"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:52da5065-10a7-4d5a-ad77-15f1ed462c1d","http://resolver.tudelft.nl/uuid:52da5065-10a7-4d5a-ad77-15f1ed462c1d","Cross-shore sediment transport; analysis of Delta Flume data and mathematical modelling","Zhang, C.","","1994","In the last decade, several mathematical models for cross-shore sediment transport have been developed under the assumption that the instantaneous sediment transport is directly related to the instantaneous horizontal velocity just above the boundary layer. Although some models took beach slopes into account, most of the calibrated data were from flat-bed experiments, and most experiments were carried out on a rather small scale. Under the framework of the European Large Installation Plan, to achieve high quality and high resolution data on hydrodynamics and sediment transport dynamics on a natural 2DV beach under equilibrium, erosive and accretive conditions, a programme of detailed measurements of hydrodynamics and sediment transport in the surf zone has been carried out in DELFT HYDRAULICS' Delta Flume in the period from April to June 1993 (DELFT HYDRAULICS 1994). Hence a set of new data about beach evolution and acting velocity moments has become available. The objectives of the present study are: (1) to derive the measured crossshore sediment transport rates from the profile measurements, (2) to predict cross-shore sediment transport rates from measured velocity moments by using several existing mathematical models, (3) to compare the results between measured and computed data and [ if (3) yields a poor comparison ] (4) to propose a modified model. This report is a summary of the work. The report includes profile analysis, the derivation of measured transport rates, the computations of cross-shore transport rates by three selected prediction models and the comparison between measured data and computed results as well as the calibration and verification of the proposed model.","sediment transport; dune erosion","en","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:2b62ccd2-cf9b-471e-bd0f-0d888d53822b","http://resolver.tudelft.nl/uuid:2b62ccd2-cf9b-471e-bd0f-0d888d53822b","Modelling of sediment transport: Link in a chain","De Vries, M.","","1977","Rather than reporting on a specific topic of current research in the broad field of sediment transport and river morphology, the writer will give a general contemplation on the state of the art. This will not be a review in the usual sense. The alloted space would then be filled easily with references. References will only be made here if it cannot be avoided. Moreover only sediment transport due to currents will be treated. To avoid confusion it is necessary to indicate that modelling of sediment transport is used at present (1977) in at least three meanings: (i) A theoretical framework for sediment transport proper. This mainly implies a relation between hydraulic parameters and the amount of sediment transport. This framework will have to be supplemented with experimental data before a useful transport predictor is attained. (ii) A mathematical framework for morphological processes in rivers, used to forecast morphological changes in rivers e.g. due to human interference (morphological computations). (iii) A scale model with mobile bed of a river in order to carry out similar predictions as under (ii) (mobile-bed scale models). In which follows the vague term ""modelling of sediment transport"" will be avoided if confusion may be introduced.","sediment transport; river morphology","en","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:5cf30bdd-d81f-438d-86ec-bcddb1fa1b07","http://resolver.tudelft.nl/uuid:5cf30bdd-d81f-438d-86ec-bcddb1fa1b07","Ontmenging van granulaire materialen bij toepassingen in waterbouwkundige constructies: Voorspelling en beoordeling van ontmengingsinvloeden in praktijksituaties","Vrijling, J.K.; Hauer, M.; Van der Meulen, T.","","1998","Het verschijnsel ontmenging is al sinds lang een bekend fenomeen bij ontwerpers en constructeurs van granuiaire constructies. Desalniettemin is nog altijd erg weinig bekend over de aard en de omvang van de gevolgen die het optreden van dit verschijnsel voor het functioneren van een constructie kan hebben. Tot op heden bleven de beschouwingen over ontmenging beperkt tot hoofdzakelijk kwalitatieve beschouwingen, waaruit voor de Nederlandse bouwwereld enkele praktische richtlijnen voor de uitvoering van granuiaire constructies voortkwamen. Numerieke schattingen voor effecten van ontmenging ontbreken echter. Deze studie is geschreven als eerste stap op weg naar een situatie waarin dergelijke numerieke schattingen wel tot de mogelijkheden zullen gaan behoren. Daarbij is ook aandacht besteed aan de mogelijke gevolgen van de effecten van ontmenging voor het functioneren van granuiaire constructies. Aangezien allereerst