scholarly journals Application of the Robust Fixed Point Iteration Method in Control of the Level of Twin Tanks Liquid

Computation ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 96
Author(s):  
Hamza Khan ◽  
Hazem Issa ◽  
József K. Tar
Keyword(s):  
Numerical Simulation ◽  
Fixed Point ◽  
Nonlinear Systems ◽  
Flow Rate ◽  
Fluid Level ◽  
Process Industries ◽  
Fixed Point Iteration ◽  
Precise Control ◽  
Strongly Nonlinear ◽  
Simulation Results

Precise control of the flow rate of fluids stored in multiple tank systems is an important task in process industries. On this reason coupled tanks are considered popular paradigms in studies because they form strongly nonlinear systems that challenges the controller designers to develop various approaches. In this paper the application of a novel, Fixed Point Iteration (FPI)-based technique is reported to control the fluid level in a “lower tank” that is fed by the egress of an “upper” one. The control signal is the ingress rate at the upper tank. Numerical simulation results obtained by the use of simple sequential Julia code with Euler integration are presented to illustrate the efficiency of this approach.

scholarly journals The Analysis of SEIRS-SEI Epidemic Models on Malaria with Regard to Human Recovery Rate

2017 ◽  
Vol 6 (3) ◽  
pp. 132-140
Author(s):  
Resmawan Resmawan ◽  
Paian Sianturi ◽  
Endar Hasafah Nugrahani
Keyword(s):  
Numerical Simulation ◽  
Fixed Point ◽  
Recovery Rate ◽  
Human Population ◽  
Equilibrium Points ◽  
Epidemic Models ◽  
Existence And Stability ◽  
Simulation Results ◽  
Model Formation ◽  
The Given

This article discusses SEIRS-SEI epidemic models on malaria with regard to human recovery rate. SEIRS-SEI in this model is an abbreviation of the population class used in the model, ie Susceptible, Exposed, Infected, and Recovered populations in humans and Susceptible, Exposed, and Infected populations in mosquito. These epidemic models belong to mathematical models which clarify a phenomenon of epidemic transmission of malaria by observing the human recovery rate after being infected and susceptible. Human population falls into four classes, namely susceptible humans, exposed humans, infected humans, and recovered humans. Meanwhile, mosquito population serving as vectors of the disease is divided into three classes, including susceptible mosquitoes, exposed mosquitoes, and infected mosquitoes. Such models are termed SEIRS-SEI epidemic models. Analytical discussion covers model formation, existence and stability of equilibrium points, as well as numerical simulation to find out the influence of human recovery rate on population dynamics of both species. The results show that the fixed point without disease ( ) is stable in condition  and unstable in condition . The simulation results show that the given treatment has an influence on the dynamics of the human population and mosquitoes. If the human recovery rate from the infected state becomes susceptible to increased, then the number of infected populations of both species will decrease. As a result, the disease will not spread and within a certain time will disappear from the population.

Estimation of Leakage Mass Flow Rate through Labyrinth Seal Using CFD Techniques

2017 ◽  
Vol 3 (02) ◽  
Author(s):  
M Neeharika ◽  
Prabhat Kumar Hensh
Keyword(s):  
Numerical Simulation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Flow Behavior ◽  
Labyrinth Seal ◽  
Empirical Correlation ◽  
Radial Clearance ◽  
Leakage Flow ◽  
Simulation Results

