scholarly journals Does a mobile laminar airflow screen reduce bacterial contamination in the operating room? A numerical study using computational fluid dynamics technique

2014 ◽  
Vol 8 (1) ◽  
pp. 27 ◽  
Author(s):  
Sasan Sadrizadeh ◽  
Ann Tammelin ◽  
Peter V Nielsen ◽  
Sture Holmberg
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Operating Room ◽  
Bacterial Contamination ◽  
Numerical Study

Cooling and Freezing of Cashew Apple Using Computational Fluid Dynamics

2020 ◽  
Vol 25 ◽  
pp. 114-132 ◽  
Author(s):  
V.A. Agra Brandão ◽  
R. Araújo de Queiroz ◽  
R. Lima Dantas ◽  
G. Santos de Lima ◽  
N. Lima Tresena ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nutritional Value ◽  
Fruits And Vegetables ◽  
Numerical Study ◽  
Freezing Process ◽  
Ansys Cfx ◽  
Cashew Apple ◽  
Freezing Period ◽  
Kinetics Of

Freezing is one the most efficient methods for conservation, especially, fruits and vegetables. Cashew is a fruit with high nutritional value and great economic importance in the Northeast region of Brazil, however, due to high moisture content, it is highly perishable. The numerical study of the freezing process is of great importance for the optimization of the process. In this sense, the objective of this work was to study the cooling and freezing processes of cashew apple using computational fluid dynamics technique. Experiments of cooling and freezing of the fruit, with the aid of a refrigerator,data acquisition system and thermocouples, and simulation using Ansys CFX® software for obtain the cooling and freezing kinetics of the product were realized. Results of the cooling and freezing kinetics of the cashew apple and temperature distribution inside the cashew apple are presented, compared and analyzed. The model was able to predict temperaturetransient behavior with good accuracy, except in the post-freezing period.

Numerical study of the biomass pyrolysis process in a spouted bed reactor through computational fluid dynamics

Energy ◽  
2021 ◽  
Vol 214 ◽  
pp. 118839
Author(s):  
Shiliang Yang ◽  
Ruihan Dong ◽  
Yanxiang Du ◽  
Shuai Wang ◽  
Hua Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Study ◽  
Pyrolysis Process ◽  
Biomass Pyrolysis ◽  
Spouted Bed

Experimental and Numerical Study of Ascending Aorta Hemodynamics Through 3D Particle Tracking Velocimetry and Computational Fluid Dynamics

2013 ◽  
Author(s):  
Utku Gülan ◽  
Diego Gallo ◽  
Raffaele Ponzini ◽  
Beat Lüthi ◽  
Markus Holzner ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Particle Tracking ◽  
Particle Tracking Velocimetry ◽  
Numerical Study ◽  
Imaging Techniques ◽  
Ascending Aorta ◽  
Human Aorta ◽  
Wide Range

The complex hemodynamics observed in the human aorta make this district a site of election for an in depth investigation of the relationship between fluid structures, transport and pathophysiology. In recent years, the coupling of imaging techniques and computational fluid dynamics (CFD) has been applied to study aortic hemodynamics, because of the possibility to obtain highly resolved blood flow patterns in more and more realistic and fully personalized flow simulations [1]. However, the combination of imaging techniques and computational methods requires some assumptions that might influence the predicted hemodynamic scenario. Thus, computational modeling requires experimental cross-validation. Recently, 4D phase contrast MRI (PCMRI) has been applied in vivo and in vitro to access the velocity field in aorta [2] and to validate numerical results [3]. However, PCMRI usually requires long acquisition times and suffers from low spatial and temporal resolution and a low signal-to-noise ratio. Anemometric techniques have been also applied for in vitro characterization of the fluid dynamics in aortic phantoms. Among them, 3D Particle Tracking Velocimetry (PTV), an optical technique based on imaging of flow tracers successfully used to obtain Lagrangian velocity fields in a wide range of complex and turbulent flows [4], has been very recently applied to characterize fluid structures in the ascending aorta [5].

Experimental and numerical study of vortex gripper with a diversion body

2011 ◽  
Vol 226 (6) ◽  
pp. 1526-1534 ◽  
Author(s):  
Q Wu ◽  
Q Ye ◽  
G X Meng
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Swirling Flow ◽  
Numerical Study ◽  
Reynolds Stress Model ◽  
Stress Model ◽  
Lifting Force ◽  
Handling Device ◽  
Simulation Results

This article introduces a new vortex gripper with a diversion body. Vortex gripper, as a pneumatic non-contact handling device, can generate lifting force to hold a workpiece without any contact. In order to predict the characteristics of this new vortex gripper, including pressure distribution on the upper surface of the workpiece, lifting force, supporting stiffness, and flowrate, a computational fluid dynamics study has been carried out. In the vortex cup, air swirling flow is a complex turbulent one; so Reynolds stress model (RSM) was used to describe internal air swirling flow. In addition, an experiment was carried out to study the characteristics of the vortex gripper. When compared with the experimental results, the reliability of numerical simulation results by RSM was verified. The vortex gripper with a diversion body could generate greater lifting force when compared with those designed by Xin et al. with the same air consumption. Therefore, the efficiency of the vortex gripper is improved.

