3 ms·

Ramjets work at supersonic airflow speeds. You really don't want your helicopter blade tips going supersonic.

• deleted 6y ago
  [deleted]
• AgloeDreams 6y ago
  Wouldn't it be possible to use a subsonic inlet but design the intake to allow for air to become super sonic in the flow?
• checker 6y ago
  Fair warning, this is probably a ridiculous idea because I'm nothing close to a mechanical/aerospace engineer. Would it be possible to mount the ramjets to a ring around the blades along with some sort of transmission in the ring? I'm thinking setup this would allow the ramjets to function supersonically at the edge of the structure to ensure the best airflow and limit the speed of the blades. However such a transmission might be overly complex or heavy and it's possible that the ring around the blades would cause some weird aerodynamic effects. Thanks for obliging my curiosity!
• chipsa 6y ago
  Ramjets do not require supersonic flow speeds. They require positive speed (they don't work at a standstill), and are usually tuned for a sweet spot. This is usually supersonic because most applications are military, where the supersonic capability is desired. That said,they usually don't produce much thrust until you get over M0.5.