Turbulent dynamical systems characterized by both a high-dimensional phase space and a large number of instabilities are ubiquitous among 4 many complex systems in science and engineering including climate, material, and neural science. The existence of a strange attractor in the turbulent systems 5 containing a large number of positive Lyapunov exponents results in a rapid growth of small unce...

0010-2180/$ see front matter 2009 The Combust doi:10.1016/j.combustflame.2009.11.009 * Corresponding author. Present address: CFD Rese AL 35805, United States. Fax: +1 256 726 4806. E-mail addresses: [email protected] (R.S. Mehta), dch [email protected] (M.F. Modest). 1 Present address: Department of Mechanical Engine Merced, CA 95348, United States. A comprehensive model for luminous turbulent ...

We study the change in the behavior of the modulation transfer function and resolution with changing properties of a turbulent medium. It is shown that the form and the behavior of the functions under study undergo significant changes at the transition from Kolmogorov's to a helical type of turbulent medium. These changes should be taken into account in developing models of electromagnetic radi...

We introduce improved reduced-order models for turbulent flows. These models are inspired from successful methodologies used in large eddy simulation, such as artificial viscosity, applied to standardmodels created by proper orthogonal decomposition of flows coupled with Galerkin projection. As a first step in the analysis and testing of our new methodology, we use the Burgers equation with a s...

The degree of linear polarization has recently been found to show wide random variations over the solar disk. These variations are presumably at least partly due to fluctuations in the flux density of turbulent photospheric magnetic fields and associated variations in the degree of Hanle depolarization. In order to understand the origin of such large scale fluctuations of the turbulent magnetic...

We present 50 individual measurements of the gas temperature and turbulent velocity in the local interstellar medium (LISM) within 100 pc. By comparing the absorption line widths of many ions with different atomic masses, we can satisfactorily discriminate between the two dominant broadening mechanisms, thermal broadening, and macroscopic nonthermal, or turbulent, broadening. We find that the s...

Mathematical modeling plays an important role whenever flow investigations are performed. In this paper special emphasis was given to models which are used in turbulent flow simulations and the effect of numerical discretization. The numerical scheme is of great importance when direct numerical simulations, i.e. the solution of the Navier-Stokes equations without any additional turbulence model...

We present 50 individual measurements of the gas temperature and turbulent velocity in the local interstellar medium (LISM) within 100 pc. By comparing the absorption line widths of many ions with different atomic masses, we can satisfactorily discriminate between the two dominant broadening mechanisms, thermal broadening and macroscopic nonthermal, or turbulent, broadening. We find that the su...

LES models for subgrid scalar transport and dissipation are assessed through joint experimental and numerical studies using experimental data from an axisymmetric, turbulent, co-flowing jet, and large eddy simulation of scalar mixing in a round turbulent jet. The dissipation models tested include: a gradient-based model, which is based on a local equilibrium assumption, a model that assumes pro...