Applied Mechanics and Materials Vols. 170-173

Abstract: The application of analytical hierarchy process (AHP) to the risk analysis of port construction project was investigated. Firstly, the happening probabilities of various risk factors during port construction were calculated. Secondly, the aftereffects of the risks were concluded by consulting the experts. Thirdly, the weight of each risk factor was obtained by AHP. Finally, the total risk of port construction project could be evaluated by fuzzy comprehensive evaluation. This risk analysis method was applied to evaluate the total risk of a real port construction project, and the exemplification verified its feasibility.

Abstract: The numerical simulation of air bubbles breakwater was presented in this paper. The two-phase fluid of water and air was assumed as a variable density fluid. The numerical models were developed by FLUENT in order to explore the air amount scale in the system of air bubbles breakwater . The continuity equation, the Reynolds average equations and the standard k-e equations were selected as the governing equations and the interface of water and air was traced by the VOF method, the additional mass source was added to the continuity equation by The Macro of UDF. The relationship between the air amount scale and the length scale was obtained, which illuminated that the air amount scale of air bubbles breakwater agrees to the gravity similarity law. Furthermore, the effect of air amount and the incident wave periods on the performance of the air bubbles breakwater was analyzed.

Abstract: The characteristics of the sound radiation and vibrational power flow of the partially submerged cylindrical shell under a harmonic excitation are studied. The approximate acoustic boundary of the free surface is used to solve the fluid domain. The structure-fluid coupling equation is established based on the Flügge and Helmholtz theories. The far-field sound pressure is calculated and compared with that in infinite field. It is found that the far-field sound pressure presents large gap in different immersion status in the presence of the free surface while the results of the input power flow in these cases have less differences.

Abstract: A three-dimensional physical model was used to study the wave distribution around breakwater in Malaysia Kuantan. Model tests were carried out by using the L-type action absorption directional wave generator in a 45m×40m wave basin at TIWTE in Tianjin China. The incident wave conditions were checked first in the laboratory and a series steps were introduced to construct the bathymetry and breakwater structure. At last, the wave distribution around the breakwater with 60yrs and 100yrs wave action were given respectively. The conclusions should be used to achieve optimization of the design.

Abstract: In this paper, the dynamic behaviors are studied for Spar type floating foundation of a 3kW in the 10m deep water considering the coupled wind turbine-tower-floating foundation and mooring lines and ocean environment load effects. The paper focus on the key issues of design of floating foundation, such as coupling dynamic analysis model and calculating method. The finite element models are established and dynamic responses of floating wind turbine system under different combinations of turbulent wind, constant current and irregular wave are calculated in frequency and time domain with SESAM software. The motion performance and lines’ tension are investigated, and some valuable conclusions are drawn. The results show that the Spar type floating foundation and mooring system can work in the ocean environment which significant wave height less than 2m, the designed large water-entrapment plate can minimized the motion of floating foundation obviously.

Abstract: Numerical simulation of the consolidation test was developed in different drainage conditions using the finite difference method. Soil sample was divided into layers to determine the time-steps of the test. A series of simulation tests were carried out to study the influence of drainage height on the coefficient ratio. Finally, some experiments data were compared with the numerical simulation results. Numerical results indicate that the simulation method broke through the limitation of test apparatus, and made it possible to conduct big size specimen consolidation test under certain conditions.

Abstract: According to the extremely uneven situation of monthly rainfall in China, in order to both improve utilization efficiency of non-traditional water resources and realize economy applicable in green residential districts, an optimization method of monthly water dynamic balance of non-traditional water resources utilization in green building based on landscape water regulation function was put forward. The optimization method was made full use of large capacity of landscape water regulation function, combined with monthly water consumption law between supply and demand of non-traditional water resources in districts. And this method was applied in a green residential demonstration district in western China.

Abstract: Ultrafiltration processes are increasingly popular in drinking water treatment, as it can provide better quality water by removing microorganism and turbidity with lower filtration pore size, even without disinfection. Nonetheless, in our experiment the bacteria was occasionally detected in ultrafiltration effluent, and the related literature once had also been reported. This study was focused on the cause of secondary pollution in the drinking water ultrafiltration system, mainly from the production tank, biological stability, bacteria in air, as well as the membrane structure. And some solutions, including production water tank chlorination periodically, changing the operating mode of the ultrafiltration system, improving the design of the production tank, were studied to control secondary pollution in the treatment system.

Abstract: In historic towns, the planning of municipal facilities varies from that in the common towns. To maintain the original styles and features, the curve dominants the street form in the planning. Additionally, combining with the rails and rivers which goes across the town, the water supply and drainage is divided into two areas at the line of the valley with the narrow and branching terrain. The existing pipeline network is taken into account as possible with the aim to compensate the skill deficiency and expand the service scope. Based on the prerequisite of lowering investment and maintaining eco-appearance, the rainwater will be collected and discharged near the site through two ways: natural drainage and pipeline network drainage. Water supply and drainage have set up the treatment facilities of water respectively, which will be planned and constructed by stages according to the development of towns.

Abstract: By experiments, separate and purify efficient sulfate—reducing bacteria (SRB), which is identified as Desulfobacter. With its treatment of acid mine drainage(AMD) containing Fe²⁺ and Mn²⁺, obtain the optimum conditions that pH=6,temperature=37,vibrating intensity=100r/min, COD/SO₄^2- =2.Under this condition ,the removal rate of SO₄^2-、Fe²⁺ and Mn²⁺ is 88.16%、99.37% and 59.18% respectively with the initial concentration 1411mg/L for SO₄^2-,257mg/L for Fe²⁺ and 325mg/L for Mn²⁺.This puts a theoretical foundation for the further study.