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1
Røstum, Jon. "Statistical modelling of pipe failures in water networks". Doctoral thesis, Norwegian University of Science and Technology, Department of Hydraulic and Environmental Engineering, 2000. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-504.
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This thesis presents an evaluation of statistical methods for modelling pipe failures for each individual pipe in a water distribution network. This thesis introduces the Non Homogeneous Poisson Process (NHPP) with covariates (i.e. explanatory variables) as an appropriate method for modelling pipe failures in water networks. As part of this research, a computer program has been developed that estimates the parameters in the NHPP (“Power law” model). The results from this NHPP model are compared to the results obtained from a modified Weibull Proportional Hazards Model (PHM), where the hazard function is allowed to continue beyond the pipe’s first failure. The models are applied in a case study using data for the water distribution network in Trondheim, Norway.
The statistical models have been calibrated, verified and used to predict failures for both networks (i.e. group of pipes) and individual pipes. Covariates that have a significant influence on the rate of occurrence of failures (ROCOF) are documented. Based on the results from the case study, NHPP is recommend over the Weibull PHM for modelling failures in water networks.
The output from the statistical models can be used for a variety of purposes in water network management. In the long term the models can be used to estimate future budget needs for rehabilitation. In the short term the models can be used to define candidates for replacement based on poor structural condition. Information about failure intensity is also required for carrying out network reliability analysis. For this purpose reliability data for each individual pipe is required, which is exactly what the predictive models described in this thesis provide.
2
Sirvole, Kishore. "Transient Analysis in Pipe Networks". Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/31444.
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Power failure of pumps, sudden valve actions, and the operation of automatic control systems are all capable of generating high pressure waves in domestic water supply systems. These transient conditions resulting in high pressures can cause pipe failures by damaging valves and fittings. In this study, basic equations for solving transient analysis problems are derived using method of characteristics. Two example problems are presented. One, a single pipe system which is solved by developing an excel spreadsheet. Second, a pipe network problem is solved using transient analysis program called TRANSNET.
A transient analysis program is developed in Java. This program can handle suddenly-closing valves, gradually-closing valves, pump power failures and sudden demand changes at junctions. A maximum of four pipes can be present at a junction. A pipe network problem is solved using this java program and the results were found to be similar to that obtained from TRANSNET program. The code can be further extended, for example by developing java applets and graphical user interphase to make it more user friendly.
A two dimensional (2D) numerical model is developed using MATLAB to analyze gaseous cavitation in a single pipe system. The model is based on mathematical formulations proposed by Cannizzaro and Pezzinga (2005) and Pezzinga (2003). The model considers gaseous cavitation due to both thermic exhange between gas bubbles and surrounding liquid and during the process of gas release. The results from the model show that during transients, there is significant increase in fluid temperature along with high pressures. In literature pipe failures and noise problems in premise plumbing are atributed to gaseous cavitation.
Master of Science
3
Sacluti, Fernando R. "Modeling water distribution pipe failures using artificial neural networks". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ40103.pdf.
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Kabaasha, Asaph Mercy. "Realistic modelling of leakage in water distribution pipe networks". Doctoral thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29241.
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Several experimental and modelling studies have established that leak areas are mostly not fixed but vary linearly with pressure. Introducing this linear relationship into the orifice equation, results in a two-part modified orifice equation for leakage modelling with pressure head exponents of 0.5 and 1.5 respectively. Current hydraulic network solvers apply the conventional power leakage equation to model pressure dependent demands such as leakage. The empirically derived power leakage equation does not explicitly consider the leak area variation with pressure and it has been found to be flawed under certain conditions. The aim of this study therefore, was to incorporate the modified orifice equation into the algorithm of a hydraulic network solver and evaluate the impact this has on leakage modelling. Epanet is the hydraulic modelling software whose algorithm of the network solver was modified. In addition, a stochastic model for network leak generation and distribution was developed. The conventional and the modified software were applied to different levels of stochastically generated and distributed leakage in three differently sized pipe networks. It was found that the conventional power leakage equation results in significant leakage volume and flow rate errors under certain conditions. A methodology was also developed to correct the conventional power leakage equation so that it can be used to model leakage realistically without a change of the software to one that uses the modified orifice equation. The methodology was thereafter applied to an existing model that detects leaks in standard water distribution pipe networks, and the results showed significant improvements in the performance of the model.
5
Starczewska, Dagmara. "Pressure transients in water distribution networks : understanding their contribution to pipe repairs". Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/17526/.
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Drinking water infrastructure functions to provide a service to meet customer demands and health requirements. Pipe repairs are one of the biggest challenges of ageing water infrastructure in the UK and world wide. Pressure transients resulting from sudden interruptions of the movement of the water can be caused by routine value operations. In a single pipeline one extreme event can burst a pipe. However the occurrences and impact of pressure transients in operational water distribution systems were not currently fully understood. This research developed new insights and understanding of pressure transient occurrences and their contribution to observed pipe repair rates. A large scale field monitoring program, including deploying and managing high-speed (100 Hz) instrumentation for 11 months, was designed and implemented to cover 67 district metered areas (DMA) subdivided into 79 pressure zones. In total 144 locations were monitored. The data was analysed using a novel method, termed transient fingerprint. This allowed the identification of discrete pressure transients and their three fundamental components (magnitude, duration and numbers of occurrences) leading to a quantitative interpretation of pressure transients. Evolutionary polynomial regression modelling was used to assess the impact of directly measured pressure transient data in context with static pressure, age, diameter and soil variables on 64 cast iron pipes. The analysis suggested that high magnitude, short duration repeatedly occurring pressure transients can have an adverse effect on the pipes. The extrapolation of pressure transient analysis into 7978 cast iron pipes showed inconclusive results suggesting that more accurate pressure transient data is required for each pipe in the network. Additional analysis carried out on 25 asbestos cement pipes, with actual measurements of pressure transients for each pipe, confirmed an adverse effect of pressure transient on water network observed in cast iron pipes. This research has provided an understanding of the occurrence of pressure transients that has implications on pipe management strategies. Mitigation techniques to locate pressure transient sources based on the project outcomes could be utilised to better manage distribution systems and ultimately reduce future pipe replacements and associated costs.
6
Nilsson, Kenneth A. "Simulating Accidental Exposures to deliberate Intrusions in Pipe Networks". University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1091122400.
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Stathis, Jonathan Alexander. "A Model for Determining Leakage in Water Distribution Systems". Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/46422.
