Almost everyone has their own definition of the term hypersonic. If we were to conduct something like a public opinion poll among those present, and asked everyone to name a Mach number above which the flow of a gas should properly be described as hypersonic there would be a majority of answers round about 5 …
Category Archives: Fluid Dynamics
Thomas D. Norum
My good friend Thomas D. Norum recently passed away. He worked as a researcher at NASA Langley over most of his career. I knew him starting in 2009 through 2016 while I was working there. He worked as an experimentalist in the jet noise lab of NASA Langley. As an experimentalist, he worked to understand …
Sonic Boom for Lilliputians
Numerical prediction of loudness metrics for N-waves and shaped sonic booms in kinematic turbulence
Abstract, “The effects of a kinematic field of velocity fluctuations on the loudness metrics of two waveforms are examined with a three-dimensional one-way propagation solver. The waveforms consist of an N-wave and a simulated low-boom from NASA’s X-59 QueSST aircraft. The kinematic turbulence is generated using a von Karman composite spectrum, which is dependent on …
AEDC von Karman Facility
On Large-Scale HPC from Viewpoint of Cebeci
One other aspect should be mentioned. When the program was transferred to El Segundo from Santa Monica, I naturally duplicated some runs. The printout was eight-decimal places, I believe. For a number of steps the new and old tab sheets would check exactly. But then after a while there would be a gradual drift; first …
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Variable Density Wind Tunnel
When visiting NASA Langley I had Josh Blake kindly take my picture by the Variable Density Wind Tunnel. Pioneered by Max Munk, leading theoretician in aerodynamics in America in our early years of aviation. National historical landmark: The test section and airflow passages built into the VDT pressure vessel formed a continuous flow of pressurized …
On the Panel Method
After this I got more into aerodynamic research. The area rule involves calculating the flow about a bumpy body of revolution. Existing methods for calculating it were very poor. K. E. Van Every, my boss, talked to me about looking over the available methods and seeing what was best. I did and discovered an entirely …