Abstract: One now famous analytical solution for shock waves was developed by Dr. Theodore Meyer within his Ph.D. dissertation under advisement of Professor Ludwig Prandtl. The original solution relies on analysis via control volume of the equations of motion. This approach has limited future development of analytical solutions for more complex flow-fields. In this presentation, …
Continue reading “APS Presentation – Alternative Analytical Solution for Planar Oblique Shock Waves”
Abstract: A new graduate class is developed at the University of Florida called Modeling Inhomogeneous Turbulence with a Historical Perspective. The course covers in-depth concepts of the science and mathematics of turbulence modeling. Major topics of the class include statistics for modeling, the Russian school, law of the wall, chaos, compressible Navier-Stokes equations, mean kinetic …
Abstract: Leading edge geometries, such as cones, moving at high-speed undergo intense loading due to the growth of instability waves and turbulent transition. These instability waves are highly spatially coherent. Aerodynamic loading related to instability waves and transition cause large-amplitude vibrations within the underlying structure, which may lead to flight-vehicle failure. We examine the effect …
I’m pleased to see my student Dr. Jianhui Cheng defend her Ph.D. successfully at University of Florida. Title: THE APPLICATION OF INSTABILITY WAVE THEORY ON ACOUSTIC RADIATION WITHIN OFF-DESIGN SUPERSONIC JETS AND ON TWO-POINT STATISTICS WITHIN HIGH-SPEED FLOW OVER SHARP AND BLUNT CONES WITH PLASMA ACTUATION Abstract: The intense noise generated by large-scale turbulent structures …
Continue reading “Congratulations to Dr. Jianhui Cheng on Defending her Ph.D.”
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 …
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 …
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 …
Continue reading “On Large-Scale HPC from Viewpoint of Cebeci”
