ORIGINAL: rednekk58
Hey FF,
Love your math. When I took flying lessons and planned on building my own plane. I read everything I could about it. (Bought plans too) If I remember correctlly, (fat chance), you want to keep prop speed about 85% of mach 1. You need to add the forward speed of the plane/PROP also.
Hope this helps.
85% is close i ahve it ranges from about 85 to 92% depending on the source, I read a full scale prop test where they noted that once the tips reacher mach one the actull trust did NOt increase but the noice did the more power they gave they got VERY little more trust out of it.
Of course once you calculate the speed of a q40 set up (that what i have been using 32krpm and 7.4 inch prop diameter).
A super sonic prop could be interesting... although it would put a ton of stress on the prop/engine as it breaks into the transonic barrier.
So i might try and calculate a more reloistic set up, how fast does a Q40 fly? What rpm while flying? and one last thing is it correct they use a 7.4 inch prop?
Q40 may already be breaking the sound barrier they really arnt that far from it and i havn't factored the speed of the aircraft.
Steven