The non-Newtonian flow of dilute aqueous polyethylene oxide (PEO) solutions through micro-fabricated planar abrupt contraction–expansions is investigated. The small lengthscales and high deformation rates in the contraction throat lead to significant extensional flow effects even with dilute polymer solutions having time constants on the order of milliseconds. By considering the definition of t...

Understanding the flow fields at the micro-scale is key to developing methods of success-fully mixing fluids for micro-scale applications. This paper investigates flow characteristics and mixing efficiency of three different geometries in micro-channels. The geometries of these channels were rectangular with a dimension of; 300 m wide, 100 m deep and 50 mm long. In first channel there was no ob...

This paper reports the results of experimentally removing ammonia from synthetically prepared ammonia solution using a micro scale mixing loop air stripper. Effects of various operational parameters (such as: pH, air flow rate, wastewater flow rate and initial ammonia concentration) were evaluated. By increasing the pH from 10 to 12.25 the amount of KLa increased from 0.26 to 0.73 hr-1. A consi...

A review is given on sensors fabricated by silicon micromachining technology using the thermal domain for the measurement of fluid flow. Attention is paid especially to performance and geometry of the sensors. Three basic types of thermal jlow sensors are discussed: anemometers, calorimetric flow sensors and time of flight flow sensors. Anemometers may comprise several heaters and temperature s...

Abstract Good understanding of micro-scale urban-wind phenomena is needed for optimizing power generation capabilities building-integrated wind turbines and safety futuristic urban transport involving drones. The current work involves development a multiscale methodology obtaining fields in an landscape. multi-scale coupling three models operating on different scales namely operational meso-sca...

Micro–macro simulations of polymeric solutions rely on the coupling between macroscopic conservation equations for the fluid flow and stochastic differential equations for kinetic viscoelastic models at the microscopic scale. In the present work we introduce a novel micro–macro numerical approach, where the macroscopic equations are solved by a finite-volume method and the microscopic equation ...

In recent years, the interest in integrated microfluidic systems has been steadily growing. In these systems (for instance (bio)chemical and DNA analysis and synthesis devices), accurate dosing of liquids and/or gases is of great importance. To achieve this, accurate (mass) flow sensing is necessary. This project is dedicated to the development of a new micro Coriolis flow sensor. The inherent ...

Compared with UV embossing and micro-contact imprinting, hot embossing technology is the first to be used in nano-imprint lithography, and is access to copying the parallel structure in micro-nano-scale at low cost and relatively faster speed. This paper explores which factors influence some pattern transferring accuracy appearing in the experiment: the adhesion between mold and polymethyl meth...

Micro-scale devices based on the Stirling cycle are an attractive choice for chipand board-level electronics. A new Stirling cycle micro-refrigeration system composed of arrays of silicon MEMS cooling elements has been designed. COMSOL is used to evaluate the thermal performance of the system. Simulation of compressible flow and heat transfer with a large deformed mesh has been successfully imp...

Optical feedback interferometry (OFI) performance for microscale-flow sensing is studied theoretically and experimentally. A new numerical modeling approach for OFI flow meter spectrum reproduction is presented in this work to study the optical effect on the signal due to the micro-scale channel geometry. Two well-defined frequency peaks are found in the OFI spectrum, this phenomenon can be att...