Post-Turbo exhaust design

[Holm86]

The regulations do form an interesting loophole here.

5.8.1 With the exception of incidental leakage through joints (either into or out of the system), all (and only) the fluids entering the compressor inlet must exit from the engine exhaust system.[/quote

So we can't spray anything but fuel into the intake and there cannot be anything but the fluids entering the compressor exiting the exhaust.

However, since EGR and crankcase breather systems are allowed, that brings up the point that if an EGR system had some type of water injection, it could be allowed if creatively implemented. They key thing here is that spraying into the exhaust isn't expressly prohibited, but any sprayed fluids must go through the compressor inlet without being considered part of the intake stream.

The reduction in available oxygen per volume of gas is no problem, as there's no limit on airflow, but this would inherently increase the volume of gas that requires compression. It's hard to judge just through handwaving whether or not this system would actually allow higher CR to the point of being beneficial; water is heavy, these are all extra components that would be adding to the weight, and are susceptible to failure.

Thats the section of the regulations Im thinking about. But Im thinking more in some leaking through joints on purpose.

[dren]

The water could have a cylinder cooling effect and also raise exhaust pressure on the turbine if injected right.

[WhiteBlue]

The water could have a cylinder cooling effect and also raise exhaust pressure on the turbine if injected right.

Can you elaborate on the latter part?

The water will have to be injected into the EGR to make it legal and it will have to be water only which will make it a bit difficult in terms of corrosion protection of the system. But perhaps they can use some lubricants in the pressurization, which accidentally find their way into the exhaust gas stream with the water. You cannot prevent a certain amount of leakage through the components of the water pressurization system. How much hdrocarbons may find their way into the exhaust gas stream would be open to speculation. Perhaps they can use a kind of lubricant that gets washed out with the water nicely?

[dren]

If injected after combustion the water will flash, taking a little heat but increasing pressure. Don't know if the expansion is more of use than the temperature in the turbine?

[WhiteBlue]

If injected after combustion the water will flash, taking a little heat but increasing pressure. Don't know if the expansion is more of use than the temperature in the turbine?

That is not allowed. You cannot inject water directly into the cylinder. The only way to do it legally is to inject it into the EGR.

[aussiegman]

The regulations do form an interesting loophole here.

5.8.1 With the exception of incidental leakage through joints (either into or out of the system), all (and only) the fluids entering the compressor inlet must exit from the engine exhaust system.

So we can't spray anything but fuel into the intake and there cannot be anything but the fluids entering the compressor exiting the exhaust.

However, since EGR and crankcase breather systems are allowed, that brings up the point that if an EGR system had some type of water injection, it could be allowed if creatively implemented. They key thing here is that spraying into the exhaust isn't expressly prohibited, but any sprayed fluids must go through the compressor inlet without being considered part of the intake stream.

If injected after combustion the water will flash, taking a little heat but increasing pressure. Don't know if the expansion is more of use than the temperature in the turbine?

That is not allowed. You cannot inject water directly into the cylinder. The only way to do it legally is to inject it into the EGR.

IMHO, you cannot use water as a cooling agent injected anywhere such as the EGR as you describe where you are utilising its latent heat of vaporisation properties due to 7.6 as it is written in the Regs (July 2013):

7.6 Cooling systems :
The cooling systems of the power unit, including that of the charge air, must not intentionally make use of the latent heat of vaporisation of any fluid with the exception of fuel for the normal purpose of combustion in the engine as described in Article 5.14.

As such a water injection system placed anywhere is not legal under 7.6 unless you want to argue it is not making use of the latent heat of vaporisation of the water being injected/introduced either in the EGR system or anywhere else. I am not sure what use you would/could argue that does not rely on the use of the latent heat of vaporisation and I doubt lubrication or cleaning properties would pass scrutiny.

