scholarly journals Modeling the Separation of Microorganisms in Bioprocesses by Flotation

2018 ◽  
Author(s):  
Stefan Schmideder ◽  
Christoph Kirse ◽  
Julia Hofinger ◽  
Sascha Rollié ◽  
Heiko Briesen
Keyword(s):  
Fluid Dynamics ◽  
Separation Efficiency ◽  
Algebraic Model ◽  
Balance Model ◽  
Separation Processes ◽  
Dissolved Air Flotation ◽  
Computational Fluid Dynamics Cfd ◽  
Cell Size Distributions ◽  
Fermentation Broths ◽  
The Impact

Bioprocesses for the production of renewable energies and materials lack efficient separation processes for the utilized microorganisms such as algae and yeasts. Dissolved air flotation (DAF) and microflotation are promising approaches to overcome this problem. The efficiency of these processes depends on the ability of microorganisms to aggregate with microbubbles in the flotation tank. In this study, different new or adapted aggregation models for microbubbles and microorganisms are compared and investigated for their range of suitability to predict the separation efficiency of microorganisms from fermentation broths. The complexity of the heteroaggregation models range from an algebraic model to a 2D population balance model (PBM) including the formation of clusters containing several bubbles and microorganisms. The effect of bubble and cell size distributions on the flotation efficiency is considered by applying PBMs, as well. To determine the impact of the model assumptions, the modeling approaches are compared and classified for their range of applicability. Evaluating computational fluid dynamics (CFD) of a DAF system shows the heterogeneity of the fluid dynamics in the flotation tank. Since analysis of the streamlines of the tank show negligible backmixing, the proposed aggregation models are coupled to the CFD data by applying a Lagrangian approach.

scholarly journals Modeling the Separation of Microorganisms in Bioprocesses by Flotation

Processes ◽  
2018 ◽  
Vol 6 (10) ◽  
pp. 184 ◽  
Author(s):  
Stefan Schmideder ◽  
Christoph Kirse ◽  
Julia Hofinger ◽  
Sascha Rollié ◽  
Heiko Briesen
Keyword(s):  
Fluid Dynamics ◽  
Separation Efficiency ◽  
Algebraic Model ◽  
Balance Model ◽  
Separation Processes ◽  
Dissolved Air Flotation ◽  
Computational Fluid Dynamics Cfd ◽  
Air Flotation ◽  
Cell Size Distributions ◽  
Dissolved Air

Bioprocesses for the production of renewable energies and materials lack efficient separation processes for the utilized microorganisms such as algae and yeasts. Dissolved air flotation (DAF) and microflotation are promising approaches to overcome this problem. The efficiency of these processes depends on the ability of microorganisms to aggregate with microbubbles in the flotation tank. In this study, different new or adapted aggregation models for microbubbles and microorganisms are compared and investigated for their range of suitability to predict the separation efficiency of microorganisms from fermentation broths. The complexity of the heteroaggregation models range from an algebraic model to a 2D population balance model (PBM) including the formation of clusters containing several bubbles and microorganisms. The effect of bubble and cell size distributions on the flotation efficiency is considered by applying PBMs, as well. To determine the sensitivity of the results on the model assumptions, the modeling approaches are compared, and suggestions for their range of applicability are given. Evaluating the computational fluid dynamics (CFD) of a dissolved air flotation (DAF) system shows the heterogeneity of the fluid dynamics in the flotation tank. Since analysis of the streamlines of the tank show negligible back mixing, the proposed aggregation models are coupled to the CFD data by applying a Lagrangian approach.

scholarly journals The Protect Air Film of an Exterior Window

2021 ◽  
Author(s):  
Sanaz Dianat
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Glass Temperature ◽  
Experimental Procedure ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Cfd ◽  
Air Film ◽  
The Impact

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed

scholarly journals The Protect Air Film of an Exterior Window

2021 ◽  
Author(s):  
Sanaz Dianat
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Glass Temperature ◽  
Experimental Procedure ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Cfd ◽  
Air Film ◽  
The Impact

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed

scholarly journals Experimental and CFD Modelling: Impact of the Inlet Slug Flow on the Horizontal Gas–Liquid Separator

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Siong Lee ◽  
Thomas Choong ◽  
Luqman Abdullah ◽  
Mus’ab Abdul Razak ◽  
Zhen Ban
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Liquid Phase ◽  
Flow Pattern ◽  
Slug Flow ◽  
Cavity Formation ◽  
Cfd Modelling ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Liquid Separator

