Dependence of Gas Bubble Diameter from the Gas Flow Rate in Upward Two-Phase Flow in an Inclined Flat Channel

2014 ◽  
Vol 9 (2) ◽  
pp. 136-144
Author(s):  
Anastasia Gorelikova ◽  
Oleg Kashinsky ◽  
Vyacheslav Randin ◽  
Aleksandr Chinak
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Gas Flow ◽  
Bubbly Flow ◽  
Bubble Diameter ◽  
Flow Rate Ratio ◽  
Flat Channel ◽  
Gas Flow Rate ◽  
Two Phase ◽  
Gas Liquid Flow

Experimental study of heat transfer and wall shear stress in an upward bubbly flow in an inclined flat channel is presented. The measurements were performed in the range of superficial liquid velocities 0.31.1 m/s and different values of volumetric gas flow rate ratio. Measurements of hydrodynamic structure were carried out by electrochemical method using a miniature sensors of friction. The values of average friction and heat transfer coefficient at different orientations of the channel were determined. It is shown that there is a significant dependence of friction and heat transfer on the channel inclination angle in the gas-liquid flow

Numerical Study on Bubble-Melt Two-Phase Flows in the Production Process of Aluminum Foams

2011 ◽  
Vol 704-705 ◽  
pp. 796-803
Author(s):  
Hong Liu ◽  
Mao Zhao Xie ◽  
Jun Rui Shi ◽  
Hong Sheng Liu
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Reference Frames ◽  
Numerical Study ◽  
Fluid Model ◽  
Bubble Diameter ◽  
Functional Materials ◽  
Gas Flow Rate ◽  
Aluminum Foams ◽  
Two Phase

Aluminum foams, as a representative of metallic foams, are a kind of very useful and promising functional materials. This paper reports progress in three-dimensional numerical simulations of gas bubble-metallic melt turbulent flows during the foaming process of aluminum foams, in which air is injected into molten aluminum composites and the melt is mechanical stirred by a pitched-blade impeller with an inclined shaft. The bubble-melt two phase flow in the tank is described with an Eulerian-Eulerian two fluid model, the impeller flow region is simulated based on the Multiple Reference Frames (MRF) method. Influences of gas flow rate, impeller rotation speed and initial bubble diameter on the characteristics of the liquid flow field and gas fraction distribution are examined. Computational results show that bubbles tend to accumulate behind the impeller blades and have an approximately uniform distribution near the top surface of the liquid. Gas holdup values are increased with increasing the impeller speed and gas flow rate and decreased with the bubble diameter.

Numerical modeling of the influence of bubbles on flow and heat transfer in the descending gas-liquid flow in a pipe

2012 ◽  
Vol 9 (1) ◽  
pp. 131-135
Author(s):  
M.A. Pakhomov
Keyword(s):  
Heat Transfer ◽  
Gas Phase ◽  
Liquid Flow ◽  
Bubble Diameter ◽  
Gas Content ◽  
Two Phase ◽  
Eulerian Description ◽  
Flow And Heat Transfer ◽  
Gas Liquid Flow ◽  
The Mathematical Model

The paper presents the results of modeling the dynamics of flow, friction and heat transfer in a descending gas-liquid flow in the pipe. The mathematical model is based on the use of the Eulerian description for both phases. The effect of a change in the degree of dispersion of the gas phase at the input, flow rate, initial liquid temperature and its friction and heat transfer rate in a two-phase flow. Addition of the gas phase causes an increase in heat transfer and friction on the wall, and these effects become more noticeable with increasing gas content and bubble diameter.

Research on Deposition of Micro-Nano Aerosols in Rising Bubble Under Pool Scrubbing Condition

2018 ◽  
Author(s):  
Yanmin Zhou ◽  
Haifeng Gu ◽  
Qiunan Sun ◽  
Zhongning Sun ◽  
Jiqiang Su ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Bubbly Flow ◽  
Aerosol Deposition ◽  
Deposition Efficiency ◽  
Filtration Efficiency ◽  
Liquid Level ◽  
Gas Flow Rate ◽  
Reactor Accident ◽  
Rising Bubble

Aerosols as the main component of radioactive products in migration performance, which is an important factor that a unclear reactor accident present strong diffusion and affects the distributions of source and dose level in reactor containment, and they are therefore expected to be deposited in liquid phase such as in suspension pool and filtered containment venting device. In this paper, the deposition characteristics of micro-nano aerosols in rising bubble under pool scrubbing condition is studied with experiment, the aerosols size in the research range from 20 nm to 600 nm, and the bubble morphology mainly concern homogeneous bubbly flow. The results show that the deposition efficiency and mechanism of aerosol closely relate to gas flow rate, liquid level, particle size and bubbles size and so on. The aerosol deposition near 85nm is proved most difficult because of the convert of deposition mechanisms. In a high liquid level condition, micro-nano aerosol filtration efficiency is enhanced but gradually gradual. Under different gas flow rate, air bubble residence time and the bubble size distributions affect the filtration efficiency of aerosols.

