Experimental and Numerical Analysis of Egg-Shaped Sewer Pipes Flow Performance

Regueiro-Picallo, Manuel; Naves, Juan; Anta, José; Puertas, Jerónimo; Suárez, Joaquín

doi:10.3390/w8120587

Cited by 18 publications

(14 citation statements)

References 14 publications

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“…The radius of the infundibular zone in typical ovoid forms is equal to half the diameter. -Picallo et al, 2016) We also suggested dividing the forms into sphere-like, roundish, obtuse, typical, drop-shaped and cone-shaped according to the location of the upper edge of the cloacal circle. We can divide these forms into short, short cut, normal, elongated, and long by the size of the lateral arcs.…”

Section: Discussionmentioning

confidence: 99%

Mathematical interpretation of artificial ovoids and avian egg shapes (part I)

Mytiai

Matsyura

2019

Regul. Mech. Biosyst.

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We performed comparative analysis of curvature characteristics of bird eggs and used ovoid profiles from various authors, our own geometric profiles, and archive bird egg profiles from our database. We suggested that the possible ovoids arise by changing the curvature radii of the polar and lateral zones. We compared the constructed curves and curves presented in oological literature with the pictures of the real bird egg profiles. The volume of actual material includes 16,490 eggs from 800 species of 20 bird orders. Specially designed computer software had calculated the radius of curvature of real bird eggs from photos and drew out the half-profiles presented in our article. We supposed that the asymmetrical ovoid is the most widespread geometric egg-shaped figure, which can easily be obtained by combination of circles. We also calculated that if the ovoid diameter were taken as a unit, then the radius obtuse (infundibular) pole would be equal to its half-length, lateral (side arcs) is equal two lengths, and the cloacal arch is 1–√2/2. From this suggestion, we concluded that the length of the ovoid is 2–√2/2 and its cloacal radius is equal to the difference between the length of ovoid and its diameter (rc = L–D). We analyzed the geometry of this asymmetrical oval and came to the conclusion that this is the basic form able to generate the derivative forms. We discovered that the centres of the arcs which form it lie on one basic/supporting circle, the diameter of which is equal to the ovoid diameter. All other ovoids, which have radius equal to radius of the infundibular zone we called the real ovoids. The changes in the radii of the lateral arcs are caused by the movement of their centres along a horizontal line passing through the centre of the base circle. This causes the prolongation or shortening of the ovoids. Sizes of cloacal arcs depended on the lateral, and their centres are placed along the vertical axis. Variability of the sizes of the abovementioned arcs caused the variability of form of the bird eggs. For their classification, we have proposed to divide them into five groups: sphere-like, circle, obtuse, droplet, and cone-shaped. Further, we separated some more groups: short, shortened, normal, lengthened, and long; according to the sizes of cloacal arcs – large radius, middle radius, and small radius ovoids. As a result, we have 80 forms of real ovoids – standards which describe the varieties of bird eggs. Each of them has its own number, name, geometrical figure, polynomic equation, and correlations of ovoid parameters. This set of ovoids is sufficient to describe the specifics of any form of bird eggs.

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Section: Discussionmentioning

confidence: 99%

Mathematical interpretation of artificial ovoids and avian egg shapes (part I)

Mytiai

Matsyura

2019

Regul. Mech. Biosyst.

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“…This could imply more risk for reduced capacity of the pipes. On the other hand, there are good examples of very old pipes that due to their shape, e.g., egg-shape section and material construction, have a better function than newer pipes [68].…”

Section: Systemic Inequity Of Flood Exposurementioning

confidence: 99%

Systemic Inequity in Urban Flood Exposure and Damage Compensation

Mobini

Becker

Larsson

et al. 2020

Water

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Urban flooding is a growing concern in Northern Europe. While all countries in this region invest substantial resources into urban flood risk management, all property owners have unequal opportunity to have their flood risk managed. This paper presents the notion of equity in the urban flood risk management, focusing on urban flood exposure and compensation after sewage surcharge on the 31 August 2014 cloudburst over Malmö in Sweden. All damage claims and the procedures assessing them were analysed based on the type of sewer system (combined or separated) that affected the properties. The results demonstrated considerable systemic inequity in both flood exposure and damage compensation. The owners of properties connected to combined systems were four times more likely to make a damage claim, while having their damage claims approved just over half as often, compared with owners of properties connected to separated sewage systems. Considering the multifaceted nature of both inequities and their possible resolution, current praxis is not sufficient for the management of future urban drainage systems; not only concerning changing climatic conditions but also concerning social conditions.

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“…In recent years, CFD models have been applied for solving several hydraulic engineering problems. In this way, CFD has been used for a variety of purposes, as simulations of flow transient in pipes [19,20], behaviour of different control valves under different conditions [21][22][23][24], mixing models in water distribution systems [25][26][27][28], or for the characterization of elements in open channels [29][30][31][32][33][34].…”

Section: Computational Fluid Dynamics (Cfd) Modellingmentioning

confidence: 99%

Computational Determination of Air Valves Capacity Using CFD Techniques

García-Todolí

Iglesias-Rey

Mora-Meliá

et al. 2018

Water

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The analysis of transient flow is necessary to design adequate protection systems that support the oscillations of pressure produced in the operation of motor elements and regulation. Air valves are generally used in pressurized water pipes to manage the air inside them. Under certain circumstances, they can be used as an indirect control mechanism of the hydraulic transient. Unfortunately, one of the major limitations is the reliability of information provided by manufacturers and vendors, which is why experimental trials are usually used to characterize such devices. The realization of these tests is not simple since they require an enormous volume of previously stored air to be used in such experiments. Additionally, the costs are expensive. Consequently, it is necessary to develop models that represent the behaviour of these devices. Although computational fluid dynamics (CFD) techniques cannot completely replace measurements, the amount of experimentation and the overall cost can be reduced significantly. This work approaches the characterization of air valves using CFD techniques, including some experimental tests to calibrate and validate the results. A mesh convergence analysis was made. The results show how the CFD models are an efficient alternative to represent the behavior of air valves during the entry and exit of air to the system, implying a better knowledge of the system to improve it.

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Experimental and Numerical Analysis of Egg-Shaped Sewer Pipes Flow Performance

Cited by 18 publications

References 14 publications

Mathematical interpretation of artificial ovoids and avian egg shapes (part I)

Mathematical interpretation of artificial ovoids and avian egg shapes (part I)

Systemic Inequity in Urban Flood Exposure and Damage Compensation

Computational Determination of Air Valves Capacity Using CFD Techniques

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