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.

Heat Convection from a Horizontal Cylinder Rotating in a Quiescent Fluid

1986 ◽  
Vol 10 (3) ◽  
pp. 141-152
Author(s):  
H.M. Badr ◽  
S.M. Ahmed
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Horizontal Cylinder ◽  
Heat Transfer Process ◽  
Two Dimensional ◽  
Two Dimensional Flow ◽  
Boussinesq Fluid ◽  
The Mathematical Model ◽  
Quiescent Fluid

The aim of this work is a theoretical investigation to the problem of heat transfer from an isothermal horizontal cylinder rotating in a quiescent fluid. The study is based on the solution of the conservation equations of mass, momentum and energy for two-dimensional flow of a Boussinesq fluid. The effects of the parameters which influence the heat transfer process namely the Reynolds number and Grashof number are considered while the Prandtl number is held constant. Streamline and isotherm patterns are obtained from the mathematical model and the results are compared with previous experimental data. A satisfactory agreement was found.

scholarly journals Experimental studies of iron transformations kinetics and autocatalysis during its physicochemical removal from underground water

2021 ◽  
Author(s):  
S. Yu Martynov ◽  
V. L. Poliakov
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Experimental Studies ◽  
Underground Water ◽  
Model Parameters ◽  
Kinetic Coefficients ◽  
Transfer Equations ◽  
The Mathematical Model ◽  
Autocatalytic Effect ◽  
Forms Of Iron

Abstract The mathematical model of physicochemical iron removal from groundwater was developed. It consists of three interrelated compartments. The results of the experimental research provide information in support of the first two compartments of the mathematical model. The dependencies for the concentrations of the adsorbed ferrous iron and deposited hydroxide concentrations are obtained as a result of the exact solution of the system of the mass transfer equations for two forms of iron in relation to the inlet surface of the bed. An analysis of the experimental data of the dynamics of the deposit accumulation in a small bed sample was made, using a special application that allowed to select the values of the kinetic coefficients and other model parameters based on these dependencies. We evaluated the autocatalytic effect on the dynamics of iron ferrous and ferric forms. The verification of the mathematical model was carried out involving the experimental data obtained under laboratory and industrial conditions.

Mathematical Simulation of Flux Film State in Gap between Mould and Solidified Shell

2017 ◽  
Vol 893 ◽  
pp. 272-275
Author(s):  
Li Jun Cao
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Slab Surface ◽  
Slab Caster ◽  
Mould Flux ◽  
Main Factors ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Casting Production ◽  
Film State

The mathematical model for heat transfer during solidification of steel in the mould of slab caster was established in this paper. The temperature distribution of slab surface was described. Based on the work which was described above, the model of flux film state was developed in present paper. Lubrication function of mould flux and the effects of main factors on lubrication had been discussed. The simulation results provided theory foundation for appraising lubrication function of flux and optimizing casting production.

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.

Analysis of Thermal Conduction Effects on Thermoelastic Temperature Measurements for Composite Materials

1992 ◽  
Vol 59 (3) ◽  
pp. 552-558 ◽  
Author(s):  
S. A. Dunn
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Composite Materials ◽  
Surface Stress ◽  
Thermal Conduction ◽  
Dissimilar Materials ◽  
Stress Fields ◽  
Temperature Changes ◽  
The Mathematical Model

Measurement of the temperature changes which occur as a body undergoes a change in stress is becoming a widely used technique for the analysis of surface stress fields. In this paper, an investigation into the effects of thermal conduction on surface thermoelastic temperature changes for composite materials is reported. A mathematical model which shows the effects of thermal conduction is developed, and the results from this model are compared with experimental data. The mathematical model is then extended to solve for heat transfer between two thermally dissimilar materials. It is shown how this model can be used to account for the effects of a surface epoxy layer on the observed thermoelastic temperature changes.

Tungsten Powder Sintering

2016 ◽  
Vol 712 ◽  
pp. 237-240 ◽  
Author(s):  
E.S. Dvilis ◽  
Anna G. Knyazeva ◽  
Svetlana N. Sorokova ◽  
Oleg L. Khasanov
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Matrix Composite ◽  
Conjugate Heat Transfer ◽  
Tungsten Powder ◽  
Experimental Studies ◽  
Synthesis Process ◽  
Porosity Evolution ◽  
Powder Sintering ◽  
The Mathematical Model

The results of theoretical and experimental studies of the synthesis process by the electric sintering of aluminum is a matrix composite. The mathematical model takes into account the conjugate heat transfer and porosity evolution.

scholarly journals Experimental studies of the method of mutual load of induction motors

2020 ◽  
pp. 44-49
Author(s):  
V. V. Kharlamov ◽  
◽  
D. I. Popov ◽  
P. S. Sokolov ◽  
L. E. Serkova ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Experimental Data ◽  
Mathematical Model ◽  
Induction Motors ◽  
Experimental Studies ◽  
Electromechanical System ◽  
Experimental Equipment ◽  
Frequency Converters ◽  
Parameter Values ◽  
The Mathematical Model

The article presents the results of comparison of experimental studies and mathematical modeling of the stand for testing induction motors by the method of mutual load. A detailed description of the composition of the experimental equipment, which is based on a pair of frequency converters and connected to them a pair of engines of the АИС71В4 type with a nominal power of 0,75 kW, the shafts of which are rigidly connected by a coupling. The mathematical model of the electromechanical system used in the calculations is presented, and its main assumptions are listed. A table of parameter values and graphs obtained from calculated and experimental data are presented. The analysis of the obtained data shows the possibility of using the considered mathematical model with the existing assumptions in the design of electrical complexes intended for testing induction motors by the method of mutual load

scholarly journals MODELING OF SOLAR RADIATION FOR USE IN RENEWABLE ENERGY AND IN CONSTRUCTION THERMAL PHYSICS

2018 ◽  
Vol 40 (1) ◽  
pp. 44-50
Author(s):  
B.I. Basok ◽  
B.V. Davydenko ◽  
V.G. Novikov ◽  
R.Ya. Sorokovoy
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Renewable Energy ◽  
Solar Radiation ◽  
Experimental Studies ◽  
Program Code ◽  
Solar Insolation ◽  
Thermal Physics ◽  
The Mathematical Model ◽  
Design And Construction

The work is devoted to the estimation of the intensity and energy of solar radiation at the earth's surface. The aim of the research is to develop a mathematical model of solar radiation, necessary for the design of devices for renewable energy, as well as in the design and construction of buildings and structures. The mathematical model of solar radiation is realized in the Python code. The program code allows you to calculate the intensity of solar radiation and solar insolation on any day of the year. The model is verified by the results of experimental studies of solar radiation in the Odessa region and by the results of our own experimental data.

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 Simulation of Electromagnetic-Acoustic Heating of the Oil Layer in Laboratory Conditions

2021 ◽  
Vol 16 (1) ◽  
pp. 109-116
Author(s):  
Gulnara R. Izmailova
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
High Frequency ◽  
Additional Term ◽  
Oil Reservoir ◽  
Combined Effects ◽  
Physical Processes ◽  
The Mathematical Model ◽  
Account Heat

This paper describes an experiment to study the combined effects of high-frequency electromagnetic and acoustic fields on a model of an oil reservoir. A mathematical model is described that describes the physical processes that occur in the reservoir. The heat equation takes into account heat transfer with the environment by introducing an additional term. The largest discrepancy between theoretical and experimental data does not exceed 28%. Qualitative coincidence of theoretical and experimental curves indicates the adequacy of the mathematical model.

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