Seal design is an essential part for turbo machinery. Seal consisting of fins is placed in a gap between stationary and rotating component to minimize the leakage flow. Seal leakage flow has been considered as an inevitable loss factor that highly affects the efficiency of any machine. During operation of the equipment, thermal expansion/contraction of components take place, which causes variation of the gap between stationary and rotating component. Importance of the study is to understand the flow behavior due to variation of the gap. The variation of gap leads to change of radial clearance between fin to metal component and subsequent change of flow pattern. The main focus of the paper is to estimate the leakage flow through a labyrinth seal placed between rotor and casing of a typical steam turbine. Numerical techniques using 3D CFD tool are used for this purpose. Three different seal configurations are proposed in the study. The variables of the three seal configurations are radial clearance, number of fins in the flow passage and pressure drop across the seal passages. As an alternative methodology, an empirical correlation is formulated based on numerical simulation results for one set of radial clearance to estimate mass flow rate through the seal. In order to validate the formulated correlation, mass flow rate is determined for another set of radial clearance and compared with numerical simulation results. It is observed that flow rate estimated from 3D CFD study is around 20% lower compared to empirical correlation.

Study on the Porous Media Used in Numerical Simulation of Temperature Characteristic for Isothermal Chambers

2011 ◽  
Vol 291-294 ◽  
pp. 1689-1692
Author(s):  
Li Hong Yang ◽  
Da Hua Liu
Keyword(s):  
Numerical Simulation ◽  
Porous Medium ◽  
Porous Media ◽  
Flow Rate ◽  
Temperature Characteristic ◽  
Test Results ◽  
Temperature Characteristics ◽  
Simulation And Experiment ◽  
Simulation Results ◽  
Metal Wires

Isothermal chamber, which is fabricated by empty chamber stuffed with thin metal wires, is a kind of test devices for flow rate characteristics of pneumatic components, and its temperature characteristics are critical to the accuracy of test results. In this paper, the stuffers in isothermal chamber were considered as porous medium with large porosity, so the temperature characteristics could be studied by numerical simulation. Though there are differences between simulation and experiment, they have same trends and the law of variation can be seen from the simulation results, which demonstrates the reliability of numerical simulation. Consequently, simulation can be an efficient method, which is energy-saving and cost-reducing.

scholarly journals The study of electrohydrodynamic printing by numerical simulation

2020 ◽  
Vol 71 (6) ◽  
pp. 413-418
Author(s):  
Xue Yang ◽  
Rui Liu ◽  
Lu Li ◽  
Zhifu Yin ◽  
Kai Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Influencing Factors ◽  
Flow Rate ◽  
Applied Voltage ◽  
Promising Technique ◽  
Electrohydrodynamic Printing ◽  
Nozzle Size ◽  
Simulation Results

AbstractEHD (Electrohydrodynamic) printing is a promising technique for alternative fabrication of highresolution micro- and nanostructures without employment of any molds or photo-masks However, the printing precision can be easily influenced by the printing conditions, such as applied voltage, printing distance (the distance between the nozzle tip and the substrate), and flow rate. Unfortunately, up to now there was no work which analyzed those influencing factors in-depth and systematically by theory and numerical simulation. In this paper, the theory of EHD printing was presented and the effect of applied voltage, printing distance, and flow rate on the width of printed line was analyzed by numerical simulation. The simulation results showed that the width of printed lines is proportional to printing distance, nozzle size, and flow rate. However, it is inversely proportional to the applied voltage.

scholarly journals Study of Local Inertial Focusing Conditions for Spherical Particles in Asymmetric Serpentines

2019 ◽  
Author(s):  
Eric Pedrol ◽  
Jaume Massons ◽  
Francesc Díaz ◽  
Magdalena Aguiló
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Spherical Particles ◽  
Flow Rates ◽  
Inertial Focusing ◽  
Dean Vortices ◽  
State Diagrams ◽  
Spreading Function ◽  
Simulation Results ◽  
Particles Trajectories

Inertial focusing conditions of fluorescent polystyrene spherical particles are studied at the pointwise level along their pathlines. This is accomplished by an algorithm that calculates a de-gree of spreading function of the particles' trajectories taking streaklines images as raw data. Different confinement ratios of the particles and flow rates are studied and the results are pre-sented in state diagrams showing the focusing degree of the particles in terms of their position within a curve of an asymmetric serpentine and the applied flow rate. In addition, together with numerical simulation results, we present empirical evidence that the preferred trajectories of inertially focused spheres are contained within Dean vortices' centerlines. We speculate about the existence of a new force, never postulated before, to explain this fact.

