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Harris, P. K. "Erosion in centrifugal compressor impellers". Thesis, Cranfield University, 1996. http://dspace.lib.cranfield.ac.uk/handle/1826/10622.
Pełny tekst źródłaVisser, Franciscus Cornelis. "On the flow in centrifugal impellers". Enschede : University of Twente [Host], 1996. http://doc.utwente.nl/32024.
Pełny tekst źródłaRose, Martin George. "Flow in centrifugal water pump impellers". Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253798.
Pełny tekst źródłaПочатко, Тетяна Володимирівна, Татьяна Владимировна Початко, Tetiana Volodymyrivna Pochatko i M. Voshchenko. "Technological regulations of the multistage pump impellers". Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/47236.
Pełny tekst źródłaAdkins, Douglas Ray Brennen Christopher E. Brennen Christopher E. "Analyses of hydrodynamic forces on centrifugal pump impellers /". Diss., Pasadena, Calif. : California Institute of Technology, 1986. http://resolver.caltech.edu/CaltechETD:etd-03262007-111453.
Pełny tekst źródłaMorris, Mary Beth. "Flow randomness and tip losses in transonic rotors". Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-07212009-040241/.
Pełny tekst źródłaLinn, Linsey Margaret. "Heat transfer in mixing vessels using induction heated impellers". Thesis, University of Bradford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253836.
Pełny tekst źródłaFerry, William Benjamin Stewart. "Virtual five-axis flank milling of jet engine impellers". Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/993.
Pełny tekst źródłaSeyed, Mahmoudi Seyed Mohammad. "Velocity and mixing characteristics of stirred vessels with two impellers". Thesis, King's College London (University of London), 1993. https://kclpure.kcl.ac.uk/portal/en/theses/velocity-and-mixing-characteristics-of-stirred-vessels-with-two-impellers(b0de9b2e-70e2-4133-9d3e-3955562edfb0).html.
Pełny tekst źródłaWahba, Waleed A. "Design optimisation of centrifugal pump impellers using parallel genetic algorithm". Thesis, Cranfield University, 2001. http://dspace.lib.cranfield.ac.uk/handle/1826/10708.
Pełny tekst źródłaWhitton, M. J. "Gas liquid mixing in tall vessels fitted with multiple impellers". Thesis, Cranfield University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312190.
Pełny tekst źródłaWahba, Waleed. "Design optimisation of centrifugal pump impellers using parallel genetic algorithm". Thesis, Cranfield University, 2001. http://dspace.lib.cranfield.ac.uk/handle/1826/10708.
Pełny tekst źródłaKanel, Jeffrey Scott. "Minimum impeller speeds and power requirements for complete dispersion of non-Newtonian liquid-liquid systems in baffled vessels". Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/11256.
Pełny tekst źródłaMc, Laughlin Declan T. "Gas entrainment into viscous polymer solutions". Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252316.
Pełny tekst źródłaHaam, Seungjoo. "Local heat transfer in a mixing vessel using heat flux sensors". The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1102528786.
Pełny tekst źródłaCurran, Stephen J. "Laminar mixing of a yield stress fluid using helical ribbon impellers". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0003/MQ34349.pdf.
Pełny tekst źródłaWong, Vui-Hong, i n/a. "Finite Element Analysis and Improvement of Impeller Blade Geometry". Griffith University. School of Engineering, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030825.150853.
Pełny tekst źródłaWong, Vui-Hong. "Finite Element Analysis and Improvement of Impeller Blade Geomtery". Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367302.
Pełny tekst źródłaThesis (Masters)
Master of Philosophy (MPhil)
School of Engineering
Full Text
Peron, Yannick L. "Mixing of immobilised cells in bioreactors". Thesis, University of Huddersfield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286090.
Pełny tekst źródłaFentiman, Nina Jane. "An experimental study of the mixing and hydrodynamic characteristics of hydrofoil impellers". Thesis, King's College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312993.
Pełny tekst źródłaBasbug, Salur. "Flow field and mixing in stirred vessels with regular and fractal impellers". Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/58102.
Pełny tekst źródłaJohn, Arwyn. "A novel reactor with two independently-driven impellers for gas-liquid processing". Thesis, University of Birmingham, 1998. http://etheses.bham.ac.uk//id/eprint/1425/.
