I’m really impressed with Professor Sankar’s website on fundamentals of aerodynamics of helicopters. It is often said in the aerospace community that if you understand the aerodynamics of helicopters then you can understand anything. It is really challenging! He has also posted a number of interesting items on aeroacoustics of rotorcraft. I have learned a lot from browsing his site. See https://sankar.gatech.edu/?q=rotoraero
Happy Lunar New Year
Year of the tiger!
Portrait of Sophia, Princess Palatine

Gerrit van Honthorst
Dutch. 1592-1656
Talking Oak

The Nightmare

On Theory and Experiments
Regarding computing as a straightforward routine, some theoreticians still tend to underestimate its intellectual value and challenge, while practitioners often ignore its accuracy and overrate its validity.
C. K. Chu, Columbia University, 1978
2022
This semester we are continuing to perform research for DARPA on analytical methods for hypersonic aerodynamics. It is a difficult task. My new students are transitioning well and former students are excelling in their new careers. I am teaching a new course on turbulence modeling. This should be placed online for everyone near the end of the spring semester 2022.
Foundations of Turbulence
The mathematical formulation of the problem of homogeneous turbulence is this: Given an infinite body of uniform fluid in which motions conform to the equations and, and given that at some initial instant the velocity of the fluid is a random function of position described by certain probability laws which are independent of position, to determine the probability laws that describe the motion of the fluid at subsequent times.
G. K. Batchelor in the Theory of Homogeneous Turbulence
When2Meet – Wonderful App
Best little piece of software for finding mutual meeting times at work. Completely free and donation supported.
Hope for Finding the Snark

