Tank Side-Wall Effect Evaluated by Using Multi-Body Interaction Computation

2007 ◽  
Author(s):  
W. Y. Duan ◽  
H. Shaheen ◽  
X. B. Chen
Keyword(s):  
Wave Diffraction ◽  
Direct Method ◽  
Side Wall ◽  
Floating Body ◽  
Wall Effects ◽  
Usual Model ◽  
Body Interaction ◽  
Parallel Side ◽  
Side Walls ◽  
Multi Body

It is well known that hydrodynamic first- and second-order loads measured on ships or offshore structures in wave tanks exhibit large scatter compared to the expected results in open sea, due to wave reflections from the side walls. A number of recent works have given theoretical models for diffraction and radiation solutions including side-wall effects. One way consisting of defining a Green function satisfying the boundary condition on two parallel side walls can yield reliable solutions for a floating body of arbitrary geometry in any position of the tank. Unlike previous studies, we evaluate the side-wall effects by directly using the option of multi-body interaction in usual model of wave diffraction and radiation. The tank side-walls are considered as an independent fixed body. The wave diffraction and radiation around a floating body in tanks is solved by taking into account of interaction between the two bodies. The excellent agreement between numerical results of first-order quantities and experimental measurements validates the present method. It is shown that this direct method is very efficient and can be further applied to the case of two side walls in non-parallel position as well as to take into account of bathymetric variation of sea bottom.

Prediction of tunnel wall upwash for delta wings including vortex breakdown effects

1999 ◽  
Vol 103 (1021) ◽  
pp. 139-142 ◽  
Author(s):  
L. W. Traub
Keyword(s):  
Vortex Breakdown ◽  
Side Wall ◽  
Vortical Flow ◽  
Navier Stokes ◽  
Wall Effects ◽  
Integral Expression ◽  
Image System ◽  
Tunnel Wall ◽  
Delta Wings ◽  
Side Walls

AbstractAn incompressible method is presented to predict the upwash corrections associated with vortical flow as a result of wind-tunnel side wall effects. An image system is used to simulate the tunnel side walls which are assumed to be solid. An integral expression is formulated, representing the average upwash induced over the wing by the image system. Wall effects may be determined for flows with and without vortex breakdown. Comparisons of the results with upwash predictions from a Navier-Stokes study show close accord. The upwash expression also displayed the ability to successfully predict corrections for flows involving vortex breakdown.

Innovative approaches in the organization of closed waste-free production of organic pork using cultural and natural agricultural land

2020 ◽  
pp. 15-25
Author(s):  
Volodymyr Ivanov ◽  
Andrii Onyshchenko ◽  
Liudmyla Ivanova ◽  
Liudmyla Zasukha ◽  
Valerii Hryhorenko
Keyword(s):  
Agricultural Land ◽  
Side Wall ◽  
Front Wall ◽  
Lower Edge ◽  
Metal Mesh ◽  
Two Phase ◽  
Transparent Plastic ◽  
Pork Production ◽  
Young Pigs ◽  
Side Walls

The mobile house for two-phase litter rearing piglets was developed in the conditions of pasture their housing, the feature of which is that its side walls and roof are made in the form of two similar in shape and length of arched panels. In the back wall of the inner shield is a litter box, a self-feeder for piglets, a feed unit for a sow and a wicket, and in the front wall of the outer shield are doors with a wicket. Along with this, all walls and the roof of the litter box are made of transparent plastic, and the wall located near the self-feeding trough is also made perforated. In addition, the lower edge of the side wall of the inner arch-shaped shield has slides in which the lower edge of the side wall of the outer arc-shaped shield is inserted. A house with transformable fences has been developed to rear the young pigs. The structural feature of the house is the presence on the outside of the walls of the bobbins with a metal mesh edged at the bottom with a flexible sleeve. In order to ensure the conditions of gentle etching of the vegetation cover and to prevent damage to the turf of the pasture, the house can be completed with another type of hedge consisting of two hinged sections with doors on each side of the fence. In addition, the horizontal wings are rigidly attached to the hedge and connected by a metal mesh around the perimeter, the size of the cells of which ensures that the grass is eaten but prevents the turf of the pasture from being undermined. The developed devices for camp-pasture and feeding of maternal stock, suckling pigs, weaning pigs, repair and fattening pigs are well suited for year-round closed non-waste organic pork production using cultural and natural agricultural land. Key words: housing, feeding, devices, sows, piglets, young animals, pasture, organic pork.

Numerical investigation of side-wall effects on the seakeeping performance of a ship advancing in waves

2021 ◽  
Vol 239 ◽  
pp. 109797
Author(s):  
Chaobang Yao ◽  
Jianghao Huang ◽  
Xiaoshuai Sun ◽  
Jiawei Yu ◽  
Dakui Feng
Keyword(s):  
Numerical Investigation ◽  
Side Wall ◽  
Wall Effects ◽  
Seakeeping Performance

Sensitivity of Thermal Conductivity of Carbon Nanotubes to Defect Concentrations and Heat-Treatment

2012 ◽  
Author(s):  
Michael F. P. Bifano ◽  
Jungkyu Park ◽  
Vikas Prakash
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Interatomic Potential ◽  
Side Wall ◽  
Chemical Vapor ◽  
Md Simulations ◽  
Heat Treated ◽  
Side Walls ◽  
Non Equilibrium Molecular Dynamics ◽  
Vacancy Concentrations

