The Gas Turbine powered Lotus 56B

[trinidefender]

great discussion. The Lotus F1 had extra-large fuel tanks, and someone earlier in thread said part-load fuel efficiency of turbines was bad. If a turbine was modified or designed from scratch in 2016 to be a plausible power unit in F1 or other top-level racecar, would it be competitive for fuel efficiency compared to a piston-turbo engine? (ignore hybrid stuff for now).

No. The best gas turbines are at currently at 42 - 43% TE and these are monsters designed to run at constant speed. A small automotive GT with some speed flexibility would struggle to exceed 30%.

OTOH it appears Mercedes are at 45% (or 50%) already.

GG those numbers for steady state gas turbines (usually used in power stations) are a little old. The latest generation add 5 or 6% onto that number.

As far as small scale gas turbines go then yes, the (lack of) development money for them combined with the smaller scale and design to work well in transient conditions means that their efficiency level isn't close. However if a turbine was placed in an F1 car that had the same weight then it would make far more power than the current PU's (ignoring the fuel flow).

The main benefits of turbines have always been low maintenance, for modern gas turbines once service schedules are adhered to properly and good fuel is used engine failures are extraordinarily rare and 2. Very high power to weight ratios.

[gruntguru]

great discussion. The Lotus F1 had extra-large fuel tanks, and someone earlier in thread said part-load fuel efficiency of turbines was bad. If a turbine was modified or designed from scratch in 2016 to be a plausible power unit in F1 or other top-level racecar, would it be competitive for fuel efficiency compared to a piston-turbo engine? (ignore hybrid stuff for now).

No. The best gas turbines are at currently at 42 - 43% TE and these are monsters designed to run at constant speed. A small automotive GT with some speed flexibility would struggle to exceed 30%.

OTOH it appears Mercedes are at 45% (or 50%) already.

GG those numbers for steady state gas turbines (usually used in power stations) are a little old. The latest generation add 5 or 6% onto that number.

That is news to me. Can you provide a source?

[wuzak]

Maybe he is thinking about combined cycle plants?

[trinidefender]

No. The best gas turbines are at currently at 42 - 43% TE and these are monsters designed to run at constant speed. A small automotive GT with some speed flexibility would struggle to exceed 30%.

OTOH it appears Mercedes are at 45% (or 50%) already.

GG those numbers for steady state gas turbines (usually used in power stations) are a little old. The latest generation add 5 or 6% onto that number.

That is news to me. Can you provide a source?

http://www.geaviation.com/press/marine/ ... 31209.html

More information here:
https://powergen.gepower.com/content/da ... lms100.pdf

Combined cycle thermal efficiency has reached over 59% in a power plant in Japan already although using a different gas turbine.

From people i have been in contact with, GE has been investing heavily into combustor technology and materials the last few years for its aerospace gas turbines. This technology will find its way into power station turbines and I think there may soon be a 0.5 - 1.0% jump in thermal efficiency in the next 5 to 10 years.

[gruntguru]

Thanks TD. Not quite the +6% you promised but impressive al the same!

[Scuderia Nuvolari]

I saw this car at an engineer's fair in the early 60's
https://en.m.wikipedia.org/wiki/Chrysler_Turbine_Car

They told me that i was too young to drive it

[Scuderia Nuvolari]

I remember reading about a car at le mans that sucked up some nuts and bolts from the track that went through the engine and still finished 3rd or 4th????

[J.A.W.]

I saw this car at an engineer's fair in the early 60's
https://en.m.wikipedia.org/wiki/Chrysler_Turbine_Car

They told me that i was too young to drive it

Check the 'Automotive News & Technology' section SN, the Chrysler T-C is discussed as a thread topic there..

[CMSMJ1]

Hi guys and girls,

After seeing the famous Lotus 56B gas turbine powered car at the Autosport show last month I have been inspired to investigate more about the car. I've collated a lot of information to do an article on my blog. Have a look, i'm open to opinions...

http://dmanf1.blogspot.co.uk/2016/02

Bit of a ZOMBIE thread, but as I was at Goodwood Festival of Speed this weekend and this car was whooshing up the hill I was minded to try and find some more techincal info about it.

Saw this, and knew the results and it's 4WD but were there any other resources that people might recommend for further reading?

[Zynerji]

great discussion. The Lotus F1 had extra-large fuel tanks, and someone earlier in thread said part-load fuel efficiency of turbines was bad. If a turbine was modified or designed from scratch in 2016(edit 2021) to be a plausible power unit in F1 or other top-level racecar, would it be competitive for fuel efficiency compared to a piston-turbo engine? (ignore hybrid stuff for now).

Strap a turbocharger/ MGUH to a slim pulse jet and drive the wheels electrically?