Pełny tekst źródłaJery, Belgacem Brennen Christopher E. Brennen Christopher E. Acosta Allan J. Caughey Thomas Kirk. "Experimental study of unsteady hydrodynamic force matrices on whirling centrifugal pump impellers /". Diss., Pasadena, Calif. : California Institute of Technology, 1987. http://resolver.caltech.edu/CaltechETD:etd-03262007-130547.
Pełny tekst źródłaLupi, Alessandro. "CFD analysis and redesign of centrifugal impeller flows for rocket pumps". Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06302009-040325/.
Pełny tekst źródłaSilva, Lima Jose Aldo. "A numerical model for three dimensional viscous flows aimed at centrifugal pump impellers". Thesis, Cranfield University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332933.
Pełny tekst źródłaCui, Dingjun. "An investigation of the performance of small high-speed electric motor/fan units". Thesis, University of Strathclyde, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366918.
Pełny tekst źródłaGamez, Victor Manuel. "Mechanics of batch slurry mixing by means of rotating impellers in a cylindrical vessel". FIU Digital Commons, 1998. http://digitalcommons.fiu.edu/etd/3446.
Pełny tekst źródłaMcKinlay, Ryan Neal. "An Investigation into the Performance of Axial Flow Refrigerator Fans". Thesis, University of Canterbury. Mechanical Engineering, 2014. http://hdl.handle.net/10092/9587.
Pełny tekst źródłaSossa, Jaime Alberto. "Experimental and computational study of mixing behavior in stirred tanks equipped with side entry impellers". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42158.
Pełny tekst źródłaNishta, B. V. "Computer analysis of the stress-deformation state of the centrifugal compressor and gas turbine impellers". Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/40623.
Pełny tekst źródłaHari-Prajitno, Danawati. "An experimental study of single, dual and triple wide-blade hydrofoil impellers : power and homogenisation characteristics". Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625480.
Pełny tekst źródłaCartwright, Craig David. "Bioprocess intensification : a study of rotating packed bed porous mesh impellers for enhancement of aerobic fermentation processes". Thesis, University of Newcastle Upon Tyne, 2011. http://hdl.handle.net/10443/1312.
Pełny tekst źródłaAl-Azzawi, Mohammad Mousa. "An advanced finite element system for static and dynamic analysis, with application to the design of radial impellers". Thesis, Cranfield University, 1987. http://dspace.lib.cranfield.ac.uk/handle/1826/5713.
Pełny tekst źródłaІгнатьєв, Олександр Савич, Александр Савич Игнатьев, Oleksandr Savych Ihnatiev, Максим Васильович Найда, Максим Васильевич Найда i Maksym Vasylovych Naida. "Теории подобия и регулирование параметров лопастных насосов". Thesis, Сумский государственный университет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45584.
Pełny tekst źródłaFuhnwi, Godwin Fonguh. "Computational modelling of a smart impeller actuated by shape memory alloys". Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/1288.
Pełny tekst źródłaSmart (SMA-Shape Memory Alloy) Technology continues to advance rapidly as engineers move closer to and understand better the industrial and commercial needs for SMA. As a matter of fact, all types of products, which exercise some type of control over their function, are rapidly making their way into the marketplace [36] Nonetheless, nowhere has been evidence in the development of a SMA impeller. Unlike traditional impellers with no control over their function and sometimes fixed angle of attack, this paper demonstrates numerical investigations using analytical algorithms (Matrix laboratory programming and excel spread sheet) and advanced computer simulation package, Engineering Fluid dynamics (EFD) into the feasibility of using a smart impeller to study the performance of a pumping system and the best angle of attack for a Shape Memory Impeller. Primarily, Bench mark data and dimensions are obtained from a standard centrifugal pump run on a FM21 demonstration unit. Using the same standard centrifugal pump, and keeping all other dimensions the same but altering the angle of attack, EFD simulations where made. From analytical algorithm and EFD comparison, it was evident that the best angle of attack is 12 degree at the outlet angle with respect to the inlet angle. From EFD results, it is palpable that, by increasing the angle of attack from 35 degree to 45 degree at the outlet there will be huge increase in flow rate by 63.47% There is also a slight decrease in the impeller Torque from 35 degrees to 42 degrees by 0.72%. It is economically feasible to work at an outlet angle of 42 degrees due to increase in efficiency of 62.1% and a drop in torque of 0.72% by varying the outlet angle from 35 degrees to 42 degree. Understanding how critical actuator design is, it should be suggested that any shape memory impeller should never be used in critical components without a prior history of thermal and mechanical loading. Therefore, a NiTi impeller constitutive model can be designed, with impeller blades made from NiTi plates, trained to remember its best angle of attack (Martensitic phase). NiTi shape memory metal alloy (plates-blades) can exist in a two different temperature-dependent crystal structures (phases) called martensite [9](lower temperature-normal pumping condition) and austenite [9] (higher temperature or parent phase-trained best angle of attack.)
