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Old 04-17-2019, 02:29 PM   #3430 (permalink)
arber333
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Quote:
Originally Posted by Quattro64 View Post
Thanks, These are all excellent food for thought. I was inspired about this type of Drive from the work by Siemens, seems they sized one of the Smart Car 3 cylinder Turbo Diesels(by FlyEco) to power their Hybrid Magnus eFusion to a generator, a light one they developed, to burn only 7 liters per hour. I am guessing the 1L Smart Car TD is running at idle to do this. They built in redundancy by using tandem resolvers and multiple controllers. This is a smaller LS Aircraft that is not using their largest E-motors. They also Developed a more powerful aircraft with Pipistrell in Slovenia.


So I thought why not try something similar with a slightly larger plane? A Velocity or similar canard style plane, the new Raptor looks great, a four or five seater.


The GM 1.6 Ecotec engine developed in 2013 is a modern engine, durable, ancillary systems like turbo etc. also durable, I can get one out of a wrecked Cruze for pretty cheap. I don't know what type of kWs it puts out at idle but its torque curve peaks at ~ 2k and the HP curve peaks at ~ 2.9k. This engine even though it puts out 135kWs at peak power is the match for the Smart Car TD in terms of MPG, the Cruze is a heavier car than the Smart Car. This 1.6 TD weights ~ 250lbs. If the fuel savings is similar to what was seen in the Siemens, litres vs gallons per hour, then I would use a far smaller fuel tank than the one I was originally considering, with much less weight.


I believe two of the EMRAX 348 Mid Voltage motors, run at about half their capability, would be enough to taxi and cruise at engine idle once aloft, for any added performance needs(take off) there would be DC battery boost. If the motor stops running then the batteries could provide an hour or so of powered controlled decent. One Run as Generator, the other as AC Motor to drive Prop. They Each weigh ~ 90lbs. If needed, in an emergency, I could also switch the EMRAX generator to run the AC prop EMRAX directly, but according to EMRAX the generator performance might lose as much as 40% without any type of invertor or controller. This would only be needed for a problem with anything in the AC-DC to DC-AC power chain.


For an Inverter I will look at the Volt's, there is also a link earlier in this thread that someone posted about using a Prius inverter, they sell on eBay fairly cheap. So I will look at those options. I imagine Paul's Controller can also be used as an Inverter? I will certainly look at His for the multiple controllers I would want for this.


For the batteries I would strongly consider the newer NMCs. The ones that just came out with the improved anode. They seem to be safe and have a better power to weight ratio than the Lifepo4s. The Chinese are just now starting to manufacture these newer NMCs.

This is all interesting brain storming and it is probably a couple of years before I go any further with this project. I think it is doable, though I'm sure some of my assumptions will fall short, or maybe not? I'll figure this out though before I put any monies aside.


thanks,

Q
I am aviation engineer with AML B1/C licence. now i work as aviation inspector. Ive seen Panthera design in Pipistrel before Siemens revoked certificate, the *******s! They were intent on using dual Siemens motors with integrated inverters. Generator would be Emrax motor on Rotax 912turbocharged or naturaly aspirated. I believe now they are intent to first certify Pantera as normal GA aircraft with Lyc540 and then try the same concept using Emrax motors combination.

I think Smart engine is running at 75% power to generate 100Hp at that consumption.

GM engine may be lightweight engine, but at 75% power output it would have to run at high RPM to sustain that power. Since it is auto engine i dont think it was designed to be run at high RPM for long.
Also i have at home 1.4l Volt engine and i ca carry it myself. However drive unit has 2 PMSM motors inside. One 115kW and one 80kW. THe case weighs like 160kg, but its a compact unit... Emrax is till way agead n power density.

Volt inverter is just to prove the design. Since it is very compact.

I would suggest using one small airplane APU to generate the power you need. They are already optimised as generators. They even output 400Hz which is nicer to components than 60Hz . Everything can be made smaller.
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