in this paper, direct numerical simulation of two-phase incompressible gas-liquid flow for simulation of bubble motion in a microtube is presented. microtube radius is 10 µm. the interface is tracked using volume of fluid (vof) method with continuous surface force (csf) model. the flow is solved using a finite volume scheme, based on piso algorithm. numerical simulation is performed on a axisym...

in the present work, b-zsm-5 zeolite membranes were synthesized on porous tubular α-alumina supports by several subsequence in situ crystallization hydrothermal treatments. the tio2- bohmite and ɣ- alumina intermediate layers were applied to improve the lattice matching between zeolite layer and the support. the uniform membrane intermediate layers with low permeation resistance were prepared o...

Introduction The formatIOn of periodIC patterns (stnatlOn) has drawn much attentIon In contInUOUS wave laser cutt time (s) tp time penod per oxidation cycle (s) U gas velOCIty profile (m/s) Uo streamwlse gas velOCIty (m/s) V Interfacial velOCIty (m/s) u lIqUId velOCIty In x dIrectIOn (m/s) v hqUId velOCIty In y dIrectIOn or cuttIng speed (m1s) v. fnctIon velOCIty (m/s) W actIvatIOn energy (J) W...

Many densely packed suspensions and colloids exhibit a behavior known as Discontinuous Shear Thickening in which the shear stress jumps dramatically and reversibly as the shear rate is increased. We performed rheometry and video microscopy measurements on a variety of suspensions to determine the mechanism for this behavior. We distinguish Discontinuous Shear Thickening from inertial effects by...

the mechanical behaviour of rockfill materials and aggregates depends not only on particle size and compaction, but also on their strength and lithological properties. in this research two types of large triaxial and direct shear tests are performed on rockfill materials. this paper compares the stress-strain behaviour of sandstone and andesibasalt materials in triaxial compression tests (3006...

it is several decades that the application of membrane processes for gas separation has become a great concern within industries. among them, the polymeric membranes of different structures have played the most important role. such application has been widely extended to gas separation and due to the necessity of both; prediction of the behavior of these processes and recognition of the effecti...

We investigated the effects of particle shape on shear thickening in densely packed suspensions. Rods of different aspect ratios and nonconvex hooked rods were fabricated. Viscosity curves and normal stresses were measured using a rheometer for a wide range of packing fractions for each shape. Suspensions of each shape exhibit qualitatively similar discontinuous shear thickening. The logarithmi...

Gas-liquid membrane contactors offer several practical advantages including high surface area per unit volume; independent control of gas and liquid velocities without any flooding, loading, weeping, or foaming, pre-determined gas–liquid interfacial area, membrane modules, capability of linear scale-up; low corrosion problems, and low operation and capital costs. Two common types of membrane co...

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...