The impact of riparian land use on the stream insect communities was studied at Kudremukh National Park located within Western Ghats, a tropical biodiversity hotspot in India. The diversity and community composition of stream insects varied across streams with different riparian land use types. The rarefied family and generic richness was highest in streams with natural semi evergreen forests a...

With discretized particle velocity space, a unified gas-kinetic scheme for entire Knudsen number flows is constructed based on the BGK model. In comparison with many existing kinetic schemes for the Boltzmann equation, the current method has no difficulty to get accurate solution in the continuum flow regime, such as the solution of the Navier-Stokes (NS) equations with the time step being much...

Smoothness of the Green functions for the complement of rarefied Cantortype sets is described in terms of the function φ(δ) = (1/ log 1 δ ) that gives the logarithmic measure of sets. Markov’s constants of the corresponding sets are evaluated.

The paper presents a parallelization technique for the finite pointset method, a numerical method for rarefied gas flows. First we give a short introduction to the Boltzmann equation, which describes the behaviour of rarefied gas flows. The basic ideas of the finite pointset method are presented and a strategy to parallelize the algorithm will be explained. It is shown that a static processor p...

A numerical simulation of micro Poiseuille flow has performed for rarefied and compressible flow at slip flow regimes. The wall roughness is simulated in two cases with triangular microelements and random micro peaks distributed on wall surfaces to study the effects of roughness shape and distribution on flow field. Two values of Mach and Knudsen numbers have used to investigate the effects of ...

There are two distinctive methods in describing the motion of fluid flows mathematically. One is based on the conservation laws of mass, momentum, and energy, and the associated constitutive relations representing the inherent properties of fluid media, which is called the Navier-Stokes-Fourier (NSF) equations in the literature. Another is based on the stochastic partial differential equation o...

A pilot model of the hypersonic rarefied wind-tunnel (HRWT) has been developed and its flow characteristics have been measured. The HRWT consists of a gas heater which produces an increase in working gas temperature, an expansion nozzle with a large expansion ratio, a vacuum chamber as the test section, and an evacuation system with high exhaust velocity to allow a continuous operation at low a...

We propose the rarefied-gas-cushion model (r-GCM), as an extended version of the gas-cushion model (GCM), to estimate the apparent slip of water flowing over a gas layer trapped at a solid surface. Nanobubbles or gas nanofilms may manifest rarefied-gas effects and the r-GCM incorporates kinetic boundary conditions for the gas component in the slip Knudsen regime. These enable an apparent hydrod...

The aim of this work is to investigate argon scattering behaviors on the smooth and rough tungsten surfaces. Current work deals with numerical simulation of nanoscale heat transfer process accompanying with rarefied gas-solid substrate interactions using molecular dynamics (MD) method. Taking into account that this method is very time consuming, MD simulation using CUDA capable Graphic Cards is...