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Launch HN: H3X (YC W21) – High power density electric aircraft motors

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Re: Launch HN: H3X (YC W21) – High power density electric aircraft motors

#21

Post by mliben »

gene-h wrote: post #17

Are ya'll doing any crazy multiphysics topology optimization to optimize magnetic fields, heat transfer, and fluid flow?

We take the 80/20 approach here. We start with analytical design (can be done pen on paper, but typically happens in excel/etc) to get a high-level view on the "continent" of design possibilities. This can be done readily with magnetic circuit models and thermal resistance networks.

From there, we identify the best high-level design traits and begin some optimization work to get most of the way to a fully-optimized solution (this is more FEA-based, both mechanical, magnetic, and thermal). This gets us climbing up the right "mountain" on the continent.

At this point, we put the pens down and start building something, because we will learn more building a prototype and iterating than we will spending too much time in simulation-land.

In parallel, we have been putting together a workflow to co-optimize the design across mechanical, magnetic and thermal simultaneously. Thus far the jump across each discipline has been a bit more on the manual side, but automatic co-optimization is a long term project, and would get us to the "peak" of the mountain.

Re: Launch HN: H3X (YC W21) – High power density electric aircraft motors

#22

Post by hbrav »

mliben wrote: post #13
mercurywells wrote: post #8

Earlier quoted context omitted.

> One aircraft we looked at required 30-35MW during takeoff and ~10MW during cruise. Do you envision some airframes to include assisted take-off technology? (JATO and the like, even catapults)

I think most forms of assisted takeoff technology would reduce electrical power requirements for takeoff, but not put much of a dent in the climb power (unless you can catapult/ JATO all the way up to cruising altitude, which would be challenging). Since climb power is still significantly higher than cruise power, and is effectively thermal steady state for these components (10-20min), it would still drive the propul…

You could have another aircraft tow you, like gliders sometimes do. Doesn't seem terribly practical though.

Re: Launch HN: H3X (YC W21) – High power density electric aircraft motors

#25

Post by mliben »

hbrav wrote: post #22
mliben wrote: post #13

Earlier quoted context omitted.

I think most forms of assisted takeoff technology would reduce electrical power requirements for takeoff, but not put much of a dent in the climb power (unless you can catapult/ JATO all the way up to cruising altitude, which would be challenging). Since climb power is still significantly higher than cruise power, and is effectively thermal steady state for these components (10-20min), it would still drive the propul…

You could have another aircraft tow you, like gliders sometimes do. Doesn't seem terribly practical though.

Not exactly what Talyn Air is doing, but along the same lines- separating out the "lift/climb" vehicle from the "cruise" vehicle. It can actually be a very compelling design!

Re: Launch HN: H3X (YC W21) – High power density electric aircraft motors

#26

Post by papertokyo »

jjsylvestre wrote: post #15
mliben wrote: post #14

Earlier quoted context omitted.

haha yeah, 100% I'm sure someone is already considering it... (looking at my co-founder eric, he loves motorcycles) We have received significant interest for high performance ground and marine applications, which we plan to leverage in the short-term as a way of getting lots of in-situ run-time for our technology without the hurdles of certification. We will be pursuing the long road to certification in parallel.

Also, cargo UAV is a big one right now. Many UAM companies are using this as a stepping stone to start generating revenue while they certify their aircraft. Marine is a big one though.. especially in Scandinavia. Lots of interest in electrifying boats and ships there.

Is the scale of the engine for marine applications very different to aviation? Ferries usually have huge hulking diesels so I'm curious what the equivalent electric powertrain is like.

I'm also assuming that a scaled down version would be ideal for personal watercraft?

Re: Launch HN: H3X (YC W21) – High power density electric aircraft motors

#28

Post by omgwtfbyobbq »

hbrav wrote: post #22
mliben wrote: post #13

Earlier quoted context omitted.

I think most forms of assisted takeoff technology would reduce electrical power requirements for takeoff, but not put much of a dent in the climb power (unless you can catapult/ JATO all the way up to cruising altitude, which would be challenging). Since climb power is still significantly higher than cruise power, and is effectively thermal steady state for these components (10-20min), it would still drive the propul…

You could have another aircraft tow you, like gliders sometimes do. Doesn't seem terribly practical though.

That could be a great use case for lighter/smaller electric motors, since a tow plane could take off, assist with takeoff, turn around and land, charge, and repeat. The tow plane wouldn't need as large of a battery pack, but having good power to weight for towing other plants to whatever altitude is very important.

Re: Launch HN: H3X (YC W21) – High power density electric aircraft motors

#29

Post by hbrav »

mliben wrote: post #14
lambda_obrien wrote: post #10

When can we buy a motorcycle with this in it? I'm joking, but you know someone wants to kill themselves that way. On a more serious note, what other applications do you intend for these?

haha yeah, 100% I'm sure someone is already considering it... (looking at my co-founder eric, he loves motorcycles) We have received significant interest for high performance ground and marine applications, which we plan to leverage in the short-term as a way of getting lots of in-situ run-time for our technology without the hurdles of certification. We will be pursuing the long road to certification in parallel.

Hey, my neighbor had a small home built plane that was powered by an old 2 cylinder generator engine. Maybe you should sell yours as generator engines too?

(Yes I'm kidding. I know. I'll stop trying to trick thermodynamics.)

Re: Launch HN: H3X (YC W21) – High power density electric aircraft motors

#30

Post by lambda_obrien »

papertokyo wrote: post #26
jjsylvestre wrote: post #15

Earlier quoted context omitted.

Also, cargo UAV is a big one right now. Many UAM companies are using this as a stepping stone to start generating revenue while they certify their aircraft. Marine is a big one though.. especially in Scandinavia. Lots of interest in electrifying boats and ships there.

Is the scale of the engine for marine applications very different to aviation? Ferries usually have huge hulking diesels so I'm curious what the equivalent electric powertrain is like. I'm also assuming that a scaled down version would be ideal for personal watercraft?

In marine use, as a former ship driver (naval, not commercial, so needs could vary), I would prefer a larger number of small engines I can vector rather than one or two larger engines. It removes the need for tugs from both the maneuverability standpoint since you have vectoring and the safety standpoint since you could have redundant systems.
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