Modeling and Simulation of a Co-current Rotary Dryer

2016 ◽  
Vol 12 (2) ◽  
pp. 189-194 ◽  
Author(s):  
Zhi-gang Huang ◽  
Yun-xuan Weng ◽  
Nan Fu ◽  
Zong-qiang Fu ◽  
Dong Li ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Moisture Content ◽  
Mathematical Models ◽  
Modeling And Simulation ◽  
Air Temperature ◽  
Good Accuracy ◽  
Rotary Dryer ◽  
Simulation Results ◽  
The Mathematical Model

Abstract Mathematical models including mass and energy conservation were developed in order to predict the outlet particles temperature and moisture. As the inlet air temperature increased, the outlet particles temperature increased as well and the outlet particles moisture decreased quickly. The outlet particles temperature and moisture changed a little as a function of the speed of rotation at the low inlet air temperature, while the outlet particles temperature and moisture increased very apparently with the speed of rotation increased at the high inlet air temperature. The error of the simulation results compared to the experimental data showed good accuracy for particles temperature and moisture content. The mathematical model performs well to predict the outlet particles temperature and moisture content.

scholarly journals Drying kinetics of Chinese garlic (Allium tuberosum) and its effect on color

2020 ◽  
Vol 42 ◽  
pp. e8
Author(s):  
Paula De Almeida Rios ◽  
Ednilton Tavares De Andrade ◽  
Kátia Soares Moreira ◽  
Filipe Da Silva De Oliveira ◽  
Bárbara Lemes Outeiro Araújo
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Air Temperature ◽  
Linear Regression Analysis ◽  
Drying Kinetics ◽  
Allium Tuberosum ◽  
Thin Slices ◽  
The Mathematical Model ◽  
Quasi Newton ◽  
Kinetics Of

Dehydrated garlic is an important component both for culinary and medicinal purposes. However, there is a scarcity of studies that characterizes its drying kinetics. Thus, the objective of this work was to study the drying kinetics of Chinese garlic (Allium tuberosum), as well as to analyze the color effect resulting from each treatment. The garlic bulbs were cut into thin slices with a width of 2 and 3 mm, subjected to the drying air temperature of 35, 45, 55 and 70 °C in a mechanical dryer of a fixed layer with forced convection. Was performed a non-linear regression analysis by the Quasi-Newton method, for adjustment to 11 mathematical models to the experimental data of drying. The Midilli equation was the mathematical model that best characterized all the drying temperatures, for the experimental data. The diffusion coefficient presented values between 1.46 x 10-11 and 7.32 x 10-11 m2.s-1. The increase of the drying air temperature caused the dimming of the samples with a reduction of the L* coordinate and reduction of the yellow of the samples according to the coordinate results h*. The temperature of 70 °C was detrimental to the maintenance of the Chinese garlic coloration. 

A numerical algorithm for constructing an individual mathematical model of HIV dynamics at cellular level

2018 ◽  
Vol 26 (6) ◽  
pp. 859-873 ◽  
Author(s):  
H. Thomas Banks ◽  
Sergey I. Kabanikhin ◽  
Olga I. Krivorotko ◽  
Darya V. Yermolenko
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Inverse Problem ◽  
Cellular Level ◽  
Free Virus ◽  
Hiv Dynamics ◽  
Infection Parameters ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Fixed Times

Abstract In this paper a problem of specifying HIV-infection parameters and immune response using additional measurements of the concentrations of the T-lymphocytes, the free virus and the immune effectors at fixed times for a mathematical model of HIV dynamics is investigated numerically. The problem of the parameter specifying of the mathematical model (an inverse problem) is reduced to a problem of minimizing an objective function describing the deviation of the simulation results from the experimental data. A genetic algorithm for solving the least squares function minimization problem is implemented and investigated. The results of a numerical solution of the inverse problem are analyzed.

scholarly journals The Mathematical Modeling of Ca And Fe Distribution In Peat Layers

