scholarly journals CFD and Experimental Characterization of a Bioreactor: Analysis via Power Curve, Flow Patterns and k L a

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 878
Author(s):  
Luis A. Ramírez ◽  
Edwar L. Pérez ◽  
Cesar García Díaz ◽  
Dumar Andrés Camacho Luengas ◽  
Nicolas Ratkovich ◽  
...  
Keyword(s):  
Lower Energy ◽  
Scaling Up ◽  
Airflow Rate ◽  
Biological Processes ◽  
Experimental Characterization ◽  
Cfd Simulations ◽  
Transfer Rates ◽  
Curve Flow ◽  
The Impact

Mixing operations in biological processes is of utmost importance due to its effect on scaling-up and heat and mass transfer. This paper presents the characterization of a bench-top bioreactor with different impeller configurations, agitation and oxygen transfer rates, using CFD simulations and experimental procedures. Here, it is demonstrated that factors such as the type of impeller and the flow regime can drastically vary the operation as in the preparation of cultures. It was observed that the bioreactor equipped with a Rushton generates a k L a of 0.0056 s−1 for an agitation velocity and airflow rate of 250 RPM and 5 L/min, respectively. It is suitable result for the dissolved oxygen (DO) but requires a considerable amount of power consumption. It is here where the importance of the agitator’s diameter can be observed, since, in the case of the two propeller types studied, lower energy consumption can be achieved with a smaller diameter, as well as a much smaller shear cup 2.376 against 0.723 s−1 by decreasing by 4 cm the standard diameter of an agitated tank (10 cm). Finally, the k L a values obtained for the different configurations are compared with the maximum shear rate values of different cell cultures to highlight the impact of this study and its applicability to different industries that use agitation processes for cell growth.

First-principles and experimental characterization of the electronic properties of CaGaSiN3 and CaAlSiN3: the impact of chemical disorder

2017 ◽  
Vol 19 (13) ◽  
pp. 9292-9299 ◽  
Author(s):  
Robin Niklaus ◽  
Ján Minár ◽  
Jonas Häusler ◽  
Wolfgang Schnick
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Theoretical Basis ◽  
Experimental Characterization ◽  
Host Materials ◽  
Chemical Disorder ◽  
The Impact

Understanding the impact of chemical disorder on the electronic properties of LED phosphor host materials on a theoretical basis.

Experimental characterization of full-scale naturally ventilated atrium and validation of CFD simulations

2014 ◽  
Vol 69 ◽  
pp. 285-291 ◽  
Author(s):  
Stephen D. Ray ◽  
Nan-Wei Gong ◽  
Leon R. Glicksman ◽  
Joseph A. Paradiso
Keyword(s):  
Full Scale ◽  
Experimental Characterization ◽  
Cfd Simulations

scholarly journals Experimental Characterization of Drag Coefficient of an UAV Recovery Parachute

2021 ◽  
Vol 31 (2) ◽  
pp. 67-74
Keyword(s):  
Drag Coefficient ◽  
Unmanned Aerial Vehicles ◽  
Drag Force ◽  
Aerodynamic Drag ◽  
Experimental Characterization ◽  
Aerial Vehicles ◽  
Flat Type ◽  
Suspension Line ◽  
The Impact

Parachute recovery systems are proved to be an efficient method to recovery and rescue unmanned aerial vehicles (UAV) as it follows most requirements of reliability and airworthiness in flights. Parachutes are key components of the recovery systems and the drag coefficient of parachutes plays a crucial role in evaluating parachute’s performance. The purpose of the research is to determine and compare the impact of some factors on aerodynamic drag force during the inflation of a parachute. The canopy’s shape (flat circular type and extended skirt 10% flat type), of the length of suspension lines (be in proportion to nominal diameter from 0.6 to 1.5) are considered. Measurement of the drag force of the parachute models is carried out in an open return wind tunnel. Experimental results show that flat circular canopy has a higher drag coefficient than extended skirt 10% flat model in the range of low speed from 3 to 6 m/s. However, when wind speed is greater than 6 m/s, the drag coefficients of both two parachute types are nearly 0.85. In terms of the suspension line, the longer length would significantly raise the coefficient of drag force.

