Viewing profile — mliben

From an active mass (electromagnetic parts, power switches, etc) perspective, our specific power is relatively consistent from 100 kW up to 1 MW. TBD on lower or higher than that. …

In general, Magnax seems to be focusing on automotive, which changes the driving factors in the design significantly (partial load efficiency becomes very important, cost is #1, et…

On Wisconsin!

Yes, this is one variation of what is referred to as "in-slot cooling". Keep in mind that putting coolant inside the slot removes precious conductor cross-sectional area. There is …

Yeah, there are a lot of factors that play into this. A couple things come to mind: 1) Considering megawatt-class machines are necessary for many future applications, the mass of t…

Using the simple drag polar approach, D = A*v^2 + B/v^2 (D is total drag, first term is parasitic drag, second term is lift-induced drag) dD/dv = 0 where v = (B/A)^(1/4) Plug in v …

We are definitely saying the same thing in very different ways. Just using the drag polar approach and neglecting second-order effects (assume negligible dependence on Re, sufficie…

Yep! SiC was part of the design DNA from the beginning.

Definitely, for sure. Like I said in the other thread, supersonic is a whole other thing, and I don't think anyone is trying to electrify anything supersonic any time soon :)

It's a common misconception that different ways of connecting and/or driving coils can emulate a CVT, multi-speed gearbox or single speed gear reduction. The maximum continuous tor…

a LOT of energy is required to fly supersonic- IMO the energy storage side (battery and/or hydrogen fuel cell) has a long way to go to make supersonic flight remotely feasible.

Yes, the range-optimal speed is where the parasitic drag is equal to the lift-induced drag. If you go through the analysis, the air density drops out of the range equation if you a…

To add to what Jason said- The characteristic current of the machine is roughly the same as the maximum inverter current, so at maximum power the power factor is between 0.7-0.8. T…

Tight integration removes an entire housing and cold plate from the inverter design (++ specific power). Allowable SiC die temperatures are ~175 C these days, which is pretty aweso…

The phenomenon is due to Paschen's law (there is a good wikipedia article on it). The breakdown potential of a gas is minimized at some pressure, and in the case of air, that press…

Less dense air -> higher angle of attack required to produce required lift -> true lift vector is more offset from vertical -> horizontal component of lift is actually producing dr…

Yes, thermal conductivity is of the utmost importance at the continuous current densities we are designing for. That being said, typically the effective thermal conductivity of the…

Aluminum has the best conductivity/mass out of all of the common conductors. Motors are actually more volume constrained than mass constrained for the windings, which is why copper…

Ampaire (among others) is already making great strides in general aviation. With significant improvements in specific energy (see QuantumScape, HyPoint) and specific power improvem…

For our technology demonstrator, we have a pretty small rotor. Future direct drive designs (typically higher power as well) will have much larger diameters. I can't be too specific…

Certainly. Infrastructure is actually one of the biggest technological challenges for flight electrification. This is one area where hydrogen / fuel cell might have a leg up since …

Well, you would need significant energy storage either in the form of batteries or hydrogen + fuel cells as well :) Our technology demonstrator is a 250 kW machine, but we have pla…

A simple physics-based plane model (like the one we made to understand vehicle-level impact of our technology development) dictates that the range-optimal cruise speed is proportio…

Silver is crazy expensive compared to copper, and the tradeoff isn't worth 6%. Also, 3d-printing pure copper is relatively new, and I'm not sure there is as much of a business case…

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!