scholarly journals Characterizing the fluid dynamics in the flow fields of cylindrical orbitally shaken bioreactors with different geometry sizes

2018 ◽  
Vol 18 (8) ◽  
pp. 570-578 ◽  
Author(s):  
Likuan Zhu ◽  
Wang Han ◽  
Boyan Song ◽  
Zhenlong Wang
Keyword(s):  
Fluid Dynamics ◽  
Flow Fields ◽  
Shaken Bioreactors

Inverse design of aircraft cabin environment using computational fluid dynamics-based proper orthogonal decomposition method

2017 ◽  
Vol 27 (10) ◽  
pp. 1379-1391 ◽  
Author(s):  
Jihong Wang ◽  
Tengfei (Tim) Zhang ◽  
Hongbiao Zhou ◽  
Shugang Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Proper Orthogonal Decomposition ◽  
Flow Fields ◽  
Orthogonal Decomposition ◽  
Inverse Design ◽  
Air Supply ◽  
Spatial Modes ◽  
Cabin Environment ◽  
Proper Orthogonal

To design a comfortable aircraft cabin environment, designers conventionally follow an iterative guess-and-correction procedure to determine the air-supply parameters. The conventional method has an extremely low efficiency but does not guarantee an optimal design. This investigation proposed an inverse design method based on a proper orthogonal decomposition of the thermo-flow data provided by full computational fluid dynamics simulations. The orthogonal spatial modes of the thermo-flow fields and corresponding coefficients were firstly extracted. Then, a thermo-flow field was expressed into a linear combination of the spatial modes with their coefficients. The coefficients for each spatial mode are functions of air-supply parameters, which can be interpolated. With a quick map of the cause–effect relationship between the air-supply parameters and the exhibited thermo-flow fields, the optimal air-supply parameters were determined from specific design targets. By setting the percentage of dissatisfied and the predicted mean vote as design targets, the proposed method was implemented for inverse determination of air-supply parameters in two aircraft cabins. The results show that the inverse design using computational fluid dynamics-based proper orthogonal decomposition method is viable. Most of computing time lies in the construction of data samples of thermo-flow fields, while the proper orthogonal decomposition analysis and data interpolation is efficient.

CFD Simulation of Spraying with Air Jet

2012 ◽  
Vol 455-456 ◽  
pp. 228-233
Author(s):  
Wei Dong Jia ◽  
Cheng Li ◽  
Jun Lu ◽  
Ning Yang ◽  
Zhen Tao Wang
Keyword(s):  
Fluid Dynamics ◽  
Software Package ◽  
Cfd Simulation ◽  
Spray Deposition ◽  
Flow Fields ◽  
Droplet Deposition ◽  
Air Jet ◽  
Tunnel Model ◽  
Spray Droplets ◽  
Jet Velocity

Droplet drift is always an accompaniment of pesticide spraying and can cause serious consequences. In this paper, we used a computational fluid dynamics software package (FLUENT) to analyze flow fields of spraying with air jet under different conditions in the tunnel model, and compared the effect of air jet on spray deposition and drift. Results of this study indicate that air jet can act directly on the spray droplets and affect their distribution and movement. Larger jet velocity has better performance on the drift reduction and droplet deposition. Droplets in the flow fields with larger jet velocity can get more kinetic energy and arrive at the root of crops easilier. When droplets are released straight down, larger velocity of droplets can be given and better performance can be achieved either in terms of drift reduction or droplet deposition.

An Initial Parametric Study on Fluid Flow Through Bileaflet Mechanical Heart Valves Using Computational Fluid Dynamics

1994 ◽  
Vol 208 (2) ◽  
pp. 63-72 ◽  
Author(s):  
M J King ◽  
T David ◽  
J Fisher
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Volumetric Flow Rate ◽  
Flow Fields ◽  
Opening Angle ◽  
Bileaflet Mechanical Heart Valve ◽  
Flow Through

The effect of leaflet opening angle on flow through a bileaflet mechanical heart valve has been investigated using computational fluid dynamics (CFD). Steady state, laminar flow for a Newtonian fluid at a Reynolds number of 1500 was used in the two-dimensional model of the valve, ventricle, sinus and aorta. This computational model was verified using one-dimensional laser Doppler velocimetry (LDV). Although marked differences in the flow fields and energy dissipation of the jets downstream of the valve were found between the CFD predictions and the three-dimensional experimental model, both methods showed similar trends in the changes of the flow fields as the leaflet opening angle was altered. As the opening angle increased the area of recirculating fluid downstream of the leaflets, the pressure drop across the valve and the volumetric flow rate through the outer orifice decreased. For opening angles greater than 80° the jet through the outer orifice recombined with the central jet downstream of the leaflet; for an opening angle of 78° the jet through the outer orifice impinged on the aortic wall before recombining with the central jet. This study suggests that the opening angle has a marked effect on the flow downstream of the bileaflet mechanical heart valve and that valves with opening angles greater than 80° are preferable.

