Vortex Shaft Outlet

Giudice, Giuseppe Del; Gisonni, Corrado; Rasulo, Giacomo

doi:10.1007/978-3-540-89465-0_352

Cited by 7 publications

(17 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The elaborations described in this paper are based on different experimental data [8,15,17,22,25,26]. All of them were collected by performing experiments in physical devices of vortex drop shafts in compliance with the standard layout of Figure 1.…”

Section: Physical Device Layoutmentioning

confidence: 99%

“…According to this scheme a rectangular inlet channel (subscript o) of width b conveys the approach flow in the inlet device. The approach flow was supercritical (F o = V o /(g•h o ) 0.5 > 1.00, with g as the gravity acceleration and V o and h o as the approach flow average velocity and depth, respectively, except for [15,25]. The inlet device consists in a tangential inlet or in a spiral inlet device, in which the approach flow is abruptly deviated towards the shaft and it assumes the typical helicoidal flow with a stable air core.…”

Section: Physical Device Layoutmentioning

confidence: 99%

“…In the end, an outlet tunnel (subscript u), with a circular or rectangular cross-section of diameter D u or width b u , respectively, exits the dissipation chamber. and depth, respectively, except for [15,25]. The inlet device consists in a tangential inlet or in a spiral inlet device, in which the approach flow is abruptly deviated towards the shaft and it assumes the typical helicoidal flow with a stable air core.…”

Section: Physical Device Layoutmentioning

confidence: 99%

“…A further energy head dissipation due to the impact of the free-jet on the chamber bottom occurs. The flow behaviour in the chamber can be still improved by installing specific appurtenances, such as baffles, weirs, venturi or sumps [2,15], aiming to dissipate more energy, calm the flow and reduce the pressure on the bottom thanks to the formation of a water cushion.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Energy Head Dissipation and Flow Pressures in Vortex Drop Shafts

Crispino

Contestabile

Vicinanza

et al. 2021

Water

Self Cite

View full text Add to dashboard Cite

Vortex drop shafts are special manholes designed to link sewer channels at different elevations. Significant energy head dissipation occurs across these structures, mainly due to vertical shaft wall friction and turbulence in the dissipation chamber at the toe of the shaft. In the present study two aspects, sometimes neglected in the standard hydraulic design, are considered, namely the energy head dissipation efficiency and the maximum pressure force in the dissipation chamber. Different physical model results derived from the pertinent literature are analyzed. It is demonstrated that the energy head dissipation efficiency is mostly related to the flow impact and turbulence occurring in the chamber. Similarly to the drop manholes, a relation derived from a simple theoretical model is proposed for the estimation of the energy head loss coefficient. The analysis of the pressures measured on the chamber bottom allows to provide a useful equation to estimate the pressure peak in the chamber as a function of the approach flow energy head.

show abstract

Section: Physical Device Layoutmentioning

confidence: 99%

Section: Physical Device Layoutmentioning

confidence: 99%

Section: Physical Device Layoutmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Energy Head Dissipation and Flow Pressures in Vortex Drop Shafts

Crispino

Contestabile

Vicinanza

et al. 2021

Water

Self Cite

View full text Add to dashboard Cite

show abstract

“…For sewer applications, a dissipation chamber is conventionally placed at the toe of the vertical shaft to reconvert the flow direction from vertical to horizontal and to de-aerate the flow. Hager and Kellenberger (1987) conceived a standard chamber configuration, and equipment in the chamber to improve the flow behavior was suggested by Del Giudice et al (2008). As for the vertical shaft, some design criteria to define the shaft diameter D s are available for both sewer and spillways (Hager and Kellenberger 1987;Kellenberger 1988;Khatsuria 2015).…”

Section: Introductionmentioning

confidence: 99%

Hydraulics of swirling flows along vortex drop shafts

Crispino¹,

Gisonni²,

Contestabile³

et al. 2020

Proceedings of the 8th IAHR International Symposium on Hydraulic Structures ISHS2020

Self Cite

View full text Add to dashboard Cite

The vortex drop shaft is a benchmark structure in hydraulic engineering. It is often used in sewers and hydropower systems, given that a significant energy dissipation combined with a reduced space occupation is achieved. Conversely, the flow pattern establishing along the structure may lead to the occurrence of unstable phenomena as vibrations, abrasion and choking, particularly if the operational conditions are different from the standard design regime. It is advantageous to study the overall hydraulic efficiency of the structure, and particularly to derive the hydraulic conditions of the swirling flow along the vertical shaft. At this regard, the paper describes a physically based approach, based on the momentum conservation, to derive the rotational angle and the velocity profiles along the shaft. The method requires the calibration of an empirical parameter accounting for the increase of the wall friction stress due to the centrifugal force. The outcomes of the application of the proposed procedure are presented with reference to the operation of two physical models of supercritical vortex drop shafts, with a tangential or a spiral inlet at the shaft top. It is shown that the application of the empirically-modified momentum approach is necessary for accounting for the significant angular momentum imparted to the swirling flow by the spiral inlet and for modelling the rotational flow distribution along the vertical shaft accurately.

show abstract

Vocational interests in the United States: Sex, age, ethnicity, and year effects.

Morris¹

2016

Journal of Counseling Psychology

View full text Add to dashboard Cite

Vocational interests predict educational and career choices, job performance, and career success (Rounds & Su, 2014). Although sex differences in vocational interests have long been observed (Thorndike, 1911), an appropriate overall measure has been lacking from the literature. Using a cross-sectional sample of United States residents aged 14 to 63 who completed the Strong Interest Inventory assessment between 2005 and 2014 (N = 1,283,110), I examined sex, age, ethnicity, and year effects on work related interest levels using both multivariate and univariate effect size estimates of individual dimensions (Holland's Realistic, Investigative, Artistic, Social, Enterprising, and Conventional). Men scored higher on Realistic (d = -1.14), Investigative (d = -.32), Enterprising (d = -.22), and Conventional (d = -.23), while women scored higher on Artistic (d = .19) and Social (d = .38), mostly replicating previous univariate findings. Multivariate, overall sex differences were very large (disattenuated Mahalanobis' D = 1.61; 27% overlap). Interest levels were slightly lower and overall sex differences larger in younger samples. Overall sex differences have narrowed slightly for 18-22 year-olds in more recent samples. Generally very small ethnicity effects included relatively higher Investigative and Enterprising scores for Asians, Indians, and Middle Easterners, lower Realistic scores for Blacks and Native Americans, higher Realistic, Artistic, and Social scores for Pacific Islanders, and lower Conventional scores for Whites. Using Prediger's (1982) model, women were more interested in people (d = 1.01) and ideas (d = .18), while men were more interested in things and data. These results, consistent with previous reviews showing large sex differences and small year effects, suggest that large sex differences in work related interests will continue to be observed for decades. (PsycINFO Database Record

show abstract

Vortex Shaft Outlet

Cited by 7 publications

References 2 publications

Energy Head Dissipation and Flow Pressures in Vortex Drop Shafts

Energy Head Dissipation and Flow Pressures in Vortex Drop Shafts

Hydraulics of swirling flows along vortex drop shafts

Vocational interests in the United States: Sex, age, ethnicity, and year effects.

Contact Info

Product

Resources

About