Results Of Hydrodynamic Model Research Articles

Economic evaluation of CO 2 pipeline transport in China

Carbon capture and sequestration (CCS) is an important option for CO 2 mitigation and an optimized CO 2 pipeline transport system is necessary for large scale CCS implementation. In the present work, a hydrodynamic model for CO 2 pipeline transport was built up and the hydrodynamic performances of CO 2 pipeline as well as the impacts of multiple factors on pressure drop behavior along the pipeline were studied. Based on the model, an economic model was established to optimize the CO 2 pipeline transport system economically and to evaluate the unit transport cost of CO 2 pipeline in China. The hydrodynamic model results show that pipe diameter, soil temperature, and pipeline elevation change have significant influence on the pressure drop behavior of CO 2 in the pipeline. The design of pipeline system, including pipeline diameter and number of boosters etc., was optimized to achieve a lowest unit CO 2 transport cost. In regarding to the unit cost, when the transport flow rate and distance are between 1–5 MtCO 2/year and 100–500 km, respectively, the unit CO 2 transport cost mainly lies between 0.1–0.6 RMB/(tCO 2 km) and electricity consumption cost of the pipeline inlet compressor was found to take more than 60% of the total cost. The present work provides reference for CO 2 transport pipeline design and for feasibility evaluation of potential CCS projects in China.

A GIS-based management and publication framework for data handling of numerical model results

There has been an increasing awareness that large-scale datasets of earth-system model results would be produced and accumulated rapidly within the next few decades with extensive usage of numerical models. The successful exploration of these data for scientific research and engineering applications requires the capability of efficient storage, retrieval, integration and visualization of these large datasets. Robust publication methods are also needed to enable data exchange through the web to increase global research collaborations. In this study, a comprehensive GIS-based data management and publication framework (GMPF) was developed and applied to the use, representation, and analysis of hydrodynamic modeling results of Hamburg Port, Germany. Linking with GIS, a desktop- and a web-based model-results data atlas were developed to provide an interactive environment for various cartography and time series plots. The implementation of the framework was based on modular software design, open specifications and reuse of open source projects. The study results showed that the project life-cycle was shortened and development efforts were reduced through applying GMPF. The developed system could be integrated into commercial hydrodynamics software platforms to enhance the capability of model-results management and publication.

Evolution of Swarna estuary and its impact on braided islands and estuarine banks, Southwest coast of India

Qualitative and quantitative evolution of the Swarna estuary, during the past 38 years (1967–2005), has been analysed by integrating the results of field surveys, satellite images, hydrodynamic modelling and topographic data in GIS context. Significant changes in erosion/accretion patterns of the estuarine banks, inlet configuration and adjacent spits, and origin, morphology, orientation and areal extent of fifteen braided islands have been estimated. Hydrodynamics of the region is studied through modelling, and probable flow pattern that is responsible for morphological changes is discussed. The simulated flow patterns indicate that current speeds are of the order of 10–20 cm/s inside the estuary and of the order of 40 cm/s at the mouth. The Right bank (Rb) of the estuary is subject to net erosion and the Left bank (Lb) is subject to net accretion. On an average, 20–30% of the area of all braided islands would be flooded, if the water level rises by 0.7 to 1.0 m. Islands of this estuary are morphologically very dynamic (migrating towards north, northeast and southwest directions) and subject to net accretion, whereas only one island (i.e., the Padu) has lost its major portion of landmass. A conceptual Inverse Distance Weighted (IDW) interpolation model has been generated and evaluated possible flooding on the estuarine shoals and braided islands, due to heavy rainfall and/or sealevel rise. The model reveals that the possibility of flooding will be higher for those islands which are located close to the Rb than those close to the Lb.

