Introduction Multiphase Flow
The simultaneous flow with two or more phases is known as multiphase flow. Multiphase flows are commonly found in various industrial applications. These phases can be made up of just one chemical component (for example, water vapor and liquid water), or several different chemical components (for example, water vapor, liquid oil and solid catalyst). For the multiphase flow processes, it is crucial to investigate all the phases together in order to predict interphase behavior and optimize overall process efficiency. Multiphase flow processes can be investigated using computational fluid dynamics (CFD). Different interphase phenomena such as mass transfer, heat transfer, momentum transfer and other related phenomena, etc. in different process geometries and operating conditions can be accurately predicted and explored for understanding, improving and scaling-up the considered multiphase flow processes.
CFD case studies
A single- or multi-impeller agitated vessel with baffles is one of the most used mixing devices. CFD now has a new option for modeling this type of vessel: a completely automated solution template where engineers can enter the geometric specifications and operating settings for the mixing tank. The entire design analysis is then automatically established and solved, and a summary report is generated, providing engineers with instant access to all of the critical parameters linked to their mixing process.
For this work, CFD is used to improve liquid mixing and propose the new commercial reactor design (reactor diameter, impeller location, gas sparger type, etc.) within current operating condition as well as scaling up criteria.
Dam break analysis plays a key role in hydraulics engineering for safety. In this work, 3D numerical simulations of dam-break flow using Finite Volume and Lattice Boltzmann methods are studied and discussed. All the computation in this work is achieved by ANSYS Fluent and XFlow. Large Eddy Simulation (LES) is employed as the turbulence model and the free surface flow is captured using a Volume of Fluid (VOF) model in the two simulation approaches. Results are then compared with experimental data on dam-break flow through complex obstacles. This experimental data is obtained by a high-speed camera aiming to capture free surface waves. The comparison between the experimental data and simulations shows good tendency. However, LBM requires less computational time.
Cyclone is one of the most popular devices used in many industrial processes in order to reduce solid emission by capturing and separating the solid particles using centrifugal and gravity forces since it is compact, low capital cost and easy to maintenance. A numerical simulation technique was employed to model the two-phase flow in cyclones using computational fluid dynamics (CFD) to investigate the inlet angles of cyclone for better separation efficiency. The outcome shows that inlet angle has significant effects on the tangential velocity which leads to the overall collection efficiency of the cyclone.
Spray injection is significant in advanced manufacturing and is also may be a safety concern. The research proposes a new turbulence model configuration for the secondary breakup by adjusting the numerical and mathematical parameters to be consistent with a coherent flow structure. High-Performance Computing is used in this study due to high complexity problems, such as turbine combustion chamber, refining chamber, pharmaceutical coating, and nuclear heat exchanger.
From this research, we can elaborate the entire flow structure interaction based on current and extreme conditions to provide the best choice for improving and preventing unexpected situations. Nevertheless, the engineer can self-adjust the process to meet the high capacity without impacting the product quality and reliability. In term of safety concern also can reduce evacuated time
Spray injection is significant in advanced manufacturing and is also may be a safety concern. The research proposes a new turbulence model configuration for the secondary breakup by adjusting the numerical and mathematical parameters to be consistent with a coherent flow structure. High-Performance Computing is used in this study due to high complexity problems, such as turbine combustion chamber, refining chamber, pharmaceutical coating, and nuclear heat exchanger.
From this research, we can elaborate the entire flow structure interaction based on current and extreme conditions to provide the best choice for improving and preventing unexpected situations. Nevertheless, the engineer can self-adjust the process to meet the high capacity without impacting the product quality and reliability. In term of safety concern also can reduce evacuated time
We applied the CFD to solve the particle contamination and water condensation in cleanroom. The results showed temperature, pressure, particle trace, velocity. The results were analyzed to find.
The optimal condition to solve the problems. https://ieeexplore.ieee.org/document/7933973
Due to the chaotic flow between the droplet and ambient gas in the combustion chamber, we applied the dynamic adaptive mesh refinement for coherent structure in the spray breakup model to investigate the soot emissions and particulate matter (PM) size. Nevertheless, not only for grid adaptive, we cooperated with the chemical reaction dynamics technique such as Dynamic Cell Clustering and Dynamic Adaptive Chemistry in this study.
The findings suggest that the ambient temperature, pressure, fraction of gases initialization, and droplet distribution size affect the soot particulate emission. In addition, both dynamics algorithms can reduce the calculation time and provide more details in Post Processing.
The natural rubber is environmentally friendly with human usage under low allergy. In Thailand, natural rubber is the economic crop that is grown all over the country and can export and generate enormous income for the country. To develop Thai rubber products to have a variety and international quality, we use CFD to improve natural rubber mixing and dispersing of floating particles in a viscous commercial process, optimizing stirred tank, impeller design, and process troubleshooting.
Saliva droplet is the leading cause of COVID-19 transmission as well as airborne particulate. The lifetime of coronavirus infected droplets under a stick-slip evaporation mode and the physics of person-to-person virus transmission from emitted droplets of oral fluid while speaking has been investigated. We can suggest the proper distance, face mark type, and air ventilation system from the CFD capabilities.
Nowadays, conventional multiphase flow reactors have many operational problems, non-uniform distribution of gas–solid particles and low heat and mass transfers. To overcome these operation problems, this study proposes the use of a micro fluidized bed reactor, verifying its feasibility with a computational fluid dynamics (CFD) simulation. The other advantages of the micro fluidized bed reactor are increased surface area and easy scale-up. However, the literature data about the CFD simulation of micro fluidized bed reactors and the effects of parameters on system mixing inside this reactor are still limited. This study objective is thus to develop the CFD simulation of a micro fluidized bed reactor and to explore the effect of design parameters on system mixing using statistical design and analysis of experimental methodology.
This system is then considered as compact operation when comparing with the conventional CFB reactor. However, the simplicity of the ICFB reactor is trade-off with a gas leakage which takes place between the two sections through the connecting ports. In addition, the solid particle movement inside the system can cause the erosion on the inserting pipes which are used for heating or cooling this ICFB reactor column. In this study, the system hydrodynamics and erosion behavior inside ICFB reactor with inserting pipe were investigated by computational fluid dynamics (CFD) using two-dimensional Eulerian-Eulerian model. The system hydrodynamics was obtained, and the wall shear stress was calculated in the existent of the erosion at the surface region of the inserting pipes. The results from this simulation were used to design the inserting pipe arrangement inside this ICFB reactor.