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Leaks in pipe networks cause significant problems for utilities and water users in terms of lost revenue and interrupted service. In many cities the leakage is as high as forty percent. A water audit is carried out to assess system-wide leakage. However, to detect leakage at the level of a pipeline, a physical measurement technique is generally employed. For large cities the distribution piping length amounts to a few thousand miles. Therefore, the physical measurements can become tedious and expensive. In this thesis it is assumed that a spatial distribution of leakage can be estimated at nodes based on a water audit bookkeeping scheme. A mathematical formulation consisting of continuity, energy (headloss), pressure-dependent demands and/or leakage, and flow direction preservation equations are utilized to distribute demand flows and leakage among pipes. The leakage is attributed to the formation of corrosion holes. Based upon the extent of corrosion, the leakage flow arriving at a particular node is apportioned among all pipes that are converging at that node. Therefore, the formulation presented in this thesis captures the two essential elements behind leakage, namely, pressure driven flow distribution and the vulnerability of pipes to corrosion.
The proposed formulation allows utilities to be more proactive in identifying leakage prone districts within the water distribution system. An understanding of the pressure-dependent leakage in the system is helpful when performing a water audit and in developing strategies for leak repair programs. Restoring the full capacity of the water distribution system will greatly increase the reliability of the system, thereby benefiting local utilities and water users.Master of Science
8
Austin, Ryan Glen. "Detailed Water Quality Modeling of Pressurized Pipe Systems and Its Effect on the Security of Municipal Water Distribution Networks". Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/202714.
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The current study expands on the body of knowledge associated with water distribution system security. The three main chapters focus on 1) the effectiveness of an incomplete mixing model (AZRED-I) with respect to multi-objective sensor placement decisions; 2) risk assessment as a tool for evaluating vulnerability and making sensor placement decisions; and 3) experimental verification of a combined axial-dispersion and incomplete-mixing water quality model (AZRED-II). The study concludes that water quality models do impact sensor placement decisions, especially in highly interconnected networks; that risk assessment is a valuable evaluation tool for providing information concerning a system's vulnerability to contamination and also information that can affect sensor placement decisions; and that AZRED-II is superior to other water quality models at predicting the spatiotemporal pattern of a pulse through a distribution network with cross junctions under laminar flow. The other sections of the study describe the connection that exists between water distribution security and water quality models.
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Mahdizadeh, Hossein. "Modelling of flood waves based on wave propagation : algorithms with bed efflux and influx including a coupled-pipe network solver". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/modelling-of-flood-waves-based-on-wave-propagation-algorithms-with-bed-efflux-and-influx-including-a-coupled-pipe-network-solver(08c8e8dc-73d6-43f2-aca7-6c3eeae9a805).html.
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Flood propagation over urban areas can cause an interaction between the free-surface flow and large underground pipe networks used for storm drainage and sewage, causing outflows and inflows at the bed. The associated waves may collide with each other and the surface waves. In this thesis the shallow water equations are used to model this type of wave interaction over dry or wet beds with bathymetry gradients and friction terms. The proposed shallow water scheme is solved based on finite volume high-resolution Godunov-type methods. The solver is well-balanced and can accurately balance the source terms and flux-gradients for the steady-state solutions. The solver also utilises a new type of Riemann wave speed to provide depth-positive results over nearly dry beds and dry states. Additionally a new type of source term is introduced in the continuity equation to model pipe inflow and outflow conditions at bed connections. For the standard one-dimensional shallow water equations the numerical results are validated with analytical solutions or other reference solutions provided in the literature. This includes the incipient Riemann problems for nearly dry and dry-states, steady flow over a hump in a rectangular channel and the wave propagation problem. Eventually, the generation of dry bed in the middle, over discontinuous topography is considered. Close agreement is achieved between the shallow water scheme and analytical or reference solutions for the above test cases. For the shallow water problems with influx/efflux source terms comparisons are made with STAR-CD, a commercial Navier-Stokes solver for general fluid flow prediction. The shallow water model is first used to simulate vertical flows through finite gaps in the bed. Next, the interaction of the vertical flows with a dam-break flow is considered for both dry and wet beds. An efflux number, En, is defined based on the vertical efflux velocity and the gap length. A parameter study is undertaken to investigate the effect of the one-dimensional approximation of the present model, for a range of non-dimensional efflux numbers. It is found that the shallow flow model gives sensible predictions at all times provided En<0.5, and for long durations for En>0.5. Dam break flow over an underground connecting pipe is also considered for the one-dimensional efflux problems. To solve two-dimensional problems the shallow water scheme uses the dimensional-splitting method which solves each one-dimensional Riemann problem in the x- and y-directions separately. The cross-derivative terms for second-order accuracy are incorporated by solving another Riemann problem in the orthogonal direction. For two-dimensional problems first the dam-break problems are considered over wet and dry beds. Then, flood propagation over complex terrain is demonstrated. Next, efflux discharge is modelled in isolation over a dry bed and then with dam-break interaction, comparing with STAR-CD results. Again very good agreement is shown between the two-dimensional shallow water model and STAR-CD for the efflux numbers of En<0.5. For modelling the inundation problem over an underground pipe network the solver is coupled with the general underground pipe network solver to calculate the efflux discharge as the flood waves pass through the pipe network. For analysing the pipe network with unknown effluxes an additional set of equations is incorporated into the solution of a general pipe network solver. The shallow water solver coupled to an underground pipe network is then used to simulate dam-break interaction with pipe networks with 9 and 25 nodes to demonstrate the versatility of the method.
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Romano, Michele. "Near real-time detection and approximate location of pipe bursts and other events in water distribution systems". Thesis, University of Exeter, 2012. http://hdl.handle.net/10871/9862.
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The research work presented in this thesis describes the development and testing of a new data analysis methodology for the automated near real-time detection and approximate location of pipe bursts and other events which induce similar abnormal pressure/flow variations (e.g., unauthorised consumptions, equipment failures, etc.) in Water Distribution Systems (WDSs). This methodology makes synergistic use of several self-learning Artificial Intelligence (AI) and statistical/geostatistical techniques for the analysis of the stream of data (i.e., signals) collected and communicated on-line by the hydraulic sensors deployed in a WDS. These techniques include: (i) wavelets for the de-noising of the recorded pressure/flow signals, (ii) Artificial Neural Networks (ANNs) for the short-term forecasting of future pressure/flow signal values, (iii) Evolutionary Algorithms (EAs) for the selection of optimal ANN input structure and parameters sets, (iv) Statistical Process Control (SPC) techniques for the short and long term analysis of the burst/other event-induced pressure/flow variations, (v) Bayesian Inference Systems (BISs) for inferring the probability of a burst/other event occurrence and raising the detection alarms, and (vi) geostatistical techniques for determining the approximate location of a detected burst/other event. The results of applying the new methodology to the pressure/flow data from several District Metered Areas (DMAs) in the United Kingdom (UK) with real-life bursts/other events and simulated (i.e., engineered) burst events are also reported in this thesis. The results obtained illustrate that the developed methodology allowed detecting the aforementioned events in a fast and reliable manner and also successfully determining their approximate location within a DMA. The results obtained additionally show the potential of the methodology presented here to yield substantial improvements to the state-of-the-art in near real-time WDS incident management by enabling the water companies to save water, energy, money, achieve higher levels of operational efficiency and improve their customer service. The new data analysis methodology developed and tested as part of the research work presented in this thesis has been patented (International Application Number: PCT/GB2010/000961).