Кондусь, Владислав Юрійович, Владислав Юрьевич Кондусь, Vladyslav Yuriiovych Kondus i Ю. О. Матвієнко. "Удосконалення конструкції робочого колеса з метою підвищення енергоефективності вільновихрового насоса". Thesis, Сумський державний університет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45605.
Pełny tekst źródłaMa, Zheng. "Impeller Power Draw Across the Full Reynolds Number Spectrum". University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1406766474.
Pełny tekst źródłaSchemmann, Christoph [Verfasser], Carsten [Akademischer Betreuer] Könke, Carsten [Gutachter] Könke, Tim [Gutachter] Ricken i Marius [Gutachter] Geller. "Optimization of Centrifugal Compressor Impellers by a Multi-fidelity Sampling Method Taking Analytical and Empirical Information into Account / Christoph Schemmann ; Gutachter: Carsten Könke, Tim Ricken, Marius Geller ; Betreuer: Carsten Könke". Weimar : Bauhaus-Universität Weimar, 2019. http://d-nb.info/1195444990/34.
Pełny tekst źródłaSchemmann, Christoph [Verfasser], Carsten [Akademischer Betreuer] Könke, Carsten Gutachter] Könke, Tim [Gutachter] [Ricken i Marius [Gutachter] Geller. "Optimization of Centrifugal Compressor Impellers by a Multi-fidelity Sampling Method Taking Analytical and Empirical Information into Account / Christoph Schemmann ; Gutachter: Carsten Könke, Tim Ricken, Marius Geller ; Betreuer: Carsten Könke". Weimar : Bauhaus-Universität Weimar, 2019. http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190910-39748.
Pełny tekst źródłaBuffo, Mariane Molina. "Transferência de oxigênio e cisalhamento em biorreator convencional com diferentes combinações de impelidores". Universidade Federal de São Carlos, 2016. https://repositorio.ufscar.br/handle/ufscar/7933.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
The type and operational conditions of a bioreactor chosen during the production phase of a product of interest affect not only the morphology and growth of filamentous microorganisms but also the product itself. Still the most common process to produce bioproducts is submerged cultures in conventional stirred and aerated bioreactors, with impeller of type six flat-blade turbine, or Rushton turbine (RT), which promotes good mixing and suitable oxygen transfer, but its power consumption is high and it causes high shear rate to the broth creating a hostile environment to the microorganisms. Alternatively, an impeller of the type “Elephant Ear” (EE) is shown in the literature as a “low shear” impeller, more suitable for the cultivation of shear sensitive microorganisms. This impeller creates a mixed flow (axial and radial) of broth with down flow (EEDP) or up (EEUP) depending on its geometry. This study aimed to evaluate the best association of impellers for filamentous fungi cultures in a conventional bioreactor. Initially the volumetric coefficient of oxygen transfer (kLa) and the power consumption of seven different association of impellers were evaluated. The results obtained the factorial design methodology showed that the associations EEDP-EEUP, RT-EEDP, and EEDP-RT, showed the best results regarding the oxygen transfer and the power consumption, being up to 87% more efficient than the standard RT-RT association. Two of the better performing association and the traditional (RT-RT) were selected to be evaluated regarding the shearing, by using empirical equations and the size of the eddies, evaluated by the Kolmogorov microscale. The association that showed higher values on the Kolmogorov scale and least shearing was EEDPEEUP, with shearing up to 60% lower than the RT-RT association. In the last step the effects of shear on the morphology of the fungi Aspergillus niger was evaluated. Short-term cultures (4h) were cultivated so that the cellular growth would not harm the analysis. The results showed that on the culture that used the EEDP-EEUP association the morphological form of cell clumps predominated, while on the culture that used the RT-RT association the morphological form of branched hyphae predominated, suggesting that the RT-RT association causes more shearing and can cause irreversible damage to the fungal cells.
