Highly Distorted Uranyl Ion Coordination and One/Two-Dimensional Structural Relationship in the Ba2[UO2(TO4)2] (T = P, As) System: An Experimental and Computational Study

2014 ◽  
Vol 53 (14) ◽  
pp. 7650-7660 ◽  
Author(s):  
Shijun Wu ◽  
Piotr M. Kowalski ◽  
Na Yu ◽  
Thomas Malcherek ◽  
Wulf Depmeier ◽  
...  
Keyword(s):  
Computational Study ◽  
Uranyl Ion ◽  
Structural Relationship ◽  
Two Dimensional

COMPUTATIONAL STUDY OF THE NON-ISOTHERMAL TWO-DIMENSIONAL PULSED FLOW OVER A CHANNEL WITH A BACKWARD-FACING STEP

2019 ◽  
Author(s):  
Gabriel Machado dos Santos ◽  
Ítalo Augusto Magalhães de Ávila ◽  
Hélio Ribeiro Neto ◽  
Aristeu Silveira Neto
Keyword(s):  
Computational Study ◽  
Two Dimensional ◽  
Backward Facing Step ◽  
Pulsed Flow

Wake Flow of Single and Multiple Yawed Cylinders

2004 ◽  
Vol 126 (5) ◽  
pp. 861-870 ◽  
Author(s):  
A. Thakur ◽  
X. Liu ◽  
J. S. Marshall
Keyword(s):  
Computational Study ◽  
Three Dimensional ◽  
Side Wall ◽  
Wake Flow ◽  
Upstream Region ◽  
Two Dimensional ◽  
Cylinder Wake ◽  
Dimensional Approximation ◽  
The Face ◽  
Drag And Lift

An experimental and computational study is performed of the wake flow behind a single yawed cylinder and a pair of parallel yawed cylinders placed in tandem. The experiments are performed for a yawed cylinder and a pair of yawed cylinders towed in a tank. Laser-induced fluorescence is used for flow visualization and particle-image velocimetry is used for quantitative velocity and vorticity measurement. Computations are performed using a second-order accurate block-structured finite-volume method with periodic boundary conditions along the cylinder axis. Results are applied to assess the applicability of a quasi-two-dimensional approximation, which assumes that the flow field is the same for any slice of the flow over the cylinder cross section. For a single cylinder, it is found that the cylinder wake vortices approach a quasi-two-dimensional state away from the cylinder upstream end for all cases examined (in which the cylinder yaw angle covers the range 0⩽ϕ⩽60°). Within the upstream region, the vortex orientation is found to be influenced by the tank side-wall boundary condition relative to the cylinder. For the case of two parallel yawed cylinders, vortices shed from the upstream cylinder are found to remain nearly quasi-two-dimensional as they are advected back and reach within about a cylinder diameter from the face of the downstream cylinder. As the vortices advect closer to the cylinder, the vortex cores become highly deformed and wrap around the downstream cylinder face. Three-dimensional perturbations of the upstream vortices are amplified as the vortices impact upon the downstream cylinder, such that during the final stages of vortex impact the quasi-two-dimensional nature of the flow breaks down and the vorticity field for the impacting vortices acquire significant three-dimensional perturbations. Quasi-two-dimensional and fully three-dimensional computational results are compared to assess the accuracy of the quasi-two-dimensional approximation in prediction of drag and lift coefficients of the cylinders.

A two dimensional computational study of a gasar porous copper microstructure

1997 ◽  
Vol 225 (1-2) ◽  
pp. 85-95 ◽  
Author(s):  
Anthony Kee ◽  
Peter Matic ◽  
Linda Popels
Keyword(s):  
Computational Study ◽  
Two Dimensional ◽  
Porous Copper

Computational Study of Grooved Microchannel Enhancements

2008 ◽  
Author(s):  
Stephen A. Solovitz
Keyword(s):  
Thermal Management ◽  
Computational Study ◽  
Internal Flow ◽  
Reynolds Numbers ◽  
Thermal Dissipation ◽  
Two Dimensional ◽  
Macro Scale ◽  
Flow Heat ◽  
Alternate Solution ◽  
Selection Of

