Comment by ChuckMcM | Hacker News Reader

Comment by ChuckMcM | Hacker News Reader

This is a pretty cool engine. 25hp is about 18.75 kW so a really good fit for a 15kW generator (sometimes marketed as "whole house" generators) its high RPM (typical of rotary engines) makes it a good match foundation for a turboprop engine. A pair of these driving ducted fan turboprop engines would give you an excellent long duration drone platform with good payload capacity.

My guess is the Army might be considering them as APUs (Auxiliary power units) on armored vehicles as this would give them long duration "sitting" capability without running the main power plant (but using the same fuel). Similarly bus style RVs could use them to run their in-vehicle electric gear (not a lot of bus RVs are designed for the "dry camping" or boon docking market but it would definitely work well for that.

The next thing they have to figure out I'm guessing is how to make them inexpensively (the Army won't care so much but I don't think the company would survive on just Army contracts).

This would definitely be interesting in an RV, it's way more compact than engines in similarly powerful generators in a vehicle where space is at a premium - and the ability to run off the same diesel fuel as the main engine is a huge plus.

Nit: it's not a turboprop if it's no longer using a turbine.

It's also not a turboprop if it's using a ducted fan. Chuck keeps using that word, I do not think it means what he thinks it means.

Benefit of doubt; they're likely using it as shorthand for 'equivalent to turboprop style/class engine' as an established feature set to have a drop in alternative to.

lol, love this. Yeah, high bypass turbofan was what I was thinking about, and yes those are "jet" engines. Model airplanes use something called an electric ducted fan or EDF[1], and it has the nice properties in that you can run it over a wide range of speeds if desired. The recent Black Sea MQ-9 incident would, in my opinion, turned out differently if that drone used a shrouded engines for propulsion.

[1] https://www.rc-airplane-world.com/rc-jets.html

There is a turbine in the supercharger… does that count?

I updated the trailer to LiFEPO4 this year, Solar is next year. It's REALLY easy to undersell just how many calories are in a gallon of gas. The 5500 watt generator can top off the batteries in 90-120 minutes and the tank is 60 gallons.

This is perhaps not totally relevant, but one fun comparison I like is that a human's total energy expenditure for a year is about equivalent to the chemical energy in a single barrel of oil.

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