2021 Engine thread

[Tommy Cookers]

[quote=Mudflap].........Other claims are that a hotter piston also helps combustion and that the reduced heat transfer improves TE - I have not seen concrete evidence of these.[/quote]

well the alloy piston revolution in the 20s was largely about increasing TE as the lower piston crown temperature allowed higher CR

highly boosted heat dilution engines have higher mean gas pressures and so relatively high piston frictional losses
a 1 piece steel piston/guide rod might well usefully eliminate side load friction and have benefits at high rpm (and give SHM)

[63l8qrrfy6]

.........Other claims are that a hotter piston also helps combustion and that the reduced heat transfer improves TE - I have not seen concrete evidence of these.

well the alloy piston revolution in the 20s was largely about increasing TE as the lower piston crown temperature allowed higher CR

highly boosted heat dilution engines have higher mean gas pressures and so relatively high piston frictional losses
a 1 piece steel piston/guide rod might well usefully eliminate side load friction and have benefits at high rpm (and give SHM)

I am not quite sure what you mean by guide rod. Something like the crosshead rods used in the big low speed industrial diesels ?

[godlameroso]

2.0L V6 ,Twin Turbo,KERS both Axle(output only rear axle),15,000 rpm redline,no fuel flow or max fuel allowed
No HERS

Qual 1200hp, Race 1000hp

So late 80's engine sound and power(more down low torque) but with heavier cars.

Why the larger displacement? They could have a V8 with that.

Who want's vegetable juice.

[wuzak]

2.0L V6 ,Twin Turbo,KERS both Axle(output only rear axle),15,000 rpm redline,no fuel flow or max fuel allowed
No HERS

Qual 1200hp, Race 1000hp

So late 80's engine sound and power(more down low torque) but with heavier cars.

The 1980s engines did that with 1.5l capacity. So why 2.0l?

Is the power output including KERS?

1987, max MAP 4 bar, qualifying ~1,000hp, race ~800hp. So similar to what the current engines produce sans ERS.
1988, max MAP 2.5 bar, qualifying ~690hp, race ~625hp.

The problem I see with using just KERS is that it limits how long it can be used.

When asked of the differences between his Force India Mercedes F1 car and Porsche 919 Le Mans car, Nico Hulkenberg said that the Le Mans car leapt out of the corner but lost momentum part way down, while the F1 car pulled all the way down the straights. I like the sound of the latter better.

[godlameroso]

In 2015, the KERS output on the Porsche was 450kW, almost 3.5x the output of the F1 KERS, also the Porsche has GU-H + front MGU-K. And although the deployment is twice as much as an F1 car, it had to be stretched out over twice the distance of an average F1 track, so they had to be strategic with their deployment, they couldn't just go full tilt down every straight, they'd run out of deployment by Mulsanne corner.

[Sasha]

2.0L V6 ,Twin Turbo,KERS both Axle(output only rear axle),15,000 rpm redline,no fuel flow or max fuel allowed
No HERS

Qual 1200hp, Race 1000hp

So late 80's engine sound and power(more down low torque) but with heavier cars.

The 1980s engines did that with 1.5l capacity. So why 2.0l?

Is the power output including KERS?

1987, max MAP 4 bar, qualifying ~1,000hp, race ~800hp. So similar to what the current engines produce sans ERS.
1988, max MAP 2.5 bar, qualifying ~690hp, race ~625hp.

The problem I see with using just KERS is that it limits how long it can be used.

When asked of the differences between his Force India Mercedes F1 car and Porsche 919 Le Mans car, Nico Hulkenberg said that the Le Mans car leapt out of the corner but lost momentum part way down, while the F1 car pulled all the way down the straights. I like the sound of the latter better.

1987 engine only had to last a few laps in Qual then replaced for race.
2021 3 or 4 engines for the whole season.

So 1000-1200 hp is very good for a engine that would has to last 5-6 race weekends.

[wuzak]

Qual 1200hp, Race 1000hp

So late 80's engine sound and power(more down low torque) but with heavier cars.

The 1980s engines did that with 1.5l capacity. So why 2.0l?

Is the power output including KERS?

1987, max MAP 4 bar, qualifying ~1,000hp, race ~800hp. So similar to what the current engines produce sans ERS.
1988, max MAP 2.5 bar, qualifying ~690hp, race ~625hp.

The problem I see with using just KERS is that it limits how long it can be used.