11
Costa, BÃrbara Cristina Alves da. "Load measurement error influence on friction factor calibration of pipe water distribution networks through do reverse transient method and genetic algorithm". Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13621.
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O estudo de redes hidrÃulicas para fins de operaÃÃo ou anÃlise de viabilidade para ampliaÃÃo ou recuperaÃÃo das mesmas à iniciado pela calibraÃÃo, neste contexto, entendida como identificaÃÃo de parÃmetros tais como: fator de atrito, rugosidade e diÃmetro. O MÃtodo Transiente Inverso em conjunto com Algoritmo genÃtico se mostra eficiente nessa tarefa. O referido mÃtodo emprega o MÃtodo das CaracterÃsticas na soluÃÃo das equaÃÃes de movimento para escoamento transiente em tubos de redes e a otimizaÃÃo das soluÃÃes à baseada na Teoria Evolutiva e avaliada por uma funÃÃo objetivo, que neste estudo à o somatÃrio do mÃdulo da diferenÃa entre as cargas medidas e calculadas pelo modelo para cada conjunto de soluÃÃes. Considerando que o objetivo do desenvolvimento de modelos matemÃticos para a calibraÃÃo de redes hipotÃticas à a utilizaÃÃo dos mesmos em redes reais, e que nessas, a coleta de dados de carga està sujeita a erros de mediÃÃo, seja devido a defeitos nos equipamentos seja por condiÃÃes ambiente desfavorÃveis ou outros efeitos aleatÃrios e tendo em vista a relevÃncia dos fatores de atrito nas tubulaÃÃes, pela sua relaÃÃo com perdas de carga que devem ser controladas para um Ãtimo funcionamento de redes, garantindo um abastecimento contÃnuo em quantidade e condiÃÃes de funcionamento adequados, este trabalho propÃe-se a verificar a interferÃncia da presenÃa de erros de mediÃÃo de carga transiente na identificaÃÃo dos fatores de atrito em duas redes hidrÃulicas hipotÃticas. As mesmas sÃo de portes diferentes com relaÃÃo ao nÃmero de anÃis, nÃs e tubos. Ambas sÃo alimentadas por um reservatÃrio cada. As condiÃÃes transientes sÃo atribuÃdas a uma manobra de vÃlvula instalada em um dos nÃs de cada rede. A coleta de dados de carga à restrita a 20% dos nÃs de cada rede, sendo que um deles à o nà onde se encontra a vÃlvula. O tempo de observaÃÃo do transiente hidrÃulico à restrito ao tempo da manobra de vÃlvula, 20s, e ocorre em intervalos de 0,1s, resultando em 200 registros de carga. A condiÃÃo permanente das redes à inicialmente desconhecida o conhecimento acerca da mesma à restrito a carga nos reservatÃrios e demandas nos nÃs, bem como diÃmetros dos tubos, os fatores de atrito sÃo inicialmente estipulados. A determinaÃÃo das condiÃÃes permanente e transiente bem como a identificaÃÃo dos fatores de atrito à realizada com a utilizaÃÃo de um modelo hidrÃulico e geram cargas transientes que sÃo consideradas convencionalmente verdadeiras, essas entÃo recebem incrementos de diversos erros sistemÃticos e aleatÃrios, que geram novas cargas e essas sÃo consideradas coletadas com erros de mediÃÃo. A partir dessas novas cargas sÃo realizadas identificaÃÃes de fatores de atrito, os quais sÃo comparados com os que foram obtidos considerando um caso ideal de cargas sem erros de mediÃÃo. A referida comparaÃÃo à realizada atravÃs do Erro MÃdio Relativo e da FunÃÃo Objetivo Ãtima. Os resultados encontrados demonstram que os erros de mediÃÃo interferem na identificaÃÃo dos fatores de atrito apesar de nÃo ser possÃvel delinear uma relaÃÃo entre os mesmos.The study of hydraulic networks for operation purposes or viability analysis for extension or renovation of the same is started the calibration in this context understood as identification parameters, such as friction coefficient, surface roughness and diameter. The Transient Inverse Method in conjunction with genetic algorithm is efficient in this task shows. This method employs the method of characteristics in the solution of the equations of motion for transient flow in networks of pipes and the optimization of solutions is based on Evolutionary Theory and evaluated by an objective function, which in this study is the sum of the difference between the module loads measured and calculated by the model for each set of solutions. Whereas the objective of the development of mathematical models for calibration hypothetical networks is their use in real networks, and that these, the collection of payload data is subject to measurement errors, is due to defects in the equipment or by conditions unfavorable environment or other random effects and taking into account the relevance of friction factors in pipelines, by their relationship to head losses that must be controlled to a great operation of networks, ensuring a continuous supply in quantity and appropriate operating conditions, this work is proposed to verify the influence of the presence of transient load measurement errors in the identification of friction factors in two hypothetical hydraulic networks. They are of different sizes with the number of rings, knots and tubes. Both are each fed by a reservoir. The transient conditions are assigned to a valve maneuver installed in one of the nodes of each network. The load data collection is restricted to 20% of the nodes in each network, one of which is the node where the valve is located. The hydraulic transient observation time is restricted to the valve maneuver time, 20s, and occurs at intervals of 0.1s, resulting in 200 charge records. The permanent condition of networks is initially unknown knowledge about the same is restricted to load in the reservoirs and demands on us as well as pipe diameter, the friction factors are initially stipulated. The determination of the permanent and transient conditions and the identification of the friction factors is performed using a hydraulic model and generate transient loads which are conventionally considered true, then these various steps of receiving systematic and random errors, which generate new burdens and these are considered collected with measurement errors. From these new loads are carried IDs friction factors, which are compared with those obtained considering an ideal case with no measurement errors loads. This comparison is performed using the mean relative error and function great goal. The results show that measurement errors in the identification of interfering friction factors although not possible to draw a relationship between them.
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Rehn, David. "Strategisk förnyelseplanering av spillvattenledningar : Med ett artificiellt neuralt nätverk som analysverktyg". Thesis, KTH, Vattendragsteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-214400.
