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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Water surface profiles in side channel spillways : comparisons between computed and experimental values

Cullen, James January 1989 (has links)
This thesis is an investigation into the water surface profiles found in side channel spillways. The classical method proposed by Hinds is investigated, with specific reference to the water surface slope equation. A literature review is given on the evolution of the theory, from the conceptual ideas of Hinds through to a systematic method of analysis. Experimental methods used over the years are also discussed. A computer program called WSPISCS (Water Surface Profiles In Side Channel Spillways), is developed to calculate the water surface profile. This in turn alleviates the laborious and tedious hand calculations necessary in the past. An iterative, step by step calculation of the water surface profile from .a known control point is conducted. A Runge Kutta fourth order algorithm is employed for the numerical integration. The program is verified with previous hand calculated examples, including the classical example calculated by Hinds. A thorough sensitivity analysis is conducted with regard to the magnitude of the step length, and also to the location of the starting point. Comparisons are made with experimental results obtained over a number of years of undergraduate research. The correlation between the calculated and experimental profiles is generally good. The only exception is a horizontal receiving channel with a hydraulically steep outflow chute, where the experimental profile falls below the calculated one as the inflow rate increases.
2

Hydraulic characteristics of siphon spillways /

Rice, Elbert Floyd. January 1955 (has links)
Thesis (Ph. D.)--Oregon State College, 1955. / Typescript. Includes bibliographical references (leaves 115-119). Also available on the World Wide Web.
3

Protrusions on stepped spillways to improve energy dissipation /

Wright, Henry-John January 2006 (has links)
Thesis (MScIng)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.
4

A study of flow conditions in shaft spillways

Mussalli, Yusuf George 12 1900 (has links)
No description available.
5

Flow characteristics of water at the entrance to a circular drop-inlet

Folsche, William Richard. January 1961 (has links)
Call number: LD2668 .T4 1961 F64
6

Numerical simulation of flow through a spillway and diversion structure

Gacek, Julian D. January 1900 (has links)
Thesis (M.Eng.). / Written for the Dept. of Civil Engineering and Applied Mechanics. Title from title page of PDF (viewed 2008/01/14). Includes bibliographical references.
7

Análise de esforços sobre vertedouros em degraus de declividade 1V:0,75H

Osmar, Fabrício Machado January 2016 (has links)
Barragens são utilizadas há séculos para diversas finalidades. Em diversas barragens os vertedouros são constituídos de degraus com o objetivo de aumentar a dissipação de energia. A presente pesquisa objetiva a caracterização dos esforços atuantes em vertedouros em degraus, através da análise da variação das pressões atuantes ao longo da calha e suas distribuições na faces do degraus. Com esse objetivo, são realizadas análises sobre modelos de vertedouros com declividade de 1V:0,75H e degraus de 3, 6 e 9 centímetros. São analisados os campos de pressões nos degraus e comparados com os resultados disponíveis na bibliografia. Também são propostos modelos para previsão de pressões nos patamares e espelhos dos degraus bem como dos esforços resultantes. Além disso, são realizadas transposições dos resultados para a escala de protótipo, inclusive com a análise da possibilidade de cavitação na estrutura. Como constatação geral sobre as pressões nos espelhos verifica-se que os esforços de tração e compressão têm magnitudes relativamente semelhantes, sendo mais intensas as pressões negativas. Sobre as pressões máximas nos patamares, destaca-se que os valores máximos de compressão ocorreram no final da calha, percebendo-se que as menores vazões geraram maiores valores de coeficientes de pressões. As variações da compressão nas faces dos patamares apresentam crescimento, no sentido da extremidade com o espelho acima deste para o vértice com o espelho abaixo do mesmo patamar. Nas faces dos espelhos, percebe-se que os mais extremos de tração são observados na parte superior, próximo à quina com os patamares. / Dams have been used throughout the centuries for a plethora of purposes. Several designs employ steps on the spillways in order to increase the power dissipation. The present research aims to characterize the forces acting on stepped spillways by analyzing both the variation of pressures acting along the pipeline and their distributions on the faces of the steps. In order to achieve this purpose, observations and discussions regarding spillways models with slope characterized as 1V: 0.75H and steps ranging from 3 to 9 centimeters are conducted. The pressure fields measured in the steps were analyzed and compared with results available in the literature. Sub sequentially, models to predict pressures on the faces of the steps and the resulting efforts were proposed. Finally, transpositions were performed on a prototype scale. Generally, it was found that the magnitude of tensile and compressive forces on the vertical faces are relatively similar, being the negative pressure slightly higher on all cases. During the experiments, it was observed that compression forces increased thought the length of the step’s horizontal face, peaking at the edge. It was also noticed that lower flows generated higher pressure coefficients. The measured compression on the horizontal faces of the step and its variation increase towards the edge of the step. It is perceived that the maximum tensile is observed on the top of the step’s vertical faces, near the corner with the horizontal faces.
8

