scholarly journals Hydrodynamic characteristics of the two-phase flow field at gas-evolving electrodes: numerical and experimental studies

2018 ◽  
Vol 5 (5) ◽  
pp. 171255 ◽  
Author(s):  
Cheng-Lin Liu ◽  
Ze Sun ◽  
Gui-Min Lu ◽  
Jian-Guo Yu
Keyword(s):  
Mathematical Model ◽  
Flow Field ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Electrode System ◽  
Hydrodynamic Characteristics ◽  
Cold Model ◽  
Two Phase ◽  
3D Space ◽  
Vertical Electrode

Gas-evolving vertical electrode system is a typical electrochemical industrial reactor. Gas bubbles are released from the surfaces of the anode and affect the electrolyte flow pattern and even the cell performance. In the current work, the hydrodynamics induced by the air bubbles in a cold model was experimentally and numerically investigated. Particle image velocimetry and volumetric three-component velocimetry techniques were applied to experimentally visualize the hydrodynamics characteristics and flow fields in a two-dimensional (2D) plane and a three-dimensional (3D) space, respectively. Measurements were performed at different gas rates. Furthermore, the corresponding mathematical model was developed under identical conditions for the qualitative and quantitative analyses. The experimental measurements were compared with the numerical results based on the mathematical model. The study of the time-averaged flow field, three velocity components, instantaneous velocity and turbulent intensity indicate that the numerical model qualitatively reproduces liquid motion. The 3D model predictions capture the flow behaviour more accurately than the 2D model in this study.

Analysis of Single- and Two-Phase Flows in Turbopump Inducers

1967 ◽  
Vol 89 (4) ◽  
pp. 577-586 ◽  
Author(s):  
P. Cooper
Keyword(s):  
Equation Of State ◽  
Flow Field ◽  
Thermal Effects ◽  
Single Phase ◽  
Fluid Pressure ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Recent Theory ◽  
Two Phase ◽  
Overall Efficiency

A model is developed for analytically determining pump inducer performance in both the single-phase and cavitating flow regimes. An equation of state for vaporizing flow is used in an approximate, three-dimensional analysis of the flow field. The method accounts for losses and yields internal distributions of fluid pressure, velocity, and density together with the resulting overall efficiency and pressure rise. The results of calculated performance of two sample inducers are presented. Comparison with recent theory for fluid thermal effects on suction head requirements is made with the aid of a resulting dimensionless vaporization parameter.

Two-Phase Flow Field Numerical Simulation in Scrubber for Exhaust Gas Desulfurization

2014 ◽  
Vol 541-542 ◽  
pp. 1288-1291
Author(s):  
Zhi Feng Dong ◽  
Quan Jin Kuang ◽  
Yong Zheng Gu ◽  
Rong Yao ◽  
Hong Wei Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flue Gas ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Flue Gas Desulfurization ◽  
Parameter Design ◽  
Phase Flow ◽  
Two Phase ◽  
Entrance Angle

Calculation fluid dynamics software Fluent was used to conduct three-dimensional numerical simulation on gas-liquid two-phase flow field in a wet flue gas desulfurization scrubber. The k-ε model and SIMPLE computing were adopted in the analysis. The numerical simulation results show that the different gas entrance angles lead to internal changes of gas-liquid two-phase flow field, which provides references for reasonable parameter design of entrance angle in the scrubber.

Research Analysis and Experiment Study on Flow Field of Hydrodynamic Coupling

2011 ◽  
Vol 418-420 ◽  
pp. 2006-2011
Author(s):  
Rui Zhang ◽  
Cheng Jian Sun ◽  
Yue Wang
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Internal Flow ◽  
Phase Flow ◽  
Complex Flow ◽  
Two Phase ◽  
Operation Conditions ◽  
Hydrodynamic Coupling

CFD simulation and PIV test technology provide effective solution for revealing the complex flow of hydrodynamic coupling’s internal flow field. Some articles reported that the combination of CFD simulation and PIV test can be used for analyzing the internal flow field of coupling, and such analysis focuses on one-phase flow. However, most internal flow field of coupling are gas-fluid two-phase flow under the real operation conditions. In order to reflect the gas-fluid two-phase flow of coupling objectively, CFD three-dimensional numerical simulation is conducted under two typical operation conditions. In addition, modern two-dimensional PIV technology is used to test the two-phase flow. This method of combining experiments and simulation presents the characteristics of the flow field when charging ratios are different.