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Sveriges kommunala spillvattenledningsnät står idag inför en enorm utmaning, då eftersattunderhåll i kombination med klimatförändringar kommer kräva stora framtida investeringaroch tidskrävande analyser. Detta examensarbete har utförts med målet att förenkla dettastundande förnyelsearbete. Som metod har en enkät utformats, och besvarats av totalt 84kommuner, med syftet att presentera en lägesbild. Vidare har ett artificiellt neuralt nätverkutvecklats, och tillämpats på data från Täby kommun, med syftet att förutspå vilkaspillvattenledningar i ett ledningsnät som har behov av förnyelse. Resultatet visar att det finns ett stort förbättringsbehov i det strategiska förnyelsearbetet.Störst behov, och potential, finns i hantering och insamling av data, där artificiella neuralanätverk kan tillämpas och utnyttjas som ett effektivt och intelligent verktyg. Det artificiellaneurala nätverket som utvecklats, och tillämpats, i detta examensarbete uppnådde en högprecision (93 %), och beräknade att Täby kommun har ca 10-20 spillvattenledningar medoupptäckt förnyelsebehov. Detta bör dock tas med viss reservation pga. bristandedatakvalitet. Avslutningsvis kan konstateras att lösningen för framtidens ledningsförnyelserelateradeproblem och utmaningar, ligger i förmågan att effektivt och intelligent samla in, struktureraoch analysera data om ledningsnäten. Artificiella neurala nätverk är ett verktyg som kanoch bör användas för detta ändamål då man, med hjälp av artificiell intelligens, kan göraprecisa analyser och skapa helhetsbilder över ledningsnät, vilket kan spara bådefinansiella, temporala och personella resurser.Aging sewer systems and deferred maintenance pose one of the greatest challenges toSwedish municipal infrastructure in the future. This degree project has been completedwith the aim to develop a method with which to sufficiently solve these future challenges,and help decision makers to properly invest in the networks, and optimise the pipe renewalprocess. As a methodology, a survey has been created, and answered by 84representatives from various municipalities and water and waste organisations, in order topresent a deeper understanding of the current situation in Sweden. Furthermore, anartificial neural network has been developed, and trained with data from Täby municipality,with the purpose of predicting which pipes in a sewer network that need to be renewed. The results show that there is a great need for improvement in the strategic renewalplanning. The greatest need, and potential, is found in the collection and processing ofdata, where artificial neural networks can be applied as a highly efficient and intelligenttool, which is proven by the high accuracy (93 %) and strong ability to predict pipes withrenewal needs (ca 10-20 pipes for Täby municipality) that the neural network developedfor this degree project showed. It is, however, important to emphasize that the quality ofthe obtained data from Täby was relatively low, and that the results therefore has to beviewed with some skepticism. It is nevertheless reasonable to assume that artificial intelligence, and more specifically,artificial neural networks, will play an important role in tackling future challenges related tostrategic asset management and renewal planning for underground sewer infrastructure.The main solution lies in the ability to efficiently and intelligently collect, structure, andprocess data, and this is a field where artificial neural networks, as made evident by thisdegree project, certainly have abilities to flourish and contribute to savings in bothfinancial, temporal and human resources.
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Mittmann, Elizabeth(Elizabeth R. ). "Smart water network management with in-pipe leak detection robots". Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122119.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (pages 85-87).
In this thesis, I created methods and designs to implement smarter, more autonomous water distribution networks (WDNs) and also improved the robots which will travel within the WDN's pipes to better differentiate pipe leaks from bumps in the pipes. Starting from the unit of the in-pipe leak detection robot, I investigated ways to make its soft leak sensors able to differentiate between pulling (due to leaks) and bending (due to bumps), and showed how a new design of adding fabric to the soft sensor allows the sensors to differentiate bending from pulling. Zooming out to the larger picture I looked at feasible ways these robots could be used throughout a cities' WDN, and created cost analyzes to compare futuristic methods of WDN management with current methods of district metered areas (DMAs). However, going from our current state of minimally instrumented pipes, to pipes with many valves to direct in-pipe inspection robots is a big leap, and thus I also created a method to help evaluate the cost trade-off of valve placement and the optimal spots for adding valves in the case where it was ideal to place valves on only some of the intersections of the WDN..
by Elizabeth Mittmann.
S.M.
S.M. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Kleiner, Yehuda. "Water distribution network rehabilitation, selection and scheduling of pipe rehabilitation alternatives". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ27979.pdf.
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Buroni, Giovanni. "Near Real-Time Detection Of Pipe Bursts in Water Distribution Systems". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
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The research work presented in the thesis describes a new methodology for the automated near real-time detection of pipe bursts in Water Distribution Systems (WDSs). The methodology analyses the pressure/flow data gathered by means of SCADA systems in order to extract useful informations that go beyond the simple and usual monitoring type activities and/or regulatory reporting , enabling the water company to proactively manage the WDSs sections.
The work has an interdisciplinary nature covering AI techniques and WDSs management processes such as data collection, manipulation and analysis for event detection. Indeed, the methodology makes use of (i) Artificial Neural Network (ANN) for the short-term forecasting of future pressure/flow signal values and (ii) Rule-based Model for bursts detection at sensor and district level.
The results of applying the new methodology to a District Metered Area in Emilia- Romagna’s region, Italy have also been reported in the thesis. The results gathered illustrate how the methodology is capable to detect the aforementioned failure events in fast and reliable manner.
The methodology guarantees the water companies to save water, energy, money and therefore enhance them to achieve higher levels of operational efficiency, a compliance with the current regulations and, last but not least, an improvement of customer service.
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Christensen, Ryan T. "Age Effects on Iron-Based Pipes in Water Distribution Systems". DigitalCommons@USU, 2009. https://digitalcommons.usu.edu/etd/505.
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Pipes in water distribution systems may change as they age. The accumulation of corrosion byproducts and suspended particles on the inside wall of aged pipes can increase pipe roughness and reduce pipe diameter. To quantify the hydraulic effects of irregular accumulation on the pipe walls, eleven aged pipes ranging in diameter from 0.020-m (0.75-in) to 0.100-m (4-in) and with varying degrees of turberculation were located and subjected to laboratory testing. The laboratory test results were used to determine a relationship between pipe diameter reduction and Hazen-Williams C. This relationship, combined with a manipulation of the Hazen-Williams equation, provided a simple and direct method for correcting the diameters of aged pipes in distribution models. Using EPANET 2, the importance of correcting pipe diameters when modeling water distribution systems containing aged pipes was investigated. Correcting the pipe diameters in the sample network reduced the modeled water age by up to 10% and changed the pattern of fluctuating water age that occurred as waters with different sources moved through the pipe network. In addition, two of the aforementioned aged pipes with diameters of 0.025-m (1-in) and 0.050-m (2-in) were modeled using Reynolds-Averaged Navier-Stokes (RANS) turbulence modeling. Flow was computed at Reynolds numbers ranging from 6700 to 31,000 using three turbulence models including a 4-equation v2-f model, and 2-equation realizable k-e; and k-ω models. In comparing the RANS results to the laboratory testing, the v2-f model was found to be most accurate, producing Darcy-Weisbach friction factors from 5% higher to 15% lower than laboratory-obtained values. The capability of RANS modeling to provide a detailed characterization of the flow in aged pipes was demonstrated. Large eddy simulation (LES) was also performed on a single 0.050-m (2-in) pipe at a Reynolds number of 6800. The Darcy-Weisbach friction factor calculated using LES was 20% less than obtained from experimental tests. Roughness elements smaller than the grid scale and deficiencies in the subgrid-scale model at modeling the complex three-dimensional flow structures due to the irregular pipe boundary were identified as likely sources of error. Even so, the utility of LES for describing complex flows was established.