However, I still believe that you could (possibly) use fuel as a cooling agent introduced pre-compressor by "spraying fuel" which is specifically excluded from prohibition as defined in 5.14.2 which specifically does not use the term "injecting" fuel. You would also have to avoid using those parts as described under the Appendix to the Technical Regulations which sets out approved DI parts for use in injection systems.

There was a discussion previously surrounding this topic on this forum which I was involved in so apologies for the re-hash..

IMHO (and Whiteblue, I know you did and likely still will disagree) that under the Regs as they stand there exists accommodations to use fuel introduced pre-compressor for the purposes of charge cooling.

It hinges on interactions of 5.8.1, 5.10.2, 5.14.2 and 7.6.

5.8.1 With the exception of incidental leakage through joints (either into or out of the system), all (and only) the fluids entering the compressor inlet must exit from the engine exhaust system.

5.8.1 prevents post-compressor introduction of any "fluids" such as fuel (the regulations specifically separate "fluids" and "exhaust gases" as separate terms to remove any and all ambiguity that under some circumstances technically gases can be regarded as fluids however here they are separate terms).

As such, you then look to 5.14.2, which sets down the "spraying" of fuel, which is excluded from prohibition under 5.14.2 and therefore permitted into the intake which must be pre-compressor as per 5.8.1.

5.14.2 Other than engine sump breather gases, exhaust gas recirculation, and fuel for the normal purpose of combustion in the engine, the spraying of any substance into the engine intake air is forbidden.

Under 5.14.2 and its interaction with 5.8.1, it specifically states that it is legal and permissable for the "spraying" of fuel for the purposes of normal combustion into the intake pre-compressor. It specifically excludes the "injection" of fuel into the intake by using the term "spraying" separate it from "injection" which then brings this situation to 5.10.2 which covers injection systems and components.

5.10.2 There may only be one direct injector per cylinder and no injectors are permitted upstream of the intake valves or downstream of the exhaust valves. Only approved parts may be used and the list of parts approved by the FIA, and the approval procedure, may be found in the Appendix to the Technical Regulations.

5.10.2 sets down that there can only be one DI per cylinder and that must be located in the cylinder while also defining what are the approved parts which can be for use in direct injection system(s).

However, so far as I am aware there are no Technical Regulations that sets down approved parts for the "spraying" fuel as described in 5.14.2.

As 5.14.2 provides for the "spraying of fuel for the the normal purpose of combustion" then you would need to spray rather than inject fuel pre-compressor and avoid using parts as described or similar to those in the Appendix to the Technical Regulations to avoid possible challenges to the "spraying" system being defined as an "injection" system..

Which takes us back to where this started under 7.6 which does not allow the intentional use of water as a cooling agent but it does allow the use of fuel as a cooling agent as 7.6 specifically sets down "with the exception of fuel for the normal purpose of combustion".

IMHO, there is an allowance for a pre-compressor fuel spraying system that provides cooling benefits which would fulfill the legal requirements of 5.8.1, 5.10.2 and 5.14.2.

To avoid possible challenges, the system should not use defined injection systems while the engine would/should maintain consistent air/fuel ratio's that are deemed to be within the scope of what would be expected from "normal combustion" then it would also fulfill the requirements of 7.6 which requires the use for fuel for the normal purposes of combustion while also legally using the fuel as a cooling agent for the intake charge through the wording "with the exception of fuel" under 7.6.

It all hinges on whether there is a performance advantage to pre-compressor spraying of fuel into the intake which as a side benefit cools the intake charge over and above what is possible with an intercooler when considering packaging contraints, fuel flow limitations, performance, weight etc.

This is by no means a 100% water tight argument, however I do believe that there is certainly a strong case to be had that you could legally use such a system under the regs as they stand and where there was a performance advantage.


It may be the FIA are unconcerned as they perceive no advantage due to the fuel flow limitation or wear induced through fuel impacting with the compressor etc, however until either FIA sets down this is not a legal system on application or provision then it would seem to be legal if perhaps controversial.

