3D Numerical Simulation of Inner Flow in a Mixed-Flow Stirred Reactor

2014 ◽  
Vol 602-605 ◽  
pp. 650-652
Author(s):  
Hui Li ◽  
Rui Li Wang
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Velocity Field ◽  
Three Dimensional ◽  
3D Numerical Simulation ◽  
Mixed Flow ◽  
Stirred Reactor ◽  
Computational Fluid Dynamics Cfd ◽  
Simulated Effect

Based on the principle and method of computational fluid dynamics (CFD), using the software, FLUENT, the inner flow field in a mixed-flow stirred reactor was simulated and the flow details were studied roundly. This article analyzed the three-dimensional velocity field distribution and testified the reliability of numerical simulation to a certain extent. The simulated effect was proved effective. The results of this paper provided a good base and reference for the further research of the stirred reactor.

scholarly journals Numerical Simulation of Velocity Field around Two Columns of Tandem Piers of the Longitudinal Bridge

Fluids ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 32
Author(s):  
Hongliang Qi ◽  
Junxing Zheng ◽  
Chenguang Zhang
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Velocity Field ◽  
Average Velocity ◽  
Cfd Simulations ◽  
Velocity Change ◽  
River Bed ◽  
Computational Fluid Dynamics Cfd ◽  
Lateral Range

This research explores the effects of different spans of two columns of tandem piers on the characteristics of x-velocity near the river bed based on computational fluid dynamics (CFD) simulations. With a span shorter than 27.5D (D is the diameter of piers), the shape and the lateral range of the x-velocity increases with the increase of distance downwards the x-direction. For the area between the tandem piers and the wall, the VRi/VR1 (the ratio of the x-velocity at the i-th row to the x-velocity of the first row in each model) near the wall increases up to 1.26. For the area between the two columns of tandem piers, the profile of VRi/VR1 changes from a “∩-shape” to an “M-shape” in each model. RAVC (average velocity change ratio) of different spans increases gradually and tends to be stable with the increases of the span. The largest RAVC is about −17.66% with a span of 0.52 m. The RMV (the ratio of the maximum x-velocity among piers in each row in different models to the maximum x-velocity of the two piers arranged side by side) of piers in the first row of different models is around 0.95. The RMV becomes 0.82 at the second pier in each model when the span is shorter than 27.5D, and increases to 0.91 if the span is longer than 27.5D. If the span is longer than 27.5D, the RMV of different piers are close to each other from the 2nd pier to the last one.

3D Numerical Simulation of the Fluidized Bed’s Cold Distributor

2011 ◽  
Vol 71-78 ◽  
pp. 2112-2115 ◽  
Author(s):  
Hui Li ◽  
Xin Hui Ma
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Fluidized Bed ◽  
Field Distribution ◽  
Pressure Field ◽  
Three Dimensional ◽  
3D Numerical Simulation ◽  
Excessive Pressure ◽  
Good Advice ◽  
Computational Fluid Dynamics Cfd

Because of excessive pressure loss when the gas went through distributor in fluidized bed (FB), based on the principle and method of computational fluid dynamics (CFD), using the software, FLUENT, the inner flow field in the fluidized bed with distributor was simulated. This article analyzed the three-dimensional velocity field distribution, pressure field distribution under the different arrangement of hole form. and the good advice was given on the structural optimization of the cold distributor.

Steel Catenary Risers at Touchdown Zone: A Fluid Dynamics Approach to Understanding the Water-Riser-Soil Interaction

2012 ◽  
Author(s):  
Anup Fouzder ◽  
Arash Zakeri ◽  
Bipul Hawlader
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Velocity Field ◽  
Cross Section ◽  
Complex Phenomenon ◽  
Two Dimensional ◽  
Steel Catenary Risers ◽  
Computational Fluid Dynamics Cfd ◽  
Critical Location

The critical location for fatigue damage in Steel Catenary Riser’s (SCR’s) often occurs within the Touchdown Zone (TDZ), where cyclic interaction of the riser with the seabed takes place. Riser-fluid-soil interaction at the TDZ is a complex phenomenon. In this study, Computational Fluid Dynamics (CFD) technique is used to investigate the velocity field and suction forces during riser-fluid-soil interaction for a two-dimensional cross section of 0.10 m diameter SCR at TDZ. Numerical simulation shows that the suction forces at the bottom of the riser are high enough to pull the clay upward when it departs from the seabed during the heave action. The influence of suction and water on trench formation mechanism is discussed.

Airflow Simulation of the Huge Telescope Assemble

2010 ◽  
Vol 439-440 ◽  
pp. 880-883
Author(s):  
Fu Zhao ◽  
Ping Wang ◽  
Yan Jue Gong ◽  
Yu De Liu ◽  
Hong Bin Xin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Convection ◽  
Temperature Distribution ◽  
Velocity Field ◽  
Three Dimensional ◽  
Horizontal Line ◽  
Air Velocity ◽  
Turbulent Airflow ◽  
Dynamics Method

With the three-dimensional computational fluid dynamics method, the airflow effects over the huge telescope assemble is investigated in this article. The distributing of velocity field and natural convection are studied by modeling and simulating the turbulent airflow of the huge telescope. Numerical simulations show the best observation direction is the 90o angle between the main optics axis and the horizontal line in which the air velocity distribution is the least. And the air temperature distribution and uniformity around the telescope are also provided by simulation.