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Cutter, Matthew R. "Dispersion in Steady Pipe Flow with Reynolds Number Under 10,000". University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1093008636.
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Vacs, Renwick Deborah Alexandra. "The effects of an intermittent piped water network and storage practices on household water quality in Tamale, Ghana". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82721.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 67-69).
The United Nations Millennium Development Goals include a target to halve the number of people without access to "improved" water sources, which include piped water supply. However, an "improved" source of water does not necessarily indicate a safe source. The city of Tamale in northern Ghana has a piped water network that supplies treated water, but the system is intermittent and many users only have access to piped water several days per week. In order to have sufficient supply of water, users are forced to store large quantities of water in their homes, sometimes in unsanitary storage containers. Samples taken from households around Tamale indicate that there is widespread contamination of drinking water as indicated by total coliform, E. coli, and lack of chlorine residual. Examination of data from Ghana Water Company Limited, the local utility shows that water quality is being degraded between the treatment plant outlet and use by households. This degradation could be caused by low-pressure situations in the intermittent distribution system, allowing contaminants to enter the system. The contamination could also be caused by unhygienic water storage practices in the home, such as storing water in open containers and dipping unwashed hands into the water supply. Interviews conducted in 40 households show that many households do not practice hygienic water storage and handling. In the short term, it is recommended that local NGOs or local government agencies increase efforts to educate users about proper water handling and storage practices to decrease bacteriological contamination of drinking water in the home. In the long-term, it is recommended that the intermittency of the system be decreased by improving maintenance on pipelines and removing illegal connections.
by Deborah Alexandra Vacs Renwick.
M.Eng.
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Andrade-Rodriguez, Manuel Alejandro. "Computationally Intensive Design of Water Distribution Systems". Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/301704.
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The burdensome capital cost of urban water distribution systems demands the use of efficient optimization methods capable of finding a relatively inexpensive design that guarantees a minimum functionality under all conditions of operation. The combinatorial and nonlinear nature of the optimization problem involved accepts no definitive method of solution. Adaptive search methods are well fitted for this type of problem (to which more formal methods cannot be applied), but their computational requirements demand the development and implementation of additional heuristics to find a satisfactory solution. This work seeks to employ adaptive search methods to enhance the search process used to find the optimal design of any water distribution system. A first study presented here introduces post-optimization heuristics that analyze the best design obtained by a genetic algorithm--arguably the most popular adaptive search method--and perform an ordered local search to maximize further cost savings. When used to analyze the best design found by a genetic algorithm, the proposed post-optimization heuristics method successfully achieved additional cost savings that the genetic algorithm failed to detect after an exhaustive search. The second study herein explores various ways to improve artificial neural networks employed as fast estimators of computationally intensive constraints. The study presents a new methodology for generating any large set of water supply networks to be used for the training of artificial neural networks. This dataset incorporates several distribution networks in the vicinity of the search space in which the genetic algorithm is expected to focus its search. The incorporation of these networks improved the accuracy of artificial neural networks trained with such a dataset. These neural networks consistently showed a lower margin of error than their counterparts trained with conventional training datasets populated by randomly generated distribution networks.
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Nemeth, Lyle John. "A Comparison of Risk Assessment Models for Pipe Replacement and Rehabilitation in a Water Distribution System". DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1599.
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A water distribution system is composed of thousands of pipes of varying materials, sizes, and ages. These pipes experience physical, environmental, and operational factors that cause deterioration and ultimately lead to their failure. Pipe deterioration results in increased break rates, decreased hydraulic capacity, and adverse effects on water quality. Pipe failures result in economic losses to the governing municipality due to loss of service, cost of pipe repair/replacement, damage incurred due to flooding, and disruptions to normal business operations. Inspecting the entire water distribution system for deterioration is difficult and economically unfeasible; therefore, it benefits municipalities to utilize a risk assessment model to identify the most critical components of the system and develop an effective rehabilitation or replacement schedule.
This study compared two risk assessment models, a statistically complex model and a simplified model. Based on the physical, environmental, and operational conditions of each pipe, these models estimate the probability of failure, quantify the consequences of a failure, and ultimately determine the risk of failure of a pipe. The models differ in their calculation of the probability of failure. The statistically complex model calculates the probability of failure based on pipe material, diameter, length, internal pressure, land use, and age. The simplified model only accounts for pipe material and age in its calculation of probability of failure. Consequences of a pipe failure include the cost to replace the pipe, service interruption, traffic impact, and customer criticality impact. The risk of failure of a pipe is determined as the combination of the probability of failure and the consequences of a failure. Based on the risk of failure of each pipe within the water distribution system, a ranking system is developed, which identifies the pipes with the most critical risk. Utilization of this ranking system allows municipalities to effectively allocate funds for rehabilitation.
This study analyzed the 628-pipe water distribution system in the City of Buellton, California. Four analyses were completed on the system, an original analysis and three sensitivity analyses. The sensitivity analyses displayed the worst-case scenarios for the water distribution system for each assumed variable. The results of the four analyses are provided below.
Risk Analysis
Simplified Model
Complex Model
Original Analysis
All pipes were low risk
All pipes were low risk
Sensitivity Analysis: Older Pipe Age
Identified 2 medium risk pipes
Identified 2 medium risk pipes
Sensitivity Analysis: Lower Anticipated Service Life
Identified 2 medium risk pipes
Identified 9 high risk pipes and 283 medium risk pipes
Sensitivity Analysis: Older Pipe Age and Lower Anticipated Service Life
Identified 1 high risk pipe and 330 medium risk pipes
Identified 111 critical risk pipes, 149 high risk pipes, and 137 medium risk pipes
Although the results appeared similar in the original analysis, it was clear that the statistically complex model incorporated additional deterioration factors into its analysis, which increased the probability of failure and ultimately the risk of failure of each pipe. With sufficient data, it is recommended that the complex model be utilized to more accurately account for the factors that cause pipe failures.
