EFFECT OF FLOCCULATING AGENTS ON DRAG IN GRAVITY-DRIVEN FLOW SYSTEMS

2017 ◽  
Vol 44 (4) ◽  
pp. 339-347
Author(s):  
M. K. S. V. Raghav ◽  
Ravi Teja ◽  
Chirravuri Subbarao
Keyword(s):  
Flow Systems ◽  
Gravity Driven ◽  
Gravity Driven Flow

Drag reduction using mixed solutions of hydrotrope and surfactant in gravity driven flow systems

2013 ◽  
Vol 8 (3) ◽  
pp. 22-27
Author(s):  
M. Venkata Ramana ◽  
◽  
Ch. V. Subbarao ◽  
P. V. Gopal singh ◽  
Krishna Prasad K.M.M ◽  
...  
Keyword(s):  
Drag Reduction ◽  
Mixed Solutions ◽  
Flow Systems ◽  
Gravity Driven ◽  
Gravity Driven Flow

Complex groundwater flow systems in the light of climate change: response of combined fluid driving forces on recharge reduction

2021 ◽  
Author(s):  
Timea Trásy-Havril ◽  
Szilvia Szkolnikovics-Simon ◽  
Judit Mádl-Szőnyi
Keyword(s):  
Climate Change ◽  
Groundwater Flow ◽  
Driving Forces ◽  
Flow System ◽  
Complex Flow ◽  
Groundwater Flow Systems ◽  
Flow Systems ◽  
Gravity Driven ◽  
Flow Domain ◽  
Gravity Driven Flow

<p>Climate change induced alteration of recharge is expected to have diverse effects on groundwater levels, which could also modify the fragmentation and hierarchy of groundwater flow systems, including their dimensions and relative positions.</p><p>This study put emphasis on how flow system hierarchy may change due to recharge reduction in complex, vertically superimposed groundwater flow systems with different fluid driving forces through an example of the Duna-Tisza Interfluve in Hungary. Two main groundwater flow domain was identified by previous authors in this area with a separate source of water. Recharge to the upper, unconfined, gravitational regime is inferred to occur from infiltrating precipitation, while the underlying confined, overpressured flow domain is maintained by pore volume reduction due to tectonic compression of the basement (Tóth and Almási 2001, Almási 2003, Mádl-Szőnyi and Tóth 2009). The exposure of these groundwater flow systems, one is driven by gravity and other one is by overpressure, is completely different to the effects of changes in hydrologic parameters. Local scale gravity-driven flow systems are identified to be the most vulnerable to atmospheric processes (Kurylyk et al., 2014), while overpressured upward flow is driven by tectonic compression, and thus independent of climatic variation.</p><p>Two-dimensional transient numerical simulations were performed to gain insight into the response of this complex flow system to the predicted climate change of the region. Special emphasis is placed on i) how relative rate and influence of the different driving forces may change due to the predicted recharge reduction, ii) how the fragmentation of the flow field may alter, iii) how the penetration depth of upper, gravity-driven flow field may adjust to these changes and iv) how groundwater-related shallow surface water bodies will be affected by these changes.</p><p>Understanding the effects of changed hydrologic conditions on such complex flow patterns and recharge-discharge relationships as well as on interactions with surface water bodies can help to set-up three-dimensional site-specific models. These models provide a base to better mitigate and prepare for the consequences of predicted future changes.</p><p>The research is supported by the ÚNKP-20-4 New National Excellence Program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation Fund, as well as by the József and Erzsébet Tóth Endowed Hydrogeology Chair. This work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 810980.</p>

Use of Surfactant Solutions for Drag Reduction in Gravity Driven Flow Systems

2013 ◽  
Vol 40 (3) ◽  
pp. 227-234
Author(s):  
Ch. V. Subbarao ◽  
Divya ◽  
D. Appala Naidu ◽  
P. King
Keyword(s):  
Drag Reduction ◽  
Surfactant Solutions ◽  
Flow Systems ◽  
Gravity Driven ◽  
Gravity Driven Flow

scholarly journals Two-Dimensional Convection Induced by Gravity and Centrifugal Forces in a Rotating Porous Layer Far Away from the Axis of Rotation