A Numerical Study of the Flow and Pollutant Dispersion in Valley-River Urban

2013 ◽  
Vol 645 ◽  
pp. 208-216
Author(s):  
Rong Huang ◽  
Naiang Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Numerical Study ◽  
Concentration Field ◽  
Pollutant Dispersion ◽  
Northwest China ◽  
Navier Stokes ◽  
The Impact ◽  
Valley City

Air flow and pollutant dispersion characteristics in a real valley city are studied under the real boundary condition. The 3D computational fluid dynamics using Reynolds-averaged Navier-Stokes modeling was carried out in Lanzhou which is a typical valley city in Northwest, China. The standard κ­-ε turbulence model as a simplified computational fluid dynamics model is used to provide moderately fast simulations of turbulent airflow in an urban environment. The modeled flow field indicated that the geometry, wind direction and source location had a significant effects on the flow field. The flow shows the funnelling is rather obvious when the wind flow through the narrow area in the middle of the city. It is obvious that in the high-altitude region, due to the impact of high and low differential pressure and terrain, SO2 and NO2 formed two cyclic concentration field in the dispersion process.

Aeroacoustics response of wind turbine blade profiles in normal and icing conditions

2018 ◽  
Vol 42 (3) ◽  
pp. 243-251 ◽  
Author(s):  
Edison H Caicedo ◽  
Muhammad S Virk
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Numerical Study ◽  
Turbulence Models ◽  
Wind Turbine Blade ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
Eddy Simulation

This article describes a multiphase computational fluid dynamics–based numerical study of the aeroacoustics response of symmetric and asymmetric wind turbine blade profiles in both normal and icing conditions. Three different turbulence models (Reynolds-averaged Navier–Stokes, detached eddy simulation, and large eddy simulation) have been used to make a comparison of numerical results with the experimental data, where a good agreement is found between numerical and experimental results. Detached eddy simulation turbulence model is found suitable for this study. Later, an extended computational fluid dynamics–based aeroacoustics parametric study is carried out for both normal (clean) and iced airfoils, where the results indicate a significant change in sound levels for iced profiles as compared to clean.

Investigating the Cause of Computational Fluid Dynamics Deficiencies in Accurately Predicting the Efficiency and Performance of High Pressure Turbines: A Combined Experimental and Numerical Study

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Meinhard T. Schobeiri ◽  
S. Abdelfattah ◽  
H. Chibli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Pressure ◽  
Numerical Study ◽  
Turbine Rotor ◽  
Sensitivity Study ◽  
Numerical Results ◽  
Performance Measurements ◽  
And Performance ◽  
The Individual

Despite the tremendous progress over the past three decades in the area of turbomachinery computational fluid dynamics, there are still substantial differences between the experimental and the numerical results pertaining to the individual flow quantities. These differences are integrally noticeable in terms of major discrepancies in aerodynamic losses, efficiency, and performance of the turbomachines. As a consequence, engine manufacturers are compelled to frequently calibrate their simulation package by performing a series of experiments before issuing efficiency and performance guaranty. This paper aims at identifying the quantities, whose simulation inaccuracies are preeminently responsible for the aforementioned differences. This task requires (a) a meticulous experimental investigation of all individual thermofluid quantities and their interactions, resulting in an integral behavior of the turbomachine in terms of efficiency and performance; (b) a detailed numerical investigation using appropriate grid densities based on simulation sensitivity; and (c) steady and transient simulations to ensure their impact on the final numerical results. To perform the above experimental and numerical tasks, a two-stage, high-pressure axial turbine rotor has been designed and inserted into the TPFL turbine research facility for generating benchmark data to compare with the numerical results. Detailed interstage radial and circumferential traversing presents a complete flow picture of the second stage. Performance measurements were carried out for design and off-design rotational speed. For comparison with numerical simulations, the turbine was numerically modeled using a commercial code. An extensive mesh sensitivity study was performed to achieve a grid-independent accuracy for both steady and transient analysis.

scholarly journals Numerical study of the effect of penstock slope on the increase in electric power of micro-hydro system using Computational Fluid Dynamics

2021 ◽  
Vol 927 (1) ◽  
pp. 012029
Author(s):  
Yoga Satria Putra ◽  
Evi Noviani ◽  
Muhardi ◽  
Azrul Azwar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Electric Power ◽  
Numerical Study ◽  
Electrical Power ◽  
Maximum Slope ◽  
The Public ◽  
Hydropower Plants ◽  
Calculation Results ◽  
Alternative Solutions

Abstract Micro-hydropower plants have become one of the alternative solutions to meet the electricity needs of people in remote villages that the public electricity company has not reached. However, the performance of a micro-hydro system has to be continuously developed. This research aims to improve the performance of a micro-hydro system by examining the effect of the slope of the penstock on the increase in electrical power. The penstock slope is varied with diverse angles, namely θ = 50 °, 60 °, 70 °, 80 °, and 90 °. Five simulations of water flow in the penstock for five slope angles were constructed using the open-source CFD software, i.e., OpenFOAM. We calculate the electric power for the five simulations aforementioned. The calculation results show that the variation of the penstock slope can affect the increase of the electric power of a micro-hydro system. The highest electric power occurs at a maximum slope, θ = 90 °.

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