Propeller Geometric Twist
Asked by: Chris Carlson 10399 views Aerodynamics, Aircraft Systems, Commercial Pilot, Flight Instructor
Question Given: "The reasons for the geometric twisting along the propeller blades is that..."
Answer explination:
"The reasons for variations in geometric pitch (twisting) along a propeller is that it permits a relatively constant angle of attack along its length when in cruising flight. Sections at the tip are moving faster than sections near the hub, causing the relative wind along the blade to vary."
Above is a statment as a correct answer to a question from the CFI question bank, brought to us by the King DVDs.
I cant seem to wrap my head around this...and it might be because im making a poor assumption.
In my understanding, the geometric twist creats an equal amount of thrust along the profile, not an equal angle of attack.
If it had an equal angle of attack along the length, and the outter parts moving faster, it would creat more lift at the tips.
The assumption that I am making, that may be why the answer given by King (and presumably the FAA) is that I am assuming the relative wind is contant along the length of the propeller, which is not a perfect assumption (more interruptions at the roots- spinner, air intake, etc)
Any help would be great, I dont have an exact question, just help explaining to me about the answer given for this qustion.
The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.