Liquid water transport and removal from the gas diffusion layer GDL and gas channel of a polymer electrolyte fuel cell PEFC are studied experimentally and theoretically. In situ observations of the liquid water distribution on the GDL surface and inside the gas channel were made in an operating transparent PEFC. Liquid droplet formation and emergence from the GDL surface are characterized and t...

The lattice Boltzmann method (LBM) emerged from the field of computational fluid dynamics as an alternative to Navier-Stokes based approaches. It has since been proven to be applicable also for the simulation of free surface flows (liquid-gas flow) and particulate flows (liquid-solid flow). In the past both algorithmss for free surface flows and particulate flows have been realized that preserv...

Microscale multiphase flows (gas-liquid and liquid-liquid) possess a number of unique properties and have applications ranging from use in microchemical synthesis systems to heat exchangers for IC chips and miniature fuel cells. Our work is focused on gas-liquid flows in microfabricated channels of rectangular or triangular cross section. We characterize the phase distribution and pressure drop...

A predictive model for droplet size and velocity distributions of a pressure swirl atomizer has been proposed based on the maximum entropy formalism (MEF). The constraint conditions of the MEF model include the conservation laws of mass, momentum, and energy. The effects of liquid swirling strength, Weber number, gas-to-liquid axial velocity ratio and gas-to-liquid density ratio on the droplet ...

Generally, unit operation processes that are used in environmental engineering are in‐ volved in interfacial reaction where mass transfer is an extremely essential component for system optimization. The purposes of this chapter were intended to provide the informa‐ tion of both theoretical model development and engineering practice for mass transfer of important processes in environmental engin...

Porous surface modified polyvinylidene ï‌‚uoride (PVDF) hollow fiber membranes are fabricated through a dry-wet phased inversion process. Surface modifying macromolecules (SMM) (1 wt. %) are used as additives in the spinning dope. The performance of the surface modified membrane in contactor application for CO2 stripping from water is assessed through the fabricated gas–liquid membrane contacto...

Liquid/gas flows are experimentally investigated in 200 and 525 mm square microchannels made of glass and silicon. Liquid and gas are mixed in a cross-shaped section in a way to produce steady and homogeneous flows of monodisperse bubbles. Two-phase flow map and transition lines between flow regimes are examined. Bubble velocity and slip ratio between liquid and gas are measured. Flow patterns ...

Beginning with a discussion of energy and exergy analysis definitions, the presented study provides a descriptive mathematical model for energy and exergy analysis for a co-current gas cooling tower. For this purpose using conservation laws of mass, energy and momentum, the variation of temperature and enthalpy of gas and liquid streams are predicted along the tower length and are used in order...

Analysis of the drilling fluid temperature due to heat transfer of drilling fluid with the formation in under-balanced drilling operation is the main objective of this study. Gas-liquid two-phase flow model considering thermal interaction with the formation is used to numerically simulate a well with real dimensions. In the present study, the continuity, momentum, and energy equations are devel...