When asked of the differences between his Force India Mercedes F1 car and Porsche 919 Le Mans car, Nico Hulkenberg said that the Le Mans car leapt out of the corner but lost momentum part way down, while the F1 car pulled all the way down the straights. I like the sound of the latter better.

1987 engine only had to last a few laps in Qual then replaced for race.
2021 3 or 4 engines for the whole season.

So 1000-1200 hp is very good for a engine that would has to last 5-6 race weekends.

If the current engines were changed to be twin turbo plus KERS, the MGUH being excluded, and the KERS power increased to 300hp from 160hp with recovery on front and rear axles, you would have 1,000+hp. In the region of 1,050-1,100hp in fact.

That is with the 100kg/h fuel flow rate.

Without the MGUH the need for the fuel flow rate formula is gone. So you could have a flat fuel flow rate which could help with the turbo lag issue.

[gruntguru]

you seem to be saying that those NA F1 people were wrong in their piston material ?

and the mass-specific stiffness of steel being equal to that of Al alloy is not a dog in this fight
the piston being substantially loaded in bending, alloy wins as if 3x the thickness has greater strength for the same weight etc
or less weight for the same strength
the reason why planes are alloy not steel

ok the temperature is the crucial factor here (as with some planes or parts thereof)
but it's hard to believe a steel piston is better rpm wise than would an alloy piston be even within its safe working temperature

While 3x thickness gives you lower stresses, the endurance strength is still lower - by about 4 times (at 10 million cycles, after than Al keeps dropping even further behind). Overall the factor of safety will favor steel pistons if only by a small margin.

Endurance strength is a material property, it is not geometry dependent.

Thickness of the section has much more effect than modulus or strength. I just ran FEA on a flat disc (think piston crown) in steel and aluminium. I adjusted thickness to give the same mass for each. (Thickness for steel was 1.72mm, Al was 5mm) With uniform pressure loading to one side of the disk, I got the following results.

Stress at centre of disc - 8x higher for steel.
Deflection at centre of disc - 8x higher for steel.

Endurance strength means squat when you are forced to design for yield strength.

[63l8qrrfy6]

you seem to be saying that those NA F1 people were wrong in their piston material ?

and the mass-specific stiffness of steel being equal to that of Al alloy is not a dog in this fight
the piston being substantially loaded in bending, alloy wins as if 3x the thickness has greater strength for the same weight etc
or less weight for the same strength
the reason why planes are alloy not steel

ok the temperature is the crucial factor here (as with some planes or parts thereof)
but it's hard to believe a steel piston is better rpm wise than would an alloy piston be even within its safe working temperature

While 3x thickness gives you lower stresses, the endurance strength is still lower - by about 4 times (at 10 million cycles, after than Al keeps dropping even further behind). Overall the factor of safety will favor steel pistons if only by a small margin.

Endurance strength is a material property, it is not geometry dependent.

Thickness of the section has much more effect than modulus or strength. I just ran FEA on a flat disc (think piston crown) in steel and aluminium. I adjusted thickness to give the same mass for each. (Thickness for steel was 1.72mm, Al was 5mm) With uniform pressure loading to one side of the disk, I got the following results.

Stress at centre of disc - 8x higher for steel.
Deflection at centre of disc - 8x higher for steel.

Endurance strength means squat when you are forced to design for yield strength.

You did not have to do fea for that - the disk you are discribing is just an axisymmetric beam. From beam bending equations you would get about 8.4 higher stress in steel and 8.6 higher deflection assuming E= 200 Gpa for steel and 70 Gpa for Al.

The problem is that you are assuming the load is carried by the crown - in reality the largest portion of the load ( that creates bending about the pin axis) is carried by the ribs joining the pin bores to the skirt. The moment of area of these is proportional to the cube of the height rather than the cube of the thickness. Now, if you redo your fea the stress in the steel rib is only 2.9 times higher than Al while deflection is virtually the same (2% higher with the elastic moduli I mentioned ).

The same results also hold true for the pin bores which can be assumed to be loaded in pure tension under inertial loads and pure compression under gas loads.

Also if you do the math the pistons experience about 12 milion load reversals in 300 km per race at 150 kmph, 10 k rpm and 5 races - not even counting qualy. At that many cycles you have to design for theoretically infinite life therefore endurance strenght is important. Classic fatigue theory assumes about 1000 cycles to failure at stresses equal to 0.9 x yield strength...