O crescimento celular e a morfologia de microrganismos filamentosos, bem como o produto de interesse são afetados pelo modelo de biorreator e pelas condições de operação adotadas durante a etapa de produção. O processo mais adotado industrialmente para produção de bioprodutos ainda são os cultivos submersos em biorreatores convencionais tipo tanque agitado e aerado, sendo o impelidor tipo turbina de seis pás planas ou turbina de Rushton (RT) o mais utilizado por promover boa mistura e adequada transferência de oxigênio, porém seu consumo de potência é alto além de impor alto cisalhamento ao caldo gerando um ambiente hostil ao microrganismo. Alternativamente, o impelidor tipo “orelha de Elefante” ou “Elephant ear” (EE) é apresentado na literatura como um impelidor de “baixo cisalhamento” mais adequado para o cultivo dos microrganismos sensíveis ao cisalhamento. Esse impelidor promove um escoamento misto (axial e radial) do caldo com escoamento para baixo (EEDP) ou para cima (EEUP) dependendo da sua geometria. O presente trabalho teve como objetivo avaliar as melhores associações de impelidores para cultivos de fungos filamentosos em biorreator convencional. Primeiramente sete diferentes associações foram avaliadas em relação ao coeficiente volumétrico de transferência de oxigênio (kLa) e consumo de energia. Os resultados obtidos utilizando a metodologia de planejamento experimental fatorial mostraram que as configurações EEDP-EEUP, RT-EEDP e EEDP-RT foram as que apresentaram melhores resultados em relação à transferência de oxigênio e consumo de potência, com eficiência até 87% superior à associação padrão RT-RT. Foram então selecionadas duas das associações de melhor desempenho e a tradicional (RT-RT) para serem avaliadas em relação ao cisalhamento, através de equações empíricas e em relação ao tamanho dos turbilhões, avaliado pela microescala de Kolmogorov. A associação que apresentou maiores valores para microescala de Kolmogorov e menor cisalhamento foi a EEDP-EEUP, com cisalhamento até 60% inferior que a observada quando utilizada a associação RT-RT. Na última etapa verificou-se os efeitos do cisalhamento na morfologia do fungo Aspergillus niger. Foram realizados cultivos de curta duração (4 h) para evitar que o crescimento celular prejudicasse a análise. Os resultados mostraram que no cultivo utilizando o sistema EEDP-EEUP predominou a forma morfológica de aglomerados celulares (clumps), enquanto que no cultivo com impelidores Rushton (RT-RT) predominou a forma morfológica de hifas ramificadas, sugerindo um cisalhamento mais intenso provocado por este sistema de agitação, que pode acarretar danos irreversíveis às células fúngicas.
Tarr, David Landon. "Scaling of impeller response to impeller-diffuser interactions in centrifugal compressors". Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44924.
Pełny tekst źródłaThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 119-121).
A numerical investigation has been conducted to quantify the effect of impeller-diffuser interaction on changes in impeller performance. An assessment is made of the hypothesis that the nondimensional parameter characterizing impeller performance change due to interaction is the ratio of the radial gap between the impeller trailing edge and the diffuser leading edge to the diffuser vane pitch. The time averaged results are found to show no measurable performance change with varying degrees of impeller-diffuser interaction, disproving the hypothesis. Analysis of the flow field shows that changes in loss and blockage due to interaction in the region of the blade leakage flow, which were expected to drive performance change, are negligible. The disproven hypothesis lacks parameters to relate the level of impeller passage unsteadiness to the level of performance change due to interaction, which are shown to be important. The ratio of the unsteady amplitude, of blade leakage velocity or blade loading, to the time average value appears to be a parameter capable of quantifying the impact of unsteadiness on impeller performance change.
by David Landon Tarr.
S.M.
Silva, Jefferson Luiz Grangeiro da. "Analise critica das correlações e parametros fundamentais em sistemas de agitação". [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267607.