This study proved that a risk assessment model is effective in identifying critical components and developing a pipe maintenance schedule. Utilization of a risk assessment model will allow municipalities to effectively allocate funds and optimize their water distribution system.
Keywords: Water Distribution System/Network, Risk of Failure, Monte Carlo Simulation, Normal Random Variable, Conditional Assessment, Sensitivity Analysis.
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Xu, Chen. "Hydraulic modeling of large district cooling systems for master planning purposes". Texas A&M University, 2003. http://hdl.handle.net/1969.1/5862.
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District Cooling Systems (DCS) have been widely applied in large institutions such
as universities, government facilities, commercial districts, airports, etc. The hydraulic
system of a large DCS can be complicated. They often stem from an original design that
has had extensive additions and deletions over time. Expanding or retrofitting such a
system involves large capital investment. Consideration of future expansion is often
required. Therefore, a thorough study of the whole system at the planning phase is
crucial. An effective hydraulic model for the existing DCS will become a powerful
analysis tool for this purpose. Engineers can use the model to explore alternative system
configurations to find an optimal way of accommodating the DCS hydraulic system to
the planned future unit.
This thesis presents the first complete procedure for the use of commercial
simulation software to construct the hydraulic model for a large District Cooling System
(DCS). A model for one of the largest DCS hydraulic systems in the United States has
been developed based on this procedure and has been successfully utilized to assist its
master planning study.
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Hallström, Jonas. "Constructing a Pipe-Bound City : A History of Water Supply, Sewerage, and Excreta Removal in Norrköping and Linköping, Sweden, 1860-1910". Doctoral thesis, Linköpings universitet, Tema vatten i natur och samhälle, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4699.
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In the mid- to late 19th century, modern pipe-bound water and sewer systems proliferated in European cities, a development that has sometimes been regarded as a necessary result of a sanitary awakening and the progress of science and technology. By analyzing the introduction and subsequent expansion of water, sewerage, and excreta collection on the local level, in the Swedish cities Norrköping and Linköping, this oversimplified picture is questioned. The main problematique of this dissertation is why piped water supply and sewerage were introduced in these two Swedish cities at this particular time in history, and why the systems were subsequently extended. The actor-network theory (ANT) is used as an analytical tool. In the local context issues of governance, economy, technology, public health, and environment were brought to a head, and, if anything stands out, it is the complexity of introducing new technology. Despite the differences between Norrköping and Linköping in terms of topography and social and economic structures, the evolution of water supply and sewerage was on the whole similar. The existence of uniform scientific, technological, ideological, and cultural influences and of legislation at the national level, coupled with suburban growth, contributed to this development. There was more variation in excreta collection, because of the differences between the cities. Poor sanitary conditions, a river sensitive to pollution, and a strong public health network caused Linköping to introduce sanitary regulations much earlier than Norrköping and in Linköping WC’s were not as common.
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Astete, Werner, e Polus Yonan. "Grundkurs i EPANET 2 : Ett förslag på hur e-lärande kan användas för att främja ett djupinriktat lärande". Thesis, KTH, Byggteknik och design, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172389.
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Lärande med elektroniska medel har potentialen att revolutionera lärande. Via datorskärmen kan man enkelt åskådliggöra fysikaliska fenomen och underlätta arbetet för läraren. Om en utbildning bedrivs elektroniskt med hjälp av en dator och på distans uppstår en del svårigheter men samtidigt möjligheter, jämfört med en traditionell utbildning med fysisk närvaro i en skola. Datorer ger möjligheten att ta hänsyn till pedagogiska aspekter som kan effektivisera lärande. I dagens läge finns det inte ett utarbetat sätt att lära ut med elektroniska medel som garanterar ett gott lärande resultat. Hur en elektronisk kurs utformas är upp till läraren och institutionen som erbjuder kursen. I denna rapport ger vi ett enkelt förslag på hur vi anser en elektronisk kurs bör vara utformad samt det innehållet i kursen bör täcka.Teaching by electronic means has the potential to revolutionize teaching. The screen of the computer can easily visualize physical phenomenon and facilitate the work of the teacher. If an education is conducted electronically and by distance it creates some difficulties but at the same time opportunities, compared to traditional education with a physical presence at a school. Today there is no prepared way to teach by electronic means that guarantees good teaching results. How an electronic course is formed is decided by the teacher and the institution offering the course. In this report we give a simple suggestion of how we consider an electronic technics course should be formed and what the course content should cover.
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Artieres, Olivier. "Les depots en reseau d'assainissement unitaire : origine, caracteristiques, pollution, transport". Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13147.
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Formation de depots dans les reseaux d'assainissement unitaire dans le cas du bassin versant d'une commune rurale. Le ruissellement pluvial apporte une grosse quantite de particules minerales susceptibles de decanter dans le reseau, d'ou son efficacite mise en cause. Mais les rejets domestiques sont la source la plus importante de matieres solides, essentiellement organiques et donc qui se decomposent et sont rapidement entraines
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Caradot, Nicolas. "L'utilisation de modèles de détérioration pour l'élaboration de stratégies de gestion patrimoniale des réseaux d'assainissement". Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI034.
