scholarly journals Improving the Performance of Surface Flow Generated by Bubble Plumes

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 262
Author(s):  
Hassan Abdulmouti
Keyword(s):  
Free Surface ◽  
Flow Structure ◽  
Flow Rate ◽  
Bubble Size ◽  
Gas Flow ◽  
Surface Flow ◽  
Bubble Motion ◽  
Gas Flow Rate ◽  
Two Phase ◽  
Bubble Plumes

Gas–liquid two-phase flow is widely used in many engineering fields, and bubble dynamics is of vital importance in optimizing the engineering design and operating parameters of various adsorptive bubble systems. The characteristics of gas–liquid two-phase (e.g., bubble size, shape, velocity, and trajectory) remain of interest because they give insight into the dynamics of the system. Bubble plumes are a transport phenomenon caused by the buoyancy of bubbles and are capable of generating large-scale convection. The surface flow generated by bubble plumes has been proposed to collect surface-floating substances (in particular, oil layers formed during large oil spills) to protect marine systems, rivers, and lakes. Furthermore, the surface flows generated by bubble plumes are important in various types of reactors, engineering processes, and industrial processes involving a free surface. The bubble parameters play an important role in generating the surface flow and eventually improving the flow performance. This paper studies the effects of temperature on bubble parameters and bubble motion to better understand the relationship between the various bubble parameters that control bubble motion and how they impact the formation of surface flow, with the ultimate goal of improving the efficiency of the generation of surface flow (i.e., rapidly generate a strong, high, and wide surface flow over the bubble-generation system), and to control the parameters of the surface flow, such as thickness, width, and velocity. Such flow depends on the gas flow rate, bubble size (mean bubble diameter), void fraction, bubble velocity, the distance between bubble generator and free surface (i.e., water height), and water temperature. The experiments were carried out to measure bubble parameters in a water column using the image visualization technique to determine their inter-relationships and improve the characteristics of surface flow. The data were obtained by processing visualized images of bubble flow structure for the different sections of the bubble regions, and the results confirm that temperature, bubble size, and gas flow rate significantly affect the flow structure and bubble parameters.

scholarly journals Designing key parameters of bubble plumes to restore water quality by using conceptual models: a case study in a sub-deep reservoir

2020 ◽  
Vol 20 (7) ◽  
pp. 2915-2927
Author(s):  
Chen Lan ◽  
Jingan Chen ◽  
Jianyang Guo ◽  
Jingfu Wang
Keyword(s):  
Flow Rate ◽  
Bubble Size ◽  
Gas Flow ◽  
Bubble Radius ◽  
Bubble Plume ◽  
Gas Flow Rate ◽  
Empirical Formulas ◽  
Bubble Plumes ◽  
Deep Reservoir ◽  
First Time

Abstract Bubble plumes are a popular hypolimnetic reaeration technique in deep-water reservoirs since they have the advantage of delivering direct reaeration to the hypolimnion. Improving the understanding of the integrated reaeration processes is beneficial to optimize the reaeration capacity of the aeration or oxygenation system. In this study, the discrete bubble model was first employed to design an oxygenation system for a sub-deep reservoir (the Aha Reservoir, southwest China, with water depths of 10–30 m). A new approach involving the discrete bubble model was used to determine the initial bubble size of the bubble plume applied. The intrusion models were demonstrated to be useful for designing the gas flow rate of the reaeration system. Using the intrusion models, we predicted the intrusion thickness and intrusion distance during operation for the first time. Subsequently, we verified the predictions and produced more realistic empirical formulas. At present, reports about recommendations on initial bubble size and gas flow rate are rare, and practical verification is absent. Taking the Aha Reservoir as an example, the initial bubble radius of 1 mm and the gas flow rate of 20 m3·h−1 were recommended for bubble plume oxygenation and were found to be successful in the field. Our understanding of the reaeration processes during the operation of the bubble plume system is far from comprehensive, but this study serves to highlight the potential of the discrete bubble model and the intrusion models for designing a bubble plume system in an individual lake.

Inclusion Removal at the Free Surface of Steel Bath by Bubble Flotation

2011 ◽  
Vol 399-401 ◽  
pp. 216-222
Author(s):  
Fang Jiang ◽  
Guo Guang Cheng
Keyword(s):  
Free Surface ◽  
Flow Rate ◽  
Bubble Size ◽  
Gas Flow ◽  
Equilibrium Concentration ◽  
Particle Removal ◽  
Gas Flow Rate ◽  
Inclusion Removal ◽  
Particle Layer ◽  
Polyethylene Particles

In the present work, physical model experiments were carried out to clarify the inclusion removal at the free surface of steel bath. Polyethylene particles were used to simulate the non-wetting inclusions like alumina and silica. The influence of gas flow rate and bubble size on the inclusion removal at the free surface was evaluated. It is demonstrated that not all particles are removed when they arrive at the free surface of liquid bath, and those which are not removed will get back to the bath. It is found an annular particle layer is formed by the removed particles at free surface, which can capture other particles arriving at the free surface. However, the attachment of particles to the annular particle layer is not stable, and re-entrainment of particles occurs at high gas flow rate. It is shown the overall particle removal is determined by a balance of removal and re-entrainment. The particle removal constant increases with the increase in the gas flow rate, but decreases with the increase in bubble size. The equilibrium concentration of particles increases with the increase in gas flow rate and bubble size.

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.