1998 ◽  
Vol 4 (2) ◽  
pp. 73-90 ◽  
Author(s):  
Peter Vadasz ◽  
Saneshan Govender
Keyword(s):  
Rayleigh Number ◽  
Porous Layer ◽  
Temperature Fields ◽  
Wave Number ◽  
Marginal Stability ◽  
Two Dimensional ◽  
Wide Range ◽  
Gravity Driven ◽  
Gravity Driven Flow ◽  
The Stability

The stability and onset of two-dimensional convection in a rotating fluid saturated porous layer subject to gravity and centrifugal body forces is investigated analytically. The problem corresponding to a layer placed far away from the centre of rotation was identified as a distinct case and therefore justifying special attention. The stability of a basic gravity driven convection is analysed. The marginal stability criterion is established in terms of a critical centrifugal Rayleigh number and a critical wave number for different values of the gravity related Rayleigh number. For any given value of the gravity related Rayleigh number there is a transitional value of the wave number, beyond which the basic gravity driven flow is stable. The results provide the stability map for a wide range of values of the gravity related Rayleigh number, as well as the corresponding flow and temperature fields.

scholarly journals Modelling gravity-driven flow over uneven surfaces

2010 ◽  
Author(s):  
K. A. Ogden ◽  
S. J. D. D’Alessio ◽  
J. P. Pascal
Keyword(s):  
Gravity Driven ◽  
Gravity Driven Flow

Steady inclined flows of granular-fluid mixtures

2009 ◽  
Vol 641 ◽  
pp. 359-387 ◽  
Author(s):  
D. BERZI ◽  
J. T. JENKINS
Keyword(s):  
Volume Flow ◽  
Angle Of Repose ◽  
Recent Theory ◽  
Fluid Mixture ◽  
Flow Rates ◽  
Fluid Mixtures ◽  
Gravity Driven ◽  
Granular Fluid ◽  
Gravity Driven Flow ◽  
Inclined Flow

We extend a recent theory for steady uniform gravity-driven flow of a highly concentrated granular-fluid mixture over an erodible bed between frictional sidewalls. We first include angles of inclination greater than the angle of repose of the particles; then, we introduce a boundary condition for flow over a rigid bumpy bed. We compare the predictions of the resulting theory with the volume flow rates, depths and angles of inclination measured in the experiments on dry and variously saturated flows over rigid and erodible boundaries. Finally, we employ the resulting theory, with the assumption that the flow is shallow, to solve, in an approximate way, for the variation of height and average velocities along a steady non-uniform inclined flow of a granular-fluid mixture that moves over a rigid bumpy bed. The solutions exhibit features of the flow seen in the experiments – for example, a dry bulbous snout in advance of the fluid, whose length increases with increasing number of the particles and that disappears with increasing velocity – for which satisfactory explanations were lacking.

Scalable Microfluidic Platform for Flexible Configuration of and Experiments with Microtissue Multiorgan Models

2018 ◽  
Vol 24 (1) ◽  
pp. 79-95 ◽  
Author(s):  
Christian Lohasz ◽  
Nassim Rousset ◽  
Kasper Renggli ◽  
Andreas Hierlemann ◽  
Olivier Frey
Keyword(s):  
Large Scale ◽  
Plastic Material ◽  
Microtiter Plate ◽  
Scale Production ◽  
Experimental Conditions ◽  
Precise Control ◽  
Open Design ◽  
Gravity Driven ◽  
Gravity Driven Flow

Microphysiological systems hold the promise to increase the predictive and translational power of in vitro substance testing owing to their faithful recapitulation of human physiology. However, the implementation of academic developments in industrial settings remains challenging. We present an injection-molded microfluidic microtissue (MT) culture chip that features two channels with 10 MT compartments each and that was designed in compliance with microtiter plate standard formats. Polystyrene as a chip material enables reliable, large-scale production and precise control over experimental conditions due to low adsorption or absorption of small, hydrophobic molecules at or into the plastic material in comparison with predecessor chips made of polydimethylsiloxane. The chip is operated by tilting, which actuates gravity-driven flow between reservoirs at both ends of every channel, so that the system does not require external tubing or pumps. The flow rate can be modulated by adjusting the tilting angle on demand. The top-open design of the MT compartment enables efficient MT loading using standard or advanced pipetting equipment, ensures oxygen availability in the chip, and allows for high-resolution imaging. Every channel can be loaded with up to 10 identical or different MTs, as demonstrated by culturing liver and tumor MTs in the same medium channel on the chip.

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