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Les infrastructures de collecte et de traitement des eaux usées représentent un investissement considérable pour les municipalités. La plupart des collectivités sont aujourd’hui confrontées au problème de la gestion durable de leur patrimoine vieillissant avec des besoins urgents de réhabilitation des infrastructures. Elles se doivent donc d’élaborer des stratégies de gestion patrimoniale efficace pour maintenir le niveau de service rendu et limiter l’augmentation des redevances. L’inspection télévisée (ITV) est la méthode standard utilisée depuis des décennies pour l'évaluation de la condition structurelle des réseaux d’assainissement. Dû à l’absence de réglementation et aux coûts élevés d’inspection, la plupart des collectivités n’ont qu’une connaissance partielle de la condition de leur réseau et manquent d’information pour planifier efficacement les actions de maintenance et renouvellement. Pour pallier à cette situation, des modèles numériques de détérioration ont été développés pour simuler la condition des conduites non-inspectées et prévoir l´évolution future de la condition des réseaux. Un des obstacles majeurs à l’appropriation de ces outils par les collectivités est le manque de preuves à grande échelle de leur bonne performance. D’autre part, l'influence de la quantité de données disponibles pour étalonner les modèles sur la fiabilité des prédictions est mal connue. Les taux d’inspection étant relativement faibles, les collectivités sont rarement assurées d’avoir les données nécessaires pour développer des modèles fiables. Enfin, de nombreuses collectivités reconnaissent les incertitudes liées aux données d’inspection mais aucune étude n’a pu mettre en évidence l’influence de ces incertitudes sur les résultats de modélisation. Ce travail de thèse vise à évaluer la performance des modèles de détérioration ainsi qu’à évaluer l’influence de la quantité de données disponibles sur la qualité de prédiction. Enfin, cette thèse a pour objectif de quantifier la fiabilité des données d’inspection et d’analyser l’influence de leur incertitude sur la performance des modèles de détériorationInsufficient public and municipal investment represent a major challenge for the long term management of urban drainage systems. Utilities are challenged to develop efficient rehabilitation strategies in order to maintain the level of service. Closed-circuit television (CCTV) inspection is used since the 1980’s as industry standard for sewer investigation system and structural performance evaluation. Due to budget restrictions, inspection rates are generally low and municipalities tend to inspect only a small part of their network (e.g. in France, less than 5% according to Ahmadi et al., 2014). Since the definition of rehabilitation strategies is limited by the lack of information about sewer condition and remaining life, deterioration models have been developed to forecast the evolution of the system according to its current and past condition. One of the main factors hampering the uptake of deterioration modelling by utilities is the lack of real scale evidence of the tangible benefits provided. In particular, most utilities are concerned by the minimum amount of CCTV data required and the relevance of using such models on their networks with limited data availability. Finally, most utilities acknowledge the uncertainties in the procedure of sewer condition assessment, mainly due to the subjectivity of the coding operator. There is a strong need to quantify precisely the uncertainty of the sewer condition assessment procedure and its influence on the outcomes of deterioration modelling. The thesis aims at addressing these gaps by assessing the performance of sewer deterioration modelling using a case study with high CCTV data availability and by identifying the influence of CCTV data quality and availability on modelling performance. The study has been performed with a statistical (GompitZ) and a machine learning (Random Forest) deterioration models using the extensive CCTV database of the cities of Braunschweig and Berlin in Germany. Our results show, that at network level, both machine learning and statistical models can simulate with sufficient accuracy the condition distribution of the network, even in case of low data availability. At the pipe level, the machine learning model outperforms the statistical model. Regarding CCTV data uncertainty, our results highlight that the probability to inspect correctly a pipe in poor condition is close to 80-85% and thus the probability to overestimate the (good) condition of the pipe is close to 15-20% (False Negative). The impact of the uncertainties on the prediction of a deterioration model is not negligible. The analysis shows that the required replacement rate to maintain a constant proportion of segments in poor condition is underestimated if the uncertainties are not included in the analysis
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Nishiyama, Michael. "Forecasting Water Main Failures in the City of Kingston Using Artificial Neural Networks". Thesis, 2013. http://hdl.handle.net/1974/8434.
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Water distribution utilities are responsible for supplying both clean and safe drinking water, while under constraints of operating at an efficient and acceptable performance level. The City of Kingston, Ontario is currently experiencing elevated costs to repair its aging buried water main assets. Utilities Kingston is opting for a more efficient and practical means of forecasting pipe breaks and the application of a predictive water main break models allows Utilities Kingston to forecast future pipe failures and plan accordingly.
The objective of this thesis is to develop an artificial neural network (ANN) model to forecast pipe breaks in the Kingston water distribution network. Data supplied by Utilities Kingston was used to develop the predictive ANN water main break model incorporating multiple variables including pipe age, diameter, length, and surrounding soil type. The constructed ANN model from historical break data was utilized to forecast pipe breaks for 1-year, 2-year, and 5-year planning periods. Simulated results were evaluated by statistical performance metrics, proving the overall model to be adequate for testing and forecasting. Predicted breaks were as follows, 33 breaks for 2011-2012, 22 breaks for 2012-2013 and 35 breaks for 2013-2016. Additionally, GIS plots were developed to highlight areas in need of potential rehabilitation for the distribution system. The goal of the model is to provide a practical means to assist in the management and development of Kingston’s pipe rehabilitation program, and to enable Utilities Kingston to reduce water main repair costs and to improve water quality at the customer's tap.Thesis (Master, Civil Engineering) -- Queen's University, 2013-10-21 15:30:10.288
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Afonso, Luís Manuel Fernandes. "Contributo para o Desenvolvimento da Teoria da Vulnerabilidade de Redes de Abastecimento de Água: a Sua Integração com as Teorias Clássicas". Master's thesis, 2010. http://hdl.handle.net/10348/1449.
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Dissertação de Mestrado em Engenharia CivilA teoria da vulnerabilidade de redes de abastecimento de água (TVRAA) é uma teoria emergente que tem vindo a ser desenvolvida no Departamento de Engenharias, da Universidade de Trás‐os‐Montes e Alto Douro (UTAD) com colaboração de outras universidades nacionais e estrangeiras. O conceito de vulnerabilidade é traduzido pela desproporcionalidade existente entre um esforço e o dano resultante numa rede de abastecimento de água (RAA). Esta teoria tem como principal objectivo identificar os elementos mais vulneráveis de uma RAA e, desta forma, dar um contributo quer na fase de projecto quer na fase de gestão e de exploração dos sistemas. A fase de projecto ajudará o projectista a decidir acerca do reforço ou redimensionamento das zonas da rede estruturalmente ou hidraulicamente mais vulneráveis. Na fase de gestão e exploração da RAA auxiliará na elaboração de planos de manutenção e de reabilitação, permitindo a sua monitorização e uma priorização criteriosa das intervenções mais adequadas. Este trabalho de investigação dá uma contribuição fundamental para o desenvolvimento da TVRAA. O teste de utilização de todos os critérios de aglutinação, a integração com as teorias clássicas de dimensionamento hidráulico, o mapeamento e a mitigação da vulnerabilidade de RAA são os aspectos que merecem o maior destaque. Estes desenvolvimentos são uma mais valia para a TVRAA tornando‐a mais realista e completa.
The theory of vulnerability of water pipe networks (TVWPN) is an emerging theory that has been developed at the Department of Engineering, Trás‐os‐Montes e Alto Douro University (UTAD) with collaboration other national and foreign universities. The vulnerability concept is translated by existing disparity between an effort and the resultant damage in a net of water pipe (WPN). This theory has as main objective to identify the most vulnerable elements of water pipe network (WPN) and thus make a contribution either in draft or in stage management and operation of systems. At the design stage will help the designer to concerning the strengthening of network areas structurally or hydraulically most vulnerable. At the stage of management and operation of WPN assist in drawing up plans for maintenance and rehabilitation, allowing their monitoring and a careful prioritization of interventions most appropriate. This research contributes to the development of TVWPN. The test of using all the criteria for agglutination, integration with the classic theories of hydraulic design, mapping and mitigating the vulnerability of WPN are those who deserve the spotlight. These developments are important to the TVWPN making it more realistic and complete.
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Ellis, D. J. (David John). "The behaviour of pipe network analysis solution techniques / by David J. Ellis". 2001. http://hdl.handle.net/2440/21926.
