scholarly journals Numerical Simulation of Flow Through Microchannels with Random Roughness

2021 ◽  
Author(s):  
Małgorzata Kmiotek ◽  
Adrian Kordos ◽  
Tomasz Iwan
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Cross Section ◽  
Circular Cross Section ◽  
Two Dimensional ◽  
Axially Symmetric ◽  
Ansys Fluent ◽  
Random Roughness ◽  
Fluent Software ◽  
Flow Through

The aim of the study is to determine the effect of a randomly generated rough surface on the laminar flow of a fluid in a microchannel. Two-dimensional axially symmetric microchannels with a circular cross-section in the range of Reynolds number Re = 100-1700 were considered. Flow numerical simulations were performed using the Ansys / Fluent software.

Numerical Simulation of Flows in a Pipe with an Aneurismal Sac (Effects of Aneurismal Models and Stents)

2008 ◽  
Vol 33-37 ◽  
pp. 1025-1030
Author(s):  
Gulbahar Wahap ◽  
Tatsuya Kobori ◽  
Yoko Takakura ◽  
Norio Arai ◽  
Yoshifumi Konishi ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Human Blood ◽  
Steady States ◽  
Computational Results ◽  
Two Dimensional ◽  
Blood Flows ◽  
Inflow Condition ◽  
Inflow Conditions ◽  
Two Dimensional Flows

Recently, the intravascular therapy using microcoils and stents to treat aneurysms has attracted researcher’s interest. In this study, in order to evaluate the effects of the stents, a numerical simulation of two-dimensional flows has been carried out for a pipe with a model of an aneurismal sac. Using aneurismal models with different inclined angles to the pipe, inflow conditions with steady states or pulsations have been applied in the range of Reynolds number in human blood flows. First, the computational results are compared with experiments under the steady inflow condition, which has shown the reliability of the numerical simulation. Furthermore, the mechanism of flows with an aneurismal model is discussed in the case with or without a stent, and consequently the effect of the stent is clarified.

Bifurcation analysis of two-dimensional laminar flow through sudden expansion channel

2022 ◽  
Vol 13 (1) ◽  
pp. 0-0
Keyword(s):  
Laminar Flow ◽  
Expansion Ratio ◽  
Sudden Expansion ◽  
Two Dimensional ◽  
Governing Equations ◽  
Bifurcation Phenomena ◽  
Different Types ◽  
Fluent Software ◽  
Flow Through ◽  
Volume Method

In this work, bifurcation characteristics of unsteady, viscous, Newtonian laminar flow in two-dimensional sudden expansion and sudden contraction-expansion channels have been studied for different values of expansion ratio. The governing equations have been solved using finite volume method and FLUENT software has been employed to visualize the simulation results. Three different mesh studies have been performed to calculate critical Reynolds number (Recr) for different types of bifurcation phenomena. It is found that Recr decreases with the increase in expansion ratio (ER).

scholarly journals NUMERICAL SIMULATION OF AIRFLOW AROUND VEHICLE MODELS

2018 ◽  
Vol 56 (3) ◽  
pp. 370
Author(s):  
Nguyen Van Thang ◽  
Ha Tien Vinh ◽  
Bui Dinh Tri ◽  
Nguyen Duy Trong
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Forces ◽  
Dissipation Energy ◽  
Ansys Fluent ◽  
Car Model ◽  
Airflow Field ◽  
Fluent Software

This article carries out the numerical simulation of airflow over three dimensional car models using ANSYS Fluent software. The calculations have been performed by using realizable k-e turbulence model. The external airflow field of the simplified BMV M6 model with or without a wing is simulated. Several aerodynamic characteristics such as pressure distribution, velocity contours, velocity vectors, streamlines, turbulence kinetic energy and turbulence dissipation energy are analyzed in this study. The aerodynamic forces acting on the car model is calculated and compared with other authors.

scholarly journals Numerical simulation and experimental research of cavitation nozzle based on equation curve

2021 ◽  
Author(s):  
Lifu Wang ◽  
Dongyan Shi ◽  
Zhixun Yang ◽  
Guangliang Li ◽  
Chunlong Ma ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Flow Field ◽  
High Speed ◽  
Quadratic Equation ◽  
Outer Contour ◽  
Study Results ◽  
Fluent Software ◽  
The Impact ◽  
Better Than

