scholarly journals Dynamics of a spherical explosion in aqueous foam taking into account heat-exchange and dissipative processes

2019 ◽  
Vol 1400 ◽  
pp. 077027
Author(s):  
R Kh Bolotnova ◽  
E F Gainullina
Keyword(s):  
Heat Exchange ◽  
Dissipative Processes ◽  
Aqueous Foam ◽  
Spherical Explosion ◽  
Account Heat

The Numerical Modeling of Spherical Explosion in the Foam

2016 ◽  
Vol 11 (1) ◽  
pp. 60-65 ◽  
Author(s):  
R.Kh. Bolotnova ◽  
E.F. Gainullina
Keyword(s):  
Shock Wave ◽  
Numerical Modeling ◽  
Initial Pressure ◽  
Water Volume ◽  
Symmetric Model ◽  
Two Phase ◽  
Experimental Conditions ◽  
Initial Water ◽  
Aqueous Foam ◽  
Spherical Explosion

The spherical explosion propagation process in aqueous foam with the initial water volume content α10=0.0083 corresponding to the experimental conditions is analyzed numerically. The solution method is based on the one-dimensional two-temperature spherically symmetric model for two-phase gas-liquid mixture. The numerical simulation is built by the shock capturing method and movable Lagrangian grids. The amplitude and the width of the initial pressure pulse are found from the amount of experimental explosive energy. The numerical modeling results are compared to the real experiment. It’s shown, that the foam compression in the shock wave leads to the significant decrease in velocity and in amplitude of the shock wave.

MODELING THE EFFECT OF HEAT EXCHANGE ON THE EFFICIENCY OF A THERMOELECTRIC COOLER

2020 ◽  
Vol 2 ◽  
pp. 132-135
Author(s):  
O.I. MARKOV
Keyword(s):  
Numerical Calculation ◽  
Heat Exchange ◽  
Solid State ◽  
Numerical Modelling ◽  
Temperature Difference ◽  
Maximum Temperature ◽  
Thermoelectric Cooler ◽  
Maximum Temperature Difference ◽  
Peltier Cooler ◽  
Account Heat

Numerical modelling thermal and thermoelectric processes in a branch of solid–state thermoelectric of Peltier cooler is performed, taking into account heat exchange by convection and radiation. The numerical calculation of the branch was carried out in the mode of the maximum temperature difference.

Modeling of the spherical explosion attenuation process using aqueous foam

2019 ◽  
Vol 14 (2) ◽  
pp. 108-114
Author(s):  
R.Kh. Bolotnova ◽  
E.F. Gainullina ◽  
E.A. Nurislamova
Keyword(s):  
Shock Wave ◽  
Numerical Solution ◽  
Volume Fraction ◽  
Strong Shock ◽  
Liquid Volume ◽  
Contact Heat ◽  
Liquid Volume Fraction ◽  
Aqueous Foam ◽  
Spherical Explosion ◽  
Droplet Mixture

The two-phase model of dry aqueous foam dynamic behavior under the strong shock wave influence is presented under assumption that the foam structure under shock loading is destroyed into a suspension of monodispersed microdrops with the formation of a gas-droplet mixture. The system of equations for the model of aqueous foam includes the laws of conservation of mass, momentum and energy for each phase in accordance with the single-pressure, two-speed, two-temperature approximations in a three-dimensional formulation, taking into account the Schiller–Naumann interfacial drag force and the Ranz–Marshall interfacial contact heat transfer. The thermodynamic properties of air and water forming a gas-droplet mixture are described by the Peng–Robinson and Mie–Grueneisen equations of state. The presence of non-uniform process in height of aqueous foam syneresis, which is due to gravitational forces, is taken into account by setting the distribution of the liquid volume fraction in the foam. An additional consideration of the syneresis process during calculating the intensity of interphase drag forces according to the Schiller–Naumann model was controlled by introducing the parameter depending on the spatial distribution of the initial liquid volume fraction of the foam. The spherical explosion is modeled in the form of the shock wave pulse whose energy coincided with the charge energy of the HE used in the experiments. The problem numerical solution is implemented using the OpenFOAM free software package based on the two-step PIMPLE computational algorithm. The numerical solution of the problem, obtained on the basis of the proposed gas-droplet mixture model, is in satisfactory agreement with the experimental data on a spherical explosion in aqueous foam. The analysis of the spherical shock wave dynamics while its propagation through aqueous foam is given. The causes of the significant decrease in the amplitude and velocity shock waves propagation in the medium under study are investigated.

