Vane-type in-stream structures and step pool storm conveyance (SPSC) are more ecologically friendly alternatives to traditional stream channel stabilization and stormwater conveyance techniques. Vane-type structures have been widely accepted as elements of stream restoration projects and are regularly implemented in streams throughout the United States. However, these structures commonly experience partial or total failures of function or stability, often due either to improper installation or misapplication. This study undertook a thorough review of the available design guidance for the single-arm vane, j-hook vane, cross vane, and w-weir, which revealed that the existing guidance is composed of non-standardized recommendations largely based on practitioner experience and rules of thumb. Existing guidance was synthesized with current structure research and practitioner surveys to create factsheets for each of the four structures and the SPSC, with the intent of improving structure application and offering concise general guidance. This study also endeavored to improve the design of the SPSC by determining the most accurate of several common prediction methods for Manning's roughness coefficient n, used in SPSC design velocity calculations. This was done by using Rhodamine WT dye tracer experiments to determine n values during storm flows in two SPSC structures in Annapolis, MD, which were then compared to predicted n values. Values of Manning's n determined in the SPSCs at low flows (0.28-12) often exceeded the predicted n values (-0.17-3.9) by several orders of magnitude. Though the applicability of these results is limited, an increase in design n to 0.1-0.2 is still recommended. / Master of Science / Vane-type in-stream structures are stone or wood structures installed within a stream channel for purposes such as streambank stabilization or aquatic habitat creation. Step pool storm conveyance (SPSC) is a technique which converts an existing steep stream or gully into a step-pool channel. Both of these techniques are more ecologically friendly than many traditional stream channel stabilization or stormwater conveyance techniques such as riprap or concrete storm drains. Vane-type structures in particular have been widely accepted as elements of stream restoration projects and are regularly implemented in streams throughout the United States. However, these structures commonly experience partial or total failures, either through structural collapse or failure to function properly. This is often either because they were improperly installed or because they were installed at a stream site where they were inappropriate or unnecessary. A review of the available guidance for the design of these structures revealed that the existing guidance is composed of non-standardized and sometimes contradictory recommendations which are largely based on designer trial and error and rules of thumb, rather than on the results of scientific experiments or modeling. The goal of this study was to improve the success of vane-type in-stream structures and the SPSC by providing factsheets offering clear and concise general design guidelines and sound recommendations for structure application. Flow studies of two SPSC structures in Annapolis, MD were also conducted to improve the design of that structure by measuring its flow characteristics in the field.

Yes / A potential flow model of the semi-inverse type is proposed to simulate flow over round crested weirs. This technique involves the construction of only streamlines over the weir instead of constructing the entire flow net. A Serre–Green–Naghdi (SGN) equation is employed to determine the initial free-surface profile, which is solved using a combined finite volume-finite difference scheme. The potential flow equations were numerically solved using a five-point central finite difference scheme. The model was applied to define the pressure and velocity fields in channel controls involving transcritical flow, such as the Gaussian weir, parabolic weir, and semicircular weir. The impact of streamline curvature on pressure and velocity distributions was investigated in the study. The curvature of the streamline strongly influenced the rise and drop of the bed pressures along the test section. A semicircular weir experiment was also conducted to validate the pressure and velocity profiles obtained using the proposed 2-D fluid flow model. The computed pressure and flow profiles from the solution of the potential flow equation agree perfectly with the present experiment and similar experiments available in the literature. In conclusion, the SGN equation provides an excellent initial profile to solve a 2-D ideal fluid flow numerically.

