scholarly journals Three-dimensional modeling of steady-state flow in lake bank filtration – Brazil

2018 ◽  
Vol 19 (1) ◽  
pp. 60-69
Author(s):  
Silvia Fernandes Rocha ◽  
Eduardo Antonio Gomes Marques

Abstract Lake bank filtration (LBF) is an alternative technique of water catchment. LBF has been used by several countries for more than 100 years as pre-treatment for water supply and hydrogeological characterization studies. LBF studies are still recent and essentially focus on water quality with little or no hydrogeological approach. The benefits obtained through this technique were the reason for the implementation of a pilot project on LBF on the lake banks of the ‘lake’ at the Federal University of Viçosa (UFV) in the city of Viçosa (MG), southeastern Brazil. Several hydrogeological studies were carried out in this research. In this article, we highlight the study by means of three-dimensional modeling of steady-state flow to learn the characteristics of the aquifer and its interaction with the ‘lake’. The three-dimensional numerical model of steady-state flow was elaborated for interpretative and predictive purposes. The results demonstrated the potential of the LBF system and how it can be used as an alternative for the UFV campus. The exposed scenario can help groundwater management in the study area.

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Stephan Mohr ◽  
Henry Clarke ◽  
Colin P. Garner ◽  
Neville Rebelo ◽  
Andrew M. Williams ◽  
...  

Flow coefficients of intake valves and port combinations were determined experimentally for a compressed nitrogen engine under steady-state and dynamic flow conditions for inlet pressures up to 3.2 MPa. Variable valve timing was combined with an indexed parked piston cylinder unit for testing valve flows at different cylinder volumes while maintaining realistic in-cylinder transient pressure profiles by simply using a fixed area outlet orifice. A one-dimensional modeling approach describing three-dimensional valve flow characteristics has been developed by the use of variable flow coefficients that take into account the propagation of flow jets and their boundaries as a function of downstream/upstream pressure ratios. The results obtained for the dynamic flow cases were compared with steady-state results for the cylinder to inlet port pressure ratios ranges from 0.18 to 0.83. The deviation of flow coefficients for both cases is discussed using pulsatile flow theory. The key findings include the followings: (1) for a given valve lift, the steady-state flow coefficients fall by up to 21% with increasing cylinder/manifold pressure ratios within the measured range given above and (2) transient flow coefficients deviated from those measured for the steady-state flow as the valve lift increases beyond a critical value of approximately 0.5 mm. The deviation can be due to the insufficient time of the development of steady-state boundary layers, which can be quantified by the instantaneous Womersley number defined by using the transient hydraulic diameter. We show that it is possible to predict deviations of the transient valve flow from the steady-state measurements alone.


2020 ◽  
Author(s):  
Sivasamy Balasubramanian ◽  
Suresh Krishnan ◽  
Magesh Kumar M. ◽  
Krishna Srihari B. ◽  
Arkadyuti Chakraborty ◽  
...  

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