In the present study, classical MD simulations using reverse non-equilibrium molecular dynamics with the AIREBO interatomic potential are used to investigate the sensitivity of thermal conductivity in SWCNTs to side-wall defect concentration and heat-treatment. Two types of defects are investigated. First, the thermal conductivity of (6,6) SWCNTs is obtained as a function of concentration of chemisorbed hydrogen adatoms. Secondly, the thermal conductivity is obtained as a function of point-vacancy concentrations. The results of the studies show that 2 atom% of hydrogenation and 1.5–2% vacancy concentrations have very similar detrimental effects on the thermal conductivity of SWCNT. Vacancy repair is evident with heat treatment, and heat-treatments at 3000°C for up to 22 ns are found to transform point vacancies into various types of non-hexagonal side-wall defects; this vacancy repair is accompanied by a ca. 10% increase in thermal conductivity. Thermal conductivity measurements in both heat-treated and non-heat treated chemical vapor deposition grown MWCNTs are also reviewed. The results suggest that CNT thermal conductivity can be drastically increased if measures are taken to remove common defects from the SWCNT side-walls.

scholarly journals The current distribution in an electrochemical cell. Part VII. Concluding remarks

2002 ◽  
Vol 67 (4) ◽  
pp. 273-278 ◽  
Author(s):  
Konstantin Popov ◽  
S.M. Pesic ◽  
Predrag Zivkovic
Keyword(s):  
Process Parameters ◽  
Current Distribution ◽  
Current Density ◽  
Electrochemical Cell ◽  
Side Wall ◽  
Cell Geometry ◽  
Electrode Edge ◽  
Side Walls ◽  
In Cells

Anew method for the determination of the ability of an electrolyte to distribute uniformly current density in an electrochemical cell is proposed. It is based on the comparison of the current in cells in which the electrode edges touch the cell side walls with the current in cells with different electrode edge ? cell side wall distances. The effects of cell geometry process parameters and current density are discussed and illustrated using the results presented in the previous papers from this series.

scholarly journals Effect of Remelting Temperature and Soaking Time on Microstructure and Mechanical Properties of the Thixoformed Part of Nano-Sized SiCp/7075 Composite

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 709
Author(s):  
Jufu Jiang ◽  
Guanfei Xiao ◽  
Yingze Liu ◽  
Ying Wang ◽  
Xi Nie
Keyword(s):  
Mechanical Properties ◽  
Aluminum Matrix ◽  
Side Wall ◽  
Aluminum Matrix Composite ◽  
Transgranular Fracture ◽  
Composite Part ◽  
Soaking Time ◽  
Ultrasonic Assisted ◽  
Bottom Side ◽  
Side Walls

Semisolid billet of the 7075 aluminum matrix composite reinforced with nano-sized SiC particles was first fabricated by an ultrasonic-assisted semisolid stirring method and rheoforming technology. Then it was thixoformed into a cylinder part under different remelting temperatures and soak times. The effects of the remelting temperature and soaking time on the mechanical properties and microstructure of the thixoformed composite part were investigated. The results show that parts of good quality were thixoformed successfully. The microstructure of the top side wall of the thixoformed part consisted of near spheroidal grains. A large quantity of elongated grains occurred in the medium and bottom side walls and the bottom itself. With increasing remelting temperatures, the size of the solid grains of the thixoformed parts showed a trend of first to increase and afterwards to decrease. High density dislocations were found in the microstructure when the remelting temperatures were 590 °C and 600 °C. When the soaking time was 15 min, the severest deformation occurred in the thixoformed part. High mechanical properties of the thixoformed parts were achieved under conditions such as a remelting temperature between 590 °C and 600 °C and a soaking time between 10 min and 15 min. The fracture mode of the thixoformed part changed from transgranular fracture to intergranular fracture when the remelting temperature was elevated from 580 °C to 610 °C. After the thixoformed parts were treated by T6, the ultimate tensile strength (UTS) and elongation of the side wall were improved to 552 MPa and 7.9%, respectively. Dispersed MgZn2 precipitates created by T6 heat treatment led to an improvement of the mechanical properties.

Separating and Reattaching Flow Structure in a Suddenly Expanding Rectangular Duct

1995 ◽  
Vol 117 (1) ◽  
pp. 17-23 ◽  
Author(s):  
G. Papadopoulos ◽  
M. V. O¨tu¨gen
Keyword(s):  
Aspect Ratio ◽  
Flow Structure ◽  
Three Dimensional ◽  
Side Wall ◽  
Stream Velocity ◽  
Rectangular Duct ◽  
Mean Flow ◽  
Wall Effects ◽  
Velocity Measurements ◽  
Aspect Ratios

The incompressible turbulent flow over a backward-facing step in a rectangular duct was investigated experimentally. The side wall effects on the core flow were determined by varying the aspect ratio (defined as the step span-to-height ratio) from 1 to 28. The Reynolds number, based on the step height and the oncoming free-stream velocity, was 26,500. Detailed velocity measurements were made, including the turbulent stresses, in a region which extended past the flow reattachment zone. Wall static pressure was also measured on both the step and flat walls. In addition, surface visualizations were obtained on all four walls surrounding the separated flow to supplement near-wall velocity measurements. The results show that the aspect ratio has an influence on both the velocity and wall pressure even for relatively large aspect ratios. For example, in the redevelopment region downstream of reattachment, the recovery pressure decreases with smaller aspect ratios. The three-dimensional side wall effects tend to slow down the relaxation downstream of reattachment for smaller aspect ratios as evidenced by the evolution of the velocity field. For the two smallest aspect ratios investigated, higher centerplane streamwise and transverse velocities were obtained which indicate a three-dimensional mean flow structure along the full span of the duct.

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