3 ms·
This is really cool. I find it very strange that it's less efficient though.
by madeuptempacct 8y ago
This is really cool. I find it very strange that it's less efficient though.
- georgeecollins 8y agoI believe it is because propellers get lift from air pressure, which is more efficient than just pushing air for thrust. If you are sucking air through an engine you don't get that bernoulli effect. I could be wrong. I am not an aerospace engineer
- dimitriarendt 8y agoThe efficiency of a propeller depends on the ratio thrust/area, the smaller this ratio the higher the efficiency. (See 11.7.3 at https://web.mit.edu/16.unified/www/FALL/thermodynamics/notes/node86.html https://web.mit.edu/16.unified/www/FALL/thermodynamics/notes...) The issue with the ducted fan is that the propeller size is constrained and the weight is higher due to the mechanical structure. A small quadcopter has twice or more propeller area for a portion of the weight.
- georgeecollins 8y agoThanks! I learned something from this.