Application of 3D hydrodynamic and particle tracking models for better environmental management of finfish culture

Hydrographic conditions, and particularly current speeds, have a strong influence on the management of fish cage culture. These hydrodynamic conditions can be used to predict particle movement within the water column and the results used to optimise environmental conditions for effective site selection, setting of environmental quality standards, waste dispersion, and potential disease transfer. To this end, a 3D hydrodynamic model, MOHID, has been coupled to a particle tracking model to study the effects of mean current speed, quiescent water periods and bulk water circulation in Mulroy Bay, Co. Donegal Ireland, an Irish fjard (shallow fjordic system) important to the aquaculture industry. A Lagangrian method simulated the instantaneous release of “particles” emulating discharge from finfish cages to show the behaviour of waste in terms of water circulation and water exchange. The 3D spatial models were used to identify areas of mixed and stratified water using a version of the Simpson–Hunter criteria, and to use this in conjunction with models of current flow for appropriate site selection for salmon aquaculture. The modelled outcomes for stratification were in good agreement with the direct measurements of water column stratification based on observed density profiles. Calculations of the Simpson–Hunter tidal parameter indicated that most of Mulroy Bay was potentially stratified with a well mixed region over the shallow channels where the water is faster flowing. The fjard was characterised by areas of both very low and high mean current speeds, with some areas having long periods of quiescent water. The residual current and the particle tracking animations created through the models revealed an anticlockwise eddy that may influence waste dispersion and potential for disease transfer, among salmon cages and which ensures that the retention time of waste substances from cages is extended. The hydrodynamic model results were incorporated into the ArcView TM GIS system for visualisation and interrogation of results and to allow effective holistic environmental management and site selection for fish cage aquaculture.

Density diagnostic of highly ionized samarium laser produced plasma using Ni-like spatially resolved spectra

AbstractDetailed spectroscopic identification and analysis of lines emitted by Ni-like ions may infer on plasma parameters, such as electron density, temperature, and ionization state. Spatially, resolved X-ray spectra of samarium laser produced plasma were recorded in the 7 to10 Å wavelength range. Measured line intensity ratios of Ni-like 3d-5f, 3p-4d, 3p-4s, and 3s-4p transitions were used for electron density diagnostic as a function of the distance from the target. Calculations using Hebrew University Lawrence Livermore Atomic Code show that these ratios are not very sensitive to the electron temperature in the range from 500 to 1000 eV. Self-absorption of some lines is found to be important at electron densities higher than 1021cm−3. The inferred ranges of electron density and temperature are found to be consistent with results of hydrodynamic simulations and models of ionization in plasma.

Numerical modelling of hydrodynamics and sediment transport processes during storm events in a non-perennial river

Numerical modelling of hydrodynamics and sediment transport processes during storm events in a non-perennial riverThis article presents the numerical modelling of hydrodynamics and sediment transport processes in the seasonal Pathri Rao River, which flows in the Northern part of India. Modelling is made by the coupled application of the hydrodynamic model called TELEMAC-2D and the morphodynamic model called SediMorph. The hydrodynamic model results are validated with the observed data and it has been found that the present model provides reasonable predictions. Likewise, the validation of the morphodynamic model is also presented. For this purpose, the suspended and bed load transport modules are validated separately for four runoff events observed during the investigations. The validation of the former is approached by comparing the depth-averaged suspended transport concentrations against experimental measurements made at the make-shift gauging station and subsequent comparison against experimental measurements. On the other hand, due to non-availability of the observed values on bed load sediment transport, the bed load sediment transport and bed evolution numerical results could not be validated quantitatively and was approached only on qualitative basis. In general, both validations present an acceptable agreement with measurements and scientific facts. Further, this study demonstrates that the coupled TELEMAC-2D/SediMorph system could be used with confidence for practical applications in the Pathri Rao River.

