How scalable is the wave disk generator engine? Are there fundamental limits to how large or small the engine can be and if so, what are they? I'm not looking for answers addressing microscale issues, but rather, I want to know if the fluid dynamics inside the engine require a certain size range in order for the combustion to work properly.
"Let me say this about that" (extra points to those who recognize the originator of that phrase).
First: yeah, they've invented a cool-looking device. But, they appear to be getting nowhere so far as either advanced funding or a fieldable model produced.
Second: I have seen at least 5 or 6 "groundbreaking new powerful/efficient/wunderdevice" internal combustion engine designs pop up over the last 30 years (not even counting the Wankel rotary). Not one has been able to show both minimal life testing and improved efficiency over modern piston-crankshaft engines. I see no reason to expect this design to do so either.
For further, quite specific, counterarguments, take a look at this review