Development and Validation of a 3-Dimensional Computational Fluid Dynamics (CFD) Model for Rectangular Settling Tanks in New York City Water Pollution Control Plants

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
K. Ramalingam ◽  
J. Fillos ◽  
S. Xanthos ◽  
M. Gong ◽  
A. Deur ◽  
...  
Keyword(s):  
Water Pollution ◽  
Fluid Dynamics ◽  
New York ◽  
Computational Fluid Dynamics ◽  
New York City ◽  
Pollution Control ◽  
York City ◽  
Three Dimensional ◽  
Cfd Model ◽  
Computational Fluid Dynamics Cfd

New York City provides secondary treatment to approximately 78.6 m3/s among its 14 water pollution control plants (WPCPs). The process of choice has been step-feed activated sludge. Changes to the permit limits require nitrogen removal in WPCPs discharging into the Long Island Sound. The City has selected step feed biological nitrogen removal (BNR) process to upgrade the affected plants. Step feed BNR requires increasing the concentration of mixed liquors, (MLSS), which stresses the Gould II type rectangular final settling tanks (FSTs). To assess performance and evaluate alternatives to improve efficiency of the FSTs at the higher loads, New York City Department of Environmental Protection (NYCDEP) and City College of New York (CCNY) have developed a three-dimensional computer model depicting the actual structural configuration of the tanks and the current and proposed hydraulic and solids loading rates. Using Computational Fluid Dynamics (CFD) Model, Fluent 6.3.26TM as the base platform, sub-models of the SS settling characteristics as well as turbulence, flocculation, etc. were incorporated. This was supplemented by field and bench scale experiments to quantify the co-efficients integral to the sub-models. As a result, a three-dimensional model has been developed that is being used to consider different baffle arrangements, sludge withdrawal mechanisms and loading alternatives to the FSTs.

Transient Simulation of a Three-Dimensional Moving Downburst

2012 ◽  
Vol 446-449 ◽  
pp. 3875-3878
Author(s):  
Bai Feng Ji ◽  
Wei Lian Qu
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Wind Field ◽  
Three Dimensional ◽  
Simulation Method ◽  
Transient Simulation ◽  
Dynamics Simulation ◽  
Transmission Tower ◽  
Transient Wind

Thunderstorm microbursts, which are sources of extreme wind loadings in nature, have caused numerous structural failures, especially collapses of transmission tower around the world. Numerical simulation using computational fluid dynamics (CFD) has recently made significant progress in simulating downbursts. In this paper, transient simulation of a three-dimensional moving downburst was studied using computational fluid dynamics simulation method. Transient simulation of a three-dimensional moving downburst was conducted using time-filtered Reynolds Averaged Navier-Stokes (RANS) numerical simulation method. The three-dimensional transient wind field characteristics in a moving downburst were studied in detail. The results indicate that transient wind field characteristics in a moving downburst present quite different characteristics compared with stationary downburst at different heights and radial positions.

Numerical and Experimental Study on a Honeycomb Ceramic Monolith

2012 ◽  
Vol 532-533 ◽  
pp. 431-435
Author(s):  
Chong Zhi Mao ◽  
Qian Jian Guo ◽  
Lei He
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Computational Fluid Dynamics ◽  
Flue Gas ◽  
Regenerative Process ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Honeycomb Ceramic ◽  
Oxidation Reactor

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.

A Generalized Computational Fluid Dynamics Approach for Journal Bearing Performance Prediction

1995 ◽  
Vol 209 (2) ◽  
pp. 99-108 ◽  
Author(s):  
P G Tucker ◽  
P S Keogh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Surface Temperature ◽  
Performance Prediction ◽  
Reynolds Equation ◽  
Three Dimensional ◽  
Rotation Effect ◽  
Performance Predictions ◽  
Computational Fluid Dynamics Cfd ◽  
Shaft Surface

The use of computational fluid dynamics (CFD) techniques enables performance predictions of bearing designs to be made when the usual operating assumptions of the Reynolds equation Jail to hold. This paper addresses the application of a full three-dimensional thermohydrodynamic CFD approach to journal bearings. The journal/shaft may extend beyond the bearing length and the rotation effect is accounted for in the thermal transport process. A circumferentially uniform shaft surface temperature is not assumed. Cavitation modelling is based on averaged lubricant/vapour properties and does not set pressures directly, allowing sub-ambient pressures to be predicted. Lubricant inlet grooves are incorporated with conservation of mass and the possibility of backflow. The modelling is validated against published experimental work on fully circumferential, single inlet and two-inlet circular bore bearings. The predicted and experimental results are in general agreement, although the predicted cyclic variation of journal surface temperature is less than the experimental value. However, an assumption in the predictions was of a non-orbiting journal. The techniques developed may, in principle, be extended to the orbiting journal case providing a dynamic cavitation model can be formulated.

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