Modelling the Effects of Sand Extraction, on Sediment Transport due to Tides, on the Kwinte Bank

In recent years, the exploitation of marine aggregates is increasing. As an example, on the Belgian continental shelf, one particular sandbank (the Kwinte Bank) is exploited extensively; this has led to the creation of a 5 m deep depression along its central part. In the present contribution, the influence of these bathymetric changes, on erosion and sedimentation patterns are studied, using numerical modelling, in order to obtain an initial impression of the effect of such intense sand extraction on the stability of the sandbank. Different numerical models are utilised. Twodimensional and three-dimensional hydrodynamic models have been used to derive currents, whilst third generation wave models have been used to simulate the waves. Two different models are presented, which calculate the total load sediment transport as a function of the local currents and waves. These models have been used to investigate the erosional and depositional patterns. The use of two different sediment transport models has some advantages, since the results of sediment transport models are still subject to some important uncertainties. The hydrodynamic model results are validated using ADCP current data, confirming the good performance of the models. Likewise the wave models provide good results, comparing their results with data from a buoy. The sediment transport model results were compared to the residual transport patterns, derived from the asymmetry of dunes. The results obtained seem to be in general agreement with these observations. The numerical models are used to simulate the response of the sediment transport to extensive sand extraction from the sandbank. One ‘worst-case’ scenario and two more realistic scenarios were simulated, whilst the effect of these bathymetric changes on sediment transport was studied. The results show that the intense sand extraction does not seem to influence extensively the stability of the sandbank, but that, as a consequence, there is less erosion and deposition. The model results show, for all of the scenarios, a small amount of deposition on the top of the sandbank; this could be an indication of a regeneration mechanism. A trench, created perpendicular to the crest of the sandbank, could be slowly refilled again. The time-scale of this regeneration and the influence of storms remain uncertain. Although the main emphasis of the paper relates to tidal forcing, a brief discussion is included on the influence of wave action, on sediment transport.

Soils fieldwork, analysis, and interpretation to support hydraulic and hydrodynamic modelling in the Murray floodplains

There are limited datasets which cover the heavy clays found in the Murray floodplain area. To understand the processes associated with the water balance within the Koondrook–Perricoota Forest (KPF), detailed hydraulic and hydrodynamic modelling of the flood inundation patterns and overland flow in the KPF is required. Reliable and accurate soils information is critical for any credible hydrologic or hydrodynamic modelling results. Extensive fieldwork across the entire KPF and detailed laboratory testing of the collected samples was undertaken to produce soils information including: spatial distribution of soil types, soil stratigraphy along the surface and subsurface flowpaths, soil hydraulic properties, soil salinity, and soil organic matter. Soil sampling and soil profile descriptions were undertaken at 26 sites spread across the forest. Deep drilling was done at 12 sites to check the existence of ancestral streams and for salinity profiles; soil hydrology testing to estimate infiltration rates was undertaken at 10 sites. Rapid appraisal methods for soil infiltration were developed for the project. Results were compared to soil pedotransfer functions generated from laboratory results; soil indexes including the dispersibilty index and electrochemical stability index; and typical infiltration and permeability rates inferred from soil texture and structure. The results from this study and the archived soil physical and hydraulic datasets can be used for any detailed hydraulic or hydrodynamic modelling exercise in the Murray floodplain area with similar soil properties.

Storm fronts over galaxy discs: models of how waves generate extraplanar gas and its anomalous kinematics

The existence of partially ionized, diffuse gas and dust clouds at kiloparsec scale distances above the central planes of edge-on, galaxy discs was an unexpected discovery about 20 yrs ago. Subsequent observations showed that this EDIG (extended or extraplanar diffuse interstellar gas) has rotation velocities approximately 10-20% lower than those in the central plane, and have been hard to account for. Here we present results of hydrodynamic models, with radiative cooling and heating from star formation. We find that in models with star formation generated stochastically across the disc an extraplanar gas layer is generated as long as the star formation is sufficiently strong. However, this gas rotates at nearly the same speed as the mid-plane gas. We then studied a range of models with imposed spiral or bar waves in the disc. EDIG layers were also generated in these models, but primarily over the wave regions, not over the entire disc. Because of this partial coverage, the EDIG clouds move radially, as well as vertically, with the result that observed kinematic anomalies are reproduced. The implication is that the kinematic anomalies are the result of three-dimensional motions when the cylindrical symmetry of the disc is broken. Thus, the kinematic anomalies are the result of bars or strong waves, and more face-on galaxies with such waves should have an asymmetric EDIG component. The models also indicate that the EDIG can contain a significant fraction of cool gas, and that some star formation can be triggered at considerable heights above the disc midplane. We expect all of these effects to be more prominent in young, forming discs, to play a role in rapidly smoothing disc asymmetries, and in working to self-regulate disc structure.

