scholarly journals Calculation of Temperature Fields in Multilayer Plates and Shells with Distributed Heat Sources

2019 ◽  
pp. 75-77
Author(s):  
Natalia Smetankina ◽  
Oleksii Postnyi
Keyword(s):  
Heat Transfer ◽  
Functional Equation ◽  
Heat Conduction Equation ◽  
Side Surface ◽  
Temperature Fields ◽  
Heat Sources ◽  
Multilayer Plate ◽  
Expansion Theorem ◽  
Plates And Shells ◽  
Three Space

The aircraft multilayer glazing is considered as arectangular multilayer plate made up of isotropic layers withconstant thickness. The temperature on the side surface of theplate is zero. Convective heat transfer occurs on outer surfaces ofthe plate; on layers' interfaces film heat sources are arranged.The heat conduction equation for an arbitrary plate layer isreduced to the functional equation. A solution of the functionalequation we search in the form of three space functions product.We get the system of ordinary differential equations. Seriesexpansion factors are determined from a system of linearalgebraic equations. A transform of the required function isfound by the second expansion theorem, and the problemsolution has the form of double trigonometrical series.The comparative analysis of the results is carried out with theresults of other method. The method offered can be used fordesigning a safe multilayer glazing under operational andemergency thermal and force loading in different vehicles.

scholarly journals NONSTATIONARY HEAT CONDUCTION IN MULTILAYER GLAZING SUBJECTED TO DISTRIBUTED HEAT SOURCES

2020 ◽  
Vol 10 (2) ◽  
pp. 28-31
Author(s):  
Natalia Smetankina ◽  
Oleksii Postnyi
Keyword(s):  
Heat Conduction ◽  
Laplace Transformation ◽  
Heat Conduction Equation ◽  
Constant Thickness ◽  
Heat Sources ◽  
Nonstationary Heat Conduction ◽  
Multilayer Plate ◽  
Expansion Theorem ◽  
Thermal Fields ◽  
Transformation Series

A method for calculation of nonstationary thermal fields in a multilayer glazing of vehicles under the effect of impulse film heat sources is offered. The glazing is considered as a rectangular multilayer plate made up of isotropic layers with constant thickness. Film heat sources are arranged on layers' interfaces. The heat conduction equation is solved using the Laplace transformation, series expansion and the second expansion theorem. The method offered can be used for designing a safe multilayer glazing under operational and emergency thermal and force loading in vehicles.

Development of Convective Heat Transfer Near Suddenly Heated, Vertically Aligned Horizontal Wires

1987 ◽  
Vol 109 (4) ◽  
pp. 912-918 ◽  
Author(s):  
J. R. Parsons ◽  
M. L. Arey
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Fluid Layer ◽  
Convective Motion ◽  
Transient Behavior ◽  
Temperature Fields ◽  
Heat Sources ◽  
Transfer Coefficients ◽  
Vertically Aligned ◽  
The Wire

Experiments have been performed which describe the transient development of natural convective flow from both a single and two vertically aligned horizontal cylindrical heat sources. The temperature of the wire heat sources was monitored with a resistance bridge arrangement while the development of the flow field was observed optically with a Mach–Zehnder interferometer. Results for the single wire show that after an initial regime where the wire temperature follows pure conductive response to a motionless fluid, two types of fluid motion will begin. The first is characterized as a local buoyancy, wherein the heated fluid adjacent to the wire begins to rise. The second is the onset of global convective motion, this being governed by the thermal stability of the fluid layer immediately above the cylinder. The interaction of these two motions is dependent on the heating rate and relative heat capacities of the cylinder and fluid, and governs whether the temperature response will exceed the steady value during the transient (overshoot). The two heat source experiments show that the merging of the two developing temperature fields is hydrodynamically stabilizing and thermally insulating. For small spacing-to-diameter ratios, the development of convective motion is delayed and the heat transfer coefficients degraded by the proximity of another heat source. For larger spacings, the transient behavior approaches that of a single isolated cylinder.

Numerical Analysis on the Temperature Field in Laser-Plasma Hybrid Welding of an Aluminum Alloy

2008 ◽  
Vol 580-582 ◽  
pp. 279-282
Author(s):  
Zhi Ning Li ◽  
Bao Hua Chang ◽  
Dong Du ◽  
Hua Zhang
Keyword(s):  
Heat Transfer ◽  
Aluminum Alloy ◽  
Laser Plasma ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Transfer Model ◽  
Heat Sources ◽  
Hybrid Welding ◽  
Plasma Arc ◽  
Simulation Results

A three dimensional heat transfer model on laser-plasma hybrid welding has been proposed, that takes into account the interaction between laser beam and plasma arc. Through FEM computation, the temperature fields were computed and analyzed for an Al-Li alloy during laserplasma hybrid welding with different distances between the two heat sources. The simulation results are in agreement with the experimental results.

scholarly journals Modelling and numerical simulation of the heat transfer and natural ventilation in storage halls

2020 ◽  
Vol 207 ◽  
pp. 01005
Author(s):  
Nina Penkova ◽  
Kalin Krumov ◽  
Boian Mladenov ◽  
Yordan Stoyanov
Keyword(s):  
Heat Transfer ◽  
Natural Ventilation ◽  
Temperature Fields ◽  
Design Stage ◽  
Temperate Climate ◽  
Heat Sources ◽  
Thermal Fields ◽  
Wind Pressures ◽  
Volume Method ◽  
Velocity Pressure

An algorithm for modelling of the heat transfer in storage halls at different combinations of open doors and smoke vents is developed. The models allow numerical simulations of velocity, pressure and temperature fields in the halls in cases of transient and steady state conditions, taking into account the indoor buoyancy, heat sources, heat transfer through the building envelopes and outdