Rotationally symmetric flow of Cu-Al2O3/water hybrid nanofluid over a heated porous boundary

2021 ◽  
pp. 095440622110231
Author(s):  
Sahreen Tahira ◽  
M Mustafa ◽  
Ammar Mushtaq
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Viscous Dissipation ◽  
Transfer Process ◽  
Vortex Flow ◽  
Heat Transfer Process ◽  
Hybrid Nanofluid ◽  
Dissipation Term ◽  
Self Similar ◽  
Similar Solutions

This paper endeavours to provide an analysis for nanofluid boundary layer that develops beneath a generalized vortex flow subjected to viscous dissipation effects. Tangential flow high above the disk is assumed to vary with radial distance [Formula: see text] as [Formula: see text]. Hybrid nanofluid comprises alumina-[Formula: see text] and copper-[Formula: see text] nanoparticles with water as base liquid. A generalized version of von Kármán relations proposed in a recent paper is opted to present self-similar solutions. In presence of viscous dissipation term, self-similar solutions are possible only when temperature difference is proportional to [Formula: see text]. Otherwise, the solutions are only locally similar. Present model reduces to two special situations namely rigid body rotation [Formula: see text] and potential vortex [Formula: see text]. It is perceived that inclusion of nanoparticles markedly affects the boundary layer development under the prescribed vortex flow, and the associated heat transfer process. Also, viscous dissipation term has important implications on the resulting heat transfer process.

scholarly journals Self-Similar Heat Transfer Processes in a Radiation-Transparent Solid Body Containing an Absorptive Inclusion with the System Featuring Phase Transitions

2019 ◽  
pp. 60-70
Author(s):  
A.V. Attetkov ◽  
I.K. Volkov ◽  
K.A. Gaydaenko
Keyword(s):  
Heat Transfer ◽  
Phase Transitions ◽  
Solid Body ◽  
Transfer Process ◽  
Sufficient Conditions ◽  
Heat Transfer Process ◽  
Similar Process ◽  
Transfer Processes ◽  
Self Similar ◽  
Phase Transition Boundary

The paper considers the problem of determining temperature field parameters in a radiation-trans-parent isotropic solid body containing an absorptive inclusion, when the system features phase transitions. We identify sufficient conditions, meeting which ensures the possibility of self-similar heat transfer process taking place in the system under con-sideration. We qualitatively investigated physical properties of the self-similar process under study and determined its specifics. We provide a theoretical validation of implementing a thermostating mode of the moving phase transition boundary in the heat transfer process investigated

EFFECTS OF URBAN CANOPY ON TURBULENCE HEAT-TRANSFER PROCESS IN CONVECTIVE BOUNDARY LAYER

2020 ◽  
Vol 76 (2) ◽  
pp. I_481-I_488
Author(s):  
Yasuo HATORI ◽  
Shuji ISHIHARA ◽  
Hitoshi SUTO ◽  
Keisuke NAKAO ◽  
Yuma HASEBE ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Transfer Process ◽  
Convective Boundary Layer ◽  
Urban Canopy ◽  
Heat Transfer Process ◽  
Convective Boundary

scholarly journals Influence of the channel arrangement for the passage of the coolant on the heat transfer process of a convective heater

2018 ◽  
Vol 251 ◽  
pp. 03055
Author(s):  
Samvel Sargsyan ◽  
Viktoria Borisova
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Transfer Process ◽  
Radiant Heat ◽  
Heat Transfer Process ◽  
Engineering Properties ◽  
Optimum Shape ◽  
Thermal Engineering ◽  
Heat Engineering ◽  
Change Function