scholarly journals Experimental Characterization of the Jet Wiping Process

2018 ◽  
Vol 180 ◽  
pp. 02064
Author(s):  
Miguel Alfonso Mendez ◽  
Adriana Enache ◽  
Anne Gosset ◽  
Jean-Marie Buchlin
Keyword(s):  
Gas Flow ◽  
Detection Algorithm ◽  
Gas Flows ◽  
Experimental Characterization ◽  
Data Set ◽  
Time Resolved ◽  
Numerical Studies ◽  
Image Velocimetry ◽  
The Impact

This paper presents an experimental characterization of the jet wiping process, used in continuous coating applications to control the thickness of a liquid coat using an impinging gas jet. Time Resolved Particle Image Velocimetry (TR-PIV) is used to characterize the impinging gas flow, while an automatic interface detection algorithm is developed to track the liquid interface at the impact. The study of the flow interaction is combined with time resolved 3D thickness measurements of the liquid film remaining after the wiping, via Time Resolved Light Absorption (TR-LAbs). The simultaneous frequency analysis of liquid and gas flows allows to correlate their respective instability, provide an experimental data set for the validation of numerical studies and allows for formulating a working hypothesis on the origin of the coat non-uniformity encountered in many jet wiping processes.

scholarly journals Experimental characterization of the impact-damage tolerance of a cross-ply graphite-fiber/epoxy laminate

2008 ◽  
Vol 29 (5) ◽  
pp. 534-543 ◽  
Author(s):  
Xiang-Fa Wu ◽  
Goutam Ghoshal ◽  
Mikhail Kartashov ◽  
Zuleyha Aslan ◽  
Joseph A. Turner ◽  
...  
Keyword(s):  
Damage Tolerance ◽  
Impact Damage ◽  
Graphite Fiber ◽  
Experimental Characterization ◽  
The Impact

Aerodynamic and Thermo-Chemical Assessment of a Post-Catalyst Burnout Zone Liner

2003 ◽  
Author(s):  
Sarento G. Nickolas ◽  
Suresh R. Vilayanur ◽  
Mark J. Spencer ◽  
Anthony Watts ◽  
Andrew Hamer
Keyword(s):  
Boundary Conditions ◽  
Thermal Design ◽  
Heat Transfer Analysis ◽  
Cfd Simulations ◽  
Seal Design ◽  
Burn Out ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
The City

A Kawasaki Heavy Industries M1A-13X engine equipped with a Xonon® Cool Combustion System was used to assess the “effectiveness” of a post-catalyst burnout zone liner. The engine is currently installed at the City of Santa Clara’s Silicon Valley Power municipal electrical generating stations and connected to the grid. Post-catalyst burnout zone liner aero-thermal design and inlet boundary conditions play an important role in achieving low CO emissions. In this particular study, these parameters have been evaluated to minimize CO emissions (by maximizing CO burnout). An aero thermal analysis was conducted using Computational Fluid Dynamics (CFD) simulations of the liner for two distinct engine configurations. The analysis includes characterization of the inlet boundary conditions, heat transfer analysis, ignition delay time, liner residence time and the aerodynamic flow field. In addition, engine tests were used to measure and evaluate the impact of design features on CO emissions. Tests were conducted using new seal design and catalyst liner interface configurations. Results from both of these investigations were then used to determine the “effectiveness” of the liner. The CFD analysis and engine test data identified potential regions of improvement to maximize CO burnout in the Burn out Zone (BOZ) liner. These improvements included changing the inlet boundary conditions as well as modifying the BOZ geometry. Ultimately, a solution scheme was selected and changes were made to the catalyst seal design as well as the catalyst to container interface. Upon implementation, these changes yielded an improved effectiveness and extended the operating range of the engine by minimizing CO emissions.

