izzy wrote: ↑
Fri Jul 05, 2019 9:07 am
Tommy Cookers wrote: ↑
Thu Jul 04, 2019 10:20 pm
a 40 kW piston-engine range extender is maybe 35% efficient
a 40 kW gas turbine range extender is maybe 10% efficient ?
wikipedia talks about 20-42% efficiency for microturbines ....
Wikipedia talks of microturbines of eg c.400 kW not 40 kW
and microturbines with recuperation (heat exchangers) - these don't ever seem to exist as marketed items
4000 kW and particularly 40000 kW turbines are rather efficient of course
40 kW turbines could produce more power from heating water in a steam engine than from their own Brayton cycle efforts
NASA in TN 2003-212615 classifies microturbines as having less than 10 lb thrust
10 lb at 70 mph is roughly 1.5 kW