Pełny tekst źródłaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: O projeto atual de agitadores químicos é essencialmente dependente de relações empíricas, visto que as leis fisicas que regem os fenômenos envolvidos nos processos químicos são expressões cuja solução analítica é ainda desconhecida. Devido a isto, trabalhos experimentais como os compilados por Nagata, (1975), Oldshue, (1983), Sano e Usui, (1985) e Tatterson, (1991) são utilizados como principais referências para o cálculo do consumo de energia destes sistemas de agitação. Este projeto de pesquisa tem por objetivo principal compilar na literatura as principais correlações e trabalhos que são utilizados como base para o cálculo convencional de agitadores utilizados na indústria química, de forma que sejam definidas as melhores correlações através da análise dos parâmetros fundamentais (relações geométricas) no cálculo do Número de Potência, Número de Reynolds, Número de Froude, Número de Fluxo, Número de Mistura e o consumo de Potência de impelidores para os sistemas de agitação. A análise dos parâmetros geométricos será particularmente importante para estágios iniciais de projetos de plantas químicas, quando são necessárias informações da geometria, tanto do tanque como do impelidor (agitador) e, principalmente, do consumo de energia específica destes equipamentos para se estimar o consumo de energia da planta. Os resultados analisados através da utilização das correlações empíricas serão comparados com o Software comercial VISIMIX. Adicionalmente o L-CFD, laboratório de Fluído Dinâmica Computacional, já desenvolveu diversos projetos que analisam a otimização de projeto de reatores de mistura utilizando a Fluido Dinâmica Computacional e este projeto contribui por complementar o conhecimento deste grupo de pesquisa sobre o projeto de agitadores através de cálculos convencionais
Abstract: The design of impellers to date depends on empirical relations, since the physical laws that describe the phenomena involved in the chemical processes are expressions whose analytical solution is still unknown. Experimental works as those compiled by Nagata, (1975), Oldshue, (1983), Sano and Usui, (1985) and Tatterson, (1991) are used as references for energy consumption estimation in these systems. The compilation of the main correlations and the works in the literature that are used as a base to the conventional way to ca1culate the main impellers used in the chemical industry is the main objective of this research; which will allow one to select the better correlations it is carried on by the analysis of fundamental paramenters (geometric relations) for the ca1culation of Power Number, Reynolds Number, Froude Number, Flow Number, Mixing Number and the Power consumption of impellers in these systems. The analysis of the geometrical parameters will be particularly important to the early stages in the design of chemical plants, when informations ofthe tank and ofthe impeller (agitator) geometries and, mainly,about the specific energy consumption of these equipments are needed. The results are analysed using empirical correlations in the literature and are compared with the commercial software VISIMIX. Additionaly the L-CFD, Computational Fluid Dynamics laboratory, has already developed several projetcs to analyse the optimization project of mixing tanks, through the use of Computational Fluid Dynamics. This project contributes to complement the knowledge of this group of research on the design of mixing impellers, through the use of conventional methods
Doutorado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química
Nataša, Lukić. "Samo-rotirajući impeleri u airlift reaktoru sa spoljašnjom recirkulacijom". Phd thesis, Univerzitet u Novom Sadu, Tehnološki fakultet Novi Sad, 2017. http://www.cris.uns.ac.rs/record.jsf?recordId=102693&source=NDLTD&language=en.
Pełny tekst źródłaThe aim of this study was intensification ofhydrodynamic and mass transfer properties ofexternal-loop airlift reactor by means of self-agitatedimpellers mounted in the riser section. The influenceof impellers’ insertion on the main hydrodynamicand mass transfer characteristics was investigated forvarious liquid phases and sparger types. The valuesof riser gas holdup, downcomer liquid velocity andvolumetric mass transfer coefficient obtained inconfigurations with and without impellers werecompared.Results showed that the installment of self-agitatedimpellers led to a significant bubble breakage anddecrease of bubble size, especially in viscouscarboxymethylcellulose solutions. The efficiency ofself-agitated impellers was immensely influenced bysuperficial gas velocity, liquid phase, and distributortype. Obtained riser gas holdup values were up to47% higher in the configuration with impellers, incomparison to the configuration wthout impellers.Despite the fact that self-agitated impellersrepresented an obstacle to liquid flow, relatively lowreduction of downcomer liquid velocity was attained(about 10%). Furthermore, the insertion of impellersinduced up to 82% higher values of volumetric masstransfer coefficient at lower superficial gas velocities.At higher superficial gas velocities, i.e. conditionsmainly operated in various fermentation processes,about 20-30% higher values of volumetric masstransfer coefficient were achieved with impellers.In addition to empirical correlations, artificial neuralnetwork models were sucessfully developed topredict riser gas holdup, downcomer liquid velocityand volumetric mass transfer coefficient in bothexternal-loop airlift configurations.
Amundsen, Siren Carstens. "Wet Gas Compression : Impeller Rig". Thesis, Norwegian University of Science and Technology, Department of Energy and Process Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9976.
