Numerical Simulation of the Spreading of Aerated and Nonaerated Turbulent Water Jet in a Tank with Finite Water Depth

Guo, Yakun

doi:10.1061/(asce)hy.1943-7900.0000903

Cited by 13 publications

(5 citation statements)

References 31 publications

(4 reference statements)

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“…The outlet boundary is set as outflow boundary condition in which a static pressure at the outlet boundary is specified (Guo, 2014). The variation of water surface is small and can be ignored.…”

Section: Numerical Schemes and Validation Casementioning

confidence: 99%

Improving the prediction of scour around submarine pipelines

Zhang¹,

Shi²,

Guo³

et al. 2016

Proceedings of the Institution of Civil Engineers - Maritime En

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Local scour around submarine pipelines can affect the stability of the pipeline. The accurate estimation of the scour around submarine pipelines has been a hot topic of research among marine engineers. This paper presents results from a numerical study of clear-water scour depth below a submarine pipeline for a range of the steady flow conditions. The flow field around the pipeline under scour equilibrium condition is numerically simulated by solving the Reynolds-Averaged Navier-Stokes (RANS) equations with the standard k-ε turbulence closure. The flow discharge through the scour hole for various flow conditions is investigated. The results are used to establish the relationship between the flow discharge and the maximum scour depth. Incorporated with the Colebrook-White equation, the bed shear stress is obtained and an iterative method is proposed to predict the scour depth around the submarine pipeline. The calculated scour depths using the present method agree well with the laboratory measurements, with the average absolute relative error being smaller than that using previous methods, indicating that the proposed method can be used to predict the clear-water scour around the submarine pipeline with satisfactory accuracy.

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Section: Numerical Schemes and Validation Casementioning

confidence: 99%

Improving the prediction of scour around submarine pipelines

Zhang¹,

Shi²,

Guo³

et al. 2016

Proceedings of the Institution of Civil Engineers - Maritime En

Self Cite

View full text Add to dashboard Cite

show abstract

“…According to the theory of jets, the velocity attenuation is influenced by the length of the potential core, which is significantly determined by the characteristic width of the impingement jet (

) [ 35 ]. In some literature, the characteristic width refers to the width or diameter of impingement jets [ 18 , 20 , 29 ]. Therefore, the accurate estimation of characteristic width (

) of impingement jets is an essential step to calculate the value of dynamic pressure.…”

Section: Predicting the Dynamic Pressurementioning

confidence: 99%

“…In terms of effective water cushions, the expression had proven useful [ 18 ]. As discussed by Guo [ 20 ], the air content of jets is a factor in maximum mean dynamic pressure and the distribution of pressure at the slab, and it was found that the maximum mean dynamic pressure decreases and the pressure distribution region become larger when air is entrained into jets. The typical pressure distribution was observed to obey the Gaussian distribution law well [ 21 , 22 , 23 ].…”

Section: Introductionmentioning

confidence: 99%

A Concise Method to Predict the Mean Dynamic Pressure on a Plunge Pool Slab

Zhou

Zhang

et al. 2021

Entropy

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Hydrodynamic pressure exerted on a plunge pool slab by jet impingement is of high interest in high dam projects. The present study experimentally investigated the characteristics of pressure induced by a jet through a constant width flip bucket (CFB) and a slit flip bucket (SFB). A pressurized plane pipe was employed in the flume experiments to control the inlet velocities in the flip buckets. A concise method is proposed to predict the mean dynamic pressure field. Its implementation is summarized as follows: First, the position of the pressure field is determined by the trajectories of free jets, and to calculate its trajectories, an equation based on parabolic trajectory theory is used; second, the maximum mean dynamic pressure is obtained through dimensional analysis, and then the pressure field is established by applying the law of Gaussian distribution. Those steps are integrated into a concise computing procedure by using some easy-to-obtain parameters. Some key parameters, such as takeoff velocity coefficient, takeoff angle coefficient, and the parameter k2, are also investigated in this paper. The formulas of these coefficients are obtained by fitting the experimental data. Using the proposed method, the easy-to-obtain geometric parameters and initial hydraulic conditions can be used to calculate the maximum mean dynamic pressure on the slab. A comparison between experimental data and calculated results confirmed the practicability of this model. These research results provide a reference for hydraulic applications.

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“…In this paper a new modeling procedure is presented, extending a relevant past publication (Koutitas and Gousidou 2004) followed by detailed laboratory experiments (Kourafalou et al 2004;Fyrillas and Nomura 2007;Guo 2014). Its aim is to test the calibration procedure and the final operational validity of the presented model.…”

Section: Introductionmentioning

confidence: 99%

Theoretical analysis and experimental investigation of air-bubble-stream-induced water circulation

Zafeirakou

Pechlivanidis

Koutitas

2023

Euro-Mediterr J Environ Integr

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Air-bubble curtain is an amount of air injected vertically into a water body. The generation of such a flow and the lack of a continuous interface cannot be described by a smooth mathematical function. Therefore, a two-phase flow model is introduced. A numerical model for the concurrent flow of buoyant bubbles continuously flowing into a 2D water field, and the water flow (generated by the bubbles), is formulated and solved. The two-phase flow model consists of the 2D Navier equations for the water phase (continuous phase) and of the active Lagrangian particles for the simulation of the air bubbles (discrete phase). The coupling of the two phases is done through the continuity and the momentum equilibriums. The numerical solution by explicit second-order Finite Differences (FD) scheme leads from a cold start to steady flow conditions, resolving for the water velocities vector field and the air bubbles’ concentration distribution. The flow configuration is repeated in laboratory conditions, and the velocity field is measured by the particle image velocimetry (PIV) technique. In this work, the numerical two-phase flow model and the hardware aspects of our measurement device are analyzed, followed by the comparison of the numerical and experimental results. This empowers the validity and credibility of the algorithm introduced. Finally, interesting conclusions are drawn regarding the operational use of the model.

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Numerical Simulation of the Spreading of Aerated and Nonaerated Turbulent Water Jet in a Tank with Finite Water Depth

Cited by 13 publications

References 31 publications

Improving the prediction of scour around submarine pipelines

Improving the prediction of scour around submarine pipelines

A Concise Method to Predict the Mean Dynamic Pressure on a Plunge Pool Slab

Theoretical analysis and experimental investigation of air-bubble-stream-induced water circulation

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