The maths of the flying is a little puzzling to me.
Back of the fag pack, let’s say it is light for an electric car and weights 1000kg. I’ll also go on a limb and guess the air flow is actually subsonic - 200m/s would make it 0.6 Ma (still insanely fast!). Even then, that requires 50 kg of air every second. Or 40 m^3. Using everyone’s favorite metric, this empties an Olympic swimming pool in 1 minute. It also requires a MW of power. I mean… that’s a lot??? Though admittedly, only about as much as accelerating 0-60 in 1 sec (50% of that in fact). So the flying would draw as much power as accelerating at full throttle.
Power requirements would go down a lot with slower exhaust speed, but then you need to shift more fluid. 40 m^3 already seems like a lot to me.
I get it’s a neat little demo and they have to get SpaceX into the picture somehow, but still I don’t understand how it’s supposed to add up. Also, what do I know - just a humble physicist.
Back of the fag pack, let’s say it is light for an electric car and weights 1000kg. I’ll also go on a limb and guess the air flow is actually subsonic - 200m/s would make it 0.6 Ma (still insanely fast!). Even then, that requires 50 kg of air every second. Or 40 m^3. Using everyone’s favorite metric, this empties an Olympic swimming pool in 1 minute. It also requires a MW of power. I mean… that’s a lot??? Though admittedly, only about as much as accelerating 0-60 in 1 sec (50% of that in fact). So the flying would draw as much power as accelerating at full throttle.
Power requirements would go down a lot with slower exhaust speed, but then you need to shift more fluid. 40 m^3 already seems like a lot to me.
I get it’s a neat little demo and they have to get SpaceX into the picture somehow, but still I don’t understand how it’s supposed to add up. Also, what do I know - just a humble physicist.