> To further improve fuel efficiency and output, ZR15DDTe engine uses Nissan's unique STARC*2 concept paired with a large turbocharger.
If we are able to consider fixed RPM operation and are willing to endure turbomachinery, I don't know why we wouldn't just go all in on a gas turbine. You can reduce the number of moving parts dramatically and accept a much wider range of fuels.
Being able to engineer everything around a one fixed operating speed makes a huge engineering difference. Reciprocating engines are responsive to load and speed changes, but there are trade offs in many other categories.
You can also make a gas turbine power module quite small relative to the alternatives. Replacing the it at major service intervals could be made economically viable.
I suspect that the improvement in efficiency is small enough at the scale of an automotive power plant that it wouldn't be worth it.
Reading around suggests that in order to achieve decent efficiency from a gas turbine, you need quite a few supporting systems that only really make economic sense at larger scales (like the 10's of MW scales, not the 100's of kW).
(Although just from a fun technology angle I'd love to see a gas turbine in a car).
Chrysler built one in the 60s: <a href="https://en.wikipedia.org/wiki/Chrysler_Turbine_Car" rel="nofollow">https://en.wikipedia.org/wiki/Chrysler_Turbine_Car
The trick in this scenario is the fact that you can run it at a constant RPM + load for a reasonably long duration. The cost of warming up a recuperator and other masses is amortized across a dependable schedule each time. The controller can ensure that the turbine (assuming the drive is long enough) will run for a minimum duration given a certain battery charge level.
The reason this stuff didn't work before is because we couldn't run the turbine this way. Now we have viable energy storage technology and can make some of the most difficult variables into constants.
bob1029 · · focus · HN ↗
If we are able to consider fixed RPM operation and are willing to endure turbomachinery, I don't know why we wouldn't just go all in on a gas turbine. You can reduce the number of moving parts dramatically and accept a much wider range of fuels.
Being able to engineer everything around a one fixed operating speed makes a huge engineering difference. Reciprocating engines are responsive to load and speed changes, but there are trade offs in many other categories.
You can also make a gas turbine power module quite small relative to the alternatives. Replacing the it at major service intervals could be made economically viable.
gertrunde · · focus · HN ↗
Reading around suggests that in order to achieve decent efficiency from a gas turbine, you need quite a few supporting systems that only really make economic sense at larger scales (like the 10's of MW scales, not the 100's of kW).
(Although just from a fun technology angle I'd love to see a gas turbine in a car).
w4der · · focus · HN ↗
gertrunde · · focus · HN ↗
And maybe fuel economy wasn't great, although I remember hearing that they could use a very wide variety of fuels?
I hadn't realised there had been other attempts as well, including a Jaguar, that get mentioned in your linked Wikipedia article.
bob1029 · · focus · HN ↗
The reason this stuff didn't work before is because we couldn't run the turbine this way. Now we have viable energy storage technology and can make some of the most difficult variables into constants.
rasz · · focus · HN ↗
BoxOfRain · · focus · HN ↗
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