We measured counter-current flow limitation (CCFL), pressure gradient dP/dz, and void fraction αG in a 40 mm diameter vertical pipe with the rounded top bottom ends working fluids of air water under flooding conditions, we obtained wall interface friction factors, fw fi. compared CCFL, αG, fi those from our previous experiments pipes sharp-edged ends, ends. As result, shape upper end affected c...

The effects of tight junction structure on water and solute fluxes across proximal tubular epithelium were examined with fiber-matrix equations previously derived by Curry and Michel (1980. Microvascular Research. 20:96-99). Using plausible estimates of tight junction fiber length and width the model predicts solute (Ps) and water permeability (Lp) coefficients that agree with the measured valu...

Abstract Recently, one of the authors suggested calculating void fraction, an essential element in thermalhydraulics, working with the ‘thermodynamic’ quality instead of the usual ‘flow’ quality. However, the standard heat balance is currently stated as a function of the ‘flow’ quality. Therefore, we should search a new energy balance between the mixture enthalpy, based on ‘thermodynamic’ quali...

Microscopic structure in bubbly flows is a topic of interest in the study of fluid flows. In the present paper, the Ultrasonic Doppler Method was applied to the measurement of bubbly flows from which Reynolds stress profiles were obtained. Experiments were carried out for an air-water dispersed bubbly flow in a 20mm x 100 mm vertical rectangular channel having a void fraction smaller than 3%. T...

The cable in conduit conductors for the various ITER coils are required to function under pulse conditions and fields up to 13 T. A parametric study, restricted to a limited variation of the reference cable lay out, is carried out to clarify the quantitative impact of various cable parameters on the coupling loss and to find realistic values for the coupling loss time constants to be used in ac...

Defocusing digital particle image velocimetry (DDPIV) is the natural extension of planar PIV techniques to the third spatial dimension. In this paper we give details of the defocusing optical concept by which scalar and vector information can be retrieved within large volumes. The optical model and computational procedures are presented with the specific purpose of mapping the number density, t...

Nonlinear acoustic wave propagation equation with void fraction (volume fraction of gas phase) is derived and numerically solved for the simulation of HIFU (High Intensity Focused Ultrasound) with micorbubbles in the present paper. HIFU is one of promising treatments for cancer. The focused pressure waves generate heat and necrose cancer cells. It has been lately reported that the existence of ...

Cassie-Baxter theory has traditionally been used to study liquid drops in contact with microstructured surfaces. The Cassie-Baxter theory arises from a minimization of the global Gibbs free energy of the system but does not account for the topology of the three-phase contact line. We experimentally compare two situations differing only in the microstructure of the roughness, which causes differ...

A pore-scale description of species and charge transport through a bilayer cathode catalyst layer CL of a polymer electrolyte fuel cell using a direct numerical simulation DNS model is presented. Two realizations of the bilayer catalyst layer structure are generated using a stochastic reconstruction technique with varied electrolyte and void phase volume fractions. The DNS calculations predict ...

In this study hydrodynamics of a fluidized bed reactor with fumed silica nano particles was modeled using CFD method. Hydrodynamics parameters such as gas and solid velocity and void fraction have been investigated. The minimum fluidization velocity was around 0.0115 m/s at solids volume fraction of 0.0077. Fluidization process was involving a high expansion ratio of bed and without large bubbl...