*C without an inter-cooler. Compressing air at 2.5 bar you are going to get about 30% higher temperatures... which can be anywhere from 116*C Celsius or higher!

In the paper, the R168E of which you speak was set in "save fuel" mode, and the some of the air was sent through the inter-cooler and the balance of that air bypassed the inter-cooler through a bypass valve... So you are still inter cooling the air.

Also.. the fuel for that engine was a newly developed fuel. It produced more power per Kg. The paper says the the volatility of the fuel was very poor, and warm temperatures helped it vapourise better. The effect levels of above the 70*C though. This is another specific imperfection (you can see the awkward location of the 12 injectors, who knows what type of sprays came out of them?) but it still doesn't change the facts.

So many things you can do to increase the BSFC.

And again thos things still don't change the fact that inter cooling is used to increase thermodynamic efficiency.
I have already stated that adding any kind of heat to engines is good (even via intake air temperature), but it is obvious that there is a balance between this and the energy it takes to compress the air inside the engine and whatever mixing and combustion effects you have thereafter. All engines have an optimal setting.

I do not understand how you categorically state that "Intercooling does not have a positive effect on engine efficiency."

So why use inter coolers in the first place?

[Saribro]

I do not understand how you categorically state that "Intercooling does not have a positive effect on engine efficiency."

Eh? You mean this?

Intercooling is useful in keeping the engine cool and improving volumetric efficiency, but it doesn't have to have a positive effect on engine efficiency.

Charge cooling doesn't automatically mean higher engine efficiency

"Doesn't have" and "doesn't have to have" are two different things.
"Doesn't automatically" is different to "never".

[ringo]

I'm going to cut your post short, as the rest of it isn't really a strong argument to the fundamental reasoning behind inter cooling.

It can be proven to you that charge cooling increases efficiency.
Mass flow and temperature difference is king in any engine design.
Take a while to consider what the inter-cooler does to the air, and how it affects it's mass flow and temperature going into the engine.
then consider the Carnot efficiency.
It's simple as that.

A gas turbine power plant can easily get a 20% increase in efficiency with an intercooler.
All the Nox and other little nuances in the rest of the post, can't compare to that 20% chunk of efficiency.

Even with consideration for isentropic efficiency below unity and pressure drop in the heat exchanger, intercooling is still very advantageous.

I suggest you look up SAE Technical Paper 890977, Fig 10, Effect of intake air temperature on power and BSFC.

And you're wrong about Carnot:

n_carnot = 1 - (Q_removed/Q_added) = 1 - (T1/T2)
T2 = T1*cr^(k-1)

Lets assume cr=10 and T1_low = 300K, T1_high = 400K:

n_carnot_low = 1 - (T1/(T1*cr^(k-1))) = 1 - (300/(300*10^(1.4-1))) = 60.19%
n_carnot_high = 1 - (T1/(T1*cr^(k-1))) = 1 - (400/(400*10^(1.4-1))) = 60.19%

You also can't compare gas turbine intercoolers with piston engine intercoolers. The gas turbine intercooler cools the gas after/during compression while the piston engine intercooler cools the gas before compression. A major difference.

Edis, an intercooler widens the range of temperature that an engine operates between.
Carnot efficiency is the maximum efficiency a heat engine can have.
No engine achieves this, but you get closer to it by adding an intercooler to a turbo charged engine.

I don't know what your example is saying.

But no compressor needs hotter air going into it.