2015 ◽  
Vol 2 ◽  
pp. 40
Author(s):  
Ērika Teirumnieka ◽  
Ilmārs Kangro ◽  
Edmunds Teirumnieks ◽  
Harijs Kalis ◽  
Aigars Gedroics
Keyword(s):  
Mathematical Modeling ◽  
Experimental Data ◽  
Mathematical Model ◽  
Trace Elements ◽  
Mathematical Models ◽  
Organic Material ◽  
Low Concentrations ◽  
The Mathematical Model ◽  
Research Show

Bogs have been formed by an accumulation of peat - a light brown-to-black organic material, built up from partial decomposition of mosses and other bryophytes, sedges, grasses, shrubs, or trees under waterlogged conditions. The total peatlands area in Latvia covers 698 918 ha or 10.7% of the entire territory. Knowledge’s of peat metals content are important for any kind of peat using. Experimental determination of metals in peat is very long and expensive work. Using experimental data mathematical model for calculation of concentrations of metals in different points for different layers can help to very easy and fast to find approximately concentration of metals or trace elements. The results of the research show that concentrations of trace elements in peat are generally low. Concentrations differ between the superficial, middle and bottom peat layers, but the significance decreases depending on the type of mire. The mathematical model for calculation of concentration of metals in different points for different 3 layers in peat blocks is developed. As an example, mathematical models for calculation of Ca and Fe concentrations have been analyzed.

scholarly journals EXPERIMENTAL STUDIES OF HEAT EXCHANGE DURING WATER COOLING AND STEAM CONDENSATION IN DEMOVER RADIATOR SECTIONS

2021 ◽  
Vol 1 (38) ◽  
pp. 107-114
Author(s):  
V. Mogila ◽  
M. Kovtanets ◽  
M. Morneva
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Cooling System ◽  
Experimental Studies ◽  
Road Transport ◽  
Thermal Calculation ◽  
Mode Of Operation ◽  
Simulation Results ◽  
The Mathematical Model

The Department of Railwayand Road Transport, lift and care system of Volodymyr Dahl East Ukrainian National University, an energy-saving cooling system for diesel locomotives using phase transitions of the coolant has been developed. The proposed cooling system allows to maintain constant optimal temperatures of cooling objects at ambient temperatures ± 40 ºC and in any mode of operation of the diesel engine. For thermal calculation of the radiator section operating in the mode of the steam condenser, the mathematical model of process of heat transfer from steam to walls of a flat tube at condensation is developed that considers geometrical features of section of a tube. The adequacy of this mathematical model is verified by comparing the simulation results with the obtained experimental data. During the tests, the outlet water temperature, inlet and outlet air temperature, and air pressure in front of and behind the radiator were measured. Having the values of wall temperature, steam temperature and condensate, knowing the value of steam consumption and the experimental heat transfer coefficient, it becomes possible to verify the adequacy of the mathematical model by comparing the simulation results with the obtained experimental data. Schemes of bench equipment, test methods, experimental planning and basic calculation dependences required for testing serial radiator sections of a locomotive in the standard mode of operation and in the mode of steam condensers are presented.

Numerical Study of the Dynamics of Particles Motion with Different Sizes from Coal-Based Thermal Power Plant

2019 ◽  
Vol 20 (2) ◽  
pp. 223-241 ◽  
Author(s):  
Alibek Issakhov ◽  
Ruslan Bulgakov ◽  
Yeldos Zhandaulet
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Mathematical Model ◽  
Power Plant ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Numerical Results ◽  
Simulation Results ◽  
Turbulent Models ◽  
The Mathematical Model

AbstractIn this paper, the propagation of particles with different sizes from a coal-based thermal power plant was investigated. It was found that the deterioration of the environment is due to the release of a large amount of SOx, NOx and the volatile particles of Suspended Particulate Matter and Respirable Suspended Particles matter, which cause human and animal diseases. This paper presents the numerical simulation results of air pollution by particles which having different sizes from thermal power plants in real sizes using a 3D model. For the adequacy of the mathematical model, a test problem was solved using different turbulent models. To assess the applicability of the mathematical model, the numerical algorithm and the choice of the optimal turbulent model, experimental data and numerical results of other authors were used. The obtained numerical simulation results are in good agreement with the experimental results and the numerical results of other authors. And to obtain more accurate numerical results for the experimental data for turbulent models ($k - \varepsilon $,$k - \omega $), there were certain corresponding boundary conditions for kinetic energy. Also, profiles of all flow characteristics were compared with and without particles and some effects of the particle on the flow were identified.