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"November 2001"Includes bibliographical references (leaves 235-240)
xiii, 285 leaves : ill. (some col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2003
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Huang, Kuo-Tai, e 黃國泰. "Set Up The Pipes And Reservoir Optimization Research In Water Distribution Network". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/53341321073797845865.
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碩士國立中央大學
土木工程學系碩士在職專班
91
Water supply construction should build a long-term plan，as the construction demand a enormous cost so that Water Supply Department should plan the water distribution pipeline together with water distribution tanks etc. in advance for fulfilling the network planned water supply rate. If only pipeline erection is being processed in the network, then the design of maximum hourly should be base on water supply rate; if water distribution tank is additionally erected for adjusting the water supply rate, we should simultaneously consider the relationship of the pipeline and water distribution tanks of different water supplying durations of everyday. Since the network planning is very complicated, generally, the flow rate and pipe diameter etc of each pipeline within the network should be first assumed in accordance with the statistical data or planned water supply rate by the expert or highly experienced personnel, then by applying the conservation principle of the flow rate and capacity etc to calculate the differed value of the assumption. Repeatedly adjusting flow rate, pipe diameter, water pressure, until up to within the allowable error. Then, process further budgeting the cost necessary for detailed designing and calculation. In this research, mathematical planning method is applied by taking the smallest construction expense as the target function. The applying hydraulic theory and water supply work specifications should separately be built as two different mathematic modes for applying to the standard pipe diameter of the selected pipeline and the arranged water distribution tank location as the optimization scheme policy. The example of this research is gravity distribution network. Water current can reach any part of the network with proper pressure and flow speed for fulfilling the demand of the water utilizing customers within the maximum water utilization period. And to probe the reasons such as pipe diameter, water pressure and flow speed that may affect the smallest construction expense for providing reference to the decision makers or designer in determining whether or not pipeline arrangement and water distribution tank are required.
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Abdel-Aal, Mohamad, Mostafa H. A. Mohamed, R. Smits, R. E. Abdel-Aal, Gussem K. De, A. Schellart e Simon J. Tait. "Predicting wastewater temperatures in sewer pipes using abductive network models". 2014. http://hdl.handle.net/10454/9104.
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NoA predictive modelling technique was employed to estimate wastewater temperatures in sewer pipes. The simplicity of abductive predictive models attracts large numbers of users due to their minimal computation time and limited number of measurable input parameters. Data measured from five sewer pipes over a period of 12 months provide 33,900 training entries and 39,000 evaluation entries to support the models' development. Two simple predictive models for urban upstream combined sewers and large downstream collector sewers were developed. They delivered good correlation between measured and predicted wastewater temperatures proven by their R(2) values of up to 0.98 and root mean square error (RMSE) of the temperature change along the sewer pipe ranging from 0.15 degrees C to 0.33 degrees C. Analysis of a number of potential input parameters indicated that upstream wastewater temperature and downstream in-sewer air temperature were the only input parameters that are needed in the developed models to deliver this level of accuracy.
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Khan, Asar, Peter D. Widdop, Andrew J. Day, Alastair S. Wood, Steve R. Mounce e James Machell. "Measured Water Temperature Characteristics in a Pipeline Distribution System". 2006. http://hdl.handle.net/10454/1036.
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YesThis paper describes the design, development, deployment and performance assessment of a prototype system for monitoring the 'health' of a water distribution network based on the temperature distribution and time-dependent variations in temperature across the network. It has been found that the water temperature can reveal unusual events in a water distribution network, indicated by dynamic variations in spatial temperature differential. Based on this indication it is shown how patterns of changes in the water temperature can be analysed using AQUIS pipeline distribution software and used in conjunction with hydraulic (e.g. flow and pressure) sensors to indicate the state of ¿health¿ of the network during operation.
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Stephens, Mark Leslie. "Transient response analysis for fault detection and pipeline wall condition assessment in field water transmission and distribution pipelines and networks". 2008. http://hdl.handle.net/2440/58241.
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Condition assessment of water distribution pipeline assets has been the focus of water authorities for many years. Transient response analysis, including Inverse Transient Analysis (ITA), provides a new potential method for performing specific nondestructive tests that gives much broader information regarding the condition of pipelines than existing technologies. The basic concept involves inducing a transient in a pipeline and measuring its pressure response. The pressure response is theoretically a function of the condition of the pipeline wall (which is the fundamental characteristic related to the propagation of a transient wavefront) and reflections and damping from any fault that may be present. If an accurate transient model of the pipeline under examination can be developed then it may then be possible to isolate particular parameters in it (relating to the wall thickness of the pipeline or faults such as blockages, air pockets and leaks) and fit these to give optimal matches between the model predicted and measured response of the pipeline. This process is often referred to as inverse analysis (and hence the derivation of the name Inverse Transient Analysis). While a significant amount of numerical and laboratory investigation has been carried out focussing on the use of ITA for leak detection, few field studies have been undertaken. The goal of this research is to determine whether transient response analysis and Inverse Transient Analysis (ITA) can be applied in field situations to provide useful information regarding the condition of pipeline walls and the presence of specific faults such as blockages, air pockets and leaks. Numerous field tests are conducted on large scale transmission pipelines, small scale distribution pipelines and a distribution network in order to obtain a view of the nature of the measured transient responses at each scale and to identify any common characteristics. The capacity of existing transient models to replicate the measured responses is then assessed and they are found to be generally incapable of replicating the field data. Given the physical complexity of field pipelines, and a number of complex phenomena that have been traditionally neglected, this result is not unexpected. The research proposes the development of transient models that can be calibrated to measured responses. These models incorporate mechanisms for including mechanical dispersion and damping and follow precedents developed in other fields of engineering in which damping of transient phenomena is significant.http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325427
Thesis (Ph.D.) -- University of Adelaide, School of Civil and Environmental Engineering, 2008
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Kopáček, Jakub. "Specifika komunikace v komunitě vodních dýmek na sociální sítích Facebook". Master's thesis, 2020. http://www.nusl.cz/ntk/nusl-435437.
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This thesis deals with the topic of how the members of online community of hookah smokers (hookah community) communicate. The core of the thesis lies in the quantitative content analysis of the content published in three hookah community Facebook groups. The results of the analysis are complemented with insight gained through semi-structured interviews conducted with seven members of the hookah community, using qualitative analysis. The first part of the thesis outlines the new media, describes basic terminology and concepts of social networks and marketing communication, provides an introduction into the topic of online communities, and describes hookahs, the hookah community, and the commercial entities involved in the hookah industry. The second part of the thesis describes the methodology of quantitative and qualitative research, presents the obtained findings, and provides their summary utilizing the knowledge presented in the theoretical part of the thesis. The thesis aims to describe and evaluate the current state of communication within the hookah community Facebook groups and map the presence of commercial communication in the analyzed content.