Mixed Flows with Depressurizing Wavefront in Circular Pipe

Bousso, Samba; Daynou, Mathurin; Fuamba, Musandji

doi:10.1061/(asce)ir.1943-4774.0000665

Cited by 5 publications

(2 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Padulano et al [15] studied the working conditions of a vertical drop shaft, with and without a venting system. Bousso et al [16] studied the effect of air pockets on the depressurization wavefront. The work mentioned above shed some light on the air-water two-phase flow in tailrace systems of hydropower stations.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Air-Water Interaction in a Hydropower Station Combining a Diversion Tunnel with a Tailrace Tunnel

Zhao¹,

Cai²,

Zhou³

et al. 2017

Water

View full text Add to dashboard Cite

Diversion tunnels are often used as tailrace tunnels in underground hydropower stations. The special layout results in complex flow regimes, including air-water two-phase flow. A set of experiments is conducted based on the model of a hydropower station which combines partial diversion tunnels with tailrace tunnels to investigate the interactions between the air and water phases in the combined diversion tunnels. Interactions between the air and water phases observed in the combined diversion tunnel significantly alter flow dynamics, and are classified into four types according to the initial tail water level. There is a range of initial tail water levels in which the interaction between the air and water phases cannot be neglected, and the range becomes greater when the change in flow rate increases. Such interactions may cause a pressure surge and the pressure surge reaches the maximum when the initial tail water level is approximately equal to the crown of the tunnel. The surge pressures do harm to the safety and stability of hydropower stations, so the condition should be considered and controlled.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Air-Water Interaction in a Hydropower Station Combining a Diversion Tunnel with a Tailrace Tunnel

Zhao¹,

Cai²,

Zhou³

et al. 2017

Water

View full text Add to dashboard Cite

show abstract

“…Free-surface-pressurized flow is free surface flow in which the conduit is pressurized during the transient state, and often occurs in sewers and in the conduits of hydroelectric power plants or pumped storage projects [2]. Based on an overall review and analysis, it was pointed out that the free-surface-pressurized flow in storm water systems is difficult to capture in modeling, and rapid pipe filling or emptying of water mains and sewer systems is accompanied by transitions between free surface and pressurized flow regimes and subatmospheric unsteady flow [3,4]. Focusing on the free-surface-pressurized flow, based on different experimental setups and further data analysis, the obtained experimental results were not only used for verification of numerical models but also revealed some obvious phenomena involved in air-water interactions; for example, the air near the pipe crown may pressurize and lead to consequent intense pressure oscillations [5][6][7][8].…”

mentioning

confidence: 99%

Modeling of the Free-Surface-Pressurized Flow of a Hydropower System with a Flat Ceiling Tail Tunnel

Zhou

2020

Water

View full text Add to dashboard Cite

For a water diversion hydropower system with a flat ceiling tail tunnel with high elevation, during transient states with relatively low tail water levels, free-surface-pressurized flow inevitably appears and its transient characteristics have obvious effects on the system’s operating stability. Using Newton–Raphson linearization in the characteristic implicit format for modeling of the free-surface-pressurized flow in the tail tunnel, the mathematical models for necessary boundary conditions were derived and linear algebraic equations with a band coefficient matrix were grouped for further transient simulation. Then, a unified mathematical model was established for hydraulic transient analysis of the hydropower system with free-surface-pressurized flow. Combined with experimental research and numerical simulation, the wave speed for the free-surface-pressurized flow was experimentally analyzed for further correctness in the unified model, and by comparative analysis the hydraulic characteristics of the free-surface-pressurized flow in the flat ceiling tail tunnel were investigated. It was found that the derived mathematical model can basically represent water behaviors in the water-surface-pressurized flow, the wave speed for the mixed water-surface-pressurized flow can be set to approximately 50m/s, and with this correctness the numerical results are in good agreement with the experimental results. Therefore, the obtained mathematical model combined with an experimental wave speed or a reference wave speed of 50 m/s for the free-surface-pressurized flow is preferable during the design stage of the hydropower system.

show abstract

Numerical and Experimental Analysis of the Pressurized Wave Front in a Circular Pipe

Bousso

Fuamba

2014

J. Hydraul. Eng.

View full text Add to dashboard Cite

Mixed Flows with Depressurizing Wavefront in Circular Pipe

Cited by 5 publications

References 14 publications

Experimental Investigation on Air-Water Interaction in a Hydropower Station Combining a Diversion Tunnel with a Tailrace Tunnel

Experimental Investigation on Air-Water Interaction in a Hydropower Station Combining a Diversion Tunnel with a Tailrace Tunnel

Modeling of the Free-Surface-Pressurized Flow of a Hydropower System with a Flat Ceiling Tail Tunnel

Numerical and Experimental Analysis of the Pressurized Wave Front in a Circular Pipe

Contact Info

Product

Resources

About