[UlleGulle]

great discussion. The Lotus F1 had extra-large fuel tanks, and someone earlier in thread said part-load fuel efficiency of turbines was bad. If a turbine was modified or designed from scratch in 2016 to be a plausible power unit in F1 or other top-level racecar, would it be competitive for fuel efficiency compared to a piston-turbo engine? (ignore hybrid stuff for now).

Well, the fuel consumption in turboshaft engines are given as g/kw/h. The new GE T901 has a fuel consumption of about 210g/kw/h. Since the maximum fuel flow is set as 100kg/h that would give you a maximum power output of 476 kw or about 671 metric hp. Not awful, but not as good as the ICE either.

The main point about turboshafts are not efficency but power to weight ratio, which is very important in helicopters. For all it's efficiency, a modern F1 PU stacks in at about 5kw/kg whilst the T901 has 10.7 kw/kg. Turboshafts are also more scalable in power, without growing in size. The T901 produces 3000 shp, but is still no larger than 1,2 meters x 0,8 meters.

[J.A.W.]

great discussion. The Lotus F1 had extra-large fuel tanks, and someone earlier in thread said part-load fuel efficiency of turbines was bad. If a turbine was modified or designed from scratch in 2016 to be a plausible power unit in F1 or other top-level racecar, would it be competitive for fuel efficiency compared to a piston-turbo engine? (ignore hybrid stuff for now).

Well, the fuel consumption in turboshaft engines are given as g/kw/h. The new GE T901 has a fuel consumption of about 210g/kw/h. Since the maximum fuel flow is set as 100kg/h that would give you a maximum power output of 476 kw or about 671 metric hp. Not awful, but not as good as the ICE either.

The main point about turboshafts are not efficency but power to weight ratio, which is very important in helicopters. For all it's efficiency, a modern F1 PU stacks in at about 5kw/kg whilst the T901 has 10.7 kw/kg. Turboshafts are also more scalable in power, without growing in size. The T901 produces 3000 shp, but is still no larger than 1,2 meters x 0,8 meters.

Actually, more than 30 years ago NASA commissioned a study to examine the potential for a 2T
diesel turbo-compound ICE helicopter engine on behalf of the US Army, being a 2.2 litre 6 cylinder,
~1000shp unit proposed by Garrett, & duly finding it would be a more than competitive helo-unit
(esp' since the fuel efficiency/load-range part of the power-to-weight/payload % is so important),
but of course, in the event - other non-technical factors - prevailed.

See link to paper below:

https://ntrs.nasa.gov/archive/nasa/casi ... 001160.pdf

[UlleGulle]

great discussion. The Lotus F1 had extra-large fuel tanks, and someone earlier in thread said part-load fuel efficiency of turbines was bad. If a turbine was modified or designed from scratch in 2016 to be a plausible power unit in F1 or other top-level racecar, would it be competitive for fuel efficiency compared to a piston-turbo engine? (ignore hybrid stuff for now).

Well, the fuel consumption in turboshaft engines are given as g/kw/h. The new GE T901 has a fuel consumption of about 210g/kw/h. Since the maximum fuel flow is set as 100kg/h that would give you a maximum power output of 476 kw or about 671 metric hp. Not awful, but not as good as the ICE either.

The main point about turboshafts are not efficency but power to weight ratio, which is very important in helicopters. For all it's efficiency, a modern F1 PU stacks in at about 5kw/kg whilst the T901 has 10.7 kw/kg. Turboshafts are also more scalable in power, without growing in size. The T901 produces 3000 shp, but is still no larger than 1,2 meters x 0,8 meters.

Actually, more than 30 years ago NASA commissioned a study to examine the potential for a 2T
diesel turbo-compound ICE helicopter engine on behalf of the US Army, being a 2.2 litre 6 cylinder,
~1000shp unit proposed by Garrett, & duly finding it would be a more than competitive helo-unit
(esp' since the fuel efficiency/load-range part of the power-to-weight/payload % is so important),
but of course, in the event - other non-technical factors - prevailed.

See link to paper below:

https://ntrs.nasa.gov/archive/nasa/casi ... 001160.pdf

Never knew about this. Very cool concept. It's pretty much the same power as a modern F1 PU, for just 51 kg more. This begs the question, why hasn't anyone raced compound engines at Le Mans?

[Just_a_fan]

Never knew about this. Very cool concept. It's pretty much the same power as a modern F1 PU, for just 51 kg more. This begs the question, why hasn't anyone raced compound engines at Le Mans?

Perhaps because carrying 51kg you don't have to is death for a racing car.

[Tommy Cookers]

.... This begs the question, why hasn't anyone raced compound engines at Le Mans?

not 'road relevant' ? (the turbo diesel having been chosen)
and compound engines gain efficiency from altitude

and 7.5 bar boost SACM Hyperbar engines were used in real-world tanks
(15 bar and motor racing having at one time been mentioned)