A Review of Wet Gas Flow Rate Measurements by Means of Single-Phase Meters

2018 ◽  
Author(s):  
Enrico Munari ◽  
Michele Pinelli
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Single Phase ◽  
Rate Measurement ◽  
Gas Flow Rate ◽  
Flow Rate Measurement ◽  
Two Phase ◽  
Beneficial Effects ◽  
Wet Gas ◽  
Depth Analysis

Nowadays, wet gas flow rate measurement is still a challenge for experimental investigators and it is becoming an even more important issue to overcome in the turbomachinery sector as well, due to the increasing trend of wet compression applications in industry. The requirement to determine gas turbine performance when processing a wet gas leads to the need to understand certain phenomena, such as type of liquid flow re-distribution, and errors introduced when the mass flow rate measurement of a two-phase gas is attempted. Unfortunately, this measurement is often affected by the presence of liquid. Literature does not offer a unique definition of the term wet gas, although it is recognized that a wet gas can generally be defined as a two-phase gas in which the liquid percentage is lower than the gas one. This paper aims to collect and describe the main works present in literature in order to clarify i) the most used parameters that describe the types of wet gas, and ii) the types of errors and flow patterns which occur in different types of applications, in terms of pressure, percentage of liquid, Reynolds number, etc. Therefore, this literature review offers a comprehensive description of the possible effects of liquid presence in a wet gas and, and an in-depth analysis of the limitations and beneficial effects of current single-phase flow rate sensors in order to identify the best solutions, and empirical corrections available in literature to overcome this challenge.

Mixing of Fluids in Tanks by Gas Bubble Plumes

1987 ◽  
Vol 109 (2) ◽  
pp. 186-193 ◽  
Author(s):  
A. M. Godon ◽  
J. H. Milgram
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Mixing Time ◽  
Empirical Relationship ◽  
Scale Model ◽  
Gas Bubble ◽  
Gas Flow Rate ◽  
Dimensionless Variable ◽  
Bubble Plumes ◽  
The Relationship

The need to rapidly mix treating agent into the oil of a ruptured ship tank motivated scale model experiments of mixing in square-bottomed tanks by gas bubble plumes, The mixing time is primarily governed by the gas flow rate, the plume length and the tank base dimensions; and is quite insensitive to tank height. An empirical relationship between the degree of mixing and a single dimensionless variable is developed and an explanation of the relationship in terms of the fundamentals of the flow is provided.

Effect of Bubble Size and Angle of Tapered Upriser Pipe on the Effectiveness of a Two Phase Lifting Pump

2009 ◽  
Author(s):  
P. Hanafizadeh ◽  
M. H. Saidi ◽  
A. Zamiri ◽  
A. Karimi
Keyword(s):  
Gas Phase ◽  
Flow Rate ◽  
Bubble Size ◽  
Gas Flow ◽  
Bubble Diameter ◽  
Design Parameters ◽  
Two Phase ◽  
Bubble Distribution ◽  
Improved Performance ◽  
Different Diameters

Two phase lifting pumps are devices with the ability of lifting liquid phase by injecting the gas phase. Parameters which affect the performance of these pumps are divided into two groups. The first group contains design parameters such as diameter of the pipe, tapering angle of the upriser pipe and the submergence ratio which is the ratio of immersed length to the total length of the upriser. The second group includes operating parameters, such as the gas flow rate, bubble diameter, bubble distribution and inlet gas pressure. In this research, the performance of two phase lifting pump is investigated numerically for different submergence ratios and different diameter of the upriser pipe. For this purpose the two phase pump with a riser length of 914 mm and different diameters (6, 8 and 10 mm), and seven tapering angles (0°, 0.25°, 0.5°, 1°, 1.5°, 2° and 3°) are numerically modeled and analyzed. Different submergence ratios are used, namely: 0.4, 0.6 and 0.8. The numerical results are compared with the existing experimental data in the literature showing a reasonable agreement. The results indicate that decrease in size of the bubble diameter increases mass flow rate of liquid at constant submergence ratios. The present study reports the improved performance of this pump with decrease in bubble size and increase in angle of tapered upriser pipe. Moreover, the results show that the tapered upriser pipe with 3° tapering angle gives the highest efficiency at nearly all submergence ratios. Further, the highest efficiency of the pump is shown to be at the largest submergence ratio, namely 0.8.

scholarly journals Measurement of Gas-Oil Two-Phase Flow Patterns by Using CNN Algorithm Based on Dual ECT Sensors with Venturi Tube

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1200 ◽  
Author(s):  
Zhuoqun Xu ◽  
Fan Wu ◽  
Xinmeng Yang ◽  
Yi Li
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Venturi Tube ◽  
Phase Flow ◽  
Gas Flow Rate ◽  
Two Phase ◽  
Oil Flow ◽  
Oil Gas

In modern society, the oil industry has become the foundation of the world economy, and how to efficiently extract oil is a pressing problem. Among them, the accurate measurement of oil-gas two-phase parameters is one of the bottlenecks in oil extraction technology. It is found that through the experiment the flow patterns of the oil-gas two-phase flow will change after passing through the venturi tube with the same flow rates. Under the different oil-gas flow rate, the change will be diverse. Being motivated by the above experiments, we use the dual ECT sensors to collect the capacitance values before and after the venturi tube, respectively. Additionally, we use the linear projection algorithm (LBP) algorithm to reconstruct the image of flow patterns. This paper discusses the relationship between the change of flow patterns and the flow rates. Furthermore, a convolutional neural network (CNN) algorithm is proposed to predict the oil flow rate, gas flow rate, and GVF (gas void fraction, especially referring to sectional gas fraction) of the two-phase flow. We use ElasticNet regression as the loss function to effectively avoid possible overfitting problems. In actual experiments, we compare the Typical-ECT-imaging-based-GVF algorithm and SVM (Support Vector Machine) algorithm with CNN algorithm based on three different ECT datasets. Three different sets of ECT data are used to predict the gas flow rate, oil flow rate, and GVF, and they are respectively using the venturi front-based ECT data only, while using the venturi behind-based ECT data and using both these data.

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