nog een goede, kwantificeerbare definitie van het verschijnsel ontmenging ontbrak is begonnen met de opstelling van een dergelijke definitie. Het verschijnsel ontmenging is in deze studie op zodanige wijze omschreven dat men met behulp van deze definitie tijdens een analyse van steekproefresultaten van meerdere monsters uit één partij stenen altijd binnen een zekere nauwkeurigheid kan vaststellen of in die partij wel of geen ontmenging is opgetreden. De niet door ontmenging veroorzaakte toevalsgebonden fluctuaties in kentallen worden daarbij als maatstaf gebruikt.","ontmenging; korrels; granulair materiaal; filters; sediment transport","nl","report","TU Delft, sectie waterbouw","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:a7275bc5-566f-4121-b6ef-9c898b578fef","http://resolver.tudelft.nl/uuid:a7275bc5-566f-4121-b6ef-9c898b578fef","Sand transport in oscillatory sheet-flow; a literature review","Janssen, C.M.","","1995","This literature review is part of the ongoing research on sand transport in oscillatory sheet-flow, as taking place at the coast during storms. Because sheet-flow corresponds to conditions of high shear stress, large amounts of sand are transported. Therefore it is an important part of the total sand transport (sheet-flow and suspended load). Sand transport is a very important phenomenon in almost all coastal engineering problems. When a harbour is to be developed it is important to know how much sand is transported and in what direction, in order to prevent sedimentation problems in the entrance channel or in the harbour itself. Another example deals with coastal defence measures to prevent erosion of a beach. Either the use of coastal structures, like breakwaters, groynes etc., or a beach nourishment scheme requires information about the magnitude and direction of the general and local sand transport. Unlike the sand transport in rivers, which can be assumed to occur in a merely one- dimensional, steady uniform flow, the sand transport at the coast is the result of a complex interaction of steady currents and a wave-induced unsteady oscillatory flow at an arbitrary angle to the current. In order to predict the resulting sand transport, many different models have been developed. The aim of this literature study is to present an overview of the models, that predict the unsteady sand transport in sheet-flow conditions. Some of the models are specifically derived for sand transport under sheet-flow conditions, while others have a more general basis. A comparison is made between the capability of the different existing models in predicting the sand transport in sheet-flow conditions. Moreover also the different experimental studies on sand transport in oscillatory flow are presented. As a result of the comparison the most encouraging direction for the ongoing research is determined.","sediment transport; waves","en","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:08388ab0-24aa-48d2-b4ce-c42f71374fcc","http://resolver.tudelft.nl/uuid:08388ab0-24aa-48d2-b4ce-c42f71374fcc","Zandtransporten evenwijdig aan de kust, vergelijking zandtransportformules","Van de Graaff, J.; Van Overeem, J.","","1977","Als T.O.W. onderzoek is door het Waterloopkundig Laboratorium een onderzoek uitgevoerd waarbij enkele moderne zandtransportformules zodanig zijn aangepast dat de gecombineerde werking van golven en stroom in rekening kan worden gebracht. Uit dat onderzoek bleek dat de aangepaste White-Ackers formule het beste aansloot bij een serie modelproeven die als vergelijkingsbasis werd gebruikt. De vakgroep Kustwaterbouwkunde van de Technische Hogeschool Delft heeft een vergelijking tussen de uitkomsten van transportberekeningen met verschillende formules en die met de CERC-formule gemaakt. Om transporten te kunnen berekenen zijn daartoe eerst snelheidsverdelingen evenwijdig aan de kust berekend. Hoewel de CERC-formule geenszins als ideale toetsingsgrond kan worden aangemerkt, is de conclusie gerechtvaardigd dat de aangepaste White-Ackers formule in geen enkel opzicht als een verbetering voor berekeningen van prototypegevallen kan worden beschouwd. De inmiddels wel enigszins geëvolueerde, oorspronkelijke Bijker-forrnule verdient verreweg de voorkeur. Omdat een zinvolle beoordeling van alle aspecten van de kwaliteit van een zandtransportforrnule pas kan geschieden aan de hand van prototype situaties , verdient het aanbeveling een deel van de onderzoekinspanningen, te richten op het verkrijgen van dergelijke situaties.","sediment transport; longshore transport; Bijker formula","nl","report","TU Delft, sectie waterbouw","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:7e4a0980-f766-470f-8126-542d03abe9d2","http://resolver.tudelft.nl/uuid:7e4a0980-f766-470f-8126-542d03abe9d2","Information on the Arnhem Sampler (BTMA)","De Vries, M.","","1979","The Subcommittee 6 of the Technical Committee 113 