Upscaling of small-scale heterogeneities to flow units for reservoir modelling     

D. Mikes  O.H.M. Barzandji  J. Bruining  C.R. Geel 《Marine and Petroleum Geology》2006,23(9-10):931-942

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固城湖生物资源利用和富营养化控制的研究   总被引：7，自引：0，他引：7  

章宗涉  黄昌筑 《海洋与湖沼》1996,27(6):651-656

于１９８９－１９９２年通过野外调查、室内试验，池塘模拟和数学模型等方法。研究江苏省固城湖的理化，初级生产生物生长及其有关因子，水草、藻和鱼，蟹间的相互关系，以及水草渔业利用对水质的影响等。  相似文献   

An inverse design approach for minimising wake at propeller plane using CFD     

V. Anantha Subramanian  R. Vijayakumar 《Ocean Engineering》2006,33(2):119-136

Knowledge of wake characteristics in the stern region is important for ensuring good propeller design and performance. This work examines the utility of CFD in the analysis of flow in the case of full aft beam vessels having characteristic cut stern shape to facilitate propeller aperture. The underwater stern shape may be more complex due to the occurrence of stern appendages such as bossings, strut supports and local shape variations. To this extent, CFD offers an effective tool for both qualitative as well as quantitative assessment of the local geometry. Wake estimate is required for choice of the most favorable propeller geometry. In the present method, the analysis quantifies the effects of small changes in stern rake angles and offers an inverse design approach towards finalising the stern shape. The method consists of solving the standard k-ε turbulent model of RANS equations in cell centered finite volume multi zone grid in the flow domain. This approach has been used in estimating the velocity at the propeller plane. The results have been compared with experimentally obtained values of nominal wake. The approach suggests that CFD can provide a cost effective and quick assessment of flow. It is also an attractive means of pre-empting heterogeneous flow related problems such as vibration and noise due to unfavorable wake in the stern region.  相似文献   

A 2D Mathematical Model for Sediment Transport by Waves and Tidal Currents   总被引：12，自引：5，他引：12  

陆永军左利钦  邵学军王红川 李浩麟 《中国海洋工程》2005,19(4):571-586

In this study, the combined actions of waves and tidal currents in estuarine and coastal areas are considered and a 2D mathematical model for sediment transport by waves and tidal currents has been established in orthogonal curvilinear coordinates. Non-equilibrium transport equations of suspended load and bed load are used in the model. The concept of background concentration is introduced, and the formula of sediment transport capacity of tidal currents for the Oujiang River estuary is obtained. The Dou Guoren formula is employed for the sediment transport capacity of waves. Sediment transport capacity in the form of mud and the intensity of back silting are calculated by use of Luo Zaosen＇ s formula. The calculated tidal stages are in good agreement with the field data, and the calculated velocities and flow directions of 46 vertical lines for 8 cross sections are also in good agreement with the measured data. On such a basis, simulations of back silting after excavation of the waterway with a sand bar under complicated boundary conditions in the navigation channel induced by suspended load, bed load and mud by waves and tidal currents are discussed.  相似文献   

On the echo interference in sound backscattering by densely aggregated targets     

Gorska  Natalia; Chu  Dezhang 《ICES Journal of Marine Science》2005,62(4):771-778

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Computation of Wave, Tide and Wind Current for the South China Sea Under Tropical Cyclones   总被引：1，自引：0，他引：1  

ZHU  Liang-sheng 《中国海洋工程》2003,17(4):505-516

Based on the third-generation oceanic wave prediction model (WAVEWATCH Ⅲ) ,the third-generation nearshore wave calculation model (SWAN) and the mathematical tide, tidal current and cyclone current model, which have been improved, interconnected and expanded, a coupled model of offshore wave, tide and sea current under tropical cyclone surges in the South China Sea has been established. The coupled model is driven by the tropical cyclone field containing the background wind field. In order to test the hindcasting effect of the mathematical model, a comparison has been made between the calculated results and the observational results of waves of 15 cyclone cases, water levels and current velocities of the of 7 cyclones. The results of verification indicate that the calculated and observed results are basically identical.  相似文献   

