Thesis (M.S.)--Brigham Young University. Dept. of Chemistry and Biochemistry, 2007. / Includes bibliographical references.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed May 22, 2007). PDF text:xviii, 204 p. : ill. (some col.) ; 2.37Mb UMI publication number: AAT 3237050. Includes bibliographical references. Also available in microfilm and microfiche formats.

M.Ing. (Engineering Management) / Please refer to full text to view abstract

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE / Includes bibliographical references. / by Kean Wong. / M.S.

In this thesis an analysis is developed to predict the leakage and dynamic characteristics for circumferentially grooved turbulent annular seals used in turbopumps. The flow in the groove is modelled using turbulent shear layer theory and an entrance loss model is applied at the inlet and land regions of the seal. The governing equations are derived using Hirs’ turbulent lubrication theory. The equations are expanded to yield zeroth and first order perturbation equations for small rotor displacements about a centered position. The leakage and velocity distribution is obtained from a numerical solution of the zeroth order equations. The first order equations define the dynamic pressure distribution which is integrated to yield the fluid force reactions. The model predictions are compared to test results for smooth walled and grooved seals. The model shows good qualitative agreement with experimental test results for seal leakage and rotordynamic coefficients. Actual quantitative agreement is unresolved given the high level of experimental uncertainty in the test results. / Master of Science

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Various design guidelines have been published over the past four decades to calculate the minimum submergence required at pump intakes to prevent vortex formation. These design guidelines also require the suction bell to be located not higher than 0.5 times the suction bell diameter (D) above the floor. Sand trap canals are an integral part of large river abstraction works, with the pump intakes located at the end of the sand trap canals. The canals need to be flushed by opening a gate, typically 1.5 m high, that is located downstream of the pump intake. This requires the suction bell be raised to not interfere with the flushing operation, which leads to the question – what impact does the raising of the suction bell have on the minimum required submergence? A physical hydraulic model constructed at 1:10 scale was used to determine the submergence required to prevent types 2, 5 and 6 vortices for prototype suction bell inlet velocities ranging from 0.9 m/s to 2.4 m/s, and for suction bells located at 0.5D, 1.0D and 1.5D above the floor. The tests were undertaken for four suction bell configurations with a conventional flat bottom suction bell, fitted with a long radius bend, being the preferred suction bell configuration in terms of the lowest required submergence levels. The experimental test results of the preferred suction bell configuration were compared against the published design guidelines to determine which published formula best represents the experimental test results for raised pump intakes. It became evident from the experimental test results that the required submergence increased markedly when the suction bell was raised higher than a certain level above the floor. It was concluded that this “discontinuity” in the required submergence occurred for all the suction bell configuration types when the ratio between the prototype bell inlet velocity and the approach canal velocity was approximately 6.0 or higher. It is recommended that, for pump intakes with a similar geometry to that tested with the physical hydraulic model, critical submergence is calculated using the equation published by Knauss (1987), i.e. S = D(0.5 + 2.0Fr), if the prototype bell inlet velocity/approach canal velocity ratio is less than 6.0, and that the equation published by the Hydraulic Institute (1998), i.e. S = D(1 + 2.3Fr), can be used where the ratio, as determined with Knauss’ (1987) equation, exceeds 6.0. It is also recommended that prototype bell inlet velocities be limited to 1.5 m/s. / AFRIKAANSE OPSOMMING: Oor die afgelope vier dekades is verskeie ontwerpriglyne vir die berekening van minimum watervlakke, om werwelvorming by pompinlate te voorkom, gepubliseer. Hierdie ontwerpriglyne vereis dat die klokmond van die pompinlaat nie hoër as 0.5 keer die deursnee van die klokmond (D) bokant die kanaalvloer geleë moet wees nie. Sandvang kanale vorm ‘n integrale deel van groot riveronttrekkingswerke, met pompinlate wat aan die einde van hierdie kanale geleë is. Die kanale word aan die stroomaf kant van die pompinlaat voorsien met sluise sodat die kanale gespoel kan word. Hierdie sluise is tipies 1.5 m hoog. Dit is derhalwe nodig om die hoogte onder die klokmond dieselfde te maak as die hoogte van die sluis sodat die klokmond die spoelwerking nie beïnvloed nie. Die vraag is egter – wat is die impak op die minimum vereiste watervlakke indien die klokmond op ‘n hoër vlak installeer word? ‘n Fisiese hidrouliese model met ‘n 1:10 skaal is gebruik om die minimum watervlakke te bepaal waar tipes 2, 5 en 6 werwels aangetref word vir prototipe inlaatsnelhede van 0.9 m/s tot 2.4 m/s en klokmond hoogtes van 0.5D, 1.0D en 1.5D bokant die kanaalvloer. Vier klokmond konfigurasies is getoets. Die minimum vereiste watervlakke was die laagste vir die tradisionele plat klokmond met ‘n lang radius buigstuk en was dus die voorkeur klokmond. Die eksperimenttoetsresultate vir die voorkeur klokmond is met die gepubliseerde ontwerpriglyne vergelyk om te bepaal watter van die ontwerpsriglyne van toepassing sal wees vir verhoogde klokmond installasies. Uit die eksperimenttoetsresultate is dit duidelik dat die vereiste watervlakke skielik verhoog sodra die klokmond installasie ‘n seker hoogte bokant die kanaal vloer oorskry. Daar is bevind dat hierdie verskynsel by al vier klokmond konfigurasies voorkom sodra die verhouding tussen die prototipe klokmond inlaatsnelheid teenoor die snelheid in die kanaal hoër as 6.0 is. Daar word aanbeveel dat die minimum vereiste watervlak vir pompinlate met dieselfde geometrie as die fisiese model, met Knauss (1987) se vergelyking bereken word, naamlik S = D(0.5 + 2.0Fr), waar die snelheidsverhouding tussen die klokmond en kanaal 6.0 nie oorskry nie, en dat die vergelyking gepubliseer deur die Hydraulic Institute (1998), S = D(1 + 2.3Fr), gebruik word waar die snelheidsverhouding 6.0, so bereken met Knauss (1987) ser vergelyking, wel oorskry. Die prototipe klokmond inlaatsnelheid moet ook beperk word tot 1.5 m/s.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009. / The aim of this study is to analyse the operation of a wind-electric pumping system (WEPS) as an alternative to conventional mechanical wind pumps for application in stand-alone water-pumping schemes. The steady-state as well as the dynamic operation of such a system is analysed. Through these analyses, practical guidelines are given in the design and sizing of the different system components to ensure efficient and reliable operation. Theoretical analyses are supported by measured results conducted on a small scale wind-electric pump system. The limitations involved in the design and implementation of a large scale wind-electric pump system are presented through a case study. It is firstly concluded that small-scale wind-electric pump systems have the potential of offering superior performance and flexibility to conventional mechanical wind pumps. It is secondly concluded that large-scale wind-electric pump systems are best suited, in terms of economic and practical feasibility, to pumping applications with low pressures and medium to high wind regimes at the turbine installation site.