of the International Standardization Organization (ISO) is dealing with measurements of sediment transport in open channels. As a back-ground paper for TC113 this report is written on the BTMA, internationally named the Arnhem Sampler. The BTMA has been developped jointly by Rijkswaterstaat, Directorate Upper Rivers in Arnhem and the Delft Hydraulics Laboratory. The BTMA (Bedload Transport Meter Arnhem) has a relatively long history; the prototype was constructed in the thirties of this century. The BTMA is still in use although insight in the mechanism of bedload transport has been increased. Hence also the insight in the measuring problem and in the use of the BTMA has undergone changes.","BTMA; Arnhem Sampler; sediment transport; measurement; measurement device; bedload transport","en","report","TU Delft, Department of Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:eccee569-9391-48e4-a550-06ffae10de39","http://resolver.tudelft.nl/uuid:eccee569-9391-48e4-a550-06ffae10de39","Analysis of basic equations for sediment-laden flows","Sloff, C.J.","","1993","Derivations and analyses of basic equations for I-dimensional sediment-laden flow (concentrations up to about 10% of volume) on a mobile bed are presented . Equations of mass and momentum conservation have been derived by means of a control section as well as by depth integration. Therefore a three-layer approach has been used (i.e., bed layer, bed-load layer, and suspended-load layer). Despite the assumptions of uniform sediment, fixed banks and constant width the derivations can easily be extended for more general models. Analysis of the basic equations b means of the method of characteristics showed that with increasing concentration wave celerities alter, and showed that critical flow occurs at Froude numbers less than unity. A stability analysis of the equations showed that the criterion for occurrence of roll waves in supercritical flow is also modified by the increased concentration. Due to increased concentrations roll waves can occur in sediment-laden flow at lower Froude numbers than in clear water flow.","sediment transport","en","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:1107be41-27fb-430c-a63c-09fe839fc928","http://resolver.tudelft.nl/uuid:1107be41-27fb-430c-a63c-09fe839fc928","Sediment exchange between the main channel and the groyne fields of a river","Yossef, M.F.M.","","2003","Report on a physical scale model test in the Fluid Mechanics lab on the effect of groynes on the bed and sediment transport in rivers.","groynes; rivers; river morphology; sediment transport; Delft Cluster; DC 03.03.04","en","report","Delft Cluster","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:2cf67a5b-d2c4-4287-8ed2-16f1b27bdbcc","http://resolver.tudelft.nl/uuid:2cf67a5b-d2c4-4287-8ed2-16f1b27bdbcc","A depth integrated model for suspended transport","Galappatti, R.","","1983","A new depth averaged model for suspended sediment transport in open channels has been developed based on an asymptotic solution to the two dimensional convection-diffusion equation in the vertical plane. The solution for the depth averaged concentration is derived from the bed boundary condition and the computation of transport rate and entrainment rate are performed therefore. Expressions are derived for adaptation length and time. The model is economical and easy to apply even in unsteady flow situations and compares favourably with the full two dimensional solution for steady flow. The stability of bed level change calculations including numerical effects can be analysed prior to application of the model. The extension to three-dimensions is outlined.","sediment transport; suspended transport","en","report","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:755509c5-6453-4a63-a397-e6faf60f272f","http://resolver.tudelft.nl/uuid:755509c5-6453-4a63-a397-e6faf60f272f","Laboratory observations of the velocity field in the entrance of a tidal harbor and the exchange of heat between harbor and river","Langendoen, E.J.","","1990","The research that has been presented in this report is a part of an ongoing study on the siltation of tidal harbors. The study deals with the water motion in the harbor entrance, which motion causes the siltation. As yet, too little is known about this complicated time-dependent water motion. The data obtained during the research will be used to calibrate the 3-D numerical model Trisula, so that this model can be used as a tool to predict the water motion in a harbor entrance. With the present knowledge of the transport of cohesive sediments, a better prediction of the siltation of a particular harbor entrance will then be possible. Experiments have been performed in a physical model at the Laboratory of Fluid Mechanics of the Delft University of Technology. In these experiments the influences, on the flow patterns in the harbor entrance