Abstract To further investigate and improve the cleaning ability of the cavitation nozzle, this paper proposes a new model that is based on the Helmholtz nozzle and with the quadratic equation curve as the outer contour of the cavitation chamber. First, the numerical simulation of the flow field in the nozzle chamber was conducted using FLUENT software to analyze and compare the impact of the curve parameters and Reynolds number on the cleaning effect. Next, the flow field was captured by a high-speed camera in order to study the cavitation cycle and evolution process. Then, experiments were performed to compare the cleaning effect of the new nozzle with that of the Helmholtz nozzle. The study results demonstrate that effective cavitation does not occur when the diameter of the cavitation chamber is too large. For the new nozzle, with the increase of the Reynolds number, the degree of cavitation in the chamber first increases and then decreases; the cleaning effect is much better than that of a traditional Helmholtz nozzle under the same conditions; the nozzle has the best cleaning effect for the stand-off distance of 300 mm.

Hydrodynamic Predictions of Dense Gas-Solids Flow in CFB Riser

2012 ◽  
Vol 516-517 ◽  
pp. 917-920
Author(s):  
Xue Yao Wang ◽  
Xue Zhi Wu ◽  
Sheng Dian Wang ◽  
Xiang Xu ◽  
Yun Han Xiao
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Circular Cross Section ◽  
Deep Understanding ◽  
Experimental Methods ◽  
Concentration Profiles ◽  
Simulation Research ◽  
Solids Concentration ◽  
High Efficient ◽  
2D Numerical Simulation

The flow character in riser is important for deep understanding the steady and high-efficient running of CFBs. In this paper, the 2D numerical simulation research for bench-scale circular cross-section riser based on EMMS methods is carried out. The solids’ transient moving profiles are captured. By analyzing the axial solids concentration profiles by simulation and experimental methods, the practicability of the EMMS model is verified.

scholarly journals Numerical simulation of minor losses coefficient on the example of elbows

2018 ◽  
Vol 180 ◽  
pp. 02093
Author(s):  
Smyk Emil ◽  
Mrozik Dariusz ◽  
Olszewski Łukasz ◽  
Peszyński Kazimierz
Keyword(s):  
Numerical Simulation ◽  
Numerical Methods ◽  
Numerical Method ◽  
Cross Section ◽  
Analytical Methods ◽  
Circular Cross Section ◽  
Experimental Methods ◽  
Loss Coefficient ◽  
Complicated Problem ◽  
Minor Losses

Determining of minor losses coefficient is very complicated problem. Analytical methods are often very difficult and experimental methods are very expensive and time-consuming. Consequently, the use of numerical methods seems to be a good solution, but there are no publications describing this issue. Therefore, the paper is describing the numerical method of determining the minor loss coefficient ξ on the example of elbows with circular cross-section.

scholarly journals The investigation of the cavitation processes in the radial labyrinth pump

2018 ◽  
Vol 8 (1) ◽  
pp. 322-328
Author(s):  
Moloshnyi Oleksandr ◽  
Szulc Przemyslaw
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Volume Fraction ◽  
Mechanical Energy ◽  
Circular Cross Section ◽  
Back Side ◽  
Numerical Investigations ◽  
Numerical Research ◽  
The Moment ◽  
Velocity Pressure

Abstract The paper concerns the analysis of the cavitation processes in the flow passages of the radial labyrinth pump. The object of the analysis contains the active (moving) and the passive (stationary) discs with straight channels trajectory and semi-circular cross-section. The conversion of the mechanical energy into hydraulic based on the exchange of the momentum between the liquid remaining in the moving and the stationary areas of the discs as well as on the centrifugal increase of the moment of momentum. The analysis of the cavitation processes was realized by the experimental research and the numerical simulation. In the article, the comparison of the cavitation characteristics was carried out. The numerical simulation had given similar results to the experimental one, the process of the cavitation was visualized. Furthermore, numerical investigations helped to describe the cavitation development. The results of the numerical research such as the distributions of the velocity, pressure and vapor volume fraction in the passages were presented. At first, cavitation starts on the back side and on the top of the wall between channels of the active disc. Further, the cavitation areas are growing along the axis of the channels. Eventually, they separation was observed and vortices of the vapour-gas mixture in the middle of the channels were formed. This phenomenon is so-called super cavitation vortices.

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