For a gas-liquid separator sizing, many engineers have neglected the flow pattern of incoming fluids. The impact of inlet slug flow which impeded onto the separator’s liquid phase will cause a separator fails to perform when sloshing happened in the separator. To date, the study on verifying the impact of inlet slug flow in a separator remains limited. In this paper, the impact of inlet momentum and inlet slug flow on the hydrodynamics in a separator for cases without an inlet device were investigated. The experimental and Computational Fluid Dynamics (CFD) results of cavity formation and sloshing occurrence in the separator in this study were compared. A User Defined Function (UDF) was used to describe the inlet slug flow at the separator inlet. Inlet slug flow occurred at inlet momentum from 200 to 1000 Pa, and sloshing occurred in the separator at 1000 Pa. Both experimental and simulated results showed similar phenomena.

scholarly journals Modelling a Biochemical Reaction with Computational Fluid Dynamics

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Sotos C. Generalis ◽  
Gregory M Cartland Glover
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Bubble Column ◽  
Reaction Model ◽  
Biochemical Reaction ◽  
Single Plane ◽  
Solids Concentration ◽  
Computational Fluid Dynamics Cfd ◽  
Specific Growth Rates ◽  
The Impact

Earlier investigations (Cartland Glover et al., 2004) into the use of computational fluid dynamics (CFD) for the modelling of gas-liquid and gas-liquid-solid flow allowed a simple biochemical reaction model to be implemented. A single plane mesh was used to represent the transport and reaction of molasses, the mould Aspergillus niger and citric acid in a bubble column with a height to diameter aspect ratio of 20:1. Two specific growth rates were used to examine the impact that biomass growth had on the local solids concentration and the effect this had on the local hydrodynamics of the bubble column.

scholarly journals Modeling And Designing Simulation Using CFD Computational Fluid Dynamics Application For The Process Of Capture Diesel Soot Particles By Hydro Cyclone

2019 ◽  
Vol 26 (3) ◽  
pp. 105-111
Author(s):  
Mai Hanna Shahda ◽  
Mahmod Alfattamah ◽  
Youssef Johar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Simulation ◽  
Diesel Soot ◽  
Product Performance ◽  
Diesel Generator ◽  
Soot Particles ◽  
Fluid Forces ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact

The research aims to predict the efficiency of capturing the soot particles generated by the diesel generator within the Hydro Cyclone by conducting the applied study using the Computational Fluid Dynamics (CFD) application through modeling and simulation of the turbulent flow within the Hydro Cyclone using SOLIDWORKS Flow Simulation. The ability to predict the impact of such flows on your product performance is time consuming and costly without some form of simulation tools...SOLIDWORKS Flow Simulation uses Computational Fluid Dynamics (CFD) analysis to enable quick, efficient simulation of fluid flow and can easily calculate fluid forces and help the designer to understand the impact of a liquid or gas on product performance and comparing the results with experimental reality. In this research, the engineering simulation confirmed the importance of using Hydro Cyclone in the capture of diesel soot particles by an error rate of only 4% compared to experimental reality.

scholarly journals Prediction of Dispersion Behavior of Typical Exhaust Pollutants From Mine Hydraulic Support Transporters Based on Numerical Simulation

2021 ◽  
Author(s):  
Wen Nie ◽  
Xiaofei Liu ◽  
Chengyi Liu ◽  
Lidian Guo ◽  
Yun Hua
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Diesel Exhaust ◽  
Preliminary Investigation ◽  
Gas Monitoring ◽  
Hydraulic Support ◽  
Idle Speed ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Monitoring Devices

Abstract To analyze the impact of exhaust emissions from mine hydraulic support transporters on the roadway environment. In this paper, the dispersion distribution of diesel exhaust pollutant during the functioning of a hydraulic support transporters were all-round simulated by Dynamic Mesh of Computational Fluid Dynamics. More specifically, the dispersion and distribution of the main exhaust pollutants CO, HC, and NOx emitted by vehicles under the influence of the roadway wind flow were simulated with computational fluid dynamics (CFD) and the dispersion of exhaust pollutants from hydraulic support transporters during multiple driving phases in an alleyway (from hauling in material, unloading at idle speed, to driving off with no load) was predicted. The simulation results show that the exhaust pollutants emitted during the movement of hydraulic support transporters can pollute the roadway environment and negatively affect gas monitoring devices in the roadway. Therefore, coal mining enterprises should optimize the ventilation design scheme to improve the roadway environment: they should increase the ventilation volume to dilute the emitted pollutants; in addition, the locations of underground gas monitoring devices should be adjusted to avoid interference from exhaust pollutants emitted by vehicles. This paper provides a theoretical basis for the preliminary investigation of the dispersion and transportation characteristics of exhaust pollutants emitted by vehicles in roadways, the research in this paper is of guiding significance to reduce the inhalation of the diesel exhaust pollutants of the miners and reduce the probability of suffering from occupational diseases.

