Use of computational fluid dynamics (CFD) to model observed nasal nitric oxide levels in human subjects

Research was undertaken in order to identify possible methodologies for the prediction of sedimentation in storage chambers based on computational fluid dynamics (CFD). The Fluent CFD software was used to establish a numerical model of the flow field, on which further analysis was undertaken. Sedimentation was estimated from the simulated flow fields by two different methods. The first approach used the simulation to predict the bed shear stress distribution, with deposition being assumed for areas where the bed shear stress fell below a critical value (τcd). The value of τcd had previously been determined in the laboratory. Efficiency was then calculated as a function of the proportion of the chamber bed for which deposition had been predicted. The second method used the particle tracking facility in Fluent and efficiency was calculated from the proportion of particles that remained within the chamber. The results from the two techniques for efficiency are compared to data collected in a laboratory chamber. Three further simulations were then undertaken in order to investigate the influence of length to breadth ratio on chamber performance. The methodology presented here could be applied to complex geometries and full scale installations.

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Improvement of real-scale raceway bioreactors for microalgae production using Computational Fluid Dynamics (CFD)

Algal Research ◽

10.1016/j.algal.2021.102207 ◽

2021 ◽

Vol 54 ◽

pp. 102207

Author(s):

Cristian Inostroza ◽

Alessandro Solimeno ◽

Joan García ◽

José M. Fernández-Sevilla ◽

F. Gabriel Acién

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Computational Fluid Dynamics Cfd ◽

Real Scale

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Design of Novel Flash Ironmaking Reactors for Greatly Reduced Energy Consumption and CO2 Emissions

Metals ◽

10.3390/met11020332 ◽

2021 ◽

Vol 11 (2) ◽

pp. 332

Author(s):

Hong Yong Sohn ◽

De-Qiu Fan ◽

Amr Abdelghany

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Large Diameter ◽

Reduction Reaction ◽

The Novel ◽

Height Ratio ◽

Fine Iron ◽

Computational Fluid Dynamics Cfd ◽

High Reduction ◽

Iron Ore Concentrate

The development of a novel ironmaking technology based on fine iron ore concentrate in a flash reactor is summarized. The design of potential industrial reactors for flash ironmaking based on the computational fluid dynamics technique is described. Overall, this simulation work has shown that the size of the reactor used in the novel flash ironmaking technology (FIT) can be quite reasonable vis-à-vis the blast furnaces. A flash reactor of 12 m diameter and 35 m height with a single burner operating at atmospheric pressure would produce 1.0 million tons of iron per year. The height can be further reduced by either using multiple burners, preheating the feed gas, or both. The computational fluid dynamics (CFD)-based design of potential industrial reactors for flash ironmaking pointed to a number of features that should be incorporated. The flow field should be designed in such a way that a larger portion of the reactor is used for the reduction reaction but at the same time excessive collision of particles with the wall must be avoided. Further, a large diameter-to-height ratio that still allows a high reduction degree should be used from the viewpoint of decreased heat loss. This may require the incorporation of multiple burners and solid feeding ports.

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Morphological and Hemodynamic Changes during Cerebral Aneurysm Growth

Brain Sciences ◽

10.3390/brainsci11040520 ◽

2021 ◽

Vol 11 (4) ◽

pp. 520

Author(s):

Emily R. Nordahl ◽

Susheil Uthamaraj ◽

Kendall D. Dennis ◽

Alena Sejkorová ◽

Aleš Hejčl ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Kinetic Energy ◽

Swirling Flow ◽

Morphological Changes ◽

Cerebral Aneurysms ◽

Patient Specific ◽

Aneurysm Wall ◽

Aneurysm Growth ◽

Computational Fluid Dynamics Cfd

Computational fluid dynamics (CFD) has grown as a tool to help understand the hemodynamic properties related to the rupture of cerebral aneurysms. Few of these studies deal specifically with aneurysm growth and most only use a single time instance within the aneurysm growth history. The present retrospective study investigated four patient-specific aneurysms, once at initial diagnosis and then at follow-up, to analyze hemodynamic and morphological changes. Aneurysm geometries were segmented via the medical image processing software Mimics. The geometries were meshed and a computational fluid dynamics (CFD) analysis was performed using ANSYS. Results showed that major geometry bulk growth occurred in areas of low wall shear stress (WSS). Wall shape remodeling near neck impingement regions occurred in areas with large gradients of WSS and oscillatory shear index. This study found that growth occurred in areas where low WSS was accompanied by high velocity gradients between the aneurysm wall and large swirling flow structures. A new finding was that all cases showed an increase in kinetic energy from the first time point to the second, and this change in kinetic energy seems correlated to the change in aneurysm volume.

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Special Issue on “CFD Based Researches and Applications for Fluid Machinery and Fluid Device”

Processes ◽

10.3390/pr9071137 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1137

Author(s):

Jin-Hyuk Kim ◽

Sung-Min Kim ◽

Minsuk Choi ◽

Lei Tan ◽

Bin Huang ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Power System ◽

Special Issue ◽

Numerical Techniques ◽

Fluid Machinery ◽

Computing Power ◽

Computational Fluid Dynamics Cfd

The demand for computational fluid dynamics (CFD)-based numerical techniques is increasing rapidly with the development of the computing power system [...]

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