Jetson One personal eVTOL looks like a ton of fun to fly

https://newatlas.com ^ | OCTOBER 21, 2021 | By Loz Blain

[JD_UTDallas]

The solution to the problem of evtol flight time is to make them hybrids. Keep just enough LIon batteries to smooth out the peaks and valleys of the electric drive motors ramping up and down for flight control. Then use a very light weight gas turbine driven turbo alternator and SCR rectifier to push high voltage DC current into the Lion and evtol drive train. A small gas turbine can ramp from 10% to full output in under 4 seconds so that’s how much buffer time the battery pack needs to smooth out. A compact wankel rotary with a similar power to weight ratio of a gas turbine can ramp from 10% to 100% in under a second as long as it’s already spinning at its max output rpm under light throttle. Rotarys are like gas turbines in that regard they have such little inertial mass in the rotors as soon as the throttle is opened WFO they are putting put max output. Nothing to spin up just more combustion gas through the rotors. With the density of JetA vs Lion batts hundreds of miles if flight range could be had for the same takeoff mass. Even including the turbo alternator and generator. Turbines are are 6hp per lb of mass or better. High speed alternator are upwards of ten kw per lb of mass, and the SCR rectifier would be a few kg for a 100kw sized rectifier. All the other mass saved over batteries is for JetA at 38 kWh per gallon in raw energy. Even at 30% efficient in converting JetA to electrons that’s still over 10 kWh per gallon of fuel. One gal JetA is 6lbs ish an order of magnitude greater total.energy density vs batteries.