Modeling the structure of molecular clouds depends upon good methods to statistically compare simulations with observations in order to constrain the models. Here we characterize a suite of hydrodynamical and magnetohydrodynamical (MHD) simulations of supersonic turbulence using an averaged wavelet transform, the ∆-variance, that has been successfully used to characterize observations. We find ...

Superpositions of different statistics on different time or spatial scales (in short, superstatistics) can naturally lead to an effective description by nonextensive statistical mechanics. We first discuss the role of escort distributions within the superstatistical framework, and then briefly describe recent physical applications of this concept to turbulent and patttern forming systems.

A synthetic spanwise-constant spatio-temporal mode is excited in a flat plate turbulent boundary layer through a spatially impulsive patch of dynamic wall-roughness. The streamwise wavelength of the synthetic mode approximately corresponds to the very large-scale motions present in high Reynolds number wall turbulence. Hot wire anemometer measurements made downstream of the roughness forcing re...

Understanding the physics of turbulence is crucial for many applications, including weather, industry, and astrophysics. In interstellar medium (ISM), supersonic plays a role in controlling gas density velocity structure, ultimately birth stars. Here we present simulation with grid resolution 10048^3 cells that allows us to determine position width sonic scale (l_s) - transition from subsonic t...

A review of existing basic turbulence modeling approaches reveals the need for the development of unified turbulence models which can be used continuously as filter density function (FDF) or probability density function (PDF) methods, large eddy simulation (LES) or Reynolds-averaged Navier–Stokes (RANS) methods. It is then shown that such unified stochastic and deterministic turbulence models c...

Turbulence is a major aviation hazard for both commercial and private aircraft. Currently, the clear-air turbulence forecasting tool Graphical Turbulence Guidance (GTG) is used by airline meteorologists and dispatchers for flight planning, and in part to determine operational Airman’s Meteorological Information (AIRMET) turbulence advisories; however, GTG has much higher resolution and intensit...