S0506-1-4 Estimation of Sensible Heat Transfer Across the Wind-Driven Air-Water Interface at the High Speed Wind Region with Breaking Wave

2010 ◽  
Vol 2010.2 (0) ◽  
pp. 7-8
Author(s):  
Satoshi SHIMADA ◽  
Naohisa TAKAGAKI ◽  
Koji IWANO ◽  
Ryoichi KUROSE ◽  
Satoru KOMORI
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Breaking Wave ◽  
Water Interface ◽  
Sensible Heat ◽  
Wind Region ◽  
Air Water Interface

J056022 Estimation of Mass Transfer across the Air-Water Interface in the High Speed Wind Region with Breaking Waves

2011 ◽  
Vol 2011 (0) ◽  
pp. _J056022-1-_J056022-3
Author(s):  
Koji IWANO ◽  
Naohisa TAKAGAKI ◽  
Emil ILYASOV ◽  
Ryoichi KUROSE ◽  
Satoru KOMORI
Keyword(s):  
Mass Transfer ◽  
High Speed ◽  
Breaking Waves ◽  
Water Interface ◽  
Wind Region ◽  
Air Water Interface

Water skating in the larvae of dixella aestivalis (Diptera) and hydrobius fuscipes (Coleoptera)

1999 ◽  
Vol 202 (7) ◽  
pp. 845-853
Author(s):  
J. Brackenbury
Keyword(s):  
High Speed ◽  
The Body ◽  
Water Interface ◽  
Body Movements ◽  
Chironomid Larvae ◽  
High Speed Video ◽  
Adhesive Organ ◽  
Video Recordings ◽  
Air Water Interface

The kinematics of locomotion was investigated in the aquatic larvae of Dixella aestivalis and Hydrobius fuscipes with the aid of high-speed video recordings. Both insects are able to skate on the surface of the water using the dorso-apical tracheal gill as an adhesive organ or ‘foot’. Progress relies on the variable adhesion of the foot between ‘slide’ and ‘hold’ periods of the locomotory cycle. The flexural body movements underlying skating in D. aestivalis can be derived directly from the figure-of-eight swimming mechanism used in underwater swimming. The latter is shown to be similar to figure-of-eight swimming in chironomid larvae. This study shows how the deployment of a ‘foot’ enables simple side-to-side flexural movements of the body to be converted into effective locomotion at the air-water interface.

scholarly journals Through-grid wicking enables high-speed cryoEM specimen preparation

2020 ◽  
Vol 76 (11) ◽  
pp. 1092-1103
Author(s):  
Yong Zi Tan ◽  
John L. Rubinstein
Keyword(s):  
Glass Fiber ◽  
High Speed ◽  
Protein Complexes ◽  
Absorption Capacity ◽  
Specimen Preparation ◽  
Water Interface ◽  
Time Resolved ◽  
Glass Fiber Filter ◽  
Liquid Absorption ◽  
Air Water Interface

Blotting times for conventional cryoEM specimen preparation complicate time-resolved studies and lead to some specimens adopting preferred orientations or denaturing at the air–water interface. Here, it is shown that solution sprayed onto one side of a holey cryoEM grid can be wicked through the grid by a glass-fiber filter held against the opposite side, often called the `back', of the grid, producing a film suitable for vitrification. This process can be completed in tens of milliseconds. Ultrasonic specimen application and through-grid wicking were combined in a high-speed specimen-preparation device that was named `Back-it-up' or BIU. The high liquid-absorption capacity of the glass fiber compared with self-wicking grids makes the method relatively insensitive to the amount of sample applied. Consequently, through-grid wicking produces large areas of ice that are suitable for cryoEM for both soluble and detergent-solubilized protein complexes. The speed of the device increases the number of views for a specimen that suffers from preferred orientations.

scholarly journals Simulation of Air–Water Interface Effects for High-speed Planing Hull

2020 ◽  
Vol 19 (3) ◽  
pp. 398-414
Author(s):  
Naga Venkata Rakesh Nimmagadda ◽  
Lokeswara Rao Polisetty ◽  
Anantha Subramanian Vaidyanatha Iyer
Keyword(s):  
High Speed ◽  
Water Interface ◽  
Fluid Forces ◽  
Transition Speed ◽  
High Speeds ◽  
Air Water Interface ◽  
Practical Design ◽  
Actual Flow ◽  
Wetted Surface Area ◽  
Interface Effects

