Propagation of linear waves in moist porous media saturated with gas, taking into account interphase heat transfer

2007 ◽  
Vol 5 ◽  
pp. 163-168
Author(s):  
V.L. Dmitriev ◽  
S.V. Volodin
Keyword(s):  
Porous Medium ◽  
Heat Exchange ◽  
Acoustic Waves ◽  
System Of Differential Equations ◽  
Interphase Interaction ◽  
Interaction Forces ◽  
Interphase Heat Transfer ◽  
Linear Waves ◽  
Exchange Processes ◽  
Fast And Slow Waves

A system of differential equations describing process of propagation of acoustic waves in a saturated saturated gas to a porous medium. A dispersion relation taking into account Interphase interaction forces and heat exchange processes between the skeleton porous medium, liquid and gas. Influence of heat exchange processes between phases on the nature of the propagation of ”fast“ and ”slow“ waves is taken into account on the basis of the heat conduction equations.

Mass and heat transfer in the problem of propagation of acoustic waves in a porous medium

2012 ◽  
Vol 9 (1) ◽  
pp. 139-141
Author(s):  
L.F. Sitdikova ◽  
V.L. Dmitriev
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Acoustic Waves ◽  
Heat Conduction Equation ◽  
Wave Processes ◽  
Common System ◽  
Inner Surface ◽  
Fast And Slow Waves ◽  
Mass And Heat Transfer ◽  
Velocity Approximation

The paper is devoted to a theoretical investigation of wave processes in moist porous media saturated with gas. Interfacial forces of interaction, heat exchange between the skeleton of a porous medium, liquid and gas, mass transfer between a liquid and a gas; material of the skeleton of a porous medium is considered viscoelastic, the liquid covers the inner surface of the pores of the medium with a thin uniform layer. The propagation of acoustic waves is considered in the two-velocity approximation. A common system is recorded equations and physical relationships describing the propagation of acoustic waves in a wet porous medium. A dispersion relation is obtained. Influence of heat transfer between phases on propagation ”Fast“ and ”slow“ waves is taken into account on the basis of the heat conduction equation.

To an estimate of the propagation velocities of acoustic waves in a relaxing saturated porous medium

2010 ◽  
Vol 7 ◽  
pp. 153-162
Author(s):  
S.V. Lukin ◽  
S.F. Urmancheev
Keyword(s):  
Porous Medium ◽  
Acoustic Waves ◽  
Wave Attenuation ◽  
Saturated Porous Medium ◽  
Relaxation Times ◽  
Saturated Porous Media ◽  
Adopted Model ◽  
Fast And Slow Waves ◽  
The Mathematical Model ◽  
Propagation Velocities

Studies have been carried out on the propagation of acoustic pulses in saturated porous media with a viscoelastic skeleton are presented in this work. The mathematical model of wave processes is considered within the framework of the mechanics of multiphase media. Estimates are given for the propagation velocities of ”fast“ and ”slow“ waves in limiting cases. The surfaces of phase velocities and damping decrements are constructed as a function of the logarithm of dimensionless relaxation times and frequencies. Areas of intense wave attenuation in the adopted model of a saturated porous medium are established.

Increase of Heat Exchange Processes Efficiency at Production Site

2017 ◽  
pp. 18-21
Author(s):  
A.F. Khasanova ◽  
◽  
M.A. Gallyamov ◽  
Z.A. Zakirova ◽  
◽  
...  
Keyword(s):  
Heat Exchange ◽  
Production Site ◽  
Exchange Processes

scholarly journals ON THE SOLUTION OF ENERGY BALANCE EQUATION SYSTEM TO PREDICT TEMPERATURE DISTRIBUTION IN THE BUILDING ELEMENTS WITH VENTILATED AIR GAP

2014 ◽  
Vol 21 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Edmundas Monstvilas ◽  
Karolis Banionis ◽  
Jurga Poderytė ◽  
Raimondas Bliūdžius ◽  
Arūnas Burlingis
Keyword(s):  
Heat Exchange ◽  
Balance Equation ◽  
Heat Balance ◽  
Internal Surface ◽  
Equation System ◽  
Energy Balance Equation ◽  
Air Gap ◽  
Exchange Processes ◽  
Calculation Results ◽  
Thermal Indicators

