Behaviour of Turbulent Water Jets in the Atmosphere and in Plunge Pools.

Ervine, Da; Falvey, Ht

doi:10.1680/iicep.1987.353

Cited by 144 publications

(87 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is caused by turbulent and fluctuating pressures. Quantification of pressure fluctuations of incident jets in stilling basins has been studied mainly by Ervine and Falvey [20], Ervine et al [21], Castillo [22], Castillo et al [23], Bollaert and Schleiss [24], Castillo and Carrillo [25,26], and Castillo et al [27,28]. Some of the main results of these papers have been included in FEMA [29].…”

Section: Semi-empirical Methodologymentioning

confidence: 99%

Scour, Velocities and Pressures Evaluations Produced by Spillway and Outlets of Dam

Castillo

Carrillo

2016

Water

View full text Add to dashboard Cite

Paute-Cardenillo (owned by Celec Ep-Hidropaute) is a dam with maximum height 135 m located in the Paute River in Ecuador. Its hydroelectric production will be integrated at the National Electric System of Ecuador with an installed capacity of 600 MW which will produce 3300 GWh per year. To evaluate the stability and safety of the structure, it is necessary to ascertain the shape and dimensions of the scour generated downstream from the dam. We studied the scour, due to the operation of the free surface spillway (700 m 3 /s) and half-height outlets (1760 m 3 /s), with three complementary procedures: empirical formulae obtained in models and prototypes, semi-empirical methodology based on pressure fluctuations-erodibility index and computational fluid dynamics simulations. The free surface weir could generate a scour around 21 m, while the intermediate outlet could reach the intact rock, located 34 m below the initial river bed. A pre-excavated basin is proposed and the velocities and pressures are analyzed. The results demonstrated the suitability of combining different methodologies to achieve an adequate resolution of this complex phenomenon.Keywords: CFD simulation; erodibility methodology; falling jets; plunge pool; scour dam Dam CharacteristicThe Paute-Cardenillo Dam, located in Ecuador, is a double curvature arch dam with a maximum height of 135 m to the foundations (Figure 1a). Considering as the reference the Universal Transverse Mercator (UTM) system with the projection PSAD 56 (Provisional South American Datum 1956) corresponding to area 17 of the Southern Hemisphere, the top level is 926 meters above mean sea level (MASL), while the normal maximum water level is 924 MASL. The river bed consists of a layer of 24 m of alluvial, below which there is a layer of 10 m of weathered rock (Figure 1b). Table 1 shows the particles characteristics size of the alluvial (24 m) and the weathered rock (10 m) in the Paute River.

show abstract

Section: Semi-empirical Methodologymentioning

confidence: 99%

Scour, Velocities and Pressures Evaluations Produced by Spillway and Outlets of Dam

Castillo

Carrillo

2016

Water

View full text Add to dashboard Cite

show abstract

“…Many researchers have studied in detail the scale effect due to aeration and some beneficial conclusions have been obtained. Ervine and Falvey [32] studied jet diffusion in the plunge pool by considering the difference between submerged and impinging jets, the role of inner core decay for impinging jets, the effect of entrained air on the reduction of impact pressures, and the pressure fluctuations caused by turbulence in the plunge pool shear layers. Ervine et al [33] studied the pressure fluctuation field on a plunge pool floor subjected to jet impingement and also considered the effects of the degree of break-up of the jet before it enters the basin and the air entrainment in the plunge pool.…”

Section: Basic Information On the Physical Modelmentioning

confidence: 99%

Experimental Research on an Improved Slope Protection Structure in the Plunge Pool of a High Dam

Liang

et al. 2017

Water

View full text Add to dashboard Cite

Due to impinging jets, the hydraulic load in a plunge pool can be very large and may cause serious damage to the slope and bottom protection structures. Conventional research mainly focuses on the stability of the plunge pool floor, and studies on slope protection safety are still lacking. Based on the Wudongde project, a physical model (that does not consider the plunge pool floor) was established. A series of experiments were conducted to investigate the protective measures for slope protection. Experimental results showed that the high seepage pressure on the back surface of the slope lining plate and poor correlation between the fluctuating pressures on both plate surfaces may cause large pressure differences that seriously threaten the stability of the slope lining plate. Therefore, a self-drainage slope protection structure was proposed to reduce the hydraulic load on a slope lining plate. It must be noted that the slope lining plate with the most violent water level fluctuation and adverse operating conditions (when the drainage system and part of the waterstops were invalid) were considered in the model tests. Test results indicated that self-drainage slope protection could enhance the synchronism of the pressure and water-level fluctuations on both plate surfaces. Therefore, the proposed slope protection structure could effectively reduce the total pressure on the plate and significantly increase the operational safety of the plunge pool.

show abstract

“…When the outer edge of the boundary layer becomes close to the free-surface, free-surface aeration takes place. Free-surface breakup and air entrainment occur because the turbulent shear stress is greater than the surface tension force per unit area resisting the interfacial breakup (Ervine and Falvey 1987, Chanson 2009, Bombardelli et al 2011). …”

Section: Introductionmentioning

confidence: 99%

Hydraulics of the Developing Flow Region of Stepped Spillways. II: Pressure and Velocity Fields

Zhang

Chanson

2016

J. Hydraul. Eng.

View full text Add to dashboard Cite

In skimming flow on a stepped spillway, the upstream flow motion is non-aerated and a turbulent boundary layer develops until the outer edge of the boundary layer interacts with the free-surface: that is, at the inception point of air entrainment. Herein new experiments were performed in the developing flow region on a large size 1V:1H stepped spillway model with step height h = 0.10 m. The flow properties in the developing flow region were carefully documented. In the developing boundary layer, the velocity distributions followed a 1/4.5 th power law at step edges. Detailed velocity and pressure measurements showed some rapid flow redistribution between step edges and above step cavities. The application of the momentum integral equation indicated an average friction factor of 0.18, close to the observed air-water flow friction factor of 0.23, suggesting that the spatially-averaged dimensionless shear stress was comparable in the developing flow and fully-aerated flow regions.

show abstract

Behaviour of Turbulent Water Jets in the Atmosphere and in Plunge Pools.

Cited by 144 publications

References 0 publications

Scour, Velocities and Pressures Evaluations Produced by Spillway and Outlets of Dam

Scour, Velocities and Pressures Evaluations Produced by Spillway and Outlets of Dam

Experimental Research on an Improved Slope Protection Structure in the Plunge Pool of a High Dam

Hydraulics of the Developing Flow Region of Stepped Spillways. II: Pressure and Velocity Fields

Contact Info

Product

Resources

About