scholarly journals Computational fluid dynamic analysis reveals the underlying physical forces playing a role in 3D multiplex brain organoid cultures

2018 ◽  
Author(s):  
Livia Goto-Silva ◽  
Nadia M. E. Ayad ◽  
Iasmin L. Herzog ◽  
Nilton P. Silva ◽  
Bernard Lamien ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Suspension Culture ◽  
Fluid Dynamic ◽  
Spinner Flask ◽  
List Type ◽  
Computational Fluid Dynamic Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Brain Organoid

AbstractOrganoid cultivation in suspension culture requires agitation at low shear stress to allow for nutrient diffusion, which preserves tissue structure. Multiplex systems for organoid cultivation have been proposed, but whether they meet similar shear stress parameters as the regularly used spinner flask and its correlation with the successful generation of brain organoids, has not been determined. Herein, we used computational fluid dynamics (CFD) analysis to compare two multiplex culture conditions: steering plates on an orbital shaker and the use of a previously described bioreactor. The bioreactor had low speed and high shear stress regions that may affect cell aggregate growth, depending on volume, whereas the CFD parameters of the steering plates were closest to the parameters of the spinning flask. Our protocol improves the initial steps of the standard brain organoid formation, and organoids produced therefrom displayed regionalized brain structures, including retinal pigmented cells. Overall, we conclude that suspension culture on orbital steering plates is a cost-effective practical alternative to previously described platforms for the cultivation of brain organoids for research and multiplex testing.HighlightsImprovements to organoid preparation protocolMultiplex suspension culture protocol successfully generate brain organoidsComputational fluid dynamics (CFD) reveals emerging properties of suspension culturesCFD of steering plates is equivalent to that of spinner flask cultures

Efficiency prediction for storage chambers using computational fluid dynamics

1996 ◽  
Vol 33 (9) ◽  
pp. 163-170 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Particle Tracking ◽  
Critical Value ◽  
Complex Geometries ◽  
Bed Shear Stress ◽  
Breadth Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Simulated Flow

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.

scholarly journals Analisis Distribusi Temperatur dan Aliran Fluida pada Proses Pengeringan Butiran Teh Bentuk Silinder Di Dalam Fluidized Bed Dryer Menggunakan Computational Fluid Dynamic (CFD)

ROTASI ◽  
2019 ◽  
Vol 20 (4) ◽  
pp. 237
Author(s):  
MSK Tony Suryo Utomo ◽  
Eflita Yohana ◽  
Mauli Astuti Khoiriyah
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluidized Bed ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Fluidized Bed Dryer ◽  
Computational Fluid Dynamics Cfd

Pengeringan merupakan proses perpindahan panas dan uap air secara simultan yang memerlukan energi panas untuk menguapkan kandungan air dari bahan yang akan dikeringkan. Penelitian ini dilakukan dengan cara simulasi. Produk yang dipilih untuk simulasi ini yaitu teh. Simulasi numerik perpindahan massa pada teh dilakukan dengan menempatkan material teh pada domain komputasi sebuah aliran eksternal. Penelitian ini bertujuan untuk menganalisis distribusi temperatur pada partikel teh dengan menggunakan Computational Fluid Dynamics (CFD) dan menganalisis pengaruh variasi kecepatan inlet dan temperatur inlet terhadap waktu pengeringan sehingga diperoleh metode pengeringan yang paling optimum pada pengeringan teh. Penurunan massa pada teh dihitung secara analitik dengan menggunakan persamaan laju penurunan massa. Teh dimodelkan dengan bentuk menyerupai silinder setelah dilakukan pelayuan untuk kemudian dikeringkan. Kecepatan masuk aliran udara dan temperatur masuk divariasikan sesuai dengan batas kecepatan minimum dan maksimum fluidisasi dan temperatur pengeringan teh untuk fluidized bed dryer. Waktu yang digunakan untuk menurunkan kadar air hingga 3% berdasarkan temperatur pada kecepatan 1,6 m/s secara berurutan adalah 354 s (880C), 300 s (930C), dan 256 s (980C). Sementara pada kecepatan 2,6 m/s waktu yag dibutuhkan adalah 277 s (880C), 234 s (930C), dan 200 s (980C) serta untuk kecepatan 3,6 m/s berturut-turut 235 s (880C), 199 s (930C), dan 169 s (980C). Untuk pengeringan teh lebih optimal dilakukan dengan menaikkan kececepatan masuk aliran fluida dibandingkan dengan menaikkan temperatur.