[coaster]

I suspect that this very website had some bearing on the decision for the 1.6 v6 turbo era, almost like a public opinion forum to which manfacturers and the fia paid heed to.
With this in mind, we are in a way responsible for the future for of the sport that we love, I just pray f1 remains the pinnacle of car technology and driver talent regardless of power unit.

[godlameroso]

While 3x thickness gives you lower stresses, the endurance strength is still lower - by about 4 times (at 10 million cycles, after than Al keeps dropping even further behind). Overall the factor of safety will favor steel pistons if only by a small margin.

Endurance strength is a material property, it is not geometry dependent.

Thickness of the section has much more effect than modulus or strength. I just ran FEA on a flat disc (think piston crown) in steel and aluminium. I adjusted thickness to give the same mass for each. (Thickness for steel was 1.72mm, Al was 5mm) With uniform pressure loading to one side of the disk, I got the following results.

Stress at centre of disc - 8x higher for steel.
Deflection at centre of disc - 8x higher for steel.

Endurance strength means squat when you are forced to design for yield strength.

You did not have to do fea for that - the disk you are discribing is just an axisymmetric beam. From beam bending equations you would get about 8.4 higher stress in steel and 8.6 higher deflection assuming E= 200 Gpa for steel and 70 Gpa for Al.

The problem is that you are assuming the load is carried by the crown - in reality the largest portion of the load ( that creates bending about the pin axis) is carried by the ribs joining the pin bores to the skirt. The moment of area of these is proportional to the cube of the height rather than the cube of the thickness. Now, if you redo your fea the stress in the steel rib is only 2.9 times higher than Al while deflection is virtually the same (2% higher with the elastic moduli I mentioned ).

The same results also hold true for the pin bores which can be assumed to be loaded in pure tension under inertial loads and pure compression under gas loads.

Also if you do the math the pistons experience about 12 milion load reversals in 300 km per race at 150 kmph, 10 k rpm and 5 races - not even counting qualy. At that many cycles you have to design for theoretically infinite life therefore endurance strenght is important. Classic fatigue theory assumes about 1000 cycles to failure at stresses equal to 0.9 x yield strength...

What if there was a way to use less material in that region but retain similar strength, for example using a diamond cubic lattice or octet truss to create the ribs via 3d printing?

[roon]

How about something like this along with an airbox-like header insulating cover that has transparent vacuum- or inert-gas-insulated panels. From above viewers could see the glowing heart of the engine.



Also, in lieu of shrouded brake ducts going away, institute injected water cooling for the brakes to bring back a visual indicator for braking. A small injector in the brake duct inlet, small feed tubes built into the suspension arms, and a water reservoir & pump inboard. Of course, make sure the steam travels *through* the disc and not over its outer surface. Plumes of steam out of the wheels under braking. Also this would give the aero nerds something to ogle.

Also, mandated some dry ice vapor on the tracksurface to get kicked up by the cars, for similar purposes. Since big aero is, and likely will, continue to be a feature of this sport, make it part of the spectacle. Visible contrails would be fantastic.

Maybe if the they did away with radiators and instituted evaporative cooling we could ramp this up a notch. The coolant would get sprayed on the engine & headers, all the hot parts. The coolant would be a depleting substance, a diminishing ballast, like the fuel. Could be replenished during pitstops. Or not, depending on consumption.

Could be kind of interesting for a formula. Evaporative cooling would make for narrow packaging (no HXs) and would exaggerate changing vehicle weight along with a depleting fuel tank, while giving some visual show from the vapor trail.

Add some plant oils to the coolant and we can provide the fans with a pleasant odor. Sandalwood, lemongrass, peppermint, citrus. Sensitive noses would be able to discern which car had just passed based on smell. "Ah, yep, that's a McLaren that one. Smells like orange."

[J.A.W.]

Castor bean oil has a lovely 'traditional' powersports aroma, if we're into iconic reboots..

& it "Breaks the ice at parties", as Monty Python would have it..
http://www.coolmaterial.com/home/two-st ... ke-candle/

[63l8qrrfy6]

What if there was a way to use less material in that region but retain similar strength, for example using a diamond cubic lattice or octet truss to create the ribs via 3d printing?

I think that such structures hamper conductive heat transfer which is critical for pistons.

I am aware of the concept f1 head done by FIT but I have yet to see something that proves it really works.

[godlameroso]

Pourus structures are far more effective at heat transfer actually. So depending on the density of your lattice, you'd get lighter weight, better stiffness and strength, along with better heat transfer. The challenge is making the darn thing with 3d printing.