and the exchange of heat between harbor and river, of the geometries of the harbor and the harbor entrance, the tidal period and tidal water level changes were examined. Measurements of the time-dependent velocity and temperature fields were made in five model harbors. In the experiments without tidal water level changes three harbors had their length axes perpendicular to the length axis of the river, namely (1) a square harbor of 1 m2, (2) a rectangular harbor of 1 x 2 m2 and (3) a square harbor of 1 m2 with a narrowed entrance of 0.5 m; one harbor, (4), of 1 m2 and an entrance width of 1 m had its length axis at an angle of 45 degrees to the length axis of the flume. In the experiment with tidal water level changes a rectangular harbor, (5), with an entrance width of 1 m and a storage area of 8 m2 had its length axis perpendicular to the length axis of the river. It can be concluded that: details of circulating flows and gyres depend markedly on the geometry of the harbor. the progress of the phenomena after slack water in model harbor (2), that is the development of a new primary gyre, does not seem to depend on the tidal period. As a consequence, the phase difference between the development of the gyre and the accelerating flow in the river increases as the period decreases. the flow pattern in the harbor is highly influenced by the orientation of the harbor entrance. An explanation for this phenomenon is deficient at the moment. in the model harbors, except harbor (3), a quite strong secondary current is present in the gyre. The maximum velocity in the secondary current is on the average 15 per cent of the main flow. This means that a three-dimensional numerical model will be necessary to simulate the flow pattern in the harbor correctly. close to the downstream sidewall, in all model harbors, larger water velocities (20 to 50 per cent larger) were observed near the bottom than higher in the water column. Near the bed high-momentum fluid from the mixing layer between harbor and river appears to be transported into the harbor. tidal water level changes cause an acceleration in the development of the new gyre towards high tide. Towards low tide the development of the new gyre is hindered by the emptying of the basin. in harbors (1), (2) and (4) a large increase in advective exchange takes place around slack water. The influence of turbulence seems to be of secondary importance during this phase of the tide. a narrowed entrance highly reduces the exchange of mass between harbor and river at slackwater. if the flow pattern in the harbor comprises various gyres, in this research harbor (2), the normalized exchange will be less because the secondary,tertiary, etc. gyres do not contribute to the exchange process. wgen the current in the river is around maximum,the flow is quasi-steady for a quite large duration. The exchange then takes place through the mixing layer between river and harbor, that is, it is caused by turbulent motions only. although during slack water a less refined turbulence model is sufficient in a numerical model, the modeling of turbulence is important during the quasi-steady phase of the tide, especially when the geometry of the entrance is more complex (e.g. harbor (4)).","siltation; tidal harbor; water motion; sediment transport; harbor entrance; velocity field; laboratory observations","en","report","TU Delft, Department of Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:61147e1f-effd-408c-a9d6-6ea4c7e7ebef","http://resolver.tudelft.nl/uuid:61147e1f-effd-408c-a9d6-6ea4c7e7ebef","In search of a better sediment mixing coefficient model","Voorendt, M.; Van de Graaf, J.","","1994","Results of sediment transport calculations are often necessary in solving practical coastal engineering problems. (Sediment transport due to waves and currents). Many transport formulae have been proposed in literature in the past. Selection of the proper one while solving a particular problem, is a difficult task for a coastal engineer. In considering sediment transport under wave-current conditions it is worthwhile to make a distinction between two situations, viz.: The fluctuations in the orbital motion have to be fully taken into account in order to find the resulting sediment transport (intra-wave type of description; often: cross-shore sediment transport); - It is sufficient to take time-averaged effects of the waves into account in order to find the resulting sediment transport rate (intra-wave type of description is not required; often: longshore sediment transport). For the longshore sediment transport mode, transport formulae based on time-averaged velocity distributions and time-averaged sediment concentration distributions over the water depth can often be used. The present paper is restricted to this type of formula.","sediment transport; mixing