scholarly journals Maximizing friction in the erosion of glacial valleys

2020 ◽  
Vol 66 (259) ◽  
pp. 876-879 ◽  
Author(s):  
Valerio Faraoni
Keyword(s):  
Variational Principle ◽  
Cross Sectional ◽  
Cross Sectional Profile ◽  
The Cross ◽  
Sectional Profile

AbstractThe cross-sectional profile of a glacial valley can be obtained with a variational principle in which the friction against the valley walls and the glacier bed is extremized, subject to a Lagrangian constraint. We show that the actual valley profile maximizes the friction, thus settling an old debate.

scholarly journals Influence of Geometric Parameters on Aerodynamic and Acoustic Performances of Bladeless Fans

2019 ◽  
Author(s):  
Ang Li ◽  
Jun Chen ◽  
Yangfan Liu ◽  
Stuart Bolton ◽  
Patricia Davies
Keyword(s):  
Cross Section ◽  
Fluid Dynamic ◽  
Geometric Parameters ◽  
Design Stage ◽  
Air Velocity ◽  
Cross Sectional ◽  
Future Design ◽  
Cross Sectional Profile ◽  
The Cross ◽  
Sectional Profile

Abstract In recent years, the bladeless fan that does not have visible impellers have been widely applied in household appliances. Since the customers are particularly sensitive to noise and the strength of wind generated by the fan, the aerodynamic and acoustic performances of the fan need to be accurately characterized in the design stage. In this study, computational fluid dynamic (CFD) and computational aeroacoustics (CAA) are applied to investigate the performances of different designs of a bladeless fan model. The influence of four parameters, namely the airfoil selection for cross-section of the wind channel, the slit width, the height of cross-section and the location of the slit, is investigated. The results indicate the streamwise air velocity increases significantly by narrowing the outlet, but the noise level increases simultaneously. In addition, the generated noise increases while the height of fan cross-section increases, and a 4mm height of the cross section is optimal for aerodynamic performance. When the slit is closer to the location of maximum thickness, the performances of the bladeless fan increases. Moreover, the performance is not changed significantly by changing the cross-sectional profile. Finally, the optimal geometric parameters are identified to guide the future design of the bladeless fan.

Rational design of capillary-driven flows for paper-based microfluidics

Lab on a Chip ◽  
2015 ◽  
Vol 15 (10) ◽  
pp. 2173-2180 ◽  
Author(s):  
Emanuel Elizalde ◽  
Raúl Urteaga ◽  
Claudio L. A. Berli
Keyword(s):  
Flow Rate ◽  
Rational Design ◽  
Front Velocity ◽  
Cross Sectional ◽  
Liquid Front ◽  
Paper Based Microfluidics ◽  
Cross Sectional Profile ◽  
The Cross ◽  
Sectional Profile ◽  
Paper Substrates

We present a tool that allows one to determine the cross-sectional profile required for a programmed liquid front velocity or flow rate during lateral imbibition in paper substrates. New regimes can be designed, i.e. constant liquid front velocity.

Deterministic Process Modelling of Micro Air Abrasive Jet Machining of Glass Channel

2010 ◽  
Vol 447-448 ◽  
pp. 272-276 ◽  
Author(s):  
Stephen Wan ◽  
Weng Seng Fong ◽  
Qi Ying Leong
Keyword(s):  
Erosive Wear ◽  
Soda Lime ◽  
Process Models ◽  
Machining Process ◽  
Cross Sectional ◽  
Deterministic Process ◽  
Abrasive Jet Machining ◽  
Cross Sectional Profile ◽  
The Cross ◽  
Sectional Profile

We present simple deterministic process models for the prediction of the evolution of the cross-sectional profile of glass channels generated by erosive wear in micro air abrasive jet machining using a round nozzle. The present work was motivated by a need to understand the sensitivity of the geometry of the generated cross-sectional profile to the degree of offset between the centre of the nozzle and the centre of the mask defining the channel. Experiments were carried out on soda lime and borosilicate glass to verify the process models. Predicted results show fairly good agreement with experimental results. We conclude that, without proper alignment, the cross-sectional profile is easily skewed, as the micro abrasive jet machining process quickly acts on any initial geometrical skewness and compounds it over time.

A study on the cross-sectional profile of flat rolled wire

2008 ◽  
Vol 200 (1-3) ◽  
pp. 325-330 ◽  
Author(s):  
M. Kazeminezhad ◽  
A. Karimi Taheri ◽  
A. Kiet Tieu
Keyword(s):  
Cross Sectional ◽  
Cross Sectional Profile ◽  
The Cross ◽  
Sectional Profile ◽  
Rolled Wire

A new carcineretid crab (upper Turonian, Cretaceous) of Colombia

2002 ◽  
Vol 76 (4) ◽  
pp. 718-724 ◽  
Author(s):  
Rodney M. Feldmann ◽  
Tomas Villamil
Keyword(s):  
New Species ◽  
Large Specimen ◽  
Cross Sectional ◽  
The Family ◽  
Cross Sectional Profile ◽  
The Cross ◽  
Sectional Profile ◽  
A New Species

A single large specimen of carcineretid crab from the Cretaceous Puerto Romero unit of Colombia constitutes the basis for a new species, Ophthalmoplax triambonatus. A re-diagnosis of the Carcineretidae results in the assignment of five genera to the family: Carcineretes Withers, 1922; Branchiocarcinus Vega, Feldmann, and Sour-Tovar, 1995; Mascaranada Vega and Feldmann, 1991; Ophthalmoplax Rathbun, 1935; and Woodbinax Stenzel, 1952. The cross-sectional profile of O. triambonatus suggests that it was a back-burrower, rather than an active swimmer.

Sign in / Sign up

Export Citation Format

Share Document