Three-Dimensional Water Temperature and Hydrodynamic Simulation of Xiangxi River Estuary

2013 ◽  
Vol 726-731 ◽  
pp. 3212-3221 ◽  
Author(s):  
Wei Ping Yin ◽  
Dao Bin Ji ◽  
Nian San Hu ◽  
Tao Xie ◽  
Yu Ling Huang ◽  
...  
Keyword(s):  
Flow Field ◽  
Exchange Process ◽  
Water Flow Rate ◽  
Three Dimensional ◽  
River Estuary ◽  
Nutrient Concentrations ◽  
Hydrodynamic Characteristics ◽  
Density Current ◽  
Transverse Distribution ◽  
Xiangxi River

When the impoundment of the Three Gorges Reservoir begins, the water level rises, and the water flow rate slows down, thus the residence time of bay and tributary pollutant extends, and the water environment changes significantly, resulting in different degrees of cyanobacteria outbreak in each spring. Numerous studies show that nutrient concentrations in mainstream is relatively higher than in tributary, so stratified density current of mainstreams and tributaries has played a key role on Bay eutrophication. In order to investigate the exchange process of mainstreams and tributaries, set boundary conditions according to the observed data, and then simulate Xiangxi estuary three-dimensional hydrodynamic characteristics by using Flow-3D software, which can simulate it well. The model theoretically confirms that the intrusion density current phenomenon does exist in typical tributaries, and the simulation results show that near the estuary region, there is a big diversity in the temperature field and the flow field along the transverse distribution, but when the estuary distance increases, the flow field in the cross section, except for a small area near the riverbank, tends to be in a mean state along the transverse distribution.

Computational and experimental investigations in a cyclone dust separator

1997 ◽  
Vol 211 (4) ◽  
pp. 247-257 ◽  
Author(s):  
S M Fraser ◽  
A M Abdel-Razek ◽  
M Z Abdullah
Keyword(s):  
Flow Field ◽  
Richardson Number ◽  
Swirling Flow ◽  
Laser Doppler Anemometry ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Cyclone Chamber ◽  
Dust Separator

Three-dimensional turbulent flow in a model cyclone has been simulated using PHOENICS code and experimental studies carried out using a laser Doppler anemometry (LDA) system. The experimental results were used to validate the computed velocity distributions based on the standard and a modified k-∊ model. The standard k-∊ model was found to be unsatisfactory for the prediction of the flow field inside the cyclone chamber. By considering the strong swirling flow and the streamlined curvature, a k-∊ model, modified to take account of the Richardson number, provided better velocity distributions and better agreement with the experimental results.

A Mathematical Analysis of Directional Solidification of Aqueous Solutions

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Gideon Ukpai ◽  
Boris Rubinsky
Keyword(s):  
Mathematical Model ◽  
Aqueous Solutions ◽  
Mathematical Models ◽  
Directional Solidification ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Design Parameters ◽  
Fundamental Study ◽  
Biological Matter ◽  
Intent To Use

Abstract Horizontal directional solidification techniques have been broadly utilized for the freezing of biological matter under conditions in which the freezing rate during solidification must be controlled and known. Directional solidification is used for diverse applications such as fundamental research on freezing of biological materials, cryopreservation of biological matter, and tissue engineering. This study is motivated by our intent to use directional solidification as a simplified model for the study of three-dimensional (3D) cryoprinting. In evaluating directional solidification in the context of 3D cryoprinting, we realized that current mathematical models of directional solidification are not adequately representative for this purpose, because they are simplified and one-dimensional (1D). Here, we introduce an experimentally verified and more representative two-dimensional (2D) mathematical model of directional solidification that can aid in the fundamental study of freezing of biological matter, in particular during 3D cryoprinting. The mathematical model was used to develop correlations between the freezing rates that a layer of an aqueous solution experiences during directional solidification and the various design parameters such as thickness of the sample and temperature gradients in the substrate. Results show that the freezing rates can be higher than those suggested by the previously used simplified 1D mathematical models. The results can be used for developing simplified models of 3D cryoprinting. In addition, the results suggest that many experimental studies on directional solidification of aqueous solutions and biological matter may require readjustment of analysis, in view of these findings.