M. Tech. (Electrical Engineering, Faculty of Engineering) Vaal University of Technology) / Water is one of the basic necessities of life. In addition to being essential for the maintenance of life, this basic resource is a crucial requirement for combating poverty, hunger and disease in South African communities. In excess of twenty-nine percent of South African households do not have water in either their dwellings, or on site (source: 2005 RSA census data). This study documents an engineering solution to the problem of water pumping, utilising renewable energy (solar power) and readily available pumping hardware, configured via a structured design process. Resultant from the research, a software application has been developed that facilitates the design of solar (photovoltaic) powered water pumping applications. The selected design configuration of a nontracking, stand-alone, directly coupled system provides for the most robust and least complex design possible, making it imminently suitable for application in rural African conditions. Operation of the program is via a simple graphical user interface, with full and context sensitive help provided. It is tailored for use in Southern Africa and is provided with comprehensive databases of location dependant design information such as solar radiation, meteorology and magnetic declination data, together with expandable databases of pre-configured pump and solar panel hardware specification data. The program is manufacturer and component independent, with no affiliations in the choice of hardware. Design methodologies, together with a component matching strategy. Optimisation is achieved by a quantitative and efficiency 'best fit' analysis of the selected hardware components within the design context. Design output predictions are tabulated and graphed by month for a period of one year, allowing design visualisation. The application has been named 'South African Stand-alone Solar (PV) Water Pumping Design Aid', abbreviated as 'SAS-SWP' in its run-time form. The SASSWP application is illustrated in the functional overview provided in Figure 1. / VUT

"This thesis presents a series of physical experiments and numerical simulations intended to determine whether the use of commercially available computational fluid dynamics (CFD) software may provide a viable alternative to the use of physical models for predicting the occurrence of vortices and swirl in pump intakes. The physical experiments were set up at Alden Research Laboratories, Inc. (ARL) of Holden, Massachusetts, using a simple pump intake model donated by ARL for use in this study. Swirl and velocity measurements and dye injections were used to characterize the flow in the physical model. Three flow conditions were chosen for the physical experiments because they demonstrated swirl and vortices developing at the pump intake. Once the physical experiments were performed, FIDAP, a general-purpose finite-element CFD package, was used to simulate the circulation patterns in the vicinity of a pump intake. The model configuration and scale were selected to simulate experimental conditions in the physical pump intake model. Some similarities were also identified in the locations of the models predicted vortex characteristics and the vortex characteristics that were observed in the experimental facility. However, the characteristics of swirl within the pump intake differed from experimental observations. Therefore, additional simulations were conducted to analyze the sensitivity of simulations to model assumptions. These additional simulations showed that the assumptions related to these model parameters have minor affects on the general nature of the predicted vortices, but do affect the predicted vortex strength. This thesis represents a first step in addressing the discrepancies between numerical and experimental results. Additional investigations are recommended to clarify the applicability of CFD to address pump intake problems."

Most patients diagnosed with End Stage Renal Disease (ESRD) undergo hemodialysis. Traditional hemodialysis treatment requires patients spending three to five hours every other day while yielding the high waste level accumulated between treatments. These limitations in the current technology have spurred the development of a portable renal replacement system. The portable system will not only free the patients from visiting the clinic but also allow more frequent treatment that will lead to lower average waste level. To realize a portable system, the size and weight of hemodialysis system components should be reduced. This work analyzes the working principle of the pump and proposes a DC-motor and cam driven finger pump design. In addition, an analytical pump model is created for the optimization of the pump design. In vitro experiment conducted using the pump measured Creatinine levels over time, and the results validitate the design for the portable renal replacement system. The proposed pump design is smaller than 188 cm³ and consumes less than 4W while providing a flow rate of more than 100ml/min (the optimum flow rate for a portable system) for both blood and dialysate flows. The smallest pump of a portable renal replacement system in the literature uses check valves, which considerably increase the overall manufacturing cost and possibility of clogging. Compared to that pump, the proposed pump design achieved reduction in size by 40% and savings in energy consumption by 65% with the removal of valves. This simple and reliable design substantially enables development of a portable renal replacement system.