Call For Paper The 9th International Workshop on Ship and Marine Hydrodynamics（IWSH＇2015, 26- 28 August 2015, Glasgow,UK）

<正>In 1999,the first International Workshop on Ship Hydrodynamics was successfully held in Wuhan,China.Then it was held in Wuhan,Shanghai,Zhenjiang,Harbin,Seoul in subsequent every two years.These Conferences had drawn a variety of international delegates including scientists,engineers and researchers with a common interest in ship hydrodynamics.They provided a forum to promote scientific advancement,technological progress,information exchange,and cooperation among engineers and researchers in ship and ocean engineering and other related fields.The coming IWSH’2015 conference will change its full name to International Workshop on Ship and Marine Hydrodynamics.It will be hosted and organized by University of Strathclyde,UK and sponsored by Lloyd’s Register,UK.The IWSH’2015 will be a platform for engineers and researchers to keep abreast     

三角形网格在水动力水环境数学模型中的应用

综合介绍了三角形网格在水动力、水环境数学模型中的若干实用技术。     

防渗渠道顶托渗漏量计算方法的理论探讨

针对灌区高地下水位条件,探讨在饱和渗流水顶托条件下,采取防渗衬砌措施前后渠道渗漏量的理论计算方法,分析研究现有解析计算经典公式的特点及其适应性.根据水力学和水动力学原理,推出理论上可行、结构合理和简便适用的解析计算方法,并用数值模拟计算进行了验证,结果表明,本文解析法与数值法的计算结果比较接近.     

水动力条件对富营养化影响规律探讨

富营养化防治的技术关键，是需要了解抑制藻类生长的外部环境条件及其影响作用规律．基于国内外对气候条件和营养盐条件对藻类生长速率影响研究成果基础上，采用机理分析和实际案例分析相结合的方法，重点探讨了以流速为表征要素的水动力条件对藻类生长速率的影响特点，并且以三峡库区支流大宁河为例，初步建立了流速对藻类生长速率影响规律的经验关系式，为预测三峡库区富营养化演变态势提供基础，进而为有效防治富营养化提供技术支撑．     

Solid Suspension in Jet Mixers

Experiments have been carried out with jet mixers to study the solid suspension characteristics. The jet velocities required for solid suspension in 0.5 and 1 m ID tanks were measured experimentally. The nozzle diameter was varied from 0.0156 to 0.05 m. The nozzle clearance from the tank bottom was varied from 0.1 to 0.9 m. Tap water and sand of average sizes 100, 300, and 500 µm were used. The solid loading was varied from 1 to 5% (wt.). The effect of nozzle angle was also studied. A semi‐empirical model has been developed to predict the jet velocity needed to achieve a certain degree of suspension.     

Hydrodynamics of the Stripper Section of Fluid Cokers

The hydrodynamics of fluid bed cokers were studied by analyzing pressure fluctuations and particle motion in a half‐column cold model, geometrically and dynamically similar (with key dimensionless groups matched) to the stripper section of two commercial fluid cokers. Superficial gas velocity and solids circulation strongly affected the hydrodynamics. The pressure drop over the top section of the stripper decreased at high solids circulation fluxes and high gas velocities due to flooding. Flooding occurred prematurely when fouling was simulated. Steam redistribution did not improve stripper performance for the conditions investigated. However, steep sheds on the top row, aeration behind the solids exit and standpipe aeration all improved solids circulation, leading to reduced fouling in two commercial fluid cokers.     

ON THE FORMATION OF THE BULGE IN A SPILLING BREAKING WATER WAVE

The early stages of a spilling breaking water wave leading to the formation of a bulge on the forward face of the wave are investigated. In this study, simultaneous space-time measurements of the free-surface elevation of a spilling breaking water wave are recorded and analyzed. The analysis, carried out in the frame of reference moving with the crest of the wave,reveals that the formation of the bulge is due to the presence of a shock-like mode. In the previous frame of reference, the shock itself is unsteady but its (spatial) location is time independent and coincides with the "toe" of the bulge. As time increases, the shock undergoes a flip (a reflection symmetry) with respect to the midpoint of our time interval. Such a flip is responsible for an abrupt increase of the wave steepe-ness, which will lead to wave breaking at later times. Following these observations, we present a two-dimensional quantitative model which reproduces both the formation of the bulge and the sudden increase of the wave stee     

Influence of geometry and solids concentration on the hydrodynamics and mass transfer of a rectangular airlift reactor for marine sediment and soil bioremediation

Hydrodynamics and mass transfer characteristics of a three-phase airlift reactor were studied in a rectangular split-vessel reactor and using an air-seawater-marine sediment system. Experiments were conducted over a range of downcomer to riser cross-sectional area ratios (A_D/A_R = 0.65 to 1.0) for two-phase systems and for five sediment concentrations (5 to 25% w/v) using marine sediments. The influence of higher sediment concentrations (30 to 50% w/v) was examined for A_D/A_R = 1. The presence of fine sediment particles in the system had little effect on hydrodynamic and mass transfer parameters compared to the two-phase systems up to 25% loading, decreasing at higher loadings. The airlift reactor was found to meet the dissolved oxygen demand needed for a contaminated sediment treatment process. Axial distribution of the particles was uniform along the riser and the downcomer. Correlations were developed that described the hydrodynamic and mass transfer behaviour for all experimental conditions examined.     

Integrated process simulation of primary shaping: multi scale approaches

We investigate simulation approaches for the modelling of the primary shaping processes micro powder injection moulding and micro casting. We could reproduce the segregation during micro powder injection moulding (MicroPIM) with a simulation using particle methods. The phase field method allows for accurate prediction of the dynamics of solidification of a melt, whereby model order reduction is used to limit the computational effort. The results give valuable advice for the process conduct and the dimensioning of the micro parts.     

Multiphase Reactor Database Interrogation and Computing at the Finger Tip

A learning approach is proposed to critically evaluate the hydrodynamic, heat and mass transfer parameters for multiphase reactors. Packaged as interactive software, this learning approach exposes students, engineers and researchers to a range of reactor features. It allows gaining insights in computing reactor characteristics, sifting through databases, choosing the fittest correlations, embedding proprietary models and databanks for critical analysis. The software developed at Laval University integrates comprehensive databanks and correlations on gas-liquid co- and counter-current packed beds.