Cyclone-induced net sediment transport pathway on the continental shelf of tropical Australia inferred from reef talus deposits

Tropical cyclones affect storm-dominated sediment transport processes that characterise Holocene shelf deposits in many shelf environments. A summary of cyclone-associated deposits in the Great Barrier Reef published by Larcombe and Carter [2004. Cyclone pumping, sediment partitioning and the development of the Great Barrier Reef shelf system: a review. Quaternary Science Reviews 23, pp. 107–135 indicates a pervasive northwards orientation of deposits on the lee side of reefs and other obstacles. In this paper, we describe the geomorphology of reef talus deposits found in the Gulf of Carpentaria and Arafura Sea, Australia, that we attribute to tropical cyclones. The orientation of these deposits is also indicative of a consistent, along-coast transport pathway. The deposits are located on the leeward side of submerged coral reefs; they are up to 10 m in thickness, comprised of re-worked carbonate sand and gravel and radiocarbon dating indicates that they are of Holocene age. An explanation for the consistent along-coast cyclone transport pathway is presented based on previously published hydrodynamic modelling results. These models illustrate how currents generated by the passage of a cyclone are asymmetric in plan view, such that stronger flows are generated between the eye of the cyclone and the coast. The result of the passage of many cyclones over geologic timescales is a net along-coast sediment transport pathway located on the inner- to mid-shelf, possibly extending over the entire length of northern Australia's coastline. This process provides an explanation for the observed sediment transport patterns on modern tropical continental shelves, as well as a basis for the interpretation of ancient tropical shelf deposits.

Coincident application of a mass balance of radium and a hydrodynamic model for the seasonal quantification of groundwater flux into the Venice Lagoon, Italy

A mass balance of the naturally occurring short-lived radium isotopes ( 223,224Ra) in the Venice Lagoon was conducted by an integrated approach combining the directly estimated individual Ra contributions and hydrodynamic model results. Hydrodynamic data allows for the calculation of the Ra mass balance in sub-sections of the Venice Lagoon (boxes), which are characterized by physically homogeneous properties, instead of investigating the entire lagoon. Utilizing this method, both the seasonal and the spatial variability of the submarine groundwater discharge in the Venice Lagoon have been estimated. Between 14–83 × 10 9 L d − 1 of water were calculated to flow across the sediment–sea interface, corresponding to 5–28 times the mean annual river input. The submarine groundwater discharge estimates were correlated with the residence time calculation to better understand spatial and seasonal variation.

Computation of the wind speed at sites with complex orographic effects

Computation of the wind speed at a given station is performed via interpretation of the hydrodynamic modelling results using the multiple regression method. The a priori model parameters—pressure and thermal gradients, the Laplace operator at the standard levels of the lower and middle troposphere, and others—were obtained from reanalysis. The wind speed at observation times at Vladivostok station was used as a dependent variable. Preliminary classifying of the vector of predictors in accordance to the surface pressure gradient has been done. This procedure, first of all, allowed us to decrease variability of the friction force impact on the wind speed formation for a given class. Experiments, which were performed with the different sets of parameters and various classification schemes, allowed selecting models that provide computation results comparable to the known methods of wind speed computation at a given station.

Identifying runoff routing parameters for operational flood forecasting in small to medium sized catchments / Identification de paramètres de propagation d'écoulement pour la prévision opérationnelle de crue au sein de bassins versants de petite à moyenne taille

This paper proposes a framework for identifying the parameters of a lumped routing model in small to medium sized catchments where lateral inflows can be large but poorly defined. In a first step, a priori estimates of the parameters are made based on topography, aerial photographs, flood marks and field surveys. In a second step, runoff data are analysed of reservoir release events and convective events where no rainfall in the direct catchments occurred. In a third step the routing model is calibrated to the results of hydrodynamic models for scenarios of different magnitudes. In a fourth step, these pieces of information are combined, allowing for soft expert judgement to be incorporated. In a fifth step, the routing parameters are fine tuned to observed flood events where lateral inflows are estimated by a rainfall—runoff model. The framework is illustrated by the Kamp flood forecasting system in Austria that has been in operational use since 2006.