Análise de esforços sobre vertedouros em degraus de declividade 1V:0,75H

Osmar, Fabrício Machado January 2016 (has links)
Barragens são utilizadas há séculos para diversas finalidades. Em diversas barragens os vertedouros são constituídos de degraus com o objetivo de aumentar a dissipação de energia. A presente pesquisa objetiva a caracterização dos esforços atuantes em vertedouros em degraus, através da análise da variação das pressões atuantes ao longo da calha e suas distribuições na faces do degraus. Com esse objetivo, são realizadas análises sobre modelos de vertedouros com declividade de 1V:0,75H e degraus de 3, 6 e 9 centímetros. São analisados os campos de pressões nos degraus e comparados com os resultados disponíveis na bibliografia. Também são propostos modelos para previsão de pressões nos patamares e espelhos dos degraus bem como dos esforços resultantes. Além disso, são realizadas transposições dos resultados para a escala de protótipo, inclusive com a análise da possibilidade de cavitação na estrutura. Como constatação geral sobre as pressões nos espelhos verifica-se que os esforços de tração e compressão têm magnitudes relativamente semelhantes, sendo mais intensas as pressões negativas. Sobre as pressões máximas nos patamares, destaca-se que os valores máximos de compressão ocorreram no final da calha, percebendo-se que as menores vazões geraram maiores valores de coeficientes de pressões. As variações da compressão nas faces dos patamares apresentam crescimento, no sentido da extremidade com o espelho acima deste para o vértice com o espelho abaixo do mesmo patamar. Nas faces dos espelhos, percebe-se que os mais extremos de tração são observados na parte superior, próximo à quina com os patamares. / Dams have been used throughout the centuries for a plethora of purposes. Several designs employ steps on the spillways in order to increase the power dissipation. The present research aims to characterize the forces acting on stepped spillways by analyzing both the variation of pressures acting along the pipeline and their distributions on the faces of the steps. In order to achieve this purpose, observations and discussions regarding spillways models with slope characterized as 1V: 0.75H and steps ranging from 3 to 9 centimeters are conducted. The pressure fields measured in the steps were analyzed and compared with results available in the literature. Sub sequentially, models to predict pressures on the faces of the steps and the resulting efforts were proposed. Finally, transpositions were performed on a prototype scale. Generally, it was found that the magnitude of tensile and compressive forces on the vertical faces are relatively similar, being the negative pressure slightly higher on all cases. During the experiments, it was observed that compression forces increased thought the length of the step’s horizontal face, peaking at the edge. It was also noticed that lower flows generated higher pressure coefficients. The measured compression on the horizontal faces of the step and its variation increase towards the edge of the step. It is perceived that the maximum tensile is observed on the top of the step’s vertical faces, near the corner with the horizontal faces.
9

Análise de esforços sobre vertedouros em degraus de declividade 1V:0,75H

Osmar, Fabrício Machado January 2016 (has links)
Barragens são utilizadas há séculos para diversas finalidades. Em diversas barragens os vertedouros são constituídos de degraus com o objetivo de aumentar a dissipação de energia. A presente pesquisa objetiva a caracterização dos esforços atuantes em vertedouros em degraus, através da análise da variação das pressões atuantes ao longo da calha e suas distribuições na faces do degraus. Com esse objetivo, são realizadas análises sobre modelos de vertedouros com declividade de 1V:0,75H e degraus de 3, 6 e 9 centímetros. São analisados os campos de pressões nos degraus e comparados com os resultados disponíveis na bibliografia. Também são propostos modelos para previsão de pressões nos patamares e espelhos dos degraus bem como dos esforços resultantes. Além disso, são realizadas transposições dos resultados para a escala de protótipo, inclusive com a análise da possibilidade de cavitação na estrutura. Como constatação geral sobre as pressões nos espelhos verifica-se que os esforços de tração e compressão têm magnitudes relativamente semelhantes, sendo mais intensas as pressões negativas. Sobre as pressões máximas nos patamares, destaca-se que os valores máximos de compressão ocorreram no final da calha, percebendo-se que as menores vazões geraram maiores valores de coeficientes de pressões. As variações da compressão nas faces dos patamares apresentam crescimento, no sentido da extremidade com o espelho acima deste para o vértice com o espelho abaixo do mesmo patamar. Nas faces dos espelhos, percebe-se que os mais extremos de tração são observados na parte superior, próximo à quina com os patamares. / Dams have been used throughout the centuries for a plethora of purposes. Several designs employ steps on the spillways in order to increase the power dissipation. The present research aims to characterize the forces acting on stepped spillways by analyzing both the variation of pressures acting along the pipeline and their distributions on the faces of the steps. In order to achieve this purpose, observations and discussions regarding spillways models with slope characterized as 1V: 0.75H and steps ranging from 3 to 9 centimeters are conducted. The pressure fields measured in the steps were analyzed and compared with results available in the literature. Sub sequentially, models to predict pressures on the faces of the steps and the resulting efforts were proposed. Finally, transpositions were performed on a prototype scale. Generally, it was found that the magnitude of tensile and compressive forces on the vertical faces are relatively similar, being the negative pressure slightly higher on all cases. During the experiments, it was observed that compression forces increased thought the length of the step’s horizontal face, peaking at the edge. It was also noticed that lower flows generated higher pressure coefficients. The measured compression on the horizontal faces of the step and its variation increase towards the edge of the step. It is perceived that the maximum tensile is observed on the top of the step’s vertical faces, near the corner with the horizontal faces.
10

