scholarly journals Study of Hydraulic Semi-Active Damper. 1st Report. Derivation of Mathematical Model and Numerical Simulation.

1997 ◽  
Vol 28 (4) ◽  
pp. 458-465
Author(s):  
Naoto SATO ◽  
Satoru HAYASHI ◽  
Akira TANAKA ◽  
Ikuro IIMURA
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Active Damper

Numerical Simulation on Mold Electromagnetic Eccentric Stirring and Central Segregation of Round Bloom

2013 ◽  
Vol 652-654 ◽  
pp. 2450-2454
Author(s):  
Zhi Hong Zhang ◽  
Guo Guang Cheng
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Electromagnetic Stirring ◽  
Center Line ◽  
Central Segregation

The paper describes multi-section round bloom casting using external MEMS, equipped with max section D600mm and min D280mm mold, the center line of D280mm mold not coincident with the axis of stirrer coils. it is exist eccentric electromagnetic stirring of mold which section less than max D600mm, a mathematical model of MEMS has been established, the index of central segregation of D280mm macrostructure had decreased less than 1.12 by optimized parameters of electromagnetic stirring and SEN immerse depth, in the end, the quality of round bloom had improved.

Numerical modelling of swirling momentumless turbulent wake dynamics

2018 ◽  
pp. 37-48
Author(s):  
Андрей Геннадьевич Деменков ◽  
Геннадий Георгиевич Черных
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Mathematical Models ◽  
Equations Of Motion ◽  
Turbulent Wake ◽  
The Body ◽  
Jet Flows ◽  
Reynolds Stresses ◽  
Bodies Of Revolution ◽  
Averaged Equations

С применением математической модели, включающей осредненные уравнения движения и дифференциальные уравнения переноса нормальных рейнольдсовых напряжений и скорости диссипации, выполнено численное моделирование эволюции безымпульсного закрученного турбулентного следа с ненулевым моментом количества движения за телом вращения. Получено, что начиная с расстояний порядка 1000 диаметров от тела течение становится автомодельным. На основе анализа результатов численных экспериментов построены упрощенные математические модели дальнего следа. Swirling turbulent jet flows are of interest in connection with the design and development of various energy and chemical-technological devices as well as both study of flow around bodies and solving problems of environmental hydrodynamics, etc. An interesting example of such a flow is a swirling turbulent wake behind bodies of revolution. Analysis of the known works on the numerical simulation of swirling turbulent wakes behind bodies of revolution indicates lack of knowledge on the dynamics of the momentumless swirling turbulent wake. A special case of the motion of a body with a propulsor whose thrust compensates the swirl is studied, but there is a nonzero integral swirl in the flow. In previous works with the participation of the authors, a numerical simulation of the initial stage of the evolution of a swirling momentumless turbulent wake based on a hierarchy of second-order mathematical models was performed. It is shown that a satisfactory agreement of the results of calculations with the available experimental data is possible only with the use of a mathematical model that includes the averaged equations of motion and differential equations for the transfer of normal Reynolds stresses along the rate of dissipation. In the present work, based on the above mentioned mathematical model, a numerical simulation of the evolution of a far momentumless swirling turbulent wake with a nonzero angular momentum behind the body of revolution is performed. It is shown that starting from distances of the order of 1000 diameters from the body the flow becomes self-similar. Based on the analysis of the results of numerical experiments, simplified mathematical models of the far wake are constructed. The authors dedicate this work to the blessed memory of Vladimir Alekseevich Kostomakha.

MATHEMATICAL ANALYSIS OF THE ENDEMIC EQUILIBRIUM OF MALARIAHYGIENE MODEL

2021 ◽  
Vol 5 (10) ◽  
Author(s):  
Oluwafemi Temidayo J. ◽  
Azuaba E. ◽  
Lasisi N. O.
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Equilibrium Point ◽  
Reproduction Number ◽  
Endemic Equilibrium ◽  
The Mathematical Model ◽  
Globally Stable ◽  
Well Posed ◽  
The Basic Reproduction Number ◽  
Invariant Principle

In this study, we analyzed the endemic equilibrium point of a malaria-hygiene mathematical model. We prove that the mathematical model is biological and meaningfully well-posed. We also compute the basic reproduction number using the next generation method. Stability analysis of the endemic equilibrium point show that the point is locally stable if reproduction number is greater that unity and globally stable by the Lasalle’s invariant principle. Numerical simulation to show the dynamics of the compartment at various hygiene rate was carried out.

Design of Digital Filter Based on Numerical Simulation

2014 ◽  
Vol 539 ◽  
pp. 79-83
Author(s):  
Chuan Ting Wei ◽  
Quan Li Ning ◽  
Dong Chen
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Digital Filter ◽  
Sampling Frequency ◽  
New Wave ◽  
Matlab Software ◽  
Frequency Wave

In MATLAB software, it has FDATool toolbox, which can design digital filter specific according to specific circuit, and analyze the performance of the filter according to the parameters of filter. In this paper we establish simulation mathematical model of digital filter based on the calculation principle of distributed multiplication accumulator. According to the logic algorithm we design delay algorithm of digital filter, and use MATLAB software to do simulation on amplitude frequency and phase frequency of digital filter. After superposition of different sampling frequency wave we get new waveform, and realize the digital filter for the new wave. It proves the availability of mathematical model and the program, and provides the technical reference for the design of digital filter.

