Jack Norris's Insight
How dare we say Perfect Props*? (essentially EXACT, Optimized all 6 Possible Ways*!)
Propeller Design: was always the most complex, least understood problem in Flight and Aerodynamics - until now. The author, Jack Norris and Dr. Andy Bauer found 7 historic giants, finally 3, Betz, Goldstein & Theodorsen, BGT, their essentially exact, rare genius, 3D math solution, 1948, never understood. Jack (see bio) understood, recognized the Historic Flight and Aerodynamics optimizing opportunity, essentially Exact Propellers! NO MATH, the genius hidden in a PC, we learn Propellers as the simple, Incisive Insight of what is happening Physically to 1. A Rotating Wing, 2. Throwing Surprisingly Heavy Air, 3. An Airscrew – Easy Enough Logic we can All Understand!
The Book Explains: Theodorsen was the acknowledged Math Genius of WW II NACA Langley. Goldstein – Theodorsen essentially exact 3D math, perhaps the most elegant, impressive Engineering solution in History, ends in a Simple Blade Loading Chart, never understood. That Loading, optimally used, directly results in the Half Teardrop Loading you see on the cover. Perfect Blade SHAPE, Pitch, Twist, creates Perfect Radial Loading, Perfect Props*!
Norris’s 6th Law, The All 6 way Optimized Prop: 1. BGT Math creates Min Induced Loss, throwing air, [ If we simply use an Optimum Angle of attack, thus CL, at all radii, (from Pitch & Twist), we get Minimum Correct Area, Precisely Placed. ] thus 2. Minimum Drag, thus 3. Min Torque Demand, thus 4. Min HP Demand, thus, 5. MAX THRUST, the Core Objective, thus, 6. Max Efficiency, the essentially perfect Propeller*, that can’t be beat! All 2D Math used by propeller designers, only approximate, never sees the major loss, radial flow feeding the gross tip vortex, misses perfect shape, pitch, twist and perfect radial loading, thus gets less than max thrust.
If you are a Propeller Designer, Manufacturer, this Book teaches what we never knew, never understood - The Rare Genius, essentially exact Betz Logic, Goldstein, Theodorsen Math, the Fact that we never saw the core issue in Propeller Design, That a Rotating Wing is a THRUST LOSS, TIP VORTEX LOSS DISASTER, that essentially exact BGT Math ideally counteracts that, Ideal Radial Blade Loading, exact blade Shape, Pitch, Twist!
Of course we use Ideal Airfoils, thicknesses, sweep tips, if too close to sonic. Reno takeoff proved - We lose by trying to be tricky, changing angles, using wider tips. BGT is essentially EXACT*!
* Engineering Integrity, credibility demands that we always mean essentially exact, essentially Perfect. There are always minute errors, ~1% error taken as the best!