Experimental, Numerical, and Statistical Investigation of Two Phase Flow in a Cylindrical Perforation Tunnel

2021 ◽  
Author(s):  
Ekhwaiter Abobaker ◽  
Abadelhalim Elsanoose ◽  
Mohammad Azizur Rahman ◽  
Faisal Khan ◽  
Amer Aborig ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Statistical Analysis ◽  
Flow Rate ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Gas Flow Rate ◽  
Two Phase ◽  
Flow Through

Abstract Perforation is the final stage in well completion that helps to connect reservoir formations to wellbores during hydrocarbon production. The drilling perforation technique maximizes the reservoir productivity index by minimizing damage. This can be best accomplished by attaining a better understanding of fluid flows that occur in the near-wellbore region during oil and gas operations. The present work aims to enhance oil recovery by modelling a two-phase flow through the near-wellbore region, thereby expanding industry knowledge about well performance. An experimental procedure was conducted to investigate the behavior of two-phase flow through a cylindrical perforation tunnel. Statistical analysis was coupled with numerical simulation to expand the investigation of fluid flow in the near-wellbore region that cannot be obtained experimentally. The statistical analysis investigated the effect of several parameters, including the liquid and gas flow rate, liquid viscosity, permeability, and porosity, on the injection build-up pressure and the time needed to reach a steady-state flow condition. Design-Expert® Design of Experiments (DoE) software was used to determine the numerical simulation runs using the ANOVA analysis with a Box-Behnken Design (BBD) model and ANSYS-FLUENT was used to analyses the numerical simulation of the porous media tunnel by applying the volume of fluid method (VOF). The experimental data were validated to the numerical results, and the comparison of results was in good agreement. The numerical and statistical analysis demonstrated each investigated parameter’s effect. The permeability, flow rate, and viscosity of the liquid significantly affect the injection pressure build-up profile, and porosity and gas flow rate substantially affect the time required to attain steady-state conditions. In addition, two correlations obtained from the statistical analysis can be used to predict the injection build-up pressure and the required time to reach steady state for different scenarios. This work will contribute to the clarification and understanding of the behavior of multiphase flow in the near-wellbore region.

Momentum and Heat Transfer in Laminar Flow of Gas With Liquid-Droplet Suspension Over a Circular Cylinder

1967 ◽  
Vol 89 (2) ◽  
pp. 185-193 ◽  
Author(s):  
M. E. Goldstein ◽  
Wen-Jei Yang ◽  
J. A. Clark
Keyword(s):  
Heat Transfer ◽  
Circular Cylinder ◽  
Skin Friction ◽  
Gas Flow ◽  
Flow Problem ◽  
Liquid Droplet ◽  
Two Phase ◽  
Momentum And Heat Transfer ◽  
Layer Flow ◽  
Gas Liquid Flow

An analysis has been made to determine the heat transfer and friction characteristics in a two-phase (gas-liquid) flow over a circular cylinder. It is demonstrated that the resulting two-layer flow problem can be formulated exactly within the framework of laminar boundary layer theory. Two cases are studied; (1) For the parameter E greater or equal to 0.1 and the drop trajectories straight and, (2) For E less or equal to 0.1 and for any drop trajectory. Solutions obtained in power series include the local liquid-film thickness, velocity and temperature profiles, skin friction and Nusselt number. Numerical results disclose a significant increase in both heat transfer rate and skin friction over those of a pure gas flow. The theoretical prediction compares favorably with experimental results of Acrivos, et al. [1].

Heat Transfer in the Non-reacting Zone of a Cement Rotary Kiln

1996 ◽  
Vol 118 (1) ◽  
pp. 169-172 ◽  
Author(s):  
P. S. Ghoshdastidar ◽  
V. K. Anandan Unni
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Rotary Kiln ◽  
Gas Flow ◽  
Transfer Model ◽  
Temperature Profiles ◽  
Gas Temperature ◽  
Gas Flow Rate ◽  
Steady State Heat ◽  
Steady State Heat Transfer

This paper presents a steady-state heat transfer model for a rotary kiln used for drying and preheating of wet solids with application to the non-reacting zone of a cement rotary kiln. A detailed parametric study indicates that the influence of the controlling parameters such as percent water content (with respect to dry solids), solids flow rate, gas flow rate, kiln inclination angle and the rotational speed of the kiln on the axial solids and gas temperature profiles and the total predicted kiln length is appreciable.

scholarly journals Influence of SiH4/CH4 gas flow rate ratio on the properties of a-SiC:H films showing a negative temperature coeffcient in D.C. conductivity.

