Novel Optical Fiber Installation by Use of Spiral Airflow

1992 ◽  
Vol 114 (3) ◽  
pp. 375-378 ◽  
Author(s):  
K. Horii ◽  
Y. Matsumae ◽  
K. Ohsumi ◽  
X. M. Cheng ◽  
S. Kage ◽  
...  
Keyword(s):  
Optical Fiber ◽  
High Performance ◽  
Spiral Structure ◽  
Tube Wall ◽  
Coanda Effect ◽  
Spiral Flow ◽  
Annular Jet ◽  
Annular Slit ◽  
Coandǎ Effect ◽  
Downstream Flow

A high performance apparatus for installing optical fiber has been developed. With this apparatus, a 2 mm-diameter optical fiber was blown through a 6 mm-diameter rolled tube over a distance of 1200 meters, which is longer than the 700 meters achieved by the best conventional techniques. The heart of the apparatus is a novel nozzle with an annular slit and a conical cylinder to create a spiral airflow. In the spiral flow, the back flow of air is prevented due to the Coanda effect and the fiber scraping along the tube wall is minimized, owing to the ordered flow structure, leading to effective fiber installation. To obtain a spiral flow, pressurized air is forced into the buffer area of a nozzle and then through the angled annular slit into the tube entrance. Due to the Coanda effect of the annular jet from the slit attaching to the nozzle walls and the conical cylinder, the downstream flow in the tube develops a highly stable spiral structure with a steep axial velocity distribution that is more ordered than typical turbulent tube flows at the same mass-flow rate.

Flow attachment to solid surfaces: The Coanda effect

AIChE Journal ◽  
1972 ◽  
Vol 18 (1) ◽  
pp. 51-57 ◽  
Author(s):  
T. Panitz ◽  
D. T. Wasan
Keyword(s):  
Solid Surfaces ◽  
Coanda Effect ◽  
Coandǎ Effect

scholarly journals Comparison of CFD simulations and measurements of flow affected by coanda effect

2012 ◽  
Vol 25 ◽  
pp. 01015 ◽  
Author(s):  
Jan Fišer ◽  
Jan Jedelský ◽  
Tomáš Vach ◽  
Matěj Forman ◽  
Miroslav Jícha
Keyword(s):  
Coanda Effect ◽  
Cfd Simulations ◽  
Coandǎ Effect

Surface Tension Effects on Discharge Capacity of Coanda-Effect Screens

2021 ◽  
Vol 147 (8) ◽  
pp. 04021026
Author(s):  
Tony L. Wahl ◽  
Christopher C. Shupe ◽  
Hajrudin Dzafo ◽  
Ejub Dzaferovic
Keyword(s):  
Surface Tension ◽  
Discharge Capacity ◽  
Coanda Effect ◽  
Coandǎ Effect

scholarly journals Biosensing with optical fiber gratings

Nanophotonics ◽  
2017 ◽  
Vol 6 (4) ◽  
pp. 663-679 ◽  
Author(s):  
Francesco Chiavaioli ◽  
Francesco Baldini ◽  
Sara Tombelli ◽  
Cosimo Trono ◽  
Ambra Giannetti
Keyword(s):  
Optical Fiber ◽  
Single Molecule ◽  
High Performance ◽  
Performance Metrics ◽  
Surrounding Medium ◽  
Remote Measurement ◽  
Fiber Gratings ◽  
Practical Applications ◽  
Technology Platforms ◽  
Optical Fiber Gratings

AbstractOptical fiber gratings (OFGs), especially long-period gratings (LPGs) and etched or tilted fiber Bragg gratings (FBGs), are playing an increasing role in the chemical and biochemical sensing based on the measurement of a surface refractive index (RI) change through a label-free configuration. In these devices, the electric field evanescent wave at the fiber/surrounding medium interface changes its optical properties (i.e. intensity and wavelength) as a result of the RI variation due to the interaction between a biological recognition layer deposited over the fiber and the analyte under investigation. The use of OFG-based technology platforms takes the advantages of optical fiber peculiarities, which are hardly offered by the other sensing systems, such as compactness, lightness, high compatibility with optoelectronic devices (both sources and detectors), and multiplexing and remote measurement capability as the signal is spectrally modulated. During the last decade, the growing request in practical applications pushed the technology behind the OFG-based sensors over its limits by means of the deposition of thin film overlays, nanocoatings, and nanostructures, in general. Here, we review efforts toward utilizing these nanomaterials as coatings for high-performance and low-detection limit devices. Moreover, we review the recent development in OFG-based biosensing and identify some of the key challenges for practical applications. While high-performance metrics are starting to be achieved experimentally, there are still open questions pertaining to an effective and reliable detection of small molecules, possibly up to single molecule, sensing in vivo and multi-target detection using OFG-based technology platforms.

scholarly journals Theoretical Modeling, Design and Simulation of an Innovative Diverting Valve Based on Coanda Effect

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 103
Author(s):  
Giancarlo Comes ◽  
Carlo Cravero
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Additive Manufacturing ◽  
Water Flow ◽  
Coanda Effect ◽  
Geometrical Parameters ◽  
Convex Wall ◽  
Fluidic Device ◽  
Coandǎ Effect

The present work is focused on the study of an innovative fluidic device. It consists of a two-ways diverter valve able to elaborate an inlet water flow and divert it through one of the two outlets without moving parts but as a result of a fluctuation of pressure induced by two actuation ports, or channels. Such apparatus is named Attachment Bi-Stable Diverter (ABD) and is able to work with the effect of the fluid adhesion to a convex wall adjacent to it, this phenomenon is known as Coanda Effect; it generates the force responsible for the fluid attachment and the consequent deviation. The main purpose of this work is to develop a knowhow for the design and development of such particular device. A mathematical model for the ABD has been developed and used to find the relationships between the geometrical parameters and the operative conditions. A configuration has been designed, simulated with a computational fluid dynamics approach. A prototype has been printed with and additive manufacturing printer and tested in laboratory to check the effective working point of the device.

Potential model of the coanda effect

1979 ◽  
Vol 13 (4) ◽  
pp. 492-503 ◽  
Author(s):  
V. M. Khanin
Keyword(s):  
Potential Model ◽  
Coanda Effect ◽  
Coandǎ Effect
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