Modelling of Quadratic-Surface Sludge Digesters by Smoothed Particle Hydrodynamics (SPH) – Finite Element (FE) Methods

• Autorzy: Tota-Maharaj Kiran , Nounu Ghassan , Ramroop Navin

Identyfikatory

DOI

10.1515/heem-2020-0003

• Języki publikacji: EN

Abstrakty

EN

The quadric-surfaced sludge digester (QSD), also known as the egg-shaped sludge digester, has proven its advantages over traditional cylindrical digesters recently. A reduction in operational cost is the dominant factor. Its shell can be described as a revolution of a parabola with the apex and base being either tapered or spherical. This shape provides a surface free of discontinuities, which is advantageous regarding the efficiency during mixing. Since the shape does not produce areas of inactive fluid motion within the tank, sludge settlement and an eventual grit build-up are avoided. The stresses developed in the shell of the sludge digester, vary along the meridian and equatorial diameters. A non-dimensional parameter, , defines the height-to-diameter aspect ratio which is used to delineate the parametric boundary conditions of the shell’s surface. Three groups of analyses were conducted to determine the orthogonal stresses in the shell of the QSD. The first-principles numerical models ran reasonably quickly, and many simulations were made during the study. The results showed that they were in within the range 5.34% to 7.2% to 2D FEA results. The 3D FEA simulation results were within the range of 8.3% to 9.2% to those from the MATLAB time-history models. This is a good indicator that the first principles numerical models are an excellent time-saving method to predict the behaviour of the QSD under seismic excitation. Upon examining the criteria for the design, analysing the results for the 2D FEA simulations showed that the fill height is not a significant variable with sloshing however the 3D FEA showed that the hydrostatic pressure is a significant variable. With the maximum tensile stress of the 3D-printed Acrylonitrile Butadiene Styrene (ABS)-a common thermoplastic polymer typically used for injection molding applications, being 24.4 MPa, the overall maximum stress of 5.45 MPa, the material can be a viable option for the use of QSD construction in small island developing states (SIDS).

Słowa kluczowe

EN

hydraulic infrastructure; Egg-shaped reactors; quadric-surfaced sludge digesters; shell structures; Small Island Developing States; SIDS

• Wydawca: Institute of Hydro-Engineering of Polish Academy of Sciences
• Czasopismo: Archives of Hydro-Engineering and Environmental Mechanics
• Rocznik: 2020
• Tom: Vol. 67, nr 1-4
• Strony: 35--53
• Opis fizyczny: Bibliogr. 8 poz., rys., tab.

Twórcy

autor

Tota-Maharaj Kiran

• Aston University Birmingham, Department of Civil Engineering, School of Infrastructure and Sustainable Engineering, Birmingham, B4 7ET, U.K.

autor

Nounu Ghassan

• University of the West of England, Civil and Environmental Engineering Cluster, Faculty of Environment and Technology, Coldharbour Ln, Stoke Gifford, Bristol BS16 1QY, U.K.

autor

Ramroop Navin

• The University of Trinidad and Tobago, Centre for Project Management and Civil Infrastructure Systems, San Fernando Campus, Tarouba Link Road, San Fernando, Trinidad. W.I.

Bibliografia

• Abramson H. (1967) The dynamic behavior of liquids in moving containers, with applications to space vehicle technology, Washington: Govt. Pr.
• Hutchinson A. (2010) RainWater Harvesting – Case Studies from the Barbados Experience, Conference Proceedings, Caribbean Waste Water Association Conference, Grenada. 1–14
• Ibrahim R. (2006) Liquid sloshing dynamics, Cambridge, Cambridge University Press.
• Johnson G., Stryk R., Beissel S. (1996) SPH for high velocity impact computations, Computer Methods in Applied Mechanics and Engineering, 139 (1–4), 347–373.
• Liu G., Liu M. (2009) Smoothed Particle Hydrodynamics, Singapore: World Scientific.
• Sumner I. E. (1966) Experimental investigation of stability boundaries for planar and nonplanar sloshing in spherical tanks, National Aeronautics and Space Administration.
• Tota-Maharaj K., Ramroop N. (2020) Numerical modelling of Quadric-Surfaced Sludge Digesters (QSD) within wastewater infrastructure using 3D printing techniques Institute of Water Journal, 4, 25–31.
• Zingoni A. (2001) Stresses and deformations in egg-shaped sludge digesters: Membrane effects, Engineering Structures, 23 (11), 1365–1372.

Uwagi

Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2021).