Shinku ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 354-357
Author(s):  
Isamu NAKAAKI ◽  
Nobuo SAITO ◽  
Norihiko TANAKA ◽  
Kazutosi YOSIDA
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Gas Flow ◽  
Negative Temperature ◽  
Flow Rate Ratio ◽  
Gas Flow Rate

scholarly journals ZnO:Al Thin Films with Buffer Layers Fabricated via Nitrogen Mediated Crystallization: Effects of N2/Ar Gas Flow Rate Ratio

2012 ◽  
Vol 37 (2) ◽  
pp. 165-168 ◽  
Author(s):  
Iping Suhariadi ◽  
Naho Itagaki ◽  
Kazunari Kuwahara ◽  
Koichi Oshikawa ◽  
Daisuke Yamashita ◽  
...  
Keyword(s):  
Thin Films ◽  
Flow Rate ◽  
Rate Ratio ◽  
Gas Flow ◽  
Buffer Layers ◽  
Flow Rate Ratio ◽  
Gas Flow Rate ◽  
Ar Gas

Effect of Flow Rate of Reactive Gas on Mechanical and Tribological Properties of Carbon Nitride Coatings

2018 ◽  
Vol 883 ◽  
pp. 48-52
Author(s):  
Yan Liang Su ◽  
Sun Hui Yao ◽  
Yi Ru Wu ◽  
Cheng Yeh Lin
Keyword(s):  
Tribological Properties ◽  
Flow Rate ◽  
Gas Flow ◽  
Carbon Nitride ◽  
Flow Rate Ratio ◽  
Gas Flow Rate ◽  
Mechanical And Tribological Properties ◽  
Nitride Coatings ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio

This study discusses the mechanical and tribological properties of a series of carbon nitride coatings deposited by unbalanced DC magnetron sputtering using nitrogen-argon mixture gas and graphite targets. The carbon nitride coatings were with varying carbon/nitrogen ratio by varying the gas flow rate ratio of nitrogen gas/argon while kept the overall gas flow rate at constant. The carbon nitride coatings with C/N ratios from 2.01 to 3.27 were obtained. The coatings were characterized and studied by nanohardness, scratching, and wear testers. It was found that the carbon nitride coatings with C/N ratio=2.36 showed the best performance of all the evaluated properties.

scholarly journals Optimization of CO2Absorption Characteristic under the Influence of SO2in Flue Gas by Hollow Fiber Membrane Contactor

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ziyi Qu ◽  
Li Zhang ◽  
Yunfei Yan ◽  
Shunxiang Ju
Keyword(s):  
Flow Rate ◽  
Hollow Fiber ◽  
Flue Gas ◽  
Gas Flow ◽  
Hollow Fiber Membrane ◽  
Flow Rate Ratio ◽  
Absorption Characteristic ◽  
Membrane Contactor ◽  
Gas Flow Rate ◽  
Fiber Membrane

Hollow fiber membrane contactor is a new, highly efficient, and the most promising technology for CO2absorption in flue gas. There is still SO2that exists in the flue gas after desulfurization tower of power plant. This paper studied the influence of SO2on CO2absorption characteristic in flue gas by hollow fiber membrane contactor with absorbent of EDA, EDA + MEA (0.6 : 0.4), and EDA + MEA + PZ (0.4 : 0.4 : 0.2). The influences of SO2concentration, cycle absorption and desorption characteristic of absorbent, absorbent concentration, and liquid-gas flow rate ratio are studied to analyze the influence of SO2on CO2absorption characteristic. The appropriate absorbent composition ratio and appropriate parameter range that can inhibit the influence of SO2are proposed by studying the hybrid sorbent with activating agent, appropriate absorbent concentration, and ratio of liquid-gas flow rate. Among the three kinds of absorbents, EDA + MEA + PZ (0.4 : 0.4 : 0.2) had the best tolerance ability to SO2and the highest efficiency. With comprehensive consideration of CO2removal efficiency and operating cost, under the condition of 1000 ppm SO2, the appropriate concentration and liquid-gas flow rate ratio of EDA, EDA + MEA, and EDA + MEA + PZ are proposed.

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