Experiments in a Large-Boundary Layer Wind Tunnel: Propagation of Noise through the Turbulent Boundary Layer

My Group recently published a paper on a multiyear experiment campaign. We used the National Science Foundation Boundary Layer Wind Tunnel and sent acoustic waves through the boundary layer. We examined how turbulent structures altered the waveforms. The purpose is to create a high quality database available to the community to understand acoustic-turbulent interactions. Zhang, …

Paul Richard Heinrich Blasius

At Easter 1902 I had sat my final college examination, and was now studying mathematics. This was not simple for me: Although one can see what follows from certain algebraic manipulations, why would this be done? “By mathematics, you are convicted, instead of convinced”, according to the philosopher Schopenhauer. After some time, I realized that, …

Sankar’s Helicopter Aerodynamics

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 …

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 …