Abstract High-speed planing crafts have successfully evolved through developments in the last several decades. Classical approaches such as inviscid potential flow–based methods and the empirically based Savitsky method provide general understanding for practical design. However, sometimes such analyses suffer inaccuracies since the air–water interface effects, especially in the transition phase, are not fully accounted for. Hence, understanding the behaviour at the transition speed is of fundamental importance for the designer. The fluid forces in planing hulls are dominated by phenomena such as flow separation at various discontinuities viz., knuckles, chines and transom, with resultant spray generation. In such cases, the application of potential theory at high speeds introduces limitations. This paper investigates the simulation of modelling of the pre-planing behaviour with a view to capturing the air–water interface effects, with validations through experiments to compare the drag, dynamic trim and wetted surface area. The paper also brings out the merits of gridding strategies to obtain reliable results especially with regard to spray generation due to the air–water interface effects. The verification and validation studies serve to authenticate the use of the multi-gridding strategies on the basis of comparisons with simulations using model tests. It emerges from the study that overset/chimera grids give better results compared with single unstructured hexahedral grids. Two overset methods are investigated to obtain reliable estimation of the dynamic trim and drag, and their ability to capture the spray resulting from the air–water interaction. The results demonstrate very close simulation of the actual flow kinematics at steady-speed conditions in terms of spray at the air–water interface, drag at the pre-planing and full planing range and dynamic trim angles.

scholarly journals Experimental Validation of RELAP5 and TRACE5 for Licensing Studies of the Boron Injection System of Atucha II

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Alejandro I. Lazarte ◽  
William Fullmer ◽  
Martín Bertodano
Keyword(s):  
Heat Transfer ◽  
Nuclear Power ◽  
Experimental Validation ◽  
Injection System ◽  
Water Interface ◽  
Experimental Facility ◽  
Pressure Losses ◽  
Air Water Interface ◽  
Loss Of Coolant ◽  
Tank Level

This paper presents an experimental validation of RELAP5 and TRACE5 for licensing studies of the Atucha II-PHWR nuclear power plant. A scaled experimental facility, representing the boron injection system of Atucha II, was built. The system has a fundamental importance for loss of coolant accidents (LOCA) and anticipated transients without scram (ATWS). The experiment consists of the discharge of a tank that represents the boron tank filled with air or a mixture of air-water onto a discharge tank that represents the moderator tank. Both tanks are connected by a pipe which includes a valve and an orifice plate to model the pressure losses due to the fittings in the real system. The pressure and water level measured in the tanks are compared with the RELAP5 and TRACE5 predictions. The codes predict the pressure in the tanks accurately. However, both codes overpredict the heat transfer in the boron tank air-water interface which produces a greater expansion of the air which leads to a small discrepancy in the boron tank level prediction.

Comparison of Profiles and Fluxes of Heat and Momentum Above and Below an Air-Water Interface

1982 ◽  
Vol 104 (1) ◽  
pp. 34-39 ◽  
Author(s):  
B. M. Howe ◽  
A. J. Chambers ◽  
S. P. Klotz ◽  
T. K. Cheung ◽  
R. L. Street
Keyword(s):  
Heat Transfer ◽  
Surface Layer ◽  
Water Surface ◽  
Temperature Fields ◽  
Water Interface ◽  
Law Of The Wall ◽  
Air Water Interface ◽  
Total Energy Flux ◽  
Momentum And Heat Transfer ◽  
Water Surface Layer

The velocity and temperature fields on both sides of an air-water interface were examined experimentally in order to understand better the physical processes of momentum and heat transfer through the surface layers about the interface. An examination of temperature and velocity profiles plotted in “law-of-the-wall” coordinates leads to the conclusion that, both in the air and in the water, the mechanism of momentum transfer is affected by surface roughness changes, but the mechanism of heat transfer is not. In the water surface layer the velocity fluctuations due to the wave-related motions are of the same order as the purely turbulent motions. The turbulent components closely resemble those found in boundary layers over solid walls. The measured total energy flux from the interface agrees well with the measured single-phase, vertical heat transport through the water surface layer.

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