Experimental Characterization of Airflow Within a Clean HEPA Filter Used for the Containment of Radioactive Contamination in Nuclear Facilities

2016 ◽  
Author(s):  
Alilou Youssef ◽  
Bourrous Soleiman ◽  
Thomas Dominique ◽  
Bardin-Monnier Nathalie ◽  
Nérisson Philippe ◽  
...  
Keyword(s):  
Pressure Drop ◽  
High Efficiency ◽  
Filter Design ◽  
Physical Models ◽  
Airflow Rate ◽  
Nuclear Facilities ◽  
Airborne Contamination ◽  
Pleated Filters ◽  
The Impact

In hazardous industrial activities such as in nuclear facilities, High Efficiency Particulate Air filters (HEPA filters) are essential to ensure the containment of airborne contamination. Most of the filters used in ventilation networks are pleated, in order to offer a larger surface of filtration. For industrial risks likely to lead to an important release of particles (e.g. fire), predicting the evolution of the pressure drop of pleated filters is very important, in order to anticipate any dysfunction, failure or breaking of these devices. Pressure drop variations are linked to airflow rate variations and to clogging process of the medium by airborne particles. Thus, the airflow pattern in a pleat channel is essential for optimizing the filter design and enhancing its lifetime. Particles are transported by the airflow and deposited at the filter surface; hence, the geometry of the dust cake (shape and location) is partially determined knowing the velocity streamlines. The present paper focuses on the characterization of airflows in a clean HEPA filter. The difficulty to perform fine measurement on a real scale filter led us to develop an experimental device, consisting in the reproduction of a single pleat, identical to a real pleat constituting industrial filters. The small dimension of the pleat makes the velocity measurement difficult to establish. That is why μ-PIV method has been adapted to measure the velocity field inside the filter for different filtration velocities at the first moments of the experiment, in order to avoid the impact of clogging by particles used to seed the flow. These particles are DEHS droplets 0.01 < St < 0.05. In the future, these well-characterized airflows will be the basis for CFD computation of particle transport and deposition inside the pleats. Ultimately, the aim is to develop or upgrade physical models predicting the pressure drop evolution of pleated filters, during clogging process in accidental situations.

scholarly journals Numerical and experimental characterization of splitter blade impact on pump as turbine performance

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042199324
Author(s):  
Daniel Adu ◽  
Jianguo Du ◽  
Ransford O Darko ◽  
Eric Ofosu Antwi ◽  
Muhammad Aamir Shafique Khan
Keyword(s):  
Rotational Speed ◽  
Simulated Data ◽  
Maximum Deviation ◽  
Cfd Simulations ◽  
Flow Rates ◽  
Turbine Performance ◽  
Hydropower Dams ◽  
The Impact ◽  
Good Agreement

Several rivers and streams are available in Africa and Asian regions with great potentials not applicable for constructing large hydropower dams but feasible for small and mini hydro generation. This study strive for investigating the impact of splitter blade on pump as turbine performance considering different speed and flow rates. Two specific centrifugal pump models one with six blades without splitter and another with four blades and four splitters were used for the study. The inlet diameter and outlet diameters of both impellers were 104 mm/116 mm, and 160 mm respectively at a designed flow rate Q = 12.5 m3/h, head H = 16 m, rotational speed n = 1450 rpm and efficiency of 56%, outlet impeller width of 0.006 m, a blade outlet angle of 30° was used for the study. CFD simulations were conducted with the use of k-ε turbulence model. The influence of splitter blade position on the performance of pump as turbine in the selected specific pumps with and without splitter blades has been investigated both experimentally and numerically at three different flow rates and rotational speed. The simulated data were in good agreement with the experimental results, the maximum deviation error between the CFD and test for each model are 5.6%, 2.6%, for the head and efficiency; 7.5% and 3.6% at different flow conditions.

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