Die hidrouliese erodeerbaarheid van rotsmassas in ombelynde oorlope met spesiale verwysing na die rol van naatvulmateriaal

Dooge, Nico January 1993 (has links)
Erosie in onbelynde oorloopkanale van damme veroorsaak skade aan die omgewing en bedreig die veiligheid van strukture. Huidige metodes om die potensiaal van erosieskade in oorloopkanale te bepaal is onbevradigend. Onnodige onkoste word dil<wels aangegaan deur goeie rots to baklee of deur regmakende aksies waar die rots te swak was om onbelyn te taat. Dit is derhalwe noodsaaklik dat praktiese metodes ontwikkel word om die erodeerbaarheid van rots te kan voorspel voor konstruksie plaasvind. 'n Uitgebreide literatuurstudie is aangepak oar aspekte van erosie, uitskuring, rotsmassaklassifikasiestelsels, vloede by damoorlope en hidrouliese parameters wat betrekking het op erodeerbaa.rheid. Nege en twintig damme in die R.S.A. is besoek in 'n paging om die invloed van verskillende geologiese, geotegniese en hidrouliese parameters op erosie te bepaal. Die omvang van die erosieskade is by elk van 43 erosiepunte bepaal en die erosiemeganisme is bestudeer. Waterspuittoetse is uitgevoer om 'n aanduiding te kry van die erosiepotensiaal en erosietempo vir spesifieke erodeerbare sones. Nate verswak die rotsmassa en hoe meer nate met vulmateriaal teenwoordig is, hoe grater is die erosiepotensiaal van die rotsmassa. Die naattoestande in verskillende tipes rotsmassas by verskillende oorloopkanale is bestudeer en aangeteken. Kohesiewe naatvulmateriaal speel 'n belangrike rol by die erodeerbaarheid van rotsmassas. Dit het daartoe gelei dat indekstoetse en vloeikanaaltoetse op gesimuleerde naatvulmateriaal uitgevoer word. Met behulp van indekstoetse is die mees geskikte materiaal en mengsel, wat so ver moontlik natuurlike vulmateriaal naboots, verkry. Toetsmonsters is van hierdie materiaal gemaak en in 'n vloeikanaal vir erosiepotensiaal en erosiemeganisme getoets. Die vloeikanaal is so aangepas dat watersnelhede van tot 10 meter per sekonde bereik kon word. Snelhede waarby die monsters begin erodeer is bepaal en die eenheids stroomdrywing (kW /m2 ) vir hierdie drumpelsnelhede is bepaal. Daar is deurgaans gepoog om met 'n skaal van 1 :1 te werk, maar aangesien dit nie altyd prakties moontlik was nie, kon die rol van skaal op die betroubaarheid van die toetsdata nie bepaal word nie. Die hidrouliese erodeerbaarheid van 'n rotsmassa is 'n funksie van die eienskappe van die rotsmassa en die versteurende effek van die water wat daaroor vloei. Deur vergelyking van die Kirsten uitgraafbaarheidsklas en die eenheids stroomdrywing met die omvang van erosie by 43 geselekteerde punte in 'n aantal oorloopkanale, is 'n tegniek ontwikkel waarmee die hidrouliese erodeerbaarheid van verskillende rotsmassas bepaal kan word. Aanbevelings aangaande die evaluering van 'n terrein vir erosiepotensiaal word gemaak. Metodes vir die voorkoming van erosieskade in 'n onbelynde oorloop word bespreek. Sekere aanbevelings omtrent terreine waar erosie reeds plaasgevind het en terreine waar moontlike erosie kan voorkom, word gemaak. Aanbevelings vir maatreels teen erosie en herstel van die skade word ook gemaak. / Dissertation (MSc)--University of Pretoria, 1993. / gm2014 / Geology / unrestricted

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