The tidal regime of Shark Bay, Western Australia   总被引：1，自引：0，他引：1  

Murray C. Burling  Charitha B. Pattiaratchi  Gregory N. Ivey 《Estuarine, Coastal and Shelf Science》2003,57(5-6):725-735

A non-linear hydrodynamic model is used to describe the tidal dynamics of Shark Bay, Western Australia. The model is forced by tidal elevations generated by M₂, S₂, K₁ and O₁ constituent data at the open boundaries. The absence of suitable boundary data required a ‘calibration’ of the boundary condition against the known constituent data from within the model domain. The model provides a good match to the available field data, and allows the surface-level and current response to be resolved over the entire domain. Due to a near quarter-wave resonance of the semi-diurnal tide along the eastern Hopeless Reach, which increases the semi-diurnal tide by a factor of 2, the tidal characteristics on each of the Reaches are different: on the eastern Hopeless Reach the tides are mainly semi-diurnal while on the western Freycinet Reach the tides are mainly diurnal. The tidal range is also higher along Hopeless Reach. Tidal harmonics, generated by non-linearity, are important in the shallow regions. The tidal wave is shown to propagate as a progressive wave into the Bay. Substantial phase-lag, attenuation and dissipation occur over the Faure Sill, a major shallow region of the eastern reach of the Bay. Non-linear generation of the M₄ and MS₄ tides is also significant in this region. Depth-averaged residual currents are presented, which show a tidally generated circulation that is enhanced in regions of complex topography. Estimates of tidal dissipation indicate that although the total dissipation is small on a global scale, the areal average is comparable with the Gulf of Carpentaria and approximately one-quarter of the value estimated for the Patagonian Shelf.  相似文献   

Variation in the abundance of sandeels Ammodytes marinus off southeast Scotland: an evaluation of area-closure fisheries management and stock abundance assessment methods     

Greenstreet  Simon P.R.; Armstrong  Eric; Mosegaard  Henrik; Jensen  Henrik; Gibb  Iain M.; Fraser  Helen M.; Scott  Beth E.; Holland  Gayle J.; Sharples  Jonathan 《ICES Journal of Marine Science》2006,63(8):1530-1550

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Modelling the effects and economics of managed realignment on the cycling and storage of nutrients, carbon and sediments in the Blackwater estuary UK     

D. Shepherd  D. Burgess  T. Jickells  J. Andrews  R. Cave  R.K. Turner  J. Aldridge  E.R. Parker  E. Young   《Estuarine, Coastal and Shelf Science》2007,73(3-4):355-367

A hydrodynamic model is developed for the Blackwater estuary (UK) and used to estimate nitrate removal by denitrification. Using the model, sediment analysis and estimates of sedimentation rates, we estimate changes in estuarine denitrification and intertidal carbon and nutrient storage and associated value of habitat created under a scenario of extensive managed realignment. We then use this information, together with engineering and land costs, to conduct a cost benefit analysis of the managed realignment. This demonstrates that over a 50–100 year timescale the value of the habitat created and carbon buried is sufficient to make the large scale managed realignment cost effective. The analysis reveals that carbon and nutrient storage plus habitat creation represent major and quantifiable benefits of realignment. The methodology described here can be readily transferred to other coastal systems.  相似文献   

近岸二维海流数值计算方法若干问题的研究和应用     

朱良生 《热带海洋学报》1995,(1)

就二维浅水流体动力方程应用物理意义明确的有限体积法，收敛快而稳定的五对角全隐格式，以及嵌套、变步长的网格和动边界技术，进行二维海流场的数值计算，并研究了开边界为斜断面的定解条件的数值方法和开边界上断面各点水位的计算方法。最后把本数值方法应用于某海岸工程的可行性研究，并验证了这种海流数值计算方法的合理性。  相似文献