Modeling and Simulation of Thermostatic Mixing Valve

2013 ◽  
Vol 365-366 ◽  
pp. 370-374
Author(s):  
Hai Chu Chen ◽  
Fang Yi Wu ◽  
Ping Zhang ◽  
Gen Liang Xiong ◽  
Yin Fa Zhu
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Flow Field ◽  
Modeling And Simulation ◽  
Adaptive Controller ◽  
Theoretical Research ◽  
New Type ◽  
Fluent Software ◽  
Simulation Results ◽  
The Mathematical Model

It researched a new type of intelligent thermostatic mixing valve which could keep the temperature and flux of the valve outlet water constant through the adaptive controller. It firstly established the mathematical model about angle - flux and angle - temperature of the valve. And then it based on thekεturbulence model and applied Fluent software to numerical simulation of the valve about the flow field. Finally, it compared the simulation results with the calculated value. The results show that they are basically consistent, prove the correctness of the theoretical research, and can be used to improve designing of the thermostatic valve.

scholarly journals Helical Flow of Polymer Melts in Extruders : Model Development and Validation with Experiments

2021 ◽  
Author(s):  
Farshid Sanjabi
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Injection Molding ◽  
Natural System ◽  
State Variables ◽  
Melt Temperature ◽  
Coupled Equations ◽  
Simulation Results ◽  
Helical Geometry ◽  
The Mathematical Model

Operating and processing conditions as well as the selection of the screw design in injection molding industry are largely based on trial-and-error exercise, which is expensive and time consuming. A better approach is to develop mathematical models for prediction of the final process performance where the conditions and parameters of a process can be used as inputs in those models. However, most of the models developed and used so far contain unrealistic geometrical and mathematical simplifications. The objective of this work is to develop a steady-state three dimensional mathematical model to describe the flow of an incompressible polymer melt inside a helical geometry, which represents the polymer's true motion in extrusion and injection molding processes. In order to develop the model in helical geometry, where at least two axes are not perpendicular, the mathematical model is first developed in a natural system (i.e. cylindrical) and using transformation tools are then changed to the physical helical one. In this initiative, we develop an iterative computational alogrithm based on shooting Newton-Raphson method in order to simulate the process. The transformation matrices to adapt the equations of change form a natural system (i.e. orthogonal cylindrical systems) to a physical system (i.e. Helical coordinates) are also developed for velocity and derivative profiles. Subsequently the solution approach to solve the indirectly coupled equations of change is explained and the simulation results are compared with experimental data. The simulation results are vallidated against data obtained from ten different experiments with an industrial injection molding machine, processing two different polymers - high density polyethylene (HDPE) and poly ethylene terephthalate (PET). It is observed that the simulation results are in good agreement with experimental data. This outcome demonstrates the utility of the developed mathematical model and simulation approach. Important features of this work are the consideration of the linear backward motion of the screw leading to calculation of proper process shot size and the incorporation of the tapering screw designs with upward and downward sections in the direction of the flow into the model. Another important feature in the development of the mathematical model is that the rheological and physical properties of plastic resins are not constant and change as the melt temperature changes during the process. From the standpoint of industrial practice, the direct benefit of this work is the ability to effectively calculate adequate shot size, recovery rate, and various state variables throughout the extent of the machine.

scholarly journals Helical Flow of Polymer Melts in Extruders : Model Development and Validation with Experiments

2021 ◽  
Author(s):  
Farshid Sanjabi
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Injection Molding ◽  
Natural System ◽  
State Variables ◽  
Melt Temperature ◽  
Coupled Equations ◽  
Simulation Results ◽  
Helical Geometry ◽  
The Mathematical Model

Operating and processing conditions as well as the selection of the screw design in injection molding industry are largely based on trial-and-error exercise, which is expensive and time consuming. A better approach is to develop mathematical models for prediction of the final process performance where the conditions and parameters of a process can be used as inputs in those models. However, most of the models developed and used so far contain unrealistic geometrical and mathematical simplifications. The objective of this work is to develop a steady-state three dimensional mathematical model to describe the flow of an incompressible polymer melt inside a helical geometry, which represents the polymer's true motion in extrusion and injection molding processes. In order to develop the model in helical geometry, where at least two axes are not perpendicular, the mathematical model is first developed in a natural system (i.e. cylindrical) and using transformation tools are then changed to the physical helical one. In this initiative, we develop an iterative computational alogrithm based on shooting Newton-Raphson method in order to simulate the process. The transformation matrices to adapt the equations of change form a natural system (i.e. orthogonal cylindrical systems) to a physical system (i.e. Helical coordinates) are also developed for velocity and derivative profiles. Subsequently the solution approach to solve the indirectly coupled equations of change is explained and the simulation results are compared with experimental data. The simulation results are vallidated against data obtained from ten different experiments with an industrial injection molding machine, processing two different polymers - high density polyethylene (HDPE) and poly ethylene terephthalate (PET). It is observed that the simulation results are in good agreement with experimental data. This outcome demonstrates the utility of the developed mathematical model and simulation approach. Important features of this work are the consideration of the linear backward motion of the screw leading to calculation of proper process shot size and the incorporation of the tapering screw designs with upward and downward sections in the direction of the flow into the model. Another important feature in the development of the mathematical model is that the rheological and physical properties of plastic resins are not constant and change as the melt temperature changes during the process. From the standpoint of industrial practice, the direct benefit of this work is the ability to effectively calculate adequate shot size, recovery rate, and various state variables throughout the extent of the machine.

Modelling and Simulation of NO2 Dispersion Phenomenon in Atmosphere by Analytical-Experimental Methods

2008 ◽  
Vol 59 (10) ◽  
Author(s):  
Delia Perju ◽  
Harieta Pirlea ◽  
Gabriela-Alina Brusturean ◽  
Dana Silaghi-Perju ◽  
Sorin Marinescu
Keyword(s):  
Mathematical Model ◽  
Nitrogen Dioxide ◽  
Modeling And Simulation ◽  
Human Health ◽  
Experimental Methods ◽  
Negative Effects ◽  
Real Situation ◽  
Experimental Values ◽  
The Mathematical Model

The European laws and recently the Romanian ones impose more and more strict norms to the large nitrogen dioxide polluters. They are obligated to continuously improve the installations and products so that they limit and reduce the nitrogen dioxide pollution, because it has negative effects on the human health and environment. In this paper are presented these researches made within a case study for the Timi�oara municipality, regarding the modeling and simulation of the nitrogen dioxide dispersion phenomenon coming from various sources in atmosphere with the help of analytical-experimental methods. The mathematical model resulting from these researches is accurately enough to describe the real situation. This was confirmed by comparing the results obtained based on the model with real experimental values.

Research on Dynamic Balance Method of Precision Centrifuge

2014 ◽  
Vol 945-949 ◽  
pp. 777-780
Author(s):  
Tao Liu ◽  
Yong Xu ◽  
Bo Yuan Mao
Keyword(s):  
Mathematical Model ◽  
Balance Control ◽  
Dynamic Balance ◽  
Dynamic Balancing ◽  
Structure Characteristics ◽  
Balance System ◽  
Simulation Results ◽  
Set Up ◽  
System Controller ◽  
The Mathematical Model

Firstly, according to the structure characteristics of precision centrifuge, the mathematical model of its dynamic balancing system was set up, and the dynamic balancing scheme of double test surfaces, double emendation surfaces were established. Then the dynamic balance system controller of precision centrifuge was designed. Simulation results show that the controller designed can completely meet the requirements of precision centrifuge dynamic balance control system.

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