As electronics devices continue to increase in thermal dissipation, novel methods will be necessary for effective thermal management. Many macro-scale enhancement techniques have been developed to improve internal flow heat transfer, with a dimple feature being particularly promising due to its enhanced mixing with potentially little pressure penalty. However, because dimples may be difficult to fashion in microchannels, two-dimensional grooves are considered here as a similar alternate solution. Computational fluid dynamics methods are used to analyze the flow and thermal performance for a groove-enhanced microchannel, and the effectiveness is determined for a range of feature depths, diameters, and flow Reynolds numbers. By producing local impingement and flow redevelopment downstream of the groove, thermal enhancements on the order of 70% were achieved with pressure increases of only 30%. Further optimization of this concept should allow the selection of an appropriate application geometry, which can be studied experimentally to validate the concept.

Computational Study on Second-Order Nonlinear Response of a Series of Two-Dimensional Carbazole-Cored Chromophores

2008 ◽  
Vol 112 (17) ◽  
pp. 7021-7028 ◽  
Author(s):  
Chun-Guang Liu ◽  
Yong-Qing Qiu ◽  
Zhong-Min Su ◽  
Guo-Chun Yang ◽  
Shi-Ling Sun
Keyword(s):  
Nonlinear Response ◽  
Computational Study ◽  
Second Order ◽  
Two Dimensional

Computational Study of Photonic Crystal Resonator for Biosensor Application

Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 307-316
Author(s):  
A. Benmerkhi ◽  
M. Bouchemat ◽  
T. Bouchemat
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Quality Factor ◽  
Computational Study ◽  
Resonant Cavity ◽  
Resonant Wavelength ◽  
Two Dimensional ◽  
Crystal Resonator ◽  
Biosensor Application ◽  
Cavity Characteristics

Abstract A two dimensional photonic crystal biosensor with high quality factor, transmission and sensitivity has been theoretically investigated using two dimensional finite difference time domain method (FDTD) and plane-wave expansion (PWE) approach. The studied biosensor consisted of two waveguide couplers and one microcavity formed by removing one air pore. Following analyte injection into the sensing holes and binding, the refractive index changes inducing a possible shift in the resonant wavelength. For the optimized structure, the biosensor quality factor is found to be over 49,767 and the obtained sensitivity is of order 15.2 nm/fg. Also, we investigated this structure in case of all air holes are applied as the functionalized holes with a sensitivity was found to be approximately equal to 292.46 nm∕RIU (refractive index units). According to the resonance cavity characteristics, the demultiplexing of different wavelengths can be achieved by regulating the radius of defects “r” inside the cavity. For this, A new design with 2D PCs for two-channel demultiplexer optofluidic biosensor has been proposed. The analysis shows that the response of each channel has a different resonant cavity wavelength and the filling of analyte in the selected holes cause resonant wavelength shifting, independently.

scholarly journals Computational Study of Zigzag Spacer Design with Elliptical Cross-Section Filaments

2020 ◽  
Vol 307 ◽  
pp. 01047
Author(s):  
Gohar Shoukat ◽  
Farhan Ellahi ◽  
Muhammad Sajid ◽  
Emad Uddin
Keyword(s):  
Mass Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Computational Study ◽  
Flow Direction ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Two Dimensional ◽  
Permeate Flux ◽  
Elliptical Cross

The large energy consumption of membrane desalination process has encouraged researchers to explore different spacer designs using Computational Fluid Dynamics (CFD) for maximizing permeate per unit of energy consumed. In previous studies of zigzag spacer designs, the filaments are modeled as circular cross sections in a two-dimensional geometry under the assumption that the flow is oriented normal to the filaments. In this work, we consider the 45° orientation of the flow towards the three-dimensional zigzag spacer unit, which projects the circular cross section of the filament as elliptical in a simplified two-dimensional domain. OpenFOAM was used to simulate the mass transfer enhancement in a reverse-osmosis desalination unit employing spiral wound membranes lined with zigzag spacer filaments. Properties that impact the concentration polarization and hence permeate flux were analyzed in the domain with elliptical filaments as well as a domain with circular filaments to draw suitable comparisons. The range of variation in characteristic parameters across the domain between the two different configurations is determined. It was concluded that ignoring the elliptical projection of circular filaments to the flow direction, can introduce significant margin of error in the estimation of mass transfer coefficient.

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