scholarly journals Reducing drag on a flat plate subjected to incompressible laminar flow

2019 ◽  
Vol 286 ◽  
pp. 07006
Author(s):  
A. Agriss ◽  
M. Agouzoul ◽  
A. Ettaouil
Keyword(s):  
Fluid Dynamics ◽  
Flat Plate ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Ansys Fluent ◽  
Low Reynolds Numbers ◽  
Computational Fluid Dynamics Cfd ◽  
Corrugated Plates ◽  
The Impact ◽  
Reference Plate

The idea behind this work comes from the question: What is the impact of plate corrugations on drag? In this context, a numerical study of laminar incompressible flow over a flat plate and over corrugated plates is carried out. Numerical analysis is performed for low Reynolds numbers (Re= 10, Re = 50, Re = 100, Re = 500, Re =1000) using the computational fluid dynamics (CFD) software ANSYS FLUENT. Simulations results are compared to each others and with those of the reference plate (flat plate (figure 4a)). Comparisons are made via drag coefficient Cd. This work is the beginning of a study that evaluates the impact of corrugations on drag reduction on a flat plate.

Evaluation of horizontal submarine slide impact force on pipeline via a modified hybrid geotechnical-fluid dynamics framework

2021 ◽  
Author(s):  
Ning Fan ◽  
Wangcheng Zhang ◽  
Fauzan Sahdi ◽  
Tingkai Nian
Keyword(s):  
Fluid Dynamics ◽  
Impact Force ◽  
Flow Behavior ◽  
Reynolds Numbers ◽  
Submarine Slide ◽  
Slide Mass ◽  
Submarine Slides ◽  
Computational Fluid Dynamics Cfd ◽  
Force Components ◽  
The Impact

There are situations in offshore energy development where potential impact forces between submarine slides and pipelines need to be estimated. The horizontal slide-pipeline impact force, parallel to the main travel direction of the sliding mass and normal to the pipeline axis, is generally dominant compared to other force components, and hence of particular concern. In practice, pipelines may be suspended at varying distances above the seabed (gap) and existing methods do not consider how this will affect the horizontal slide-pipeline forces. This paper investigates the effects of pipeline-seabed gap and pipeline diameter on the horizontal slide-pipeline impact force via 181 computational fluid dynamics (CFD) simulations at Reynolds numbers of 0.36 - 287. Results show that variation in the pipeline-seabed gap and pipeline diameter alters the slide mass flow behavior as it flows past the pipeline and hence the impact force when the pipeline-seabed gap is below a critical value. A modified hybrid geotechnical-fluid dynamics framework for estimating the horizontal impact force is proposed by considering the effects of the pipeline-seabed gap and pipeline diameter, which is validated with existing experimental datasets.

Flotation of algae for water reuse and biomass production: role of zeta potential and surfactant to separate algal particles

2015 ◽  
Vol 72 (5) ◽  
pp. 762-769 ◽  
Author(s):  
Dong-Heui Kwak ◽  
Mi-Sug Kim
Keyword(s):  
Zeta Potential ◽  
Anionic Surfactant ◽  
Water Reuse ◽  
Separation Efficiency ◽  
Microalgae Cultivation ◽  
Separation Processes ◽  
Dissolved Air Flotation ◽  
Chemical Coagulation ◽  
Dissolved Air

The effect of chemical coagulation and biological auto-flocculation relative to zeta potential was examined to compare flotation and sedimentation separation processes for algae harvesting. Experiments revealed that microalgae separation is related to auto-flocculation of Anabaena spp. and requires chemical coagulation for the whole period of microalgae cultivation. In addition, microalgae separation characteristics which are associated with surfactants demonstrated optimal microalgae cultivation time and separation efficiency of dissolved CO2 flotation (DCF) as an alternative to dissolved air flotation (DAF). Microalgae were significantly separated in response to anionic surfactant rather than cationic surfactant as a function of bubble size and zeta potential. DAF and DCF both showed slightly efficient flotation; however, application of anionic surfactant was required when using DCF.

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