How do the current power units meter air flow into the engine?

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
User avatar
godlameroso
407
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

How do the current power units meter air flow into the engine?

Post

Do they use MAP sensors MAF sensors or a combination of both, or neither?

I suppose they'd have to use both to some extent, because MAP sensors are more geared towards predetermined maps, but at the same time you lose some precision in comparison to a MAF sensor. The drawback of the MAF sensor of course being sensitive to pressure waves in the intake depending on flow, pipe length, frequency.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

toraabe
toraabe
16
Joined: Thu Oct 09, 2014 9:42 am

Re: How do the current power units meter air flow into the engine?

Post

godlameroso wrote:
Wed Mar 29, 2017 3:36 pm
Do they use MAP sensors MAF sensors or a combination of both, or neither?

I suppose they'd have to use both to some extent, because MAP sensors are more geared towards predetermined maps, but at the same time you lose some precision in comparison to a MAF sensor. The drawback of the MAF sensor of course being sensitive to pressure waves in the intake depending on flow, pipe length, frequency.
They use the MGU-H to control the RPM of the turbine according to RPM

User avatar
godlameroso
407
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

Re: How do the current power units meter air flow into the engine?

Post

What does that have to do with metering airflow into the engine? Genuinely curious here, usually you need a host of sensors in order to determine how much fuel to inject, how is this done with the MGU-H?
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

3jawchuck
3jawchuck
45
Joined: Tue Feb 03, 2015 7:57 am

Re: How do the current power units meter air flow into the engine?

Post

toraabe wrote:
Thu Mar 30, 2017 9:08 am
godlameroso wrote:
Wed Mar 29, 2017 3:36 pm
Do they use MAP sensors MAF sensors or a combination of both, or neither?

I suppose they'd have to use both to some extent, because MAP sensors are more geared towards predetermined maps, but at the same time you lose some precision in comparison to a MAF sensor. The drawback of the MAF sensor of course being sensitive to pressure waves in the intake depending on flow, pipe length, frequency.
They use the MGU-H to control the RPM of the turbine according to RPM
So, they know how much air is pumped because they know the rate of spin?
Wouldn't that be subject to losses and uncertainty?

wuzak
wuzak
356
Joined: Tue Aug 30, 2011 2:26 am

Re: How do the current power units meter air flow into the engine?

Post

3jawchuck wrote:
Thu Mar 30, 2017 12:12 pm
toraabe wrote:
Thu Mar 30, 2017 9:08 am
godlameroso wrote:
Wed Mar 29, 2017 3:36 pm
Do they use MAP sensors MAF sensors or a combination of both, or neither?

I suppose they'd have to use both to some extent, because MAP sensors are more geared towards predetermined maps, but at the same time you lose some precision in comparison to a MAF sensor. The drawback of the MAF sensor of course being sensitive to pressure waves in the intake depending on flow, pipe length, frequency.
They use the MGU-H to control the RPM of the turbine according to RPM
So, they know how much air is pumped because they know the rate of spin?
Wouldn't that be subject to losses and uncertainty?
Yes, probably in conjunction with a MAP sensor.

I doubt very much that they use an air flow sensor.

User avatar
godlameroso
407
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

Re: How do the current power units meter air flow into the engine?

Post

Probably why the drivers have to choose engine maps. Unless they're not really maps but mapping strategy for the ecu.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

mrluke
mrluke
124
Joined: Fri Nov 22, 2013 7:31 pm

Re: How do the current power units meter air flow into the engine?

Post

Don't think anybody in motorsport would willingly choose to use a maf??

User avatar
godlameroso
407
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

Re: How do the current power units meter air flow into the engine?

Post

wuzak wrote:
Thu Mar 30, 2017 1:46 pm
3jawchuck wrote:
Thu Mar 30, 2017 12:12 pm
toraabe wrote:
Thu Mar 30, 2017 9:08 am


They use the MGU-H to control the RPM of the turbine according to RPM
So, they know how much air is pumped because they know the rate of spin?
Wouldn't that be subject to losses and uncertainty?
Yes, probably in conjunction with a MAP sensor.

I doubt very much that they use an air flow sensor.
And a TPS and IATS and CTS and a wideband, at the very least.

A MAF sensor has some benefits over a MAP sensor. A lot of OEMs use combination sensors, Porsche, GM among others. Honda for a fact loves using MAP sensors, it's why they need tuning even for bolt ons.

MAF sensors are more precise, but also more prone to signal distortion, particularly in part throttle conditions.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

neilbah
neilbah
17
Joined: Fri Jul 10, 2009 7:36 pm

Re: How do the current power units meter air flow into the engine?

Post

I was wondering about this, the speed of turbine wouldnt be enough to determine the volume of air because there are other factors involved such as altitude and temperature. A MAP sensor used to be the more common on turbocharged engines although there are examples of both being used together.

gruntguru
gruntguru
455
Joined: Sat Feb 21, 2009 6:43 am

Re: How do the current power units meter air flow into the engine?

Post

Probably a more interesting question is "what role does air flow play in regulating the output of these engines?"

Traditional approach.
Driver's foot demands a change in torque output. Butterfly valve(s) adjsut to change airflow to engine. ECU senses any change in airflow and/or MAP and/or Throttle position and adjusts fuel quantity to maintain best-power AFR.