Numerical Simulation Study of Metal Transfer in MIG Welding with Magnetic Control

2014 ◽  
Vol 532 ◽  
pp. 545-548 ◽  
Author(s):  
Chao Yang ◽  
Shu Yuan Jiang ◽  
Hai Bo Bi
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Mathematical Model ◽  
Simulation Study ◽  
Electromagnetic Theory ◽  
Metal Transfer ◽  
Experimental Result ◽  
Magnetic Control ◽  
Mig Welding ◽  
Model Based

This paper simulate the mode of metal transfer in MIG magnetic control welding by using CFD software FLUENT, establishing mathematical model based on fluid dynamics and electromagnetic theory, and simulate the form, grow and drop process of metal transfer with and without magnetic. Meanwhile, do experiments to confirm the simulate result, and it is well consistent with the experimental result.

Numerical Simulation of Subsea Cluster Manifold Installation by the Sheave Method

2018 ◽  
Author(s):  
Yu Zhao ◽  
Yingying Wang ◽  
Liwei Li ◽  
Chao Yang ◽  
Yang Du ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
South China Sea ◽  
Deep Sea ◽  
High Reliability ◽  
Two Dimensional ◽  
Complex Environment ◽  
Lumped Mass ◽  
Lumped Mass Method ◽  
The Mathematical Model

The sheave installation method (SIM) is an effective and non-conventional method to solve the installation of subsea equipment in deep water (>1000m), which has been developed to deploy the 175t Roncador Manifold I into 1,885 meters water depth in 2002. With the weight increment of subsea cluster manifold, how to solve its installation with the high reliability in the deep sea is still a great challenge. In this paper, the installation of the 300t subsea cluster manifold using the SIM is studied in the two-dimensional coordinate system. The mathematical model is established and the lumped mass method is used to calculate the hydrodynamic forces of the wireropes. Taking into account the complex environment loads, the numerical simulation of the lowering process is carried out by OrcaFlex. The displacement and vibration of the subsea cluster manifold in the z-axis direction and the effective tension at the top of the wireropes can be gotten, which can provide guidance for the installation of the cluster manifold in the South China Sea.

scholarly journals Population Behavior in the Mathematical Model of the Spread of COVID19 Type SEIRS

2021 ◽  
Vol 6 (2) ◽  
pp. 83-88
Author(s):  
Asmaidi As Med ◽  
Resky Rusnanda
Keyword(s):  
Mathematical Modeling ◽  
Numerical Simulation ◽  
Mathematical Model ◽  
Everyday Life ◽  
Applied Mathematics ◽  
Living Things ◽  
Simulation Results ◽  
Parameter Values ◽  
The Mathematical Model ◽  
Disease Free

Mathematical modeling utilized to simplify real phenomena that occur in everyday life. Mathematical modeling is popular to modeling the case of the spread of disease in an area, the growth of living things, and social behavior in everyday life and so on. This type of research is included in the study of theoretical and applied mathematics. The research steps carried out include 1) constructing a mathematical model type SEIRS, 2) analysis on the SEIRS type mathematical model by using parameter values for conditions 1and , 3) Numerical simulation to see the behavior of the population in the model, and 4) to conclude the results of the numerical simulation of the SEIRS type mathematical model. The simulation results show that the model stabilized in disease free quilibrium for the condition  and stabilized in endemic equilibrium for the condition .

scholarly journals Numerical simulation of changes in the electric properties of biological tissues under local heating by laser radiation

2021 ◽  
Vol 2090 (1) ◽  
pp. 012049
Author(s):  
N V Kovalenko ◽  
A V Smirnov ◽  
O A Ryabushkin
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Laser Radiation ◽  
Optical Radiation ◽  
Local Heating ◽  
Biological Tissues ◽  
Electric Properties ◽  
Reliable Tool ◽  
The Mathematical Model

Abstract The mathematical model that describes the local heating of biological tissues by optical radiation is introduced. Changes of the electric properties of biological tissues in such process can be used as a reliable tool for analyzing heating and damage degrees of tissues.

scholarly journals Numerical Simulation of Diffusion Absorption Refrigerator

2021 ◽  
Vol 233 ◽  
pp. 01044
Author(s):  
Guoyan Zhang ◽  
Shengyong Liu ◽  
Jie Lu ◽  
Jiong Wang ◽  
Yongtao Ma
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Gas Phase ◽  
Radial Direction ◽  
Tube Length ◽  
Lifting Capacity ◽  
Fluent Software ◽  
Lower Temperature ◽  
Absorption Refrigerator ◽  
Diffusion Absorption

Based on Fluent software, a mathematical model of thermosyphon pump is established and numerical simulation is carried out to study the influence of riser tube length, tube diameter and immersion ratio on liquid lifting capacity and efficiency. The results showed that: the liquid lifting volume increased with the increase of immersion ratio, whereas the lifting efficiency showed a trend of increasing followed by decreasing. The highest lifting efficiency for a 340mm long, 6mm diameter riser achieved when the immersion ratio is 0.35. With the increasing of the height in riser, the velocity of the gas phase close to the wall in the thermosyphon pump was higher than the velocity along the radial direction. In order to enhance fluid interchange, corners of the refrigeration box were designed to be arc-shaped with a higher corner speed and lower temperature.

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