An Introduction to Rotorcraft Aerodynamics
What you'll learn
- Grasp the physics behind the working of a helicopter rotor under a variety of flight conditions
- Using models of increasing complexity, derive expressions linking thrust and power of a rotor to flow and geometry variables
- Design 'ideal' and 'optimum' rotors using the Blade-Element-Momentum-Theory model
- Learn how to estimate important helicopter performance metrics such as climb rates, maximum speed, service ceiling etc
- High School Physics
- Elementary Calculus
This is meant to be an exposition of the simple, yet elegant models used to understand the working and performance of rotorcraft like helicopters, autogiros etc. Using first principles, thought experiments and the occasional Hollywood video, learners will understand how to gauge the efficiency of a rotor, and how to predict its performance (even on distant planets!). They will grasp how a rotor operates in climb and how to produce the universal inflow curve. They will gather the necessary tools and techniques to predict the descent rate of a maple seed when it is in an 'autorotative' state. The asymmetries inherent to forward flight will also be covered in detail. Using a hybrid model, they will be learn how to compute the inflow variation across the rotor disk. Students will finally be exposed to the fundamentals of efficient rotor design ('optimum' vs 'ideal' rotors) before an in-depth look into the calculation of typical helicopter performance metrics (maximum speed, service ceiling etc).
The course will cover and use the following three models in a variety of conditions:
(1) Momentum Theory
(2) Blade Element Theory (BET)
(3) Blade Element Momentum Theory (BEMT)
When applicable, lectures will be accompanied with optional Python scripts for interested students to run and extend.
Finally, if you think you'd derive some benefit from this course, but can't afford the price, reach out to me via email and I'll send you a customized free link, no questions asked.
Who this course is for:
- Students, engineers interested in aerodynamics
I'm an aerodynamicist with ten years of industry experience, working on ushering in the exciting future of autonomous and sustainable urban air mobility. My interests broadly include helicopter aerodynamics and acoustics, computational fluid dynamics and high performance computing. I live in North Carolina, with my wife and our two lazy Schnauzers.