Showing 1 - 10 of 81
A direct numerical simulation of a turbulent flow field with a lattice BGK method is presented. A spatial coarse graining of the numerical results is compared with the expected LBGK dynamics for a flow field on a reduced lattice size. This comparison permits to exhibit subgrid properties of the...
Persistent link: https://www.econbiz.de/10011063549
The potential role of resummation techniques in the kinetic-theory approach to subgrid turbulence modeling is discussed.
Persistent link: https://www.econbiz.de/10010874001
Based on the well-known mapping between the Burgers equation with noise and the Kardar–Parisi–Zhang (KPZ) equation for fluctuating interfaces, we develop a fluctuating lattice Boltzmann (LB) scheme for growth phenomena, as described by the KPZ formalism. A very simple LB-KPZ scheme is...
Persistent link: https://www.econbiz.de/10010874413
A mean-field approach (filtering out subgrid scales) is applied to the Boltzmann equation in order to derive a subgrid turbulence model based on kinetic theory. It is demonstrated that the only Smagorinsky type model which survives in the hydrodynamic limit on the viscosity time scale is the...
Persistent link: https://www.econbiz.de/10010591363
A thermodynamical formalism for resistor networks is developed in order to extract full information on the multifractal scaling structure. We introduce a matrix representation and study the moments of the voltage distribution Z̃(β) = ∑i=1N|Vi|β α N -F̄(β) where N is the number of...
Persistent link: https://www.econbiz.de/10011057265
This brief overview is designed to introduce some of the advances that have occurred in our understanding of percolation phenomena. We organize our presentation around three simple questions: (i) What are percolation phenomena? (ii) Why do we care? (iii) What do we actually do? To answer the...
Persistent link: https://www.econbiz.de/10011057657
We model the time series of the S&P500 index by a combined process, the AR+GARCH process, where AR denotes the autoregressive process which we use to account for the short-range correlations in the index changes and GARCH denotes the generalized autoregressive conditional heteroskedastic process...
Persistent link: https://www.econbiz.de/10011058262
This manuscript is based on four opening lectures, which were designed to offer a brief and somewhat parochial overview of some “exotic” statistical physics puzzles of possible interest to biophysicists, medical physicists, and econophysicists. These include the statistical properties of DNA...
Persistent link: https://www.econbiz.de/10011058411
We review recent numerical simulations of several models of interface growth in d-dimensional media with quenched disorder. These models belong to the universality class of anisotropic diode-resistor percolation networks. The values of the roughness exponent δ=0.63±0.01 (d=1+1) and...
Persistent link: https://www.econbiz.de/10011059081
It is known that some dimeric tandem repeats (DTR) are very abundant in noncoding DNA. We find that certain DTR length distribution functions in noncoding DNA can be fit by a power law function. We analyze a simplified model of unequal chromosomal crossing over and find that it produces a stable...
Persistent link: https://www.econbiz.de/10011059603