Hydrodynamic and Mathematical Simulations of Flow Field and Temperature Profile in an Asymmetrical T-type Single-strand Continuous Casting Tundish

To further remove mini-size nonmetallic inclusions and improve surface quality of stainless steel slab at No. 2 Steelmaking Plant of Shanxi Taigang Stainless Steel Company Limited, the flow field and temperature profile of molten stainless steel in an asymmetrical T-type single-strand continuous casting tundish with a capacity of 18–20 tons have been investigated by both hydrodynamic and mathematical simulations. The influences of height for low-wall of turbulence inhibitor, dam height, weir depth, distance between dam and weir, submerged depth of ladle shroud and casting speed on flow field in the tundish have been studied in a 1 : 3 reduced scale hydrodynamic model. The streamlines, velocity vector fields and temperature profiles are also mathematically simulated.The hydrodynamic modelling results indicate that height for low-wall of turbulence inhibitor, dam height and weir depth are three important structural parameters on flow field of molten stainless steel in the tundish. The optimization of the three parameters can improve dispersed plug zone and reduce dead zone effectively. Changing casting speed can improve turbulent flow, and thus reduce dead zone of molten stainless steel in the tundish. As a result, five groups of optimized structural parameters of the tundish have been recommended, which can reduce volume fraction of dead zone down to 15–30% and increase volume fraction of dispersed plug zone to more than 20%. In addition, it is verified that the optimized groups of structural parameters of the tundish can maintain their advantage at different casting speeds in a narrow range.The mathematical modelling results suggest that heat losses around the tundish must be considered in order to accurately simulate the streamline, velocity vector field and temperature profile. The calculated temperature drop of molten stainless steel between inlet and outlet of the tundish is about 4.4 K; the maximum temperature drop in the whole tundish is about 10 K. The modification of flow filed by changing structural parameters of the tundish can slightly affect temperature profile of molten stainless steel in the tundish.

Sediment transport under wave and current combined flows on a tide-dominated shoreface, northern coast of France

Hydrodynamic circulation and sediment transport patterns were investigated on a macrotidal shoreface off the southern North Sea coast of France from in situ directional wave and current measurements and through numerical modeling of sediment flux. Current meters equipped with wave gauges were deployed at two sites on the mid-upper shoreface, in approximately 5–6 m water depth, during 6 and 15 days. Sediment flux was estimated using the SEDTRANS96 numerical model (Li, M.Z., Amos, C.L, 2001. SEDTRANS96: the upgraded and better calibrated sediment transport model for continental shelves. Comp. Geosc. 27, 619–645) based on Grant and Madsen's (Grant, W.D., Madsen, O.S., 1986. The continental shelf bottom boundary layer. Ann. Rev. Fluid Mech. 18, 265–305) combined flow boundary layer theory. The hydrodynamic measurements and modeling results show that sediment on the shoreface is essentially transported alongshore in response to shore-parallel tidal currents. The direction of the net sediment transport is largely determined by the asymmetry of the tidal flows, which can be flood- or ebb-dominated, but during important wind speed events, winds blowing in the same direction as tidal flow can significantly reinforce tidal currents, or conversely, can limit tidal current speeds when acting in the opposite direction. Although sediment transport on this macrotidal shoreface is strongly controlled by tidal processes, waves can significantly enhance bed shear stresses, resulting in increased sediment remobilization, and hence higher sediment flux. Wave-induced onshore sediment transport may occasionally occur, but is several orders of magnitude lower than longshore transport. This macrotidal shoreface is thus characterized by a hydraulic regime strongly dominated by shore-parallel tidal flows that favour longshore sediment dispersal rather than shore-normal transport. Our results imply that the water depths from which sediment may be transported shoreward to beaches is certainly much more restricted on a macrotidal shoreface, such as the one bordering the northern coast of France, than on micro- and mesotidal shoreface environments where weaker tidal currents do not significantly limit cross-shore sediment movements.

