2014 We investigate numerically the statistical properties of the Kuramoto-SivashinskyTsuzuki model [1-3], which describes the phase fluctuations of extended systems near the transition to turbulence. This model has some similarities with hydrodynamic turbulence [4]. The time fluctuations exhibit an unexpected scaling corresponding to anomalous diffusion of the phase. Other results also point t...

Comparisons with respect to the sooting tendency are made between stationary diffusion flames and diffusion flames with pulsations induced by oscillating fuel flow. Time-resolved measurements of the soot particle properties in the flames are obtained by combining Rayleigh-scattering, laser-induced incandescence, and extinction measurements into the RAYLIX method. Furthermore, flame luminosity a...

Turbulence is believed to play important roles in the origin of cosmic magnetism. While it is well known that turbulence can efficiently amplify a uniform or spatially homogeneous seed magnetic field, it is not clear whether or not we can draw a similar conclusion for a localized seed magnetic field. The main uncertainty is the rate of magnetic field diffusion on scales larger than the outer sc...

Soot concentration distribution is investigated both numerically and experimentally in methane-air diffusion flame. The experimental work is conducted with a cylindrical swirl stabilized combustor. Filter paper technique is used to measure soot volume fraction inside the combustor. The numerical simulation is based on the solution of the fully-coupled conservation equations for swirling turbule...

The extinction process of cup-burner flames under normal-gravity conditions were previously studied. As the low-speed diffusion flames behave differently in microgravity compared to those on earth, it is important to understand the structure of cup-burner flame and its extinction characteristics under 0g conditions. A numerical study was performed in the present paper using a time-dependent, ax...

This paper describes the simultaneous application of time-sequenced laser-induced fluorescence imaging of OH radicals and stereoscopic particle image velocimetry for measurements of the flame front dynamics in lean and premixed LP turbulent flames. The studied flames could be acoustically driven, to simulate phenomena important in LP combustion technologies. In combination with novel image post...

A numerical study of the supercritical combustion of a liquid oxygen (LOX) droplet in a stagnant environment of hot hydrogen is carried out with a detailed chemistry model. Special attention is devoted to ignition process and diffusion flame structure. Ignition consists typically of the propagation of a premixed flame which is initiated in the H,-rich hot side. Propagation takes place in a nonh...

We prove long time diffusive behavior (homogenization) for convec-tion-diffusion in a turbulent flow that it incompressible and has a stationary and square integrable stream matrix. Simple shear flow examples show that this result is sharp for flows that have stationary stream matrices. Contents 1 Introduction 279 2 Outline of the paper 286 3 Abstract framework 288 4 Variational principles 294 ...

Merging the adaptive networks with the free space optical (FSO) communication technology is a very interesting field of research because by adding the benefits of this technology, the adaptive networks become more efficient, cheap and secure. This is due to the fact that FSO communication uses unregistered visible light bandwidth instead of the overused radio spectrum. However, in spite of all ...