In 2014 a new Hydro-technical laboratory was built at the High School of Civil Engineering in Vysoké Mýto. The laboratory’s hydraulic circuit is equipped with a reserve line enabling independent standing models of hydro-technical structures to be connected. Two interactive instructional models are designed for this laboratory. The first is a model of a concrete dam. The dam is equipped with one bottom outlet, a hydraulic power plant and an emergency spillway crest gate. The discharge part of the model is equipped with a downflow baffle for regulating the tailwater level and a measuring weir enabling the flow rate to be measured at the discharge point from the model. The total capacity of the model is 10 l/s. The second model is a model of a weir structure. The weir structure consists of a controlled segment sluice gate weir composed of three sections. The model includes a one-nave lock chamber and hydraulic power plant. The tailwater level can also be regulated using a downflow baffle. The total capacity of this model is 20 l/s. The models can be used for teaching the subjects of hydraulics, hydrology and hydro-technical structures. They can be used to demonstrate various hydraulic phenomena and to describe individual functional objects using specialist terminology. This thesis contains the full project documentation for both proposed models, including hydro-technical calculations and text appendices.

This diploma thesis deals with finding the minimal countercurrent distance of the water surface sensors used in practice for use with a V-notch weir. The thesis complements the previously obtained results of measurements in the longitudinal vertical plane of symmetry of the inlet channel with measurements on the whole countercurrently located plane of the inlet channel. The measurements are obtained experimentally in the water management research laboratory at the Department of the Water Structures Faculty of Civil Engineering in Brno. Measurements on each individual weir with top angle cutouts of 90°, 53°8´ and 28°4´ are taken at five possible positions of the sensor towards the plane of the measuring weir. All measurements are also repeated for three different vertical distances between the lowest level of the spillway edge and the bottom of the inlet channel. The obtained data are evaluated and subsequently the minimal distances for the location of the water surface sensor in front of a counter weir is determined. The thesis also includes recommendations for practical application presented in the form of text, tables and also graphically.

This diploma thesis deals with a design of the reconstruction of a smixed weir on the Oslava river in Oslavany town. The introduction describes the site of interest and the the occurrence of ice events. There are several types of fish ladders described theoretically. Further on in the thesis there is desribed the state of the objects on the flow and the state of the river basin in the area of interest of Oslava river. Next part of the thesis deals with the design of a movable baying structure (a hollow flap) and fish ladder type bypass channel. An impact assessment of the current and newly proposed weir on flow in the HEC-RAS program was carried out. The project also includes the basin adjustment in overweir and an evaluation of the stability of the newly designed construction.

The purpose of the diploma thesis „Design of a movable weir on the Želivka river" is a design of the reconstruction of a fixed weir in Soutice village on the river Želivka at km 1,639. The first part of the thesis deals with the localization of the area of interest and a description of all documents needed for the weir design. The first part also includes a short search of the considered structures, the findings of which are further applied in the design of a movable weir structure. Furthermore, the work continues by determining the design flow and selecting a suitable structure of the fixed weir substructure and movable closure, which is fitted to the substructure. Based on the selected types of structures, hydrotechnical calculations are performed, which also include a partial assessment of the weir stability. The thesis ends with a technical description of the proposed objects and a final evaluation of the determined achievements of the work. Part of the study is a drawing part documenting designed objects.

The thesis deals with possibilities of numerical modelling of an overflow over selected types of auxiliary spillways and then the possibilities are verified in particular localities. In thesis, there is carried out the determination of capacity of selected spillways by using several methods: the calculation of the overflow equation, one-dimensional and two-dimensional numerical models and physical model. The author created parametric analysis to each single method. Parametric analysis represent various hydraulic conditions. Subsequently, there is possible to express the effect of parametric analysis. The author makes a comparison of water levels received by mentioned methods set out under the specific hydraulic conditions by calibration of each model with the physical model. Finally, author recommends values of all coefficients which have an impact on results of numerical modelling of the flow over selected types of weirs mostly using like auxiliary spillways.

Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The use of computational fluid dynamics (CFD) as a design tool is becoming increasingly popular in the water resources field. This thesis aims to extend the knowledge of CFD and determine the usefulness of current CFD programs as a modelling tool. This thesis also seeks to determine the accuracy of CFD modelling when compared to physical modelling, the more established form of model testing. It is important that research is conducted on the validation of CFD because with an increase in computer power, processing speed and continual development in the programs used to generate the models, CFD could become an essential tool for the hydraulic engineer. A current key difficulty faced by CFD programs is the mapping of the free surface level of a body of fluid in a two-phase (water and air) flow condition. This is further complicated by the existence of three-dimensional flow over a labyrinth weir and a fluctuating nappe, which at times requires a free surface level to be mapped both above and below the nappe. This thesis begins by detailing the design methods and actual design of a typical labyrinth weir. It then describes the construction of a 1:20 scale physical model, testing procedures, goals, and the results of the physical model tests. Following the physical model study, the thesis discusses the development of a three-dimensional CFD model, designed in a way that matched the physical model. Simulation results obtained from the CFD model are then compared to those from the physical model study and the accuracy and suitability of CFD modelling as a design tool are evaluated. This evaluation considers the surcharge upstream of the weir and transient pressures on the weir. The thesis concludes with recommendations for further research in this field. The results achieved show that the CFD model was able to accurately map the movement of particles within the domain, to fully develop a flow profile, and to accurately predict the water surface level. The pressure readings obtained during CFD modelling were in the same order as those obtained during physical modelling. However, the CFD modelling pressure readings did not often accurately correspond with the physical modelling data, with the average error being 92%. These results indicate that there is still further development required in CFD before it can be relied upon as a design tool independent of other experimental methods. The difficulty and the length of time taken to generate the results also indicate that, at this stage and in this particular scenario, the engineer would be better served through the use of a physical model. / AFRIKAANSE OPSOMMING: Die gebruik van gerekenariseerde vloeidinamika (CFD) as ’n ontwerpinstrument het toenemend gewild begin raak op die gebied van waterhulpbronne. Die doel van hierdie verslag is om kennis van CFD uit te brei en die nut van huidige CFD-programme as ’n modelleringsinstrument te bepaal. Daar word voorts ook gepoog om die akkuraatheid van CFD-modellering te bepaal in vergelyking met fisiese modellering – die meer gevestigde vorm van modeltoetsing. Dit is noodsaaklik dat navorsing gedoen word oor die bekragtiging van CFD, want met ’n toename in rekenaarkrag, verwerkingsnelheid en deurlopende ontwikkeling in die programme wat gebruik word om die modelle te genereer, sal CFD ’n noodsaaklike instrument vir die hidroulika-ingenieur word. ’n Belangrike probleem wat CFD-programme tans inhou, is die kartering van die vry oppervlak van ’n liggaam vloeistof in ’n tweefasse vloeitoestand (water en lug). Dit word verder bemoeilik deur die bestaan van driedimensionele vloei oor ’n labirint-stuwal en ’n skommelende “nappe”, wat by tye vereis dat ’n vry oppervlak sowel bo as onder die “nappe” gekarteer met word. Die verslag begin met ’n uiteensetting van die ontwerpmetodes en fisiese ontwerp van ’n tipiese labirintstuwal. Die bou van ’n 1:20-skaal- fisiese model, toetsprosedures, doelwitte en die resultate van die toetse op die fisiese model word dan beskryf. Ná die studie van die fisiese model, word die ontwikkeling van ’n driedimensionele CFD-model bespreek, wat ontwerp is om by die fisiese model te pas. Die simulasie-resultate van die CFD-model word dan vergelyk met dié van die studie van die fisiese model en die akkuraatheid en geskiktheid van CFD-modellering as ’n ontwerpinstrument word geëvalueer. In hierdie evaluering word die opdamming stroomop van die stuwal en druk op die stuwal ondersoek. Die verslag word afgesluit met aanbevelings vir verdere navorsing op hierdie gebied. Die resultate toon dat die CFD-model die beweging van partikels in die domein akkuraat kon karteer ten einde ’n volledige vloeiprofiel te ontwikkel en die watervlak akkuraat te voorspel. Die drukke wat tydens CFD-modellering verkry is, stem egter nie ooreen met die lesings wat tydens fisiese modellering verkry is nie. Die gemiddelde fout is 92%. Hierdie resultate toon dat verdere ontwikkeling in CFD nodig is voordat daarop staat gemaak kan word as ’n ontwerpinstrument wat onafhanklik van ander eksperimentele metodes gebruik kan word. Die moeilikheidsgraad en die lang tydsduur betrokke by die generering van resultate is ook ’n aanduiding dat die gebruik van ’n fisiese model die ingenieur op hierdie stadium en in hierdie spesifieke scenario beter tot diens sal wees.