scholarly journals Study of Local Inertial Focusing Conditions for Spherical Particles in Asymmetric Serpentines

Fluids ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Eric Pedrol ◽  
Jaume Massons ◽  
Francesc Díaz ◽  
Magdalena Aguiló
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Spherical Particles ◽  
Flow Rates ◽  
Inertial Focusing ◽  
Dean Vortices ◽  
State Diagrams ◽  
Spreading Function ◽  
Simulation Results ◽  
Particles Trajectories

Inertial focusing conditions of fluorescent polystyrene spherical particles are studied at the pointwise level along their pathlines. This is accomplished by an algorithm that calculates a degree of spreading function of the particles’ trajectories taking streaklines images as raw data. Different confinement ratios of the particles and flow rates are studied and the results are presented in state diagrams showing the focusing degree of the particles in terms of their position within a curve of an asymmetric serpentine and the applied flow rate. In addition, together with numerical simulation results, we present empirical evidence that the preferred trajectories of inertially focused spheres are contained within Dean vortices’ centerlines. We speculate about the existence of a new force, never postulated before, to explain this fact.

scholarly journals Numerical Modelling of the Influence of Argon Flow Rate and Slag Layer Height on Open-Eye Formation in a 150 Ton Steelmaking Ladle

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1048 ◽  
Author(s):  
Ramasetti ◽  
Visuri ◽  
Sulasalmi ◽  
Fabritius ◽  
Savolainen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Slag Layer ◽  
Porous Plug ◽  
Argon Flow Rate ◽  
Layer Height ◽  
Argon Flow ◽  
Simulation Results ◽  
Eye Formation

A transient computational fluid dynamics (CFD) modelling approach was used to study the complex multi-phase flow in an argon-stirred industrial scale ladle with a nominal capacity of 150 tons. During the stirring process, when gas was injected through the porous plug from the bottom into the steel bath, it breaks up into bubbles and infringes the slag layer creating an open-eye. The volume of fluid model was used to investigate the open-eye formation process in the simulations. In the numerical simulations, the open-eye area changed from 0.7 to 2.24 m2 with the increment of argon flow rate from 200 to 500 NL/min for slag layer thickness of 40 cm. Furthermore, the influence of slag layer height on the open-eye area was investigated. An argon flow rate of 200 NL/min was able to break the slag layer for slag layer height of 40 cm, and the open-eye formation was not possible for the same flow rate when the slag layer height was elevated from 40 to 55 cm. The numerical simulation results were validated against industrial measurements carried out at Outokumpu Stainless located in Tornio, Finland. The numerical simulation results of dynamics and time-averages of the slag area showed a good agreement when compared to the industrial measurements. To conclude, it is necessary to define gas flow rate based on the slag layer height to have an open-eye suitable for alloying.

Numerical Simulation of a New Typed Sprinkler Irrigation System

2011 ◽  
Author(s):  
Xingye Zhu ◽  
Xinkun Wang ◽  
Junping Liu
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Irrigation System ◽  
Sprinkler Irrigation ◽  
Optimization Approach ◽  
Working Pressure ◽  
Simulation Results ◽  
Important Significance

It has important significance and practical value for studying Sprinkler Irrigation System. In this study, numerical simulation was carried out. According to the selected materials and setting modes, both the pressure and the velocity distribution along the lateral were calculated out. Experimental study was carried out for this system to verify the correctness of numerical simulation. The following parameters were measured in the experiments: the flow-rate, rotational speed of the pump, and working pressure for the sprinklers. The numerical simulation results agreed to the experimental results within 5 percent. It supplied a foundation for the reasonable application of sprinkler irrigation system for the future. It can be concluded that structural optimization approach can be effectively implement by CFD simulation.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

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