[WhiteBlue]

I simply think that 7.6 does not apply because EGR is not part of the cooling system. 7.6 has the purpose of stopping you using a Rankine type cooling process which would be a closed system with a medium that evaporates and condenses. But as I said it is obviously not applicable in my view when you use water outside of the cooling system and manage to get it somewhere legally into the charge air, for instance in the EGR. IMO it's a bit ambiguous and you would have to have the opinion of the FiA on it. If we were in a patent litigation lawyers would probably love this one for the ton of money they could make from it. In the end it comes down to what the FiA and possibly an IT would make out of it.

[aussiegman]

I simply think that 7.6 does not apply because EGR is not part of the cooling system.

AFAIK, the regulations do not specifically define the term EGR or exhaust gas recirculation. Exhaust gas recirculation is referenced only in 5.14.2 as one of the possible “substances” permissible for inclusion in the engine intake air charge.

Further, the Regulations do not specify what is or is not a cooling system. Article 7 simply defines specification for coolant tanks and what system of operation a cooling system can use, namely a closed and pressurized liquid heat management system with a maximum of 3.75 bar operating pressure. It then goes further to set down coolant lines cannot run through the cockpit. As such water introduction fails under Article 7 on two counts.

Firstly, if you were to use an EGR system and then allow that system to have components that introduce any fluid other than fuel, such as water, to the EGR system where it mixes with the exhaust gas prior to recirculation into the engine intake air where it becomes part of the intake charge air, such inclusion would have a primary effect of cooling the recirculated exhaust gas prior to introduction. As such it fails Article 7 as it is not a close and pressurized cooling system.

Secondly, it would fall foul of the requirement of Regulation 7.6 insomuch as it would be a charge air cooler (by cooling the exhaust gas undergoing recirculation) that uses the latent heat of vaporization of a fluid (water) for cooling of the recirculated gas in contravention of Regulation 7.6.

Additionally you would fail 5.14.2 as by introducing a fluid other than fuel, in this case water, into the recirculated exhaust gases you breach the requirement that “Other than engine sump breather gases, exhaust gas recirculation, and fuel for the normal purpose of combustion in the engine, the spraying of any substance into the engine intake air is forbidden”. Water or other fluids, gases, plasma’s or phase conjugates etc are not permitted to be introduced into the intake charge by systems contained on the vehicle under the regulations . By recirculating the exhaust gas it becomes part of the intake charge and subject to the relevant regulations.

7.6 has the purpose of stopping you using a Rankine type cooling process which would be a closed system with a medium that evaporates and condenses.

I think you are stretching a little to far on this for what ever reason and I strongly (vehemently even) contest this is the purpose of 7.6 as I just do not see any possible incarnation where using a Rankine cooling system would derive sufficient benefit to be of advantage due to weight and complexity involved in deriving any benefit from a Rankine cooling process and the fact that any energy derived would not be able to be utilised.

IMHO, 7.6 simply goes to defining that cooling systems must be closed systems that do not use evaporation of fluid(s) for effect. By removing the ability to utilise the latent heat of vaporisation of fluids the cooling system must simply be a closed heat transfer system.

But as I said it is obviously not applicable in my view when you use water outside of the cooling system and manage to get it somewhere legally into the charge air, for instance in the EGR.

I just can’t see any way you could legally get water from the cooling system into the intake charge legally under the current regulations.

IMO it's a bit ambiguous and you would have to have the opinion of the FiA on it. If we were in a patent litigation lawyers would probably love this one for the ton of money they could make from it. In the end it comes down to what the FiA and possibly an IT would make out of it.

Again, we must agree to disagree and that’s the whole point, different points of view. The regs to my mind simply do not allow for the introduction of any fluid other than fuel into the intake charge by systems contained within the vehicle systems. It only allows for the injection of fuel via the individual direct injection fuel injectors or vi an undetermined system that could “spray” fuel pre compressor.