The article presents the solution of heat balance equation system, describing heat exchange processes in ventilated envelopes, which was applied to derive formulas for the calculation of temperatures in the ventilated layers of the envelopes. The accurateness of the formulas was assessed by experimental research and analysis of the calculation results. During the process of heat exchange balance equation solution, the equations were simplified by introducing the following restriction into the derived formulas: they may only be applied for the ventilated envelopes with steel or similar coatings as their external layers, i.e. coatings having small heat capacity and minor difference between the external and internal surface temperatures. The derived formulas enable the calculation of the temperatures of the ventilated envelopes in the distance which does not exceed a half of the ventilated air gap length measuring from the air entrance into the gap. However, this restriction does not impede the estimation of the average thermal indicators of the ventilated envelopes.

scholarly journals Solar Dryer with Integrated Energy Unit

2021 ◽  
Vol 2(50) ◽  
Author(s):  
Sergey Korobka ◽  
◽  
Sergey Syrotyuk ◽  
Dmitry Zhuravel ◽  
Boris Boltianskyi ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Solar Energy ◽  
Moisture Transfer ◽  
Diagnostic Techniques ◽  
Material Surface ◽  
Drying Process ◽  
Energy Unit ◽  
Solar Dryer ◽  
Exchange Processes ◽  
Deformed State

The work is devoted to the issue of the rational use of the solar energy in the technological process of fruit drying based on the use of solar drying devices, which are applied in various sections of the agro-industrial centers of Ukraine. The aim of this research was intensification of the fruits drying process using the solar energy by combining an air collector and drying chamber into a single power unit. To achieve the aim the heat exchange diagnostic techniques with alternative potentials of diffusion and moisture transfer was developed. This technique differs from those existing for the heat exchange research in that it allows the intensity of the moisture evaporation from a unit of the material surface to be calculated, based on the synthesis of the moisture content and the irreversible major laws of processes of the heat exchange characteristics of the fruits drying using the solar dryer. The above model makes it possible to diagnose the heat exchange processes and analyze the mathematical model of the heat exchange processes. It also allows modeling the changeable diffusion and moisture transfer potentials based on the dependences obtained and for the purpose of a further application in the methods and devices development to control the strain-deformed state of the fruits during the drying process. The method is offered for the calculation of diffusion and moisture transfer during drying fruits in the solar dryer.

scholarly journals The influence of the charge shape on heat exchange of a recessed nozzle

2021 ◽  
Vol 2057 (1) ◽  
pp. 012013
Author(s):  
B Ya Benderskiy ◽  
A A Chernova
Keyword(s):  
Heat Exchange ◽  
Power Plant ◽  
Combustion Products ◽  
Triangular Form ◽  
Topological Features ◽  
Exchange Processes ◽  
Charge Shape ◽  
Intensification Of Heat Exchange ◽  
Thermally Conductive ◽  
Control Volumes

Abstract The paper deals with the numerical simulation of the flow of thermally conductive viscous gaseous combustion products in the flow paths of a power plant. The influence of the shape of the mass supply surface on the gas dynamics and heat exchange near the recessed nozzle of the power plant is investigated. The coupled problem of heat exchange is solved by the method of control volumes. It is shown that the compensator geometry determines the localization of both the topological features of the flow near the recessed nozzle and the position of local maximums of the heat transfer coefficient. It has been revealed that The use of a channel with a star-shaped cross section and a triangular form of compensator rays leads to an intensification of heat exchange processes near a recessed nozzle.

Entransy dissipation minimization for generalized heat exchange processes

2016 ◽  
Vol 59 (10) ◽  
pp. 1507-1516 ◽  
Author(s):  
ShaoJun Xia ◽  
LinGen Chen ◽  
ZhiHui Xie ◽  
FengRui Sun
Keyword(s):  
Heat Exchange ◽  
Entransy Dissipation ◽  
Exchange Processes
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