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / Department of Communication Studies

A exploraÃÃo de Ãreas de emprÃstimo para obtenÃÃo de materiais para obras civis tem resultado na degradaÃÃo ambiental, muitas vezes, com sÃrios impactos nos meio fÃsico e biÃtico. Assim, os impactos ambientais de Ãreas de emprÃstimo devem ser identificados, para que sejam propostas e executadas medidas visando à sua recuperaÃÃo. Neste trabalho, procurou-se avaliar a eficÃcia das medidas mitigadoras propostas nos estudos de impacto ambiental dos aÃudes pÃblicos Aracoiaba e SÃtios Novos, no estado do CearÃ, para a recuperaÃÃo das Ãreas degradadas durante a obtenÃÃo de matÃria prima para suas obras civis. A pesquisa teve inÃcio com o levantamento dos EIA/RIMA dos AÃudes PÃblicos Aracoiaba e SÃtios Novos, com Ãnfase na anÃlise dos impactos identificados como possÃveis de ocorrerem nas Ãreas de emprÃstimo dos dois empreendimentos. Foram tambÃm levantadas as medidas mitigadoras propostas para recuperaÃÃo das Ãreas de emprÃstimos dos dois reservatÃrios. A partir de pesquisas de campo foi realizado levantamento das medidas mitigadoras efetivamente implantadas para recuperaÃÃo das Ãreas de emprÃstimo. A pesquisa permitiu a realizaÃÃo de estudo comparativo entre as medidas propostas e as efetivamente implantadas nas Ãreas de emprÃstimo dos dois aÃudes. Constatou-se que vÃrias medidas propostas nÃo foram implantadas, principalmente nas Ãreas de emprÃstimo do AÃude SÃtios Novos, resultando na existÃncia de Ãreas ainda degradadas, necessitando de recuperaÃÃo. Ao final, propÃe-se a adoÃÃo de aÃÃes visando mitigar a degradaÃÃo ambiental resultante dos dois aÃudes, nas suas Ãreas de emprÃstimo. / Exploitation of borrow areas to obtain materials for civil works has resulted in environmental degradation , often with serious impacts on physical and biotic environment . Thus , the environmental impacts of borrow areas should be identified , to be proposed and implemented measures aimed at their recovery . In this study, we sought to assess the effectiveness of mitigation measures proposed in the environmental impact studies and public dams Aracoiaba Novos , in the state of Cearà , for the recovery of degraded areas for obtaining feedstock for its civil works . The research began with a survey of the EIS / EIR for Public and Sites New Dams Aracoiaba , with emphasis on the analysis of the impacts identified as possible to occur in the areas of loan of two developments . Were also raised proposals for the rehabilitation of the two reservoirs loans mitigation measures . From field research was conducted survey of mitigation measures effectively implemented for the rehabilitation of loan. The survey allowed for a comparative study between the proposed measures and effectively implemented in the areas of borrowing of the two dams . It was observed that several proposed measures were not implemented , mainly in the areas of loan Novos Dam, resulting in the existence of yet degraded areas needing recovery . At the end, we propose the adoption of actions to mitigate environmental degradation resulting from the two dams in their lending areas.