coefficient","en","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:2dbed657-4801-4c34-a139-7d9d95ae6583","http://resolver.tudelft.nl/uuid:2dbed657-4801-4c34-a139-7d9d95ae6583","Suspended-load experiments in a curved flume, run no. 3","Talmon, A.M.; De Graaff, J.","","1989","A laboratory experiment in a 180 degree curved flume with a mobile bed and suspended sediment transport is described. The flow is steady. The bed topography is measured by means of a profile indicator. The bed topography is characterized by a slowly damped oscillation of the transverse bed slope. Downstream of the bend entrance a pool and a submerged point-bar are present, here the radial bed slope is maximal. Further downstream the transverse bed slope decreases and subsequently increases again. No axi-symmetrical part is present. The bed topography is very similar to the topography of an earlier experiment. Suspended sediment concentrations are determined by the method of siphoning and by optical measurement. Concentration verticals are measured throughout the whole bend (at 1/4, 1/2 and 3/4 of the channel width). At one specific location a denser measuring grid is used.","suspended-load; experiments; curved flume; morphology; bed topography; suspended sediment; sediment transport","en","report","TU Delft, Department of Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:8f759809-4a01-4407-bad3-d1f63b081a04","http://resolver.tudelft.nl/uuid:8f759809-4a01-4407-bad3-d1f63b081a04","Bed-levelling experiments with suspended load","Talmon, A.M.; De Graaff, J.","","1991","Bed-levelling experiments are conducted in a straight laboratory channel. The experiments involve a significant fraction of suspended sediment transport. The purpose of the experiments is to provide data for modelling of the direction of sediment transport on a transverse sloping alluvial river bed, specifically in presence of suspended sediment transport. The transverse slope parameter for these experiments is determined.","suspended load; experiments; bed-levelling; suspended sediment; morphology; sediment transport; transverse slope","en","report","TU Delft, Department of Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4c00f467-0997-4361-a724-cab28d4ac01d","http://resolver.tudelft.nl/uuid:4c00f467-0997-4361-a724-cab28d4ac01d","Technical note for sediment transport rate: Analysis of delta flume data and calculations","Zhang, C.K.","","1994","Data analysis of Delta flume observations and calculationsThe objective of the present study is to analyse the measurement data of profiles and velocity moments, to derive the measured cross-shore sediment transport rates from the profile records and to compare the observed transport rates with the results from several existing prediction models of cross-shore sediment transport. This report is a summary of preliminary analysis and calculations of 2 tests with test number 2A and 2B. The report includes profile analysis, the derivation of measured transport rates, the computations of cross-shore transport rate by Bailard's formula and t h e comparison between the measured and the computed results.","sediment transport; waves; cross-shore transport","en","report","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:677a707f-7554-4db5-9139-9f1e9d1d25ef","http://resolver.tudelft.nl/uuid:677a707f-7554-4db5-9139-9f1e9d1d25ef","Heavy metal pollution and sediment transport in the rhinemeuse estuary, using a 2D model Delft3D: Water quality and calamities. Case study Biesbosch","Jose Alonso, J.J.","","2010","Different measures will be executed in the framework PKB “Room for the River” in order to lower the water levels in the river area during normative high discharges. The plan Ontpoldering Noordwaard is one of them and has as aim to inundate parts of the Noordwaard during high discharges. Water coming from the Nieuwe Merwede as result of high water levels will flow into the Noordwaard and leave the area through the south part. As consequence the creeks in the Brabantse Biesbosch will process more water and flow velocities will increase. This may result in higher sediment transport en possible erosion of the gullies. Dankers et al. (2008) studied the flow velocities in the Brabantse Biesbosch under different discharge conditions and the possible effects of the velocities on erosion and transport of contaminated bed material. This study was a combination of computer model simulations and expert judgment. The model simulations were obtained with the combination of boundary conditions for discharges with a return period of once in 100 year for the Rhine and Meuse and a water level of the sea of 1 m above normal. In this case flow velocities higher than 1 m/s and shear stresses higher than 1 N/m2 were found at different locations of the Brabantse Biesbosch. This means that a transition may occur from a situation without spreading of contaminated bed material towards a