scholarly journals Comparison between the finite differences, finite volume and finite element methods for the modelling of convective drying of fruit slices

Author(s):  
Fabian Leonardo Moreno ◽  
Adriana María Castro ◽  
Edgar Yesid Mayorga

Three numerical methods, finite differences, finite volume and finite element, were compared to know their convenience in the simulation of convective drying of fruit slices. The mathematical treatment, the stability, the convergence and the sensibility were analysed for each method. The data of the simulations were compared with the data of feijoa dried at 60°C, 5 mm of thickness and air velocity of 0.5ms-1. The error was 7%, 13% and 17% for finite element, finite volume and finite differences respectively. The method selection depends on the software, the required data precision and the use of the model. Keywords: mathematical model; convective drying; numerical methods 

2021 ◽  
Author(s):  
James Kent

<p>GungHo is the mixed finite-element dynamical core under development by the Met Office. A key component of the dynamical core is the transport scheme, which advects density, temperature, moisture, and the winds, throughout the atmosphere. Transport in GungHo is performed by finite-volume methods, to ensure conservation of certain quantaties. There are a range of different finite-volume schemes being considered for transport, including the Runge-Kutta/method-of-lines and COSMIC/Lin-Rood schemes. Additional horizontal/vertical splitting approaches are also under consideration, to improve the stability aspects of the model. Here we discuss these transport options and present results from the GungHo framework, featuring both prescribed velocity advection tests and full dry dynamical core tests. </p>


2020 ◽  
Vol 175 ◽  
pp. 12019
Author(s):  
Vladimir Zaitsev ◽  
Artem Kravtsov ◽  
Vladimir Konovalovi

In the course of the study, methods for ensuring the centeringof particlesofbulkmaterialintheairflowmovinginthepneumaticductofthe seeder were investigated. To solve this problem, it is proposed to use a conical confusor. The aim of the study was to obtain the functional dependences of the movement of particles in a conical airflow guide (confusor) for the conditions of transportation of the sown particles on the basis of force analysis and to identify the nature of the movement of the sownparticlesinataperingairflow.Duringthestudy,todescribethemotion of particles in a vertical tapering pipe, a system of expressions was substantiated. The developed mathematical model of particle motion in a conical air flow, implemented in the MathCAD mathematical package, allowscalculatingboththeparticletrajectoryandthevelocityparametersof the air flow and the particles to be sown. The digital calculation results in the MathCAD program are in good agreement with the finite element calculations. The magnitude of the error in air velocity is less than 1%. The differences in the velocities of the transported particles in the calculation options do not exceed 7%. The installation of a conical guide helps tofocus the flow of particles in the central part of the narrowed air line. In this case, part of the particles in the central part of the guide will retain the initial longitudinaltrajectory.Theangleattheapexoftheconeandtheparameters of the particles affect the speed and angle of the tangent contact of the particle with theguide.


Author(s):  
G. Kh. Murzakhanov ◽  
A. A. Barsukov ◽  
A. S. Semenov ◽  
A. V. Makshin

Article considered main stages of strength calculation of the steel gas pipeline under the Novodevichy Duker project. Specialists of the Moscow city Center used the basis of the finite element for calculation. The list of tasks consists of: 1. Strength calculation of the underground laying gas pipeline section. 2. The calculation of the stability of the two vertical sections. According to the results of strength calculation, specialists made the conclusion about ensuring the strength and stability of the considered section of the gas pipeline.


2017 ◽  
Vol 62 (3) ◽  
pp. 653-669 ◽  
Author(s):  
Mohammadali Sepehri ◽  
Derek Apel ◽  
Wei Liu

AbstractPredicting the stability of open stopes can be a challenging task for underground mine engineers. For decades, the stability graph method has been used as the first step of open stope design around the world. However, there are some shortcomings with this method. For instance, the stability graph method does not account for the relaxation zones around the stopes. Another limitation of the stability graph is that this method cannot to be used to evaluate the stability of the stopes with high walls made of backfill materials. However, there are several analytical and numerical methods that can be used to overcome these limitations. In this study, both empirical and numerical methods have been used to assess the stability of an open stope located between mine levels N9225 and N9250 at Diavik diamond underground mine. It was shown that the numerical methods can be used as complementary methods along with other analytical and empirical methods to assess the stability of open stopes. A three dimensional elastoplastic finite element model was constructed using Abaqus software. In this paper a sensitivity analysis was performed to investigate the impact of the stress ratio “k” on the extent of the yielding and relaxation zones around the hangingwall and footwall of the understudy stope.


2018 ◽  
Vol 931 ◽  
pp. 127-132
Author(s):  
Batyr M. Yazyev ◽  
Serdar B. Yazyev ◽  
Anatoly P. Grinev ◽  
Elena A. Britikova

The comparison of the numerical methods: the finite element method, the Galerkin Method, the difference method is considered for the study of the stability of the rods. The dependence of the solution of the stability problem on the parameters of the discretization of these numerical methods is studied. It is shown that the mathematical models are sufficiently accurate to analyze the stability of the rods of constant and variable sections.


2012 ◽  
Vol 482-484 ◽  
pp. 62-65 ◽  
Author(s):  
Lu Lu ◽  
Zhao Xu Wang ◽  
Fu Zhong Wang

In this paper, the finite element method (FEM) is used for simulation of piercing process of the tube in Mannesmann mill. The sensitivity of the simulation results to numerical methods and physical parameters is discussed. The simulated results visualize dynamic evolution of force in the piercing process. The stability of the process and force condition is analyzed by FEM simulation. The model is verified by comparing the values of calculated force parameters and those measured in laboratory conditions. Finally, the future plans are presented.


Author(s):  
Henian Xia ◽  
Xiaopeng Zhao ◽  
Kwai Wong

We study electromechanical dynamics in paced cardiac tissue using numerical simulations of a mathematical model that accounts for excitation-contraction coupling as well as mechanoelectrical feedback. A previously developed finite element based parallel platform is adopted. Extensive numerical simulations are carried out on a 2d tissue and a 3d tissue to investigate the influences of various parameters on the stability of propagating cardiac waves, including conduction velocity, pathological scars, contraction, and stretch activated channels.


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