A numerical procedure to determine the equivalent hydrodynamic dispersion coefficients and Péclet number (Pe) of a fractured rock is presented using random walk particle tracking method. The geometrical effects of fracture system on hydrodynamic dispersion are studied. The results obtained from the proposed method agree well with those of empirical models, which are the scale-dependent hydrodyn...

A hydrodynamic permeability of membranes built up by porous cylindrical or spherical particles with impermeable core is investigated. Different versions of a cell method are used to calculate the hydrodynamic permeability of the membranes. Four known boundary conditions, namely, Happel's, Kuwabara's, Kvashnin's and Cunningham/Mehta-Morse's, are considered on the outer surface of the cell. Compa...

The average scattered intensity is determined by the optical characteristics of particles in dispersion. The normalized time auto-correlation function of the scattered light intensity g (τ ) includes both the optical and hydrodynamic information of particles. From the different characteristics of particles, the particle sizes can be obtained. In this paper, three sizes: the static radius Rs, th...

Flow cytometry is a technique capable of optically characterizing biological particles in a high-throughput manner. In flow cytometry, three dimensional (3D) hydrodynamic focusing is critical for accurate and consistent measurements. Due to the advantages of microfluidic techniques, a number of microfluidic flow cytometers with 3D hydrodynamic focusing have been developed in recent decades. How...

rayleigh-taylor (rt) instability has a growing importance in many fields including aircraft industry and astrophysics. the development and the growth of rt instability were investigated using sinusoidal disturbances with different wavelength at the interface of two fluids. numerical simulations were performed by solving navier-stokes unsteady equations with the vof formulation. results of the 2...

Two sets of hydrodynamic equations for a mixture of four gases undergoing a bimolecular chemical reaction are discussed. The former consists in a system of balance laws for the case of a chemical relaxation time of the same order of the macroscopic processes (slow reaction). Conversely, the latter is a system of conservation laws for the case of short chemical relaxation time (fast reaction). A...

Abstract. In this paper we study the hydrodynamic limit of a B.G.K. like kinetic model on domains with boundaries via BVloc theory. We obtain as a consequence existence results for scalar multidimensional conservation laws with kinetic boundary conditions. We require that the initial and boundary data satisfy the optimal assumptions that they all belong to L ∩L∞ with the additional regularity a...

Exploration of intrachain hydrodynamics of dsDNA within channels has been limited to indirect analysis of global coil dynamics. In this Letter, we isolate hydrodynamic interactions within single molecules of dsDNA confined to slitlike channels by making use of density covariance measurements. We show that the strength of hydrodynamic interactions in DNA is dependent on the intrachain correlatio...

Abstract. In this paper, the global existence of smooth solutions for the three-dimensional (3D) non-isentropic bipolar hydrodynamic model is showed when the initial data are close to a constant state. This system takes the form of non-isentropic Euler–Poisson with electric field and frictional damping added to the momentum equations. Moreover, the L-decay rate of the solutions is also obtained...