CaracterizaciĆ³n del flujo sobre vertederos escalonados con paredes convergentes
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Fecha
2019
Profesor/a GuĆa
Facultad/escuela
Idioma
es
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Universidad AndrƩs Bello
Nombre de Curso
Licencia CC
Licencia CC
Resumen
En este trabajo se aborda el estudio numĆ©rico de las caracterĆsticas del flujo
sobre un vertedero escalonado con paredes convergentes comparando luego
este tipo de obra con un vertedero escalonado de ancho constante. Dentro de
las caracterĆsticas del flujo estudiadas se encuentra la velocidad media, altura de
agua, vorticidad y distribuciĆ³n de presiones. Para esto, se replicĆ³ el estudio
experimental de Hunt et al. (2012), el cual consistĆa en un vertedero de paredes
convergentes, constituido por 27 peldaƱos con una pendiente 3H:1V. El ancho
del vertedero es de 4,5 m, cuenta con una cresta tipo Ogee y un rango para el
Ć”ngulo de convergencia de 0 a 70Ā°. Se modelaron dos casos utilizando el
software OpenFOAM. El caso A corresponde a un modelo 2D de un vertedero
escalonado, con el fin de emular el funcionamiento de un vertedero escalonado
de paredes paralelas. El caso B corresponde al modelo 3D del caso A, lo cual
permitiĆ³ estudiar los efectos de las paredes sobre las caracterĆsticas del flujo.
Los resultados obtenidos muestran una buena relaciĆ³n con investigaciones
recientes, tal como es el caso de la distribuciĆ³n de presiones adimensional, y la
profundidad del flujo en el eje central y en la zona cercana a las paredes. Se
encontrĆ³ que la profundidad del flujo para la zona que limita con las paredes, es
hasta 2 veces mayor que la profundidad del flujo en el eje central del vertedero.
Para el caso de la presiĆ³n, se localizaron los valores mĆ”ximos en las zonas
cercanas a las paredes. AdemĆ”s, se encontrĆ³ que los valores mĆ”ximos de
velocidad se ubican en el eje central, a una distancia 3āā5 del pseudo-bottom,
perpendicular a la superficie libre. Finalmente, se encontrĆ³ que los valores
mƔximos de TKE se ubican en la zona central cerca de la superficie libre y cerca
de la onda secundaria.
This work addresses the numerical study of the characteristics of the flow over a stepped spillway with converging walls comparing this type of work with a stepped spillway of constant width. Among the characteristics studied are the mean flow velocity, the water depths, the vorticity and the pressure distribution. For this purpose, the experimental study by Hunt et al. (2012) was replicated, which consisted of a stepped spillway with converging walls, made up of 27 steps and a slope of 3H:1V. The width of the spillway is 4.5 m, with an Ogee crest profile, and a convergence angle ranging from 0 to 70Ā°. Two cases were modeled using the software OpenFOAM. Case A corresponds to a 2D model of the stepped spillway, in order to emulate the operation of a stepped spillway with parallel walls. Case B corresponds to the 3D model of case A, which allowed to study the effects of the walls on the flow characteristics. The results obtained show a good agreement with recent investigations, such as the distribution of dimensionless pressure, and the flow depths in the central axis and in the region close to the walls. It was found that the flow depth close to the walls is up to two times greater than that in the central axis. Regarding pressure distributions, maximum values were located in the region near the walls. In addition, it was found that the velocity values were maximum in the central axis, and located at a distance of 3h/5 from the pseudo-bottom, perpendicular to the free surface. Finally, it was found that the maximum values of TKE were located in the central region near the free surface and near the secondary wave.
This work addresses the numerical study of the characteristics of the flow over a stepped spillway with converging walls comparing this type of work with a stepped spillway of constant width. Among the characteristics studied are the mean flow velocity, the water depths, the vorticity and the pressure distribution. For this purpose, the experimental study by Hunt et al. (2012) was replicated, which consisted of a stepped spillway with converging walls, made up of 27 steps and a slope of 3H:1V. The width of the spillway is 4.5 m, with an Ogee crest profile, and a convergence angle ranging from 0 to 70Ā°. Two cases were modeled using the software OpenFOAM. Case A corresponds to a 2D model of the stepped spillway, in order to emulate the operation of a stepped spillway with parallel walls. Case B corresponds to the 3D model of case A, which allowed to study the effects of the walls on the flow characteristics. The results obtained show a good agreement with recent investigations, such as the distribution of dimensionless pressure, and the flow depths in the central axis and in the region close to the walls. It was found that the flow depth close to the walls is up to two times greater than that in the central axis. Regarding pressure distributions, maximum values were located in the region near the walls. In addition, it was found that the velocity values were maximum in the central axis, and located at a distance of 3h/5 from the pseudo-bottom, perpendicular to the free surface. Finally, it was found that the maximum values of TKE were located in the central region near the free surface and near the secondary wave.
Notas
Tesis (Ingeniero Civil)
Palabras clave
Vertederos Escalonados, Modelos MatemĆ”ticos, SimulaciĆ³n por Computador