Evolution of Phosphine from Aluminum Phosphide Pellets

2021 ◽  
Vol 64 (2) ◽  
pp. 615-624
Author(s):  
Sherif Elsayed ◽  
Mark E. Casada ◽  
Ronaldo G. Maghirang ◽  
Mingjun Wei
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Computational Model ◽  
Solid Material ◽  
Effect Of Temperature ◽  
Published Data ◽  
List Type ◽  
Limited Information ◽  
Cfd Model ◽  
Computational Fluid Dynamics Cfd

HighlightsThis study developed a mathematical relationship accounting for the production rate of phosphine.The effect of temperature on phosphine sorption into wheat is described mathematically.A computational fluid dynamics (CFD) model was built to predict the phosphine concentration in fumigated grain.Experiments were conducted to validate the CFD model.Abstract. Phosphine gas (PH3) is widely used as a fumigant for stored product insect infestations due to its relatively low price and the near absence of residual chemical on the grain. Understanding the behavior of phosphine gas inside the fumigated space is crucial to maintaining a lethal dosage and protecting stored grain from subsequent insect damage. Phosphine is available either in gas form or is produced from a solid material, as pellets or tablets, that reacts with water in the air. The solid form is the most commonly used; however, limited information is available on the rate of phosphine gas generated from the solid material. In this study, a mathematical equation was formulated, based on previous studies in the literature, to describe the gas generation rate. This equation was incorporated into a computational model using ANSYS Fluent 19.1, a commercial software for computational fluid dynamics (CFD) analysis. The computational model developed here allows prediction of the phosphine concentration within a fumigated grain bulk. The PH3 sorption was included in the model. The effect of temperature on the sorption rate was investigated based on published data, and the rate change due to temperature was characterized. The gas generated by a single pellet was measured in laboratory experiments in a 0.208 m3 sealed barrel. The measurements confirmed the CFD results with an error of 0.3%, 0.9%, and 7.2% for three different configurations. The deviations seen between the experimental replicates increased the error and show the need for further investigation of the effects of temperature, grain age and history, leakage, and other factors. Keywords: CFD, Evolution rate, Phosphine, Sorption.

Air Pressure Reducer Modeling by CFD Methodology

2014 ◽  
Vol 960-961 ◽  
pp. 547-550
Author(s):  
Ran Ran Wu ◽  
Ding Fan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Turbulence Model ◽  
Physical Experiment ◽  
Air Pressure ◽  
Pressure Characteristic ◽  
Computational Fluid Dynamics Cfd ◽  
Good Agreement ◽  
Pressure Characteristics

In this paper, the computational fluid dynamics (CFD) methodology as well as the shear-stress transport (SST) k-omega turbulence model was adopted to model the air pressure reducer (APR). Changing the gas needle’s displacement of APR continuously, the writer obtains the displacement-pressure characteristics of APR. In order to demonstrate the validity of these characteristics, a physical experiment was conducted, which generates another displacement-pressure characteristic. Comparing the two characteristics with a good agreement, it is indicated that the CFD methodology is suitable to study the displacement-pressure characteristics of APR.

scholarly journals ANALISA PERFORMA HIDRO-TURBIN CROSS-FLOW DENGAN SUDUT DIAMETER RUNNER 10° DAN JUMLAH SUDU 8, 16, DAN 24 MENGGUNAKAN METODE CFD

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Muhammad Mu'izzul As'ad ◽  
Ahmad Janan Febrianto ◽  
Dandun Mahesa Prabowoputra
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Renewable Energy ◽  
Angular Velocity ◽  
Cross Flow ◽  
Shear Stress Transport ◽  
Computational Fluid Dynamics Cfd

Hidro turbin adalah salah satu komponen utama pada pembangkit listrik tenaga air. Penelitian terhadap turbin air memiliki peran penting dalam pengembangan renewable energy yang bersumber dari tenaga hidro. Dimana Indonesia memiliki potensi sumber energi hidro yang sangat besar. Hidro-turbin memiliki beberapa jenis yaitu turbin Sumbu Horizontal, Turbin Sumbu vertical dan turbin Cross-Flow. Penelitian ini dilakukan pada turbin air tipe Cross-Flow, dan dilakukan dengan metode Computational Fluid Dynamics (CFD). Simulasi dilakukan secara tiga dimensi dan menggunakan perangkat lunak Ansys Student 2021 dengan solver CFX. Turbin cross-flow menggunakan runner dengan sudut 10°, dengan variasi jumlah sudu 8, 16, dan 24. Penelitian ini bertujuan untuk mengetahui performa turbin Cross-flow dan mengetahui pengaruh jumlah sudu pada performa tersebut. Turbin Cross-flow beroperasi pada kecepatan fluida 3m/s dan angular velocity 50-250 rpm. Simulasi menggunakan tipe turbulensi Shear Stress Transport dalam kondisi tunak, Hasil menunjukan turbin cross-flow dengan sudut runner 10o dan jumlah sudu 24 memiliki performa terbaik bila dibandingkan dengan jumlah sudu 8 dan 16.

