scholarly journals Using a Dynamic and Constant Mesh in Numerical Simulation of the Free-Rising Bubble

Fluids ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 38 ◽  
Author(s):  
Zlatko Rek

A two-phase bubbly flow is often found in the process industry. For the efficient operation of such devices, it is important to know the details of the flow. The paper presents a numerical simulation of the rising bubble in a stagnant liquid column. The interFOAM solver from the open source Computational Fluid Dynamics (CFD) toolbox OpenFOAM was used to obtain the necessary data. The constant and dynamic computational grids were used in the numerical simulation. The results of the calculation were compared with the measured values. As expected, by using the dynamic mesh, the bubble trajectory was closer to the experimental results due to the more detailed description of the gas–liquid interface.

2018 ◽  
Vol 8 (3) ◽  
pp. 2897-2900
Author(s):  
F. P. Lucas ◽  
R. Huebner

This paper aims to apply computational fluid dynamics (CFD) to simulate air flow and air flow with water droplets, as a reasonable hypothesis for real flows, in order to evaluate a vertical separator vessel with inclined half-pipe inlet device (slope inlet). Thus, this type was compared to a separator vessel without inlet device (straight inlet). The results demonstrated a different performance for the two types in terms of air distribution and liquid removal efficiency.


2013 ◽  
Vol 68 (12) ◽  
pp. 2534-2544 ◽  
Author(s):  
N. Ratkovich ◽  
T. R. Bentzen

Membrane bioreactors (MBRs) have been used successfully in biological wastewater treatment to solve the perennial problem of effective solids–liquid separation. A common problem with MBR systems is clogging of the modules and fouling of the membrane, resulting in frequent cleaning and replacement, which makes the system less appealing for full-scale applications. It has been widely demonstrated that the filtration performances in MBRs can be greatly improved with a two-phase flow (sludge–air) or higher liquid cross-flow velocities. However, the optimization process of these systems is complex and requires knowledge of the membrane fouling, hydrodynamics and biokinetics. Modern tools such as computational fluid dynamics (CFD) can be used to diagnose and understand the two-phase flow in an MBR. Four cases of different MBR configurations are presented in this work, using CFD as a tool to develop and optimize these systems.


Author(s):  
Rajnish K. Calay ◽  
Arne E. Holdo

The Computational Fluid Dynamics (CFD) is now increasingly being used for modeling industrial flows, i.e. flows which are multiphase and turbulent. Numerical modeling of flows where momentum, heat and mass transfer occurs at the interface presents various difficulties due to the wide range of mechanisms and flow scenarios present. This paper attempts to provide a summary of available mathematical models and techniques for two-phase flows. Some comments are also made on the models available in the commercially available codes.


2012 ◽  
Vol 532-533 ◽  
pp. 431-435
Author(s):  
Chong Zhi Mao ◽  
Qian Jian Guo ◽  
Lei He

Honeycomb ceramic is the key component of the regenerative system. The numerical simulation was performed using FLUENT, a commercial computational fluid dynamics (CFD) code, to compare simulation results to the test data. The regenerative process of a honeycomb ceramic regenerator was simulated under different conditions. Experiments were carried out on honeycomb regenerators that are contained in a methane oxidation reactor. The calculated temperatures of flue gas inlet were compared with the ones measured. The tendency of the temperature is the same as the experiment.


2013 ◽  
Vol 805-806 ◽  
pp. 1785-1789
Author(s):  
Chang Bin Wang ◽  
Miao Wang ◽  
Xiao Xu Li ◽  
Yu Liu ◽  
Jie Nan Dong

A three dimensional fluid flow model was set up in this paper, based on the computational fluid dynamics (CFD) and the elasticity theory. Using the finite volume method, a 120° bend was taken as a research object to simulate the erosion to the wall of fluid with sparse particles, finally, to determine the most severe wear areas.At the same time, the distribution of two-phase flows pressure and velocity was analyzed in 45° and 90° bends, then tracked the trajectory of the particles. The results show that the 90°bend has the smallest wear area and particle distribution or combination property is the best.


2012 ◽  
Vol 594-597 ◽  
pp. 2106-2111
Author(s):  
Yi Tang ◽  
Jin Feng Wang ◽  
Jing Xie ◽  
Zheng Zhang ◽  
Rui Liu

The sales volume of vertical air conditioner in China mainland has developed rapidly. The researches in the field to the operation of vertical air conditioner are lacked since it is hardly to analyze different kinds of operating condition. Computational Fluid Dynamics (CFD) has been applied in engineering with the advance of the computer science and technology. In this article, both temperature and air flow distributions were analyzed to a meeting room which putted a vertical air conditioner. The model was used and the equations for numerical simulation (e.g. energy, residual, continuity, etc) were chosen as second order to get the higher accuracy. The results to simulation were showed reasonable and could offer a reference to the practical.


1997 ◽  
Vol 163 ◽  
pp. 832-833
Author(s):  
Rob Whitehurst

AbstractThe difficulties associated with numerical simulation of accretion discs are outlined along with a potential treatment, FLAME. This technique bridges the gap between existing finite difference codes and particle methods in modern computational fluid dynamics (CFD).


2013 ◽  
Vol 448-453 ◽  
pp. 3847-3850
Author(s):  
Da Li ◽  
Fang Qin Cheng ◽  
Jian Feng Li ◽  
Yun Shan Guan

Despite the widespread use of hydrocyclone in the process of potash ore desliming, its accurate design is often difficult because the feed composition is complicated and the viscosity is high in the brine system. In this study, a numerical approach based on computational fluid dynamics (CFD) was performed to describe the flow field. The numerical simulation of flow pattern in hydrocyclones for potash ore desliming was presented. Some basic information concerning the velocity and pressure distribution is given, and the results can be used as the fundamental basis for its design.


Hydrology ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 151
Author(s):  
Mehdi Heyrani ◽  
Abdolmajid Mohammadian ◽  
Ioan Nistor

This study uses a computational fluid dynamics (CFD) approach to simulate flows in Parshall flumes, which are used to measure flowrates in channels. The numerical results are compared with the experimental data, which show that choosing the right turbulence model, e.g., v2−f and LC, is the key element in accurately simulating Parshall flumes. The Standard Error of Estimate (SEE) values were very low, i.e., 0.76% and 1.00%, respectively, for the two models mentioned above. The Parshall flume used for this experiment is a good example of a hydraulic structure for which the design can be more improved by implementing a CFD approach compared with a laboratory (physical) modeling approach, which is often costly and time-consuming.


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