Physical and numerical modeling of swirling flow in a scroll vortex intake

Chan, Syin; Guo, Jiuhao; Lee, Heung Wing Joseph

doi:10.1016/j.jher.2021.11.004

Cited by 6 publications

(1 citation statement)

References 23 publications

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“…The vortex structure consists of three main parts: the inlet structure, the vertical shaft, and the energy dissipater structure. The certain geometry of the inlet structure which is formed in various configurations such as spiral inlet 10 , 11 , tangential inlet 8 , and scroll nlet 12 , is capable to convert the approach flow to vortex flow 13 . The vortex flow sticks to the vertical shaft wall to form an air core in column the center and moves downward annularly.…”

Section: Introductionmentioning

confidence: 99%

Experimental evaluation of the energy dissipation efficiency of the vortex flow section of drop shafts

Mahmoudi-Rad

Najafzadeh

2023

Sci Rep

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In urban wastewater collection and drainage networks, vortex structures are recruited to transfer fluid between two conduits with significant level differences. During the drop shaft, in addition to preventing the fluid from falling due to vortex flow formation, a significant amount of the fluid energy is dissipated due to wall friction of vertical shaft. In the present study, by constructing a physical model with a scale of 1:10 made of Plexiglas, the energy dissipation efficiency in the vertical shaft has been investigated. In this way, the performance of dimensional analysis indicates that the flow Froude number (Fr) and the ratio of drop total height to shaft diameter (L⁄D) are parameters affecting the efficiency of flow energy dissipation in the vertical shaft (ηs). This research considers four levels of Fr factor (1.77, 2.01, 2.18, and 2.32) and three levels of L⁄D factor (10, 13, and 16). Additionally, four replications for 12 possible combinations allow us to carry out 48 experiments and the full factorial method. The results demonstrated that the energy dissipation efficiency in the vertical shaft changes varies from 10.80 to 62.29%. Moreover, ηs values decrease with an increase in Fr whereas the efficiency increases with increasing L⁄D ratio. Furthermore, the regression analysis gave a second-order polynomial equation which is a function of Fr and L⁄D to accurately estimate the flow energy dissipation efficiency in the vertical shaft.

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Section: Introductionmentioning

confidence: 99%

Experimental evaluation of the energy dissipation efficiency of the vortex flow section of drop shafts

Mahmoudi-Rad

Najafzadeh

2023

Sci Rep

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Effect of oil properties on spilled oil recovery using a mechanism coupling surface vortices and cyclone separation

et al. 2022

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Numerical study on scroll vortex intake with non-uniform approach flow conditions

Wang,

Yu,

Zhang

et al. 2024

Physics of Fluids

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Scroll vortex dropshafts have been adopted as an effective tool to convey flow from higher to lower elevations in drainage systems. To ensure the reliability of these dropshafts, the approach channel would normally need to achieve uniform inflow conditions through a minimum channel length requirement. In dense urbanized cities, however, these conditions are occasionally unattainable due to land space constraint. Hence, further investigation is needed to examine the effect of non-uniform inflow conditions on the flow regimes and hydraulic performance of scroll vortex dropshafts. This study aims to quantify the effect of various non-uniform inflow factors on the non-dimensional head-discharge relationship and minimum air core size of the scroll vortex dropshaft by means of computational fluid dynamics simulations. Three-dimensional numerical models with different approach channel lengths are first constructed, and simulations in uniform inflow conditions are then performed and validated by experiment data. Subsequently, simulations with non-uniform inflow conditions are carried out with varying discharges as well as cross-sectional velocity distributions. The results showed that the effect on the performance of the dropshaft depends more on the distribution profile than its peakiness. A higher water level at the entrance and dilated minimum air core size in the dropshaft are typically observed for biased inflow conditions with inward velocity distributions toward the vortex chamber center, while outward distributions toward the outer wall of the vortex chamber lead to an opposite effect. A shorter approach channel would aggravate the disparity magnitude as expected. Finally, regression equations are established based on the simulation results to enable the assessment on the effect of non-uniform inflow conditions in the design stage.

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Physical and numerical modeling of swirling flow in a scroll vortex intake

Cited by 6 publications

References 23 publications

Experimental evaluation of the energy dissipation efficiency of the vortex flow section of drop shafts

Experimental evaluation of the energy dissipation efficiency of the vortex flow section of drop shafts

Effect of oil properties on spilled oil recovery using a mechanism coupling surface vortices and cyclone separation

Numerical study on scroll vortex intake with non-uniform approach flow conditions

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