Current Measurements in Rivers by Spaceborne Along-Track InSAR

The global monitoring of river discharges is a technologically challenging problem, with important applications in a variety of disciplines. Due to the limited availability and/or quality of river runoff data from many regions, an increasing use of remote sensing techniques is highly desirable. Altimeter specialists have already demonstrated water level retrievals in rivers from available data. The along-track interferometric synthetic aperture radar [along-track InSAR (ATI)] capabilities of state-of-the-art imaging radars on satellites such as the German TerraSAR-X, which was launched on June 15, 2007, also permit high-resolution line-of-sight surface current measurements. In this paper, we evaluate the potential of current measurements in rivers by spaceborne ATI on the basis of fundamental theoretical considerations, existing spaceborne InSAR data from the shuttle radar topography mission (SRTM), and simulated TerraSAR-X data. We show that an SRTM-derived line-of-sight surface current field in the Elbe river, Germany, agrees well with numerical hydrodynamic model results. The data quality is sufficient to resolve characteristic lateral variations of the currents in the river around a pronounced main flow channel. Assuming that the flow direction is usually aligned with the river bed, even a quasi-2D total surface current field can be derived. Simulations indicate that TerraSAR-X was even better suited for current measurements in rivers. Depending on width, surface roughness, and relative flow direction of a river, current estimates with an accuracy better than 0.1 m/s were possible with an effective spatial resolution of a few hundred meters to kilometers.

Structure of ore fields and deposits: Current status and outlook for further development

The current status of investigations of the structure of ore fields and deposits in Russia is considered. The importance of traditional lines of research in this field and the great body of information acquired is emphasized. The changes in ideas of geodynamic and tectonic crustal evolution have made it necessary to alter concepts of the geological and structural position of ore fields and deposits. New challenges are caused by these changes and progress in the knowledge of ore deposits and the depth of their formation, as well as geodynamic, tectonophysical, and hydrodynamic processes in ore-bearing crustal blocks. The results of hydrodynamic modeling of deposit formation controlled by deeply penetrating fault zones are discussed. Various relationships between hydrodynamic and structural factors in ore formation are considered.

One-dimensional GIS-based model compared with a two-dimensional model in urban floods simulation

A GIS-based one-dimensional flood simulation model is presented and applied to the centre of the city of Nîmes (Gard, France), for mapping flow depths or velocities in the streets network. The geometry of the one-dimensional elements is derived from the Digital Elevation Model (DEM). The flow is routed from one element to the next using the kinematic wave approximation. At the crossroads, the flows in the downstream branches are computed using a conceptual scheme. This scheme was previously designed to fit Y-shaped pipes junctions, and has been modified here to fit X-shaped crossroads. The results were compared with the results of a two-dimensional hydrodynamic model based on the full shallow water equations. The comparison shows that good agreements can be found in the steepest streets of the study zone, but differences may be important in the other streets. Some reasons that can explain the differences between the two models are given and some research possibilities are proposed.

Landau Hydrodynamics and RHIC Phenomena

The basic physical assumptions and results of Landau's hydrodynamic model of particle production are reviewed. It is argued that these results have a substantial descriptive and predictive power in strong-interaction phenomenology, including recent RHIC data.

Flare diagnostics from loop modeling of a stellar flare observed with XMM-Newton

XMM-Newton data of an X-ray flare observed on Proxima Centauri provide detailed and challenging constraints for flare modeling. The comparison of the data with the results of time-dependent hydrodynamic loop modeling of this flare allows us to constrain not only the loop morphology, but also the details of the heating function. The results show that even a complex flare event like this can be described with a relatively few – though constrained – components: two loop systems, i.e., a single loop and an arcade, and two heat components, an intense pulse probably located at the loop footpoints followed by a low gradual decay distributed in the coronal part of the loop. The similarity to at least one solar event (the Bastille Day flare in 2000) indicates that this pattern may be common to solar and stellar flares.