Laws of Thermodynamics

A long time ago, the running joke of the three laws of thermodynamics was introduced. They are the following: You cannot win. You cannot break even. You cannot get out of the game.

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 …

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 …

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 …

BOLT2

Congratulations to the entire BOLT2/NASA/AFRL hypersonics boundary layer transition flight-test team on their successful launch yesterday.