Study of Blade Sweep Effects of Compressor

2005 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Flow Field ◽  
Turbine Blade ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Experimental Results ◽  
Numerical Analyses ◽  
Blade Design ◽  
3D Flow ◽  
Efficient Manner ◽  
Blade Row

The three dimensional blading had been used for years in the process of turbomachine designs. In need of turbine blade designs in an efficient manner, the current advancement of CFD technologies allows effective 3D predictions of a complex 3D flow field in turbine blade passages, which can improve the turbine blade performances. Since numerous advantages of 3-D CFD usage had been reported in the open literature, many industries already started to use 3D blading in their turbomachines. In addition, a blade lean and a sweep for the blade design had been also implemented to increase the blade row efficiency. Experimental studies have shown some advantages of these lean and sweep features. Most of the experimental results combine many other features together. However, it is difficult to determine what the effects of different features should be. In this study, detailed numerical analyses were developed and these were used to present the results to gain better understanding of different feature of 3D blading for turbine designers and engineers. Throughout this paper performance impacts on different 3D features are presented and the superiority of the present approach is discussed.

Experimental Investigation of a Generic Compressor Bleed System

2006 ◽  
Author(s):  
Reinaldo A. Gomes ◽  
Carsten Schwarz ◽  
Michael Pfitzner
Keyword(s):  
Flow Field ◽  
Annular Flow ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Complex Flow ◽  
Pressure Losses ◽  
Aero Engines

Extensive experimental studies on axial compressor bleed-flow systems have been carried out on a three dimensional model of a generic bleed-flow configuration typical for aero engines. The compressor flow is modeled as a clean annular flow. One row of stator vanes is used to impart a constant swirl upstream of the bleed system. The rig is designed modularly in order to allow for inexpensive changes in all of its components and therefore to enlarge the variability of the model. The research is focused onto the generation of an experimental data base, which can be used to derive correlations for the calculation of effective areas and pressure losses. Those data are gained using steady pneumatic measurement technique. In addition, the highly complex flow field in the manifold, which has an important effect onto the bleed-flow, is analyzed using Doppler-Global-Velocimetry (DGV). These measurements were conducted in collaboration with DLR Cologne, who have developed the DGV technique. In this paper the flow field in the manifold is analyzed in detail for two different configurations featuring two and four bleed ducts, respectively. Furthermore the use of a flush design of the slot is compared with a lip design. These data are compared to results from the literature achieved using 2-dimensional configurations.

scholarly journals Optimizing the cleanliness in multi-segment disk amplifiers based on vector flow schemes

2018 ◽  
Vol 6 ◽  
Author(s):  
Zhiyuan Ren ◽  
Jianqiang Zhu ◽  
Zhigang Liu ◽  
Xiaowei Yang
Keyword(s):  
Flow Field ◽  
Particle Concentration ◽  
Flow Model ◽  
Three Dimensional ◽  
Phase Flow ◽  
Three Dimensional Flow ◽  
Two Phase ◽  
Key Factor ◽  
Measurement Experiment ◽  
Laser Induced Damage

The objective of maintaining the cleanliness of the multi-segment disk amplifier in Shenguang-II (SG-II) is to reduce laser-induced damage for optics. The flow field of clean gas, which is used for the transportation of contaminant particles, is a key factor affecting the cleanliness level in the multi-segment disk amplifier. We developed a gas–solid coupling and three-dimensional flow numerical simulation model. The three-dimensional and two-phase flow model is verified by the flow-field smog experiment and the particle concentration measurement experiment with the 130-disk amplifier in SG-II. By optimizing the boundary conditions with the same flow rate, the multi-inlet vector flow scheme can not only effectively reduce the purging time, but also prevent the reverse diffusion of contaminant particles in the multi-segment disk amplifier and the deposition of contaminant particles on the surface of the Nd:glass.

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