Time filter

Source Type

Liu G.,National University of Singapore | Chen H.,Marine Design and Research Institute of China | Liu D.,Harbin Engineering University | Khoo B.C.,National University of Singapore
Bulletin of the Seismological Society of America | Year: 2010

Wave propagation in a half-space with complex surface configuration is often encountered in fields like seismology and ocean engineering. This article presents a theoretical study of multiple scattering of SH waves by two hills of different geometries (a triangle and a semicircle) on a solid half-space. The standing waves in the triangular and semicircular hills are constructed by the fractional-order Bessel function method and Fourier integral transform method, respectively. The unknown coefficients of the standing waves are determined via the region-matching method. It is shown that the apexes of the hills are very sensitive to the external dynamic load because of multiple incidences; in particular, the apex of the triangular hill exhibiting maximum amplitude is most susceptible to the external load. Furthermore, the effect of the interaction between the triangular and semicircular hills is evaluated. It is found that the amplitudes on the showdown zone that connects the two hills have been largely amplified due to the interaction between the two hills. The mutual interaction between the hills should not be neglected if the distance between them is less than O(100) times the typical dimension of the hill.

Liu S.M.,Ocean University of China | Li R.H.,Ocean University of China | Zhang G.L.,Ocean University of China | Wang D.R.,Marine Design and Research Institute of China | And 4 more authors.
Marine Chemistry | Year: 2011

Biogeochemical observations were carried out in the Wenchanghe and Wenjiaohe Estuary, Bamen Bay and Gaolong Bay during 2006-2009 to understand the nutrient dynamics of these areas and their relationship with the sustainability of the ecosystems in the coastal areas of Eastern Hainan Island and its adjacent South China Sea. Nutrients in river/estuary waters, groundwater, aquaculture effluents and rainwater samples were analyzed using spectrophotometry. Nutrient levels in the tropical Wenchanghe and Wenjiaohe show a wide range of variation depending on the system, nutrient element and season. These two rivers are enriched with DIN and depleted in PO4 3- with the DIN:PO4 3- ratios varied from 60 to 411. In the rivers, TDP was mainly composed of DOP, representing ~65%. DON accounted for 40% of TDN in the Wenchanghe and 76% of that in the Wenjiaohe. Dissolved silicate levels in the Wenjiaohe and Wenchanghe were lower than average levels in tropical systems.Nutrients in the Wenchanghe and Wenjiaohe Estuary behave either conservatively or non-conservatively depending on the element being considered and the season. Based on observations of nutrients in various aquatic environments, a simple steady-state mass-balance box model was employed to assess nutrient budgets in the estuary system. Nutrients in the studied system were mostly from riverine input, groundwater discharge and aquaculture effluents. The nutrients exported in the studied system are largely confined to the immediate estuaries. The typhoon-induced runoff of terrestrial rainwater can not only increase nutrient inputs to the coastal ecosystem but can also result in nutrient imbalance, affecting phytoplankton production and composition. © 2011 Elsevier B.V.

Ni C.-B.,Shanghai JiaoTong University | Zhu R.-C.,Shanghai JiaoTong University | Miao G.-P.,Shanghai JiaoTong University | Fan S.-M.,Marine Design and Research Institute of China
Shuidonglixue Yanjiu yu Jinzhan/Chinese Journal of Hydrodynamics Ser. A | Year: 2010

A method for ship resistance prediction based on CFD computation is outlined, with ship form factor obtained by solving the viscosity resistance of double-model in turbulence flow theory and the wave making resistance in ideal flow theory. Comparing with the experimental results of series-60 and KCS advancing with different speeds, the new method of ship resistance prediction is economical, practical and meets the engineering needs.

Song J.,Marine Design and Research Institute of China
Ship Building of China | Year: 2015

This paper elaborates some key technology aspects in general design of FLNG, which is a floating LNG production unit together with natural gas pre-treatment, liquification, storage and offloading system. Hull's main dimension, lines and typical loading conditions are studied, and then a FLNG with main dimension of 250, 000 m3 is provided to get good hull motion and assure high efficiency of topside production system. Characteristics of LNG cargo containment system for FLNG unit are described, and membrane type of tank is compared with SPB independent tank. Seawater lift submersible electric pump system is proposed as a cooling seawater supply system for topside liquification unit. ©, 2015, Editorial Office of Shipbuilding of China. All right reserved.

Zhao G.,Marine Design and Research Institute of China
Materials China | Year: 2014

Just like the structure in the aerospace which is defined as aircraft internationally, is divided into aviation and astronavigation, the author divides the structure in the sea which is collectively named as marine steel structure into two branches, i.e. ship and marine engineering. The author focuses on marine and offshore oil and gas drilling equipment mainly from the perspective of the shipbuilding industry, describes the features, design criteria and steel selection principles of marine steel structures, and lists the steel amount of typical transport ships and the carriers of offshore oil and gas engineering plants, as well as the mount of the typical steel pipes on the offshore oil and gas engineering plants. The author tells about the special requirements for Extra High Strength Steel and Special Steel(including Low Temperature Steel, Corrosion-Resistant Steel, Lamellar-Tearing-Resistance Steel, Welding-Crack-Resistance Steel, Cast and Low Magnetic Steel mainly) on carriers. The author also introduces the applications of steel pipe on marine steel structures. For becoming the powerful country on shipbuilding and marine industry, Chinese metallurgical industry is to contribute. The author also suggests that Chinese shipbuilding steel market should rationalize the system and communication needs, stand out essentials and get close to projects.

Discover hidden collaborations