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 …

Standard k-Epsilon Model

In the last few years a number of models of turbulent heat and momentum transport have been developed in which the effective transport coefficients are related to local values of certain turbulent correlations; these correlations are computed simultaneously with the mean field variables. Models of this kind achieve significantly greater breadth of applicability than do …