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- Hung V. Vu (4)
- Binh D. Pham (3)
- Cuong T. Nguyen (2)
- Hoe D. Nguyen (2)
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- Compound droplet (2)
- Ban-Chat Reservoir (1)
- Diffusive (1)
- Empty drop of water (1)
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Sustainability requires that once reservoirs are built, they should be managed as environmentally friendly as possible. If the management policy does not achieve efficiency, there might be a man-made disaster occurred. There is a need for establishing a national strategy for developing hydrological forecasting techniques. In this study, hydrological models MARINE and SWAT were established for the Ban-Chat reservoir basin by testing performance in simulating hourly inflow during flood season for short term forecast and daily inflow for long term management respectively. Both models are set up using the same available database but they differ in terms of spatial discretization, infiltration and water redistribution representation and river flow transfer. Overall, it is argued that MAR... |
Compound and simple droplets have been studied and appeared in many life applications, e.g., drug processing and microfluidic systems. Many studies have been conducted on the thermocapillary effects on simple droplets, but similar studies on compound droplets are quite rare. Filling this missing gap, this paper presents the front-tracking-based simulation results of the thermocapillary effects on compound droplets in a certain limited domain. The compound droplet consists of a single inner core that is initially concentric with the outer one. Various dimensionless parameters including Reynolds number from 1 to 50, Marangoni number from 1 to 100, droplet radius ratio from 0.3 to 0.8, and viscosity ratios from 0.1 to 6.4 are varied to reveal their influences on the migration of a comp... |
This study’s aim is to improve the understanding of the dynamical behavior of a multi-core compound droplet traveling in an axisymmetric channel consisting of a diffuser element. The compound droplet typically consisting of two inner droplets distributed one after another is initially located at a certain distance from the entrance of the channel. A front-tracking method is used to handle the movement and deformation of the droplet. The numerical simulation results show that the compound droplet is stretched in the channel, and it takes a certain time, “the transit time”, to pass through the diffuser. The compound droplet has the largest deformation in the diffuser region and tends to return to its nearly original shape after leaving the diffuser. The deformation and transit time of... |
A compound droplet solidifying on a cold curved surface in a gaseous environment is numerically studied by an axisymmetric three-phase front tracking method. The compound droplet containing an inner core of gas is initially assumed to be part of a sphere, and the curved surface is maintained at temperature below the solidification point of the shell liquid. The effects of the radius of the cold surface, volume change (in terms of the solid-to-liquid density ratio ρsl), supercooling degree (in terms of the Stefan number St), growth angle ϕgr and shell liquid thickness on the solidified droplet shape, the solidification rate and the solidification times are under consideration. Volume expansion (ρsl < 1.0) induces an apex, and volume shrinkage (ρsl > 1.0) results in a cavity on top of... |
In this study, the solidification process of a compound droplet is numerically simulated by an axisymmetric front-tracking/finite difference technique. The compound droplet placed on a cold flat surface in a gas environment consists of an inner gas core surrounded by a concentric shell phase-change liquid that forms an outer droplet. The initial droplet shape assumed as a spherical cap is therefore determined by two wetting angles known as the inner wetting angle (?0i for the inner core) and the outer wetting angle (?0o for the outer droplet). During the solidification process, there is the presence of two three-junction points where a prescribed growth angle ? is specified. We analyze the solidification process undergoing the influence of the geometrical aspects of the compound dro... |
We present a numerical investigation of the breakup and freezing of a pendant hollow water drop beneath a cold curved surface. The drop contains a bubble surrounded by a shell of water that forms at an outer wetting angle of θo with the surface. The freezing begins on the cold curved surface and evolves in the direction of gravity. As it freezes, the water accumulates and forms a bulbous end at the bottom of the drop. Breakup can occur, inducing a daughter water drop. As a result, the freezing process of the remaining hollow drop attached to the surface takes less time, and the frozen drop shrinks. However, this breakup has no effect on the bubble. The various parameters under consideration include the Bond number Bo, the Stefan number St, the size of the bubble, and the angle θo. I... |