New approach.
Driver's foot demands a change in torque output. ECU immediately adjust fuel quantity to match the torque demanded. (This is possible under most conditions because the engine is running in a highly-excess-air state and more fuel will produce more power - instantly). At the same time the ECU will adjust butterfly valves and/or MGUH output to bring the MAP and exhaust-backpressure (and therefore air flow) to the most efficient levels for the new fuel rate.

So airflow plays a slightly less critical role in the current lean-burn ICE.

BTW. Sensing exhaust-backpressure would also be essential.
je suis charlie

roon
roon
449
Joined: Sat Dec 17, 2016 6:04 pm

Re: How do the current power units meter air flow into the engine?

Post

Good post, gg. It makes me wonder if the drafting of the current engine formula to include an MGUH was less about energy recovery and more about the need for fine airflow control in an efficiency formula.

Said another way: could the ICE-only efficiency of the current PUs have been achieved without pressure charging? (And well controlled pressure charging at that—as is delivered from an MGUH.)

Tommy Cookers
Tommy Cookers
535
Joined: Fri Feb 17, 2012 3:55 pm

Re: How do the current power units meter air flow into the engine?

Post

[quote=roon post]
Good post, gg. It makes me wonder if the drafting of the current engine formula to include an MGUH was less about energy recovery and more about the need for fine airflow control in an efficiency formula.
Said another way: could the ICE-only efficiency of the current PUs have been achieved without pressure charging? (And well controlled pressure charging at that—as is delivered from an MGUH.)[/quote]

if you mean could this ICE-only efficiency be achieved NA ? - definitely not

because designing around NA heat dilution (leaning) means making the engine bigger dimensionally
yes, the heat loss to coolant is reduced - but it's reduced less NA than boosted
to put it another way - the efficiency-optimal leaning (and its scope) is less with NA engines than than boosted engines
(though NA downsizes by exhaust blowdown recovery, about 10% more power is available free ie without penalty in crankshaft power)

agreed the F1 engines have no more need than did their predecessors for exact mixture control in the short-term
they will produce more power by reducing the AFR - but this can only be temporary (for cooling and fuel use reasons)
reducing the AFR/boost (raising compressor efficiency) lowers the charge temperature before ignition, so alleviating potential problems post ignition
also, temporarily reducing the AFR seems likely for combustion stability in transient conditions


exhaust recovery makes the F1 engine further downsized wrt heat loss (than turbo downsizing)
but the mechanical losses are not further downsized (because the higher compression work etc)
and exhaust recovery seems unimproved

because heat dilution works best at high % power, burning fuel hybrid-driving the K is used to improve efficiency at lower % power
for the road a much cheaper way is to buy a smaller, simpler, engine - but shareholders don't want us to do this
Last edited by Tommy Cookers on Fri Mar 31, 2017 5:56 pm, edited 1 time in total.

roon
roon
449
Joined: Sat Dec 17, 2016 6:04 pm

Re: How do the current power units meter air flow into the engine?

Post

Thanks, TC. Further to the point, as ICE efficiency continues to improve, the MGU-H may be regarded as an electric supercharger & variable backpressure device (that spinning baffle interfering the exhaust stream heretofore known as the turbine). Since the 'G' & 'H' in MGU-H become less important as combustion efficiency improves.

User avatar
godlameroso
407
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

Re: How do the current power units meter air flow into the engine?

Post

gruntguru wrote:
Fri Mar 31, 2017 4:24 am
Probably a more interesting question is "what role does air flow play in regulating the output of these engines?"

Traditional approach.
Driver's foot demands a change in torque output. Butterfly valve(s) adjsut to change airflow to engine. ECU senses any change in airflow and/or MAP and/or Throttle position and adjusts fuel quantity to maintain best-power AFR.

New approach.
Driver's foot demands a change in torque output. ECU immediately adjust fuel quantity to match the torque demanded. (This is possible under most conditions because the engine is running in a highly-excess-air state and more fuel will produce more power - instantly). At the same time the ECU will adjust butterfly valves and/or MGUH output to bring the MAP and exhaust-backpressure (and therefore air flow) to the most efficient levels for the new fuel rate.

So airflow plays a slightly less critical role in the current lean-burn ICE.

BTW. Sensing exhaust-backpressure would also be essential.
The MGU-K also plays a role as far as torque fill and crank output is concerned in relation to engine maps.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

Tommy Cookers
Tommy Cookers
535
Joined: Fri Feb 17, 2012 3:55 pm

Re: How do the current power units meter air flow into the engine?

Post

@ roon
afaik ......
in-cylinder combustion efficiency (with non-rich mixtures) has always been better than 95%
ie CE lower than this proclaims over-leaning, low CE seems always to involve inconsistent combustion

turbine recoverable power seems from calculations that some have posted to be rather independent of exhaust pressure
leaning/heat dilution with greater air mass yields greater exhaust mass at greater pressure and a temperature that is reduced less than proportionately
actual back pressure is a small proportion of induction pressure and mean exhaust pressure
Last edited by Tommy Cookers on Fri Mar 31, 2017 6:00 pm, edited 1 time in total.