As a lawyer, I can see what you mean by the "patent lawyer" comment but then again as a lawyer I think the regulations simple preclude using water in any way other than as a fluid heat transfer medium with in a sealed cooling system.

[WhiteBlue]

I agree to disagree. You are obviously no familiar with the prior use of latent heat in turbo F1 and with the research that was done by BMW.

[aussiegman]

I agree to disagree. You are obviously no familiar with the prior use of latent heat in turbo F1 and with the research that was done by BMW.

I am familiar with previous research in this area ( Honda as well as BMW and numerous Diesel engine manufacturers have done research in this area), however given the current restrictions in the 2014 regulations I don't see how it is either possible or relevant to consider a Rankine WHR system.

Regardless of 7.6 which i do not think covers the system you are considering, 5.2.1 covers any Rankine type WHR system as it states quite clearly:

5.2.1 The use of any device, other than the engine described in 5.1 above, and one MGU-K, to propel the car, is not permitted.

So no Rankine WHR system due to 5.2.1 and not 7.6, IMHO.

[Holm86]

If you have a WHR system to drive the turbo I don't see how it would conflict with 5.2.1

[aussiegman]

If you have a WHR system to drive the turbo I don't see how it would conflict with 5.2.1

Under the regs IMHO i do not believe you could use a Rankine WHR system to drive the turbo and that includes the definitions under 5.2.1.

1.2.6 describes that an electrical engine or the exhaust driven turbine drives the turbine (turbo) and 5.2.1 defines what can drive/propel the car.

The MHU-H is described under 1.2.6 as

1.26 Motor Generator Unit - Heat (MGU-H) :
The Heat Motor Generator Unit is the electrical machine linked to the exhaust turbine of a pressure charging system as part of the ERS.

5.2.1 The use of any device, other than the engine described in 5.1 above, and one MGU-K, to propel the car, is not permitted

So under 5.2.1 only allows the engine and one MGU-K not a Rankine device to propel the car.

[Holm86]

If you have a WHR system to drive the turbo I don't see how it would conflict with 5.2.1

Under the regs IMHO i do not believe you could use a Rankine WHR system to drive the turbo and that includes the definitions under 5.2.1.

1.2.6 describes that an electrical engine or the exhaust driven turbine drives the turbine (turbo) and 5.2.1 defines what can drive/propel the car.

The MHU-H is described under 1.2.6 as

1.26 Motor Generator Unit - Heat (MGU-H) :
The Heat Motor Generator Unit is the electrical machine linked to the exhaust turbine of a pressure charging system as part of the ERS.

5.2.1 The use of any device, other than the engine described in 5.1 above, and one MGU-K, to propel the car, is not permitted

So under 5.2.1 only allows the engine and one MGU-K not a Rankine device to propel the car.

The Rankine wouldn't propel the car. It would assist the turbo. The turbo does not propel the car just as the fuel pump does not propel the car.

[aussiegman]

The Rankine wouldn't propel the car. It would assist the turbo. The turbo does not propel the car just as the fuel pump does not propel the car.

Maybe OK maybe I am casting a wide definition, however regardless, I still think it is excluded under 5.2.1.

Nevertheless, it is excluded by every other aforementioned regulation.

In short, no Rankine device or system is allowable anywhere to drive the car, the turbine, the compressor or to provide WHR anywhere.

As a side, a fuel pump is not an energy recovery system such as a Rankine WHR system. It is a mechanical or electrical device for the purpose of fluid transfer or movement. A Rankine specifically recovers energy that is use by the vehicle to propel it forward, either directly of indirectly. In the end the energy directly recovered propels the car. Different to a fuel pump but sure.

[WhiteBlue]

Never argue with a lawyer particularly when you deal with F1 regs that are notoriously ambiguous and often redundant. I had the Honda toluene evaporation system in mind when I read this thing. It would certainly be forbidden and i think that was the initial intention here. IMO they looked at anything that could be useful to an inventive designer and banned it wholesale so that our aero loving TDs in F1 can keep their beloved toys.