situation where spreading can occur. By comparing the quality of the top layer of the areas with risk of erosion according to De Straat (2004) with the intervention values for river beds (“Circulaire Sanering Waterbodems 2008”) and the MACsediment (Maximum Allowed Concentration in the Sediment), Dankers et al. (2008) found that different areas in the Brabantse Biesbosch may exceed the intervention values and/or the MAC for sediments. The areas Gat van de Visschen, Gat van Den Kleine Hil and Gat van de Noorderklip present concentrations of metals in the top layer that are higher than the intervention values and the MAC. In the areas Gat van Van Kampen, Gat van de Binnennieuwensteek and Spijkerboor a small violation of the MACsediment was observed. This study concluded that there are unacceptable risks of spreading of contaminated mud to the surface water.","heavy metal; pollution; sediment transport; rhine; meuse; 2D model; Delft3D; water quality and calamities; case study; Biesbosch; river; room for the river; ontpoldering Noordwaard; high water levels; serosion; computer model simulations; Delft Cluster; CT04.20; waterkwaliteit; CT04.24.11; risicomanagement van calamiteiten; waterquality","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:a80c8586-9b32-4b9f-8b93-e71094637ac4","http://resolver.tudelft.nl/uuid:a80c8586-9b32-4b9f-8b93-e71094637ac4","Experiments with non-uniform sediment in case of bed-load transport","Ribberink, J.S.","","1983","An experimental study was carried out in the framework of a research project concerning the development of a mathematical model for morphological computations in rivers in case of non-uniform sediment. The study consists of a series of laboratory experiments in a straight flume under steady, uniform (equilibrium) conditions with a restriction to bed-load transport and dune regime. The flume was fed upstream by different mixtures of two very narrow sieved size fractions. During one experiment the total amount and composition of the input mixture, the water discharge and the downstream water level were kept constant. When equilibrium was reached besides regular registrations of water and bed level the dunes were extensively sampled. The latter occurred in such a way that vertical probability distributions of the size fractions could be determined. The main results of the experiments are: (i) Vertical sorting of the size fractions occurred in all experiments: at the steep lee side of the dunes the coarse size fraction is generally deposited at a lower level than the fine size fraction. Differences in volume concentration per size fraction until 30% occur between upper and lower layers. (ii) A transition layer was found which is generally below the propagating dunes; it has a relatively coarse composition (vertical sorting:) and has a thickness of 0.1 - 0.5 H (H = average dune height). Exchange of size fractions between this layer and the upper bed layer occurs at a time scale much larger than the dune period. (iii) Because of the phenomena described above several assumptions in a mathematical model for non-uniform sediment (Ribberink, 1980) concerning the transport layer and the deposition/erosion of size fractions to/from non-moving bed are generally not fulfilled. (iv) Data are obtained for the verification and development of semi empirical components in the mathematical model (i.e. transportformula per size fraction, predictors for dune height and bed roughness).The theory of Egiazaroff (1965) concerning the critical bed shear stress per size fraction seems to be useful in a bed-load formula per size fraction of the type of Meyer-Peter & Mueller (1948). (v) A bed sampling technique was developed and suggestions are made concerning the conditions of a non -equilibrium experiment which has the aim to verify the above-mentioned mathematical model for non-uniform sediment.","sediment transport; bed load transport; sediment transport measurement","en","report","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:ae972b2c-176a-4833-b5a6-6f58a938d4c9","http://resolver.tudelft.nl/uuid:ae972b2c-176a-4833-b5a6-6f58a938d4c9","Laboratory observations and calculations of the depth averaged flow patterns in a square harbor on a tidal river","Langendoen, E.J.","","1989","Many harbors in the world suffer from siltation in their basins and in many cases removal of the deposited sediment leads to high costs. This siltation results from a net transport of sediment into the harbor caused by the water motion in the harbor entrance. The water motion is very complex and of a three-dimensional nature. Three main mechanisms can be distinguished: (1) exchange in consequence of water flowing along the mouth of the harbor and the resulting eddies in the harbor entrance, (2) exchange in consequence of variations in water level of the adjacent waterbody (e.g. sea, estuary or river) , and (3) exchange in consequence of a density difference between harbor and adjacent waterbody. For a more extensive discussion of the problem see Langendoen (1988). The first two mechanisms are being examined in a physical model in the Laboratory of Fluid Mechanics of the Delft University. Measurements were made to generate a dataset by which numerical models of the flow in harbor entrances can be tested. A more distant goal of this project is to obtain insight in the influence of the geometry of the entrance on siltation of the harbor. The first part of the research is discussed in this report. It concerns the water motion in a square harbor due to an oscillatory flow in the adjacent waterbody (here a tidal river). The time-varying depth averaged flow patterns in the harbor have been measured. These flow patterns are then compared to the results of preliminary calculations with a numerical model that solves the shallow water equations. In this report a simple geometry of the tidal river and the harbor was considered as a first step. Depth averaged flow patterns were measured and calculated. The phenomena which occurred in the harbor entrance around and after slack water may be important for the exchange of matter between harbor and river. Large parcels of water from the river are exchanged with water from the harbor. This convective exchange is much larger than the exchange around maximum current in the river, when there is only a turbulent transport through the shear layer at the transition between harbor and river. The mathematical model ESTRA, which has been used to study the exchange of a well-mixed solute, also predicted this behavior.","flow pattern; harbor; tidal river; siltation; sediment transport; laboratory observations","en","report","TU Delft, Department of Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:759597b8-ed4c-435b-97f3-3ac7a17859c0","http://resolver.tudelft.nl/uuid:759597b8-ed4c-435b-97f3-3ac7a17859c0","Erosie onder een geometrisch open filter","Booij, R.","","1998","Deze notitie beschrijft de resultaten van een inleidend onderzoek naar de mechanismen van de erosie van de basislaag onder geometrisch open filters. Hierbij wordt in eerste instantie uitgegaan van de beter onderzochte erosie van de bodem van een waterloop zonder beschermende filterlaag. Op basis van metingen van Van Os (1998) in een inleidend onderzoek wordt daama de stroming in een filterlaag geanalyseerd. De stroming tussen de filterelementen blijkt qua karakter sterk te verschillen van de strorning in de waterloop. Gemiddelde snelheid en schuifspanning zijn gering. Bij de relatief sterke fluctuaties van de snelheid kunnen twee duidelijk verschillende schalen onderscheiden worden: kortdurende fluctuaties die te maken hebben met de turbulentie in de porien tussen de filterelementen en langdurende fluctuaties die lijken samen te hangen met de grootschalige turbulenties in de waterloop. Gebaseerd op de analyse van de metingen in de filterlaag is het volgende beeld van het mechanisme van de erosie van de basislaag onder een filter ontwikkeld. Drukkrachten samenhangend met de kortdurende fluctuaties maken de zandkorrels los uit de basislaag en de langdurende fluctuaties zorgen voor het transport van de zandkorre1s over de filterlaag. Aangetoond wordt dat in elk geval bij de besproken metingen dit laatste transport bepalend is voor de uiteindelijke erosie van de basislaag. Op grond van het geschetste model van de erosie onder filters lijkt het goed mogelijk tot ontwerpregels voor verschillende soorten waterlopen en stromingssituaties te komen. Een schatting geeft aan dat deze erosie de toepasbaarheid van de gebruikelijke geometrisch open filters beperkt. Om de vele vragen en onzekerheden die op grond van deze uitwerking van het inleidend onderzoek van Van Os kunnen worden geformuleerd op te lossen is aanvullend onderzoek nodig. Hiervoor worden suggesties gedaan.","erosion; filter; geometrically open filter; sediment transport","nl","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:42dc0cb5-c452-4c0c-a1bb-d8e47b9ce011","http://resolver.tudelft.nl/uuid:42dc0cb5-c452-4c0c-a1bb-d8e47b9ce011","Probabilistic approach on course material transport under waves: Vol. 1 Theory and experiment.","Katsui, H.","","1982","The probabilistic design method of a cover layer of pipe line under the horizontal bottom is described. By assuming that the water velocity at the bottom is Rayleigh distributed, probability of bottom shear stress was derived. With a combination of the probability function of bottom shear and a simple sediment transport formula given by Madsen and Grant (1976), the expected transport rate was calculated. The results gave a warning that conventional design methods have a risk to underestimate the amount of loss.of covering material. To confirm the established formulas about inception of motion of particles and