scholarly journals Numerical Characterization of the Performance of Fluid Pumps Based on a Wankel Geometry

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Stephen Wan ◽  
Jason Leong ◽  
Te Ba ◽  
Arthur Lim ◽  
Chang Wei Kang
Keyword(s):  
Three Dimensional ◽  
Mechanical Efficiency ◽  
Planar Geometry ◽  
Pump Efficiency ◽  
Capacity Coefficient ◽  
Numerical Characterization ◽  
Pump Flow Rate ◽  
Low Efficiency ◽  
First Time

The performance of fluid pumps based on Wankel-type geometry, taking the shape of a double-lobed limaçon, is characterized. To the authors’ knowledge, this is the first time such an attempt has been made. To this end, numerous simulations for three different pump sizes were carried out and the results were understood in terms of the usual scaling coefficients. The results show that such pumps operate as low efficiency (<30%) valveless positive displacements pumps, with pump flow-rate noticeably falling at the onset of internal leakage. Also, for such pumps, the mechanical efficiency varies linearly with the head coefficient, and, within the onset of internal leakage, the capacity coefficient holds steady even across pump efficiency. Simulation of the flow field reveals a structure rich in three-dimensional vortices even in the laminar regime, including Taylor-like counterrotating vortex pairs, pointing towards the utility of these pumps in microfluidic applications. Given the planar geometry of such pumps, their applications as microreactors and micromixers are recommended.

DISPERSIVE FRACTAL CHARACTERIZATION OF KIDNEY ARTERIES BY THREE-DIMENSIONAL MASS-RADIUS-ANALYSIS

Fractals ◽  
1995 ◽  
Vol 03 (04) ◽  
pp. 879-891 ◽  
Author(s):  
M. SERNETZ ◽  
M. JUSTEN ◽  
F. JESTCZEMSKI
Keyword(s):  
Fractal Structure ◽  
Three Dimensional ◽  
Arterial System ◽  
Data Sets ◽  
Scaling Properties ◽  
Local Scaling ◽  
Living Organisms ◽  
Global And Local ◽  
First Time

Three-dimensional data sets of kidney arterial vessels were obtained from resin casts by serial sectioning and by micro-NMR-tomography, and were analyzed by the mass-radius-relation both for global and local scaling properties. We present for the first time the spatial resolution of local scaling and thus the dispersion of the fractal dimension within the organs. The arterial system is characterized as a non-homogeneous fractal. We discuss and relate the fractal structure to the scaling and allometry of metabolic rates in living organisms.

A study of the mineralization of bone by high voltage EM tomography

1992 ◽  
Vol 50 (1) ◽  
pp. 582-583
Author(s):  
James Arena ◽  
Bruce F. McEwen ◽  
Min Ja Song ◽  
William J. Landis
Keyword(s):  
High Voltage ◽  
Three Dimensional ◽  
Structural Features ◽  
Complete Characterization ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Vertebrate Model ◽  
Em Tomography ◽  
First Time

Complete characterization of the inorganic and organic interaction in calcifying tissues is fundamental to understanding their structure-function relations. In this context, high resolution tomographic three-dimensional (3D) reconstruction of normally calcifying avian tendon imaged by high voltage electron microscopy has recently been used to determine specific structural features of hydroxyapatite crystals associated with collagen fibrils in this vertebrate model of biological mineralization. The present work is an extension of these previous investigations, now applied to bone for the first time.

scholarly journals Multiobjective Optimization Design and Experimental Study of Desulfurization Dust Removal Centrifugal Pump Based on Immune Particle Swarm Algorithm

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yuqin Wang ◽  
Xinwang Huo ◽  
Hailong Ji
Keyword(s):  
Centrifugal Pump ◽  
Optimization Design ◽  
Control Method ◽  
Three Dimensional ◽  
Particle Swarm ◽  
Experimental Results ◽  
Dust Removal ◽  
Particle Swarm Algorithm ◽  
Pump Efficiency ◽  
Low Efficiency

In view of the problems of low efficiency, poor anticavitation performance, and curve hump for current centrifugal pump in the process of desulfurization and dust removal, the desulfurization dust removal centrifugal pump was designed. The velocity coefficient method was used for hydraulic design of centrifugal pump, and the three-dimensional modeling and numerical simulation of flow field of centrifugal pump were carried out by using computational fluid dynamics technology (CFD). The optimal mathematical model with the highest efficiency and the lowest pump net positive suction head NPSHr as the objective function was established under the condition of no curve hump. The immune particle swarm optimization algorithm was used to optimize the multiobjective function, and the optimal combination of the main parameters was obtained. The simulation results showed that, compared with the traditional centrifugal pump, the performance of the optimized centrifugal pump had been greatly improved, which eliminated the phenomenon of curve hump. Based on IH model chemical pump to build a prototype test platform, the experimental results of the external characteristics of the prototype pump and the optimization pump under different working conditions were obtained. At the rated flow rate, the optimization pump efficiency was increased by 13.30%, the head was increased by 11.52%, and NPSHr was decreased by 10.14%. The experimental results showed that the optimized indexes met the design requirements and improved the performance of centrifugal pump. At the same time, the accuracy of the immune particle swarm control method was verified, which provided some reference for the design of desulfurization dust removal centrifugal pump.