Influence of Heat Transfer on Decreasing Intensity of a Spherical Explosion in Aqueous Foam

2019 ◽  
Vol 54 (7) ◽  
pp. 970-977 ◽  
Author(s):  
R. Kh. Bolotnova ◽  
E. F. Gainullina
Keyword(s):  
Heat Transfer ◽  
Aqueous Foam ◽  
Spherical Explosion

scholarly journals The influence of the length of heat sources on the external border on the temperature distribution in profiled polar-orthotropic ring plates taking into account there heat exchange with the external environment

2020 ◽  
pp. 86-91
Author(s):  
Uladzimir V. Karalevich ◽  
Dmitrij G. Medvedev
Keyword(s):  
Heat Exchange ◽  
Temperature Distribution ◽  
Heat Conduction Problem ◽  
External Environment ◽  
Heat Sources ◽  
Stationary Heat ◽  
Annular Plates ◽  
Outer Border ◽  
Polar Orthotropic ◽  
Account Heat

We study the influence of N extended heat sources at external boundaries on the nonaxisymmetric temperature distribution on profiled polar-orthotropic ring plates and take into account heat exchange with the external environment. The solution of the stationary heat conduction problem for anisotropic annular plates of a random profile is resolved through the solution of the corresponding Volterra integral equation of the second kind. The formula of a temperature calculations in anisotropic annular plates of an random profile is given. The exact solution of stationary heat conductivity problem for a reverse conical polar-orthotropic ring plate is recorded. The temperature distribution in such anisotropic plate from N extended heat sources at its outer border is more complex than in the case of temperature distribution from N point heat sources at their external border.

scholarly journals HEAT ACCESS ON THE FACADE BUILDING IN THE DEVELOPMENT WHEN TAKING INTO ACCOUNT HEAT EXCHANGE BY RADIATION

2019 ◽  
pp. 46-53
Author(s):  
Е. Коркина ◽  
E. Korkina ◽  
Е. Войтович ◽  
E. Voytovich ◽  
Н. Плющенко ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Solar Radiation ◽  
Temperature Regime ◽  
Heating Temperature ◽  
Heating Surface ◽  
Radiant Heat ◽  
Urban Environments ◽  
Factors Affecting ◽  
Urban Conditions ◽  
Account Heat

When considering the temperature regime in urban conditions, various factors affecting the increase in air temperature are studied. However, other components can influence the temperature regime. It is interesting to consider the heating of the surfaces of the facades due to solar radiation and further heat exchange by radiation between the heated surfaces. For this, a method based on the use of the formula of A.M. Shklover, which determines the heating of the surface from solar radiation, with further calculation using the Stefan-Boltzmann formula of the amount of additional radiant heat supplied to the facade of the building from adjacent objects and determining the additional heating of the surface of the facade. The application of the method is illustrated by an example of calculation for buildings that are sequentially located in cities with different climates: Moscow, Krasnodar and Chita. The calculation of the heating surface of the facade was carried out for a clear day in one hour. The influence of adjacent objects on the influx of solar radiation to the studied surfaces was taken into account. An increase in the heating temperature of the investigated facade is shown when taking into account the radiant heat input from the adjacent objects. The development of the proposed method can be used to study the temperature regime in urban environments.

scholarly journals Modelling of propane emissions from a tank containing a liquefied phase

2018 ◽  
Vol 240 ◽  
pp. 01034
Author(s):  
Zdzisław Salamonowicz ◽  
Radosław Makowski
Keyword(s):  
Heat Exchange ◽  
Liquid Phase ◽  
Mass Loss ◽  
Gas Phase ◽  
Vapor Phase ◽  
Thermal Response ◽  
Shell Temperature ◽  
Proposed Model ◽  
Liquefied Gas ◽  
Account Heat

During gas-phase release from the tank containing liquefied gas, the phenomenon of boiling, heat transfer from moist air to the tank, heat exchange between shell, liquid, and vapor, and mass loss can be observed. The aim of this paper is modelling the thermal response of the tank containing liquefied gas during jet emission of the vapor phase. The model takes into account heat exchange between air, tank’s shell, liquid phase, vapor phase and mass balance. The proposed model predicts: pressure inside the tank, tank’s shell temperature in part with liquid and vapor, the temperature of the liquid phase and vapor phase, and mass loss from the tank. The results of the theoretical model were compared with experimental results. An experiment based on the typical home container for LPG, containing 10 kg of propane (27 dm3 volume) was conducted. In general, the proposed model predicts well the changes in measured parameters temperatures and pressure - during vapor phase emission from a tank containing liquefied gas.

NUMERICAL INVESTIGATION OF INFLUENCE OF HEAT EXCHANGER СHANNEL CURVATURE ON HEAT TRANSFER

2016 ◽  
Vol 6 (4) ◽  
pp. 134-138
Author(s):  
Ekaterina N. MENYALKINA ◽  
Anna A. TSINAEVA
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Turbulence Models ◽  
Software Systems ◽  
Computational Domain ◽  
Tetrahedral Grids ◽  
Turn Radius ◽  
Account Heat

In this paper the infl uence of the curvature of the portion of the heat exchanger on heat exchange with the use of software systems Salome Meca and Code Saturne is numerically studied the verifi cation of the numerical model by comparing with experimental data of other researchers without taking into account heat exchange is made. The solution is held for an average fl ow rate equal to 11 m/s. To investigate the infl uence on heat transfer of the curvature of the channel carried out the construction of the computational domain in the form of the heat exchanger of the same length with diff erent turn radius. For discretization of the computational domain were used tetrahedral grids containing approximately 850 thousand of elements with local refi nement near the surface of the channel. As a result of simulation values of the fl ow temperature at the outlet of the channels are obtained. It is revealed that the design of heat exchanger channel, of course, aff ects the heat transfer, as well as data on the applicability of diff erent turbulence models for this type of task are collected.

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