Investigation of computational flow fields and aeroacoustic characteristics over a re-entry command module

2016 ◽  
Vol 232 (3) ◽  
pp. 532-544 ◽  
Author(s):  
J Bruce Ralphin Rose ◽  
P Saranya ◽  
JV Bibal Benifa
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Separated Flow ◽  
Computational Design ◽  
Aerodynamic Characteristics ◽  
Flow Fields ◽  
Order Of Accuracy ◽  
Tunnel Model ◽  
Computational Fluid Dynamics Analysis

Design and analysis of a wind tunnel model for re-entry vehicle configuration is a prolonged and expensive mission. As the aerothermodynamics loads acting on the vehicle are based on geometry, various wind tunnel models need to be built for aerodynamic characterization by experimental procedure. Alternatively, the intention of this article is to present the influence of aerodynamic and aero acoustic characteristics of a typical re-entry capsule by computational fluid dynamics analysis. A typical re-entry capsule is designed using computational design software and it is imported to a computational fluid dynamics solver and flow simulations are done at various input conditions. Stanford University unstructured computational fluid dynamics solver is used for this purpose to solve complex, multiphysics analysis, and optimization tasks. Computational fluid dynamics results are presented to understand the influence of aerodynamic characteristics of a typical re-entry capsule, by visualizing the flow field around the command module at all the flow regimes like subsonic, supersonic, and hypersonic flows. The flow fields are studied in detail and regions of high flow unsteadiness due to wake separated flow zone are identified. Aeroacoustic loading on the command module at these regions especially at shock wave zone are predicted in the present investigation with high order of accuracy.

The Practical Application of CFD in the Design of Industrial Centrifugal Compressors

2000 ◽  
Author(s):  
James M. Sorokes ◽  
Bradley R. Hutchinson
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Flow ◽  
Gas Turbine ◽  
Flow Fields ◽  
Practical Application ◽  
Jet Engine ◽  
Flow Problems ◽  
Computational Fluid Dynamics Cfd ◽  
Complex Fluid

Abstract In the development of industrial turbomachinery, the aerodynamic designer is faced with many complex fluid flow problems. In the mid to late 1980’s, Computational Fluid Dynamics (CFD) software was developed to assist in the solution of these flow fields. Initially applied only by high end gas turbine or jet engine designers, these sophisticated tools eventually found their way to engineers at industrial turbomachinery manufacturers. However, it has only been in the last five to ten years that industrial users have begun to make more widespread use of CFD. There are a variety of reasons for this slow adoption.

scholarly journals Understanding Angiography-Based Aneurysm Flow Fields through Comparison with Computational Fluid Dynamics

2017 ◽  
Vol 38 (6) ◽  
pp. 1180-1186 ◽  
Author(s):  
J.R. Cebral ◽  
F. Mut ◽  
B.J. Chung ◽  
L. Spelle ◽  
J. Moret ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Fields

Numerical Simulation of the Inner Flow Field and the Optimal Design of Hema-Type ATY Nozzle Based on Fluent

2013 ◽  
Vol 634-638 ◽  
pp. 3774-3777
Author(s):  
Min Hua Zhang ◽  
Hong Mei Zheng ◽  
Cui Liu ◽  
Yin Hu Qu ◽  
Tao Liang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Optimal Design ◽  
Flow Field ◽  
Flow Fields ◽  
Fluent Software ◽  
Simulation Results

the inner flow fields of twelve Hema-type ATY nozzles which have different structure and parameters are simulated by the Fluent software, which is based on the CFD (Computational Fluid Dynamics) theory.Then the simulation results are analyzed，through wich the best designed nozzle is determined.

Effects of Mesh Density and Flow Conditioning in Simulating 7-Pin Wire Wrapped Fuel Pins

2008 ◽  
Author(s):  
Jeffrey G. Smith ◽  
Bruce R. Babin ◽  
W. David Pointer ◽  
Paul F. Fischer
Keyword(s):  
Fluid Dynamics ◽  
Fuel Assembly ◽  
Fast Reactor ◽  
Fluid Dynamic ◽  
Argonne National Laboratory ◽  
Flow Fields ◽  
Initial Assessment ◽  
Plant Design ◽  
Fuel Rod ◽  
The Wire

In response to the goals outlined by the U.S. Department of Energy’s Global Nuclear Energy Partnership program, Argonne National Laboratory has initiated an effort to create an integrated multi-physics multi-resolution thermal hydraulic simulation tool package for the evaluation of nuclear power plant design and safety. As part of this effort, the applicability of a variety of thermal hydraulic analysis methods for the prediction of heat transfer and fluid dynamics in the wire-wrapped fuel-rod bundles found in a fast reactor core is being evaluated. The work described herein provides an initial assessment of the capabilities of the general purpose commercial computational fluid dynamics code Star-CD for the prediction of fluid dynamic characteristics in a wire wrapped fast reactor fuel assembly. A 7-pin wire wrapped fuel rod assembly based on the dimensions of fuel elements in the concept Advanced Burner Test Reactor [1] was simulated for different mesh densities and domain configurations. A model considering a single axial span of the wire wrapped fuel assembly was initially used to assess mesh resolution effects. The influence of the inflow/outflow boundary conditions on the predicted flow fields in the single-span model were then investigated through comparisons with the central span region of models which included 3 and 5 spans. The change in grid refinement had minimal impact on the inter-channel exchange within the assembly resulting in roughly a 5 percent maximum difference. The central span of the 3-span and 5-span cases exhibits much higher velocities than the single span case,, with the largest deviation (15 to 20 percent) occurring furthest away from the wire spacer grids in the higher velocity regions. However, the differences between predicted flow fields in the 3-span and 5-span models are minimal.

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