My former student, Dr. Alex Carr, along with Dr. J. Lonzaga, who are both of NASA Langley Research Center, and myself published an article on the propagation of sonic boom through the turbulent atmosphere. Abstract: The effects of atmospheric boundary layer turbulence on the loudness variability of a sonic boom N-wave and shaped boom are …
Category Archives: Navier-Stokes
DARPA Director’s Fellow
I am very fortunate to be awared the 2023-2024 DARPA Director’s Fellowship. The linked article from my department is at the following link: https://mae.ufl.edu/2023/08/09/darpa-directors-fellowship-awarded-to-steven-a-e-miller/ The article text is below Associate Professor Steven A. E. Miller, Ph.D., is awarded the Director’s Fellowship from the Defense Advanced Research Projects Agency (DARPA) for 2023-2024. The award recognizes technical …
A simplified semi-empirical model for long-range low-frequency noise propagation in the turbulent atmosphere
My student, Dr. Tianshu Zhang, and myself recently published a modified long range acoustic propagation model that handles turbulence in the atmosphere. The abstract is We present a semi-empirical long-range low-frequency acoustic propagation model, which accounts for atmospheric turbulence. Ostashev and Wilson’s scattering model is combined with a ray-theory based refraction model to account for …
Viscosity Coefficients
Often viscosity is isotropic, meaning that it is the same in all directions. In such a case, only two of the six components of the strain rate tensor are independent, so two coefficients of viscosity can be used to describe the viscous behavior of the fluid. These two coefficients are related by -2/3. This relationship …
Chairing Turbulence Theory at APS Division of Fluid Dynamics – Highlight of the year
All our presenters were present and traveled internationally. DNS is the tool of choice for numerical simulations. Theory emerged from results, and I hope that new relations will guide those making turbulence models today. High-order inertial range scaling exponents in incompressible turbulence using generalized extended self-similarityPresenter: Sualeh Khurshid, Massachusetts Institute of Technology, Author: Sualeh Khurshid, …
APS Presentation – Alternative Analytical Solution for Planar Oblique Shock Waves
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, …
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The prediction of cross-spectra from first mode instability waves within high-speed flow over sharp and blunt cones with plasma actuation
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 …
On Challenges in Turbulent Flow Theory and Experiment
Research in macroscopic classical physics, such as fluid dynamics or aspects of condensed matter physics, continues to confront baffling challenges that are by no means less demanding than those at the post-Newtonian frontiers of physics that have been explored since the beginning of this century. This is so even though the basic equations of macroscopic …
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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 …
The History of the Navier-Stokes Equations
Over the course of a few years I have collected pictures, biographies, and other tidbits about the many famous people who have created, studied, and dedicated their lives to the Navier-Stokes equations. I set it to the music of Carmina Burana of the MIT Choir (Creative Commons). Enjoy!