scholarly journals A Computational Fluid Dynamics Protocol for The Hemodynamic Analysis of a Microfluidic Model of Thrombosis

2021 ◽  
Author(s):  
Yunduo Charles Zhao ◽  
Sarah Elizabeth Keogh ◽  
Parham Vatankhah ◽  
Renee Ellen Preketes-Tardiani ◽  
Lining Arnold Ju
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Experimental Analysis ◽  
Microfluidic Channels ◽  
Cfd Simulations ◽  
Disturbed Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Time Observation ◽  
Real Time Observation

Abstract Thrombosis is both attributed to biochemical agonists and mechanical stresses applied to platelets. Whilst the effect of biochemical agonists has been extensively studied, the mechanosensitive factors remain poorly defined. Stenotic microfluidic channels mimic the narrowing vessels, providing the real-time observation of platelets under disturbed flow. Though the experimental analysis of platelets in disturbed flow confirms the mechanosensitive behavior of platelets, it cannot explicate detailed thresholds for platelet activation. Computational Fluid Dynamics (CFD) could be utilized alongside experimental analysis to characterize thresholds for platelet behavior under imposed shear stress. CFD simulations, however, are prone to uncertainties and errors which should be minimized to obtain compelling results. Hereby, we have presented a CFD protocol for researchers in the field of microfluidic and hemodynamic studies.

scholarly journals Computational Fluid Dynamics (CFD) Investigation of Aerodynamic Characters inside Nasal Cavity towards Surgical Treatments for Secondary Atrophic Rhinitis

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ya Zhang ◽  
Xudong Zhou ◽  
Miao Lou ◽  
Minjie Gong ◽  
Jingbin Zhang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Atrophic Rhinitis ◽  
Nasal Resistance ◽  
Septal Perforation ◽  
Virtual Operation ◽  
Nasal Floor ◽  
Computational Fluid Dynamics Cfd ◽  
Surgical Treatments

Purpose. To use computational fluid dynamics (CFD) technology to fundamentally understand (1) the effect of surgical treatments on nasal physiology for secondary atrophic rhinitis and (2) the priority of operations. Subjects and Methods: With the aid of medical imaging and CFD modeling, three virtual operations (nasoseptal perforation repair, cavity narrowing, and a combination of both) were performed to analyze airflow, nasal resistance, and wall shear stress. Results. Compared with the cavity-narrowing virtual operation, nasal resistance was not significantly altered by septal perforation repair virtual operation. Airflow allocation changed with more air flowing through the olfactory area and less though the nasal floor after all operations, especially the cavity-narrowing operation. Wall shear stress at the original epistaxis area and the nasal floor was reduced after the cavity-narrowing operation. Conclusions. Simulation results suggest that the cavity-narrowing operation takes priority over septal perforation repair if a staged surgery approach is adopted. If only one operation can be chosen, the cavity-narrowing operation is better than the septal perforation repair. This work shows that CFD-based modeling may aid precision medicine.

Some Aspects of Uncertainty in Computational Fluid Dynamics Results

1991 ◽  
Vol 113 (4) ◽  
pp. 538-543 ◽  
Author(s):  
U. B. Mehta
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Sensitivity Analysis ◽  
Uncertainty Analysis ◽  
Dynamic Systems ◽  
Fluid Dynamic ◽  
Practical Method ◽  
Computational Fluid Dynamics Cfd

Uncertainties are inherent in computational fluid dynamics (CFD). These uncertainties need to be systematically addressed and managed. Sources of these uncertainties are identified and some aspects of uncertainty analysis are discussed. Some recommendations are made for quantification of CFD uncertainties. A practical method of uncertainty analysis is based on sensitivity analysis. When CFD is used to design fluid dynamic systems, sensitivity-uncertainty analysis is essential.

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