sediment transport under waves, some experiments were carried out. As for inception of particle motion, comparison between steady flow condition and wave condition was, done. It turned out that the one gives lower value than the other, and that Shields' curve gives the lower limit of the total experimental data. The data of critical velocity under waves agreed to Komar-Miller's formula which involves the factor of wave period. The critical velocity in the direction of wave propagation was found considerably higher than that against it. Sediment transport rate was measured together with velocity. As had been already presented by van de Graaff and Tilmans (1980), the transport-rate could be related to the Fourier components of the velocity. It could also be related to the maximum and minimum velocity. The influence of a phase lag between the first and second terms of the Fourier components, which is closely related to the acceleration and the deceleration of the total velocity, was not clear yet in that specific condition. Critical velocity obtained by the visual observation generally agreed to the limit line of transport-rate (zero line) on both u1 - u2 plane and u(max) - u(min) plane.","sediment transport; course material; probabilistic approach; waves; shear stress","en","report","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:fcb49e4d-b0e0-45a4-9d67-be7ec4430ffd","http://resolver.tudelft.nl/uuid:fcb49e4d-b0e0-45a4-9d67-be7ec4430ffd","A Hybrid Approach to Combine Physically Based and Data-Driven Models in Simulating Sediment Transportation","Sewagudde, S.","","2008","The objective of this study is to develop a methodology for hybrid modelling of sedimentation in a coastal basin or large shallow lake where physically based and data driven approaches are combined. This research was broken down into three blocks. The first block explores the possibility of approximating a physically based model using a data driven model to predict suspended particulate matter (SPM) concentrations. It identifies the necessary input variables and data manipulation operations to expose maximum information to a data driven modelling tool. The second block investigates the effect of specifying time varying open boundary condition instead of fixed boundary conditions on the simulation of (SPM) along the Dutch coast. First, a methodology for generating time varying open boundary conditions using a data driven model is developed. Local hydrodynamic and meteorological conditions are used as input variables. Secondly the improvement of the time varying open boundary conditions (OBC) on the simulation results is studied The third block examines how knowledge gained in modelling sediment transport along the Dutch coast can be transfer to understand sediment transport in Lake Victoria. This part lays ground for more accurate and reliable modelling of sediment transport in Lake Victoria in future through transfer of methods developed in the preceding sections.","hybrid approach; physically based; data driven; simulating sediment transportation; hybrid modelling; sedimentation; coastal basin; shallow lake; model; suspended particulate matter; SPM; simulation; Dutch coast; hydrodynamic; meteorological; open boundary conditions; OBC; sediment transport; Lake Victoria; North sea; Delft Cluster; CT05.20; Noordzee & kust; CT05.24.11; morfodynamiek van Noordzee en kust en kustverdediging","en","report","Delft Cluster","","","","","","","","","","","","",""
"uuid:2ec6784e-288e-4d87-b7d0-56a9223ebee1","http://resolver.tudelft.nl/uuid:2ec6784e-288e-4d87-b7d0-56a9223ebee1","An entrainment model for fluid mud","Kranenburg, C.","","1993","An entrainment model for fluid mud is derived by integrating the equation for turbulent kinetic energy across the mixed layer and introducing some modelling assumptions. The resulting entrainment model is similar to models of mixed-layer deepening in lakes and reservoirs, but in addition accounts for the work needed to entrain bed material. Two basically different flow conditions are considered: (1) flow in the water layer but no flow in the fluid-mud layer, and (2) flow in both layers driven by a tide-induced streamwise pressure gradient. In the first case, which applies to laboratory experiments in an annular flume, for example, the water layer is the turbulent mixed layer that erodes the quiescent fluid-mud layer. In the second case the fluid-mud layer is the mixed layer, which deepens because of entrainment of water from the overlying water layer. The water layer then is the quiescent layer. The viscous drag of the quiescent layer due to the flow in the mixed layer, which effect can play a part in laboratory experiments, is accounted for. Empirical model coefficients are obtained from the literature.","sediment transport; mud","en","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","","","","",""