Pełny tekst źródłaWet gas compression technology is of great value to the oil and gas industry for boosting of unprocessed well stream and to reduce investment costs related to equipment and personnel. The growing interest in wet gas compression leads to a general request for accurate performance calculation procedures and proper measurement techniques for multiphase flow metering in compressors. An impeller rig for examination of single-phase and multiphase performance and aerodynamic stability is under construction at the test facility at NTNU. The construction of the compressor rig is behind time due to late deliveries of the compressor components and instrumentation. The performance calculations are therefore based upon one compressor test conducted with dry gas at part-load. The thermodynamic equation of state for ambient air is verified to be consistent with the ideal gas law in the compressor pressure and temperature range. The calculated polytropic performance is calculated with ideal gas assumptions and compared to values estimated by PRO/II. By analyzing the results the sensitivity of the calculation procedures is identified and the suitability for the ideal polytropic performance calculations is validated for the actual compressor test and operating range. A sensitivity analysis is conducted in order to determine the effect of measurement uncertainties on performance calculations. Due to the low pressures involved for the compressor test, the performance calculation procedures are highly sensitive to uncertainties in the pressure measurements. Uncertainties in the temperature measurements will only slightly influence the polytropic head, but have great influence on the polytropic efficiency. The efficiency and operating range of a compressor are constrained by aerodynamic instabilities. This thesis describes the different flow phenomena associated with compressor instability and presents recommendations for suitable instrumentation and measuring techniques. Various visualization techniques are in addition evaluated to determine the suitability for multiphase compressors. Dynamic pressure transducers installed in the inlet and discharge piping are recommended for detection of pressure pulsation throughout the compressor system. Unsteady internal pressure measurements can be obtained from circumferentially distributed pressure transducers at various locations within the compressor components. Vibration probes installed at each end of the rotor are recommended for the vibration measurements. By analyzing the frequency spectrum for the pressure fluctuation and radial vibrations one can identify the type of instability phenomenon that occur. Laser measurement techniques are recommended for the flow visualization in order to obtain information on the main features of the multiphase flow field.
Ahmed, N. A. "Flow studies in impeller passages". Thesis, Cranfield University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234510.
Pełny tekst źródłaKee, Kim Chung. "Particle impacts on impeller blades". Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624407.
Pełny tekst źródłaForrester, Stephanie E. "Hydrodynamics of a gas-inducing impeller". Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362961.
Pełny tekst źródłaShum, Yu Kwong 1968. "Impeller-diffuser interaction in centrifugal compressors". Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/8594.
Pełny tekst źródła"February, 2000."
Includes bibliographical references (p. 109-114).
A study has been conducted, using an unsteady three-dimensional Reynolds-averaged Navier-Stokes simulation, to define the effect of impeller-diffuser interaction on the performance of a centrifugal compressor stage. The principal finding from the study was that the most influential aspect of this unsteady interaction was the effect on impeller tip leakage flow . In particular, the unsteadiness due to the upstream potential effect of the diffuser vanes led to larger viscous losses associated with the impeller tip leakage flow. The consequent changes at the impeller exit with increasing interaction were identified as reduced slip, reduced blockage, and increased loss. The first two were beneficial to pressure rise while the third one was detrimental. The magnitudes of the effects were examined using different impeller-diffuser spacings and it was shown that there was an optimal radial gap size for maximum impeller pressure rise. The physical mechanism was also determined: when the diffuser was placed closer to the impeller than the optimum, increased loss overcame the benefits of reduced slip and blockage. The findings provide a rigorous explanation for experimental observations made on centrifugal compressors. The success of a simple flow model in capturing the pressure rise trend indicated that although the changes in loss, blockage and slip were due largely to unsteadiness, the consequent impacts on performance were mainly onedimensional. The influence of flow unsteadiness on diffuser performance was found to be less important than the upstream effect, by a factor of seven in terms of stage pressure rise in the present geometry. It is thus concluded that the beneficial effects of impeller-diffuser interaction on overall stage performance come mainly from the reduced blockage and reduced slip associated with the unsteady tip leakage flow in the impeller.
by Yu Kwong Patrick Shum.
Ph.D.
Shehata, Hussein A. H. "HVAC systems using flexible fibre impeller fans". Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297764.
Pełny tekst źródłaArellano-Huacuja, A. "Impeller agitated aerobic bioreactor : influence of impeller design on power consumption and gas hold-up structure in highly viscous liquids". Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242329.
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