scholarly journals Fabrication, Experiments, and Analysis of an LBM Additive-Manufactured Flexure Parallel Mechanism

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 572 ◽  
Author(s):  
Huaxian Wei ◽  
Li Wang ◽  
Xiaodong Niu ◽  
Jian Zhang ◽  
Alessandro Simeone
Keyword(s):  
Additive Manufacturing ◽  
Parallel Mechanism ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Element Analysis ◽  
Flexure Mechanism ◽  
Laser Beam Melting ◽  
Stiffness Characteristics ◽  
First Time

Additive manufacturing technology has advantages for realizing complex monolithic structures, providing huge potential for developing advanced flexure mechanisms for precision manipulation. However, the characteristics of flexure hinges fabricated by laser beam melting (LBM) additive manufacturing (AM) are currently little known. In this paper, the fabrication and characterization of a flexure parallel mechanism through the LBM process are reported for the first time to demonstrate the development of this technique. The geometrical accuracy of the additive-manufactured flexure mechanism was evaluated by three-dimensional scanning. The stiffness characteristics of the flexure mechanism were investigated through finite element analysis and experimental tests. The effective hinge thickness was determined based on the parameters study of the flexure parallel mechanism. The presented results highlight the promising outlook of LBM flexure parts for developing novel nanomanipulation platforms, while additional attention is required for material properties and manufacturing errors.

Organic–inorganic hybrid three-dimensional metal sulfite-oxalates with honeycomb-like structures

2017 ◽  
Vol 46 (18) ◽  
pp. 5911-5917 ◽  
Author(s):  
Ranjay K. Tiwari ◽  
J. N. Behera
Keyword(s):  
Three Dimensional ◽  
Hydrothermal Conditions ◽  
Inorganic Hybrid ◽  
Mixed Metal ◽  
First Time

The crystallographic signatures and characterization of two novel mixed metal hybrid open-frameworks [Na2Mn2(C2O4)(SO3)2(H2O)2], 1 and [NaEu(C2O4)(SO3)(H2O)3], 2 are reported for the first time; they are synthesized under hydrothermal conditions to generate 3D assemblies and honeycomb-like structures.

scholarly journals Characterization of the planetary nebula Tc 1 based on VLT X-shooter observations

2019 ◽  
Vol 490 (2) ◽  
pp. 2475-2494 ◽  
Author(s):  
Isabel Aleman ◽  
Marcelo L Leal-Ferreira ◽  
Jan Cami ◽  
Stavros Akras ◽  
Bram Ochsendorf ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Three Dimensional ◽  
Central Star ◽  
Gas Temperature ◽  
Spatially Resolved ◽  
Morphological Model ◽  
Density Enhancement ◽  
First Time ◽  
The Empirical Analysis

ABSTRACT We present a detailed analysis of deep VLT/X-Shooter observations of the planetary nebula Tc 1. We calculate gas temperature, density, extinction, and abundances for several species from the empirical analysis of the total line fluxes. In addition, a spatially resolved analysis of the most intense lines provides the distribution of such quantities across the nebula. The new data reveal that several lines exhibit a double peak spectral profile consistent with the blue and redshifted components of an expanding spherical shell. The study of such components allowed us to construct for the first time a three-dimensional morphological model, which reveals that Tc 1 is a slightly elongated spheroid with an equatorial density enhancement seen almost pole on. A few bright lines present extended wings (with velocities up to a few hundred km s−1), but the mechanism producing them is not clear. We constructed photoionization models for the main shell of Tc 1. The models predict the central star temperature and luminosity, as well as the nebular density and abundances similar to previous studies. Our models indicate that Tc 1 is located at a distance of approximately 2 kpc. We report the first detection of the [Kr iii] 6825 Å emission line, from which we determine the Krypton abundance. Our model indicates that the main shell of Tc 1 is matter bounded; leaking H ionizing photons may explain the ionization of its faint AGB-remnant halo.

Characterization of the three-dimensional residual stress distribution in SiC bulk crystals by neutron diffraction

CrystEngComm ◽  
2017 ◽  
Vol 19 (43) ◽  
pp. 6527-6532 ◽  
Author(s):  
Xuejian Xie ◽  
Xiaobo Hu ◽  
Xiufang Chen ◽  
Fafu Liu ◽  
Xianglong Yang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Neutron Diffraction ◽  
Three Dimensional ◽  
Diffraction Method ◽  
Residual Stress Distribution ◽  
Bulk Crystals ◽  
First Time ◽  
Neutron Diffraction Method

The neutron diffraction method was adopted to study the three-dimensional residual stress distribution in SiC bulk crystals for the first time.

Numerical characterization of three‐dimensional serpentine micromixers

AIChE Journal ◽  
2008 ◽  
Vol 54 (8) ◽  
pp. 1999-2008 ◽  
Author(s):  
Jang Min Park ◽  
Tai Hun Kwon
Keyword(s):  
Three Dimensional ◽  
Numerical Characterization
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