The availability of highly economical indicators of convective type heating appliances, as well as the wide use of window sills, solid glazing of walls in the construction equipment, and the expansion of the use of convective (ribbed) type heating appliances, taking into account the possible improvement of their sanitary and hygienic and heat engineering properties. Constructions of convective type (convector) type heating devices with rather low heat engineering indicators. To improve the thermo-technical qualities of convectors, special attention is paid to the determination of the optimum dimensions of the fin, the channel for the passage of the coolant, the fin length, the optimum shape of the rib, and so on. The task of this work is to find new ways that require the heat transfer process of ribbed heating devices. The problem of the optimal distribution of the heat source (channel for the passage of the coolant) relative to the horizontal axis of symmetry of the rib is considered. Analytical dependences are obtained, which allow to determine the local values of heat transfer changes for nonisothermal plates, the temperature change at which is a step-change function. The process of convection in a laminar boundary layer is shown as a process of nonstationary thermal conductivity of a semi-boundary body. When solving the problem of radiant heat exchange between the ribs and surrounding surfaces, and between the edge and the environment. The directions of the experimental study are presented with the purpose of determining: the thickness of the boundary layer near the surface of the rib; the nature of the distribution of temperature along the edge with different locations of the source of heat; thermal engineering studies on convectors, various measurements of the channel for the passage of the coolant, various finning steps, and various fin sizes.

scholarly journals Investigation of transient and steady heat transfer in saturated porous medium filled in a vertical cylinder with thermal dispersion and radiation

2021 ◽  
pp. 344-344
Author(s):  
Shaban Abu ◽  
Ahmad Manasrah ◽  
Ibraheem Nasser
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Pore Size ◽  
Transfer Process ◽  
Convection Heat Transfer ◽  
Vertical Cylinder ◽  
Heat Transfer Process ◽  
Natural Convection Heat Transfer ◽  
Thermal Dispersion ◽  
Convection Heat

In this study, the influence of thermal radiation and dispersion on a porous medium which was filled in a vertical cylinder was numerically solved. A finite-difference method was used to solve the non-dimensional equations by applying a Crank-Nicolson implicit numerical technique. Moreover, an experimental setup has been initially built to investigate the effect of three different grain sizes of the porous materials on the heat transfer process. The numerical results indicated that the thermal radiation increased the momentum and the thickness of the thermal boundary layer during the natural convection heat transfer process. Whereas, the thermal dispersion factor decreased the momentum and the thickness of the boundary layer during the natural convection heat transfer process, which enabled a steady and transient heat transfer. The experimental results indicated that the pore size of the medium significantly affected the rate of the heat transfer process. A smaller pore size showed a greater effect and could be used in different applications that involve a higher heat transfer rate, while a larger pore size can potentially be used as an insulating material.

Design of the Blast Furnace Wall Structure Made of Efficient Materials. Part 4. Calculation Examples

2020 ◽  
Vol 786 (11) ◽  
pp. 30-34
Author(s):  
A.M. IBRAGIMOV ◽  
◽  
L.Yu. GNEDINA ◽  
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Blast Furnace ◽  
Boundary Value Problems ◽  
Transfer Process ◽  
Rational Design ◽  
Boundary Value ◽  
Heat Transfer Process ◽  
Furnace Wall ◽  
Time Interval

This work is part of a series of articles under the general title The structural design of the blast furnace wall from efficient materials [1–3]. In part 1, Problem statement and calculation prerequisites, typical multilayer enclosing structures of a blast furnace are considered. The layers that make up these structures are described. The main attention is paid to the lining layer. The process of iron smelting and temperature conditions in the characteristic layers of the internal environment of the furnace is briefly described. Based on the theory of A.V. Lykov, the initial equations describing the interrelated transfer of heat and mass in a solid are analyzed in relation to the task – an adequate description of the processes for the purpose of further rational design of the multilayer enclosing structure of the blast furnace. A priori the enclosing structure is considered from a mathematical point of view as the unlimited plate. In part 2, Solving boundary value problems of heat transfer, boundary value problems of heat transfer in individual layers of a structure with different boundary conditions are considered, their solutions, which are basic when developing a mathematical model of a non-stationary heat transfer process in a multi-layer enclosing structure, are given. Part 3 presents a mathematical model of the heat transfer process in the enclosing structure and an algorithm for its implementation. The proposed mathematical model makes it possible to solve a large number of problems. Part 4 presents a number of examples of calculating the heat transfer process in a multilayer blast furnace enclosing structure. The results obtained correlate with the results obtained by other authors, this makes it possible to conclude that the new mathematical model is suitable for solving the problem of rational design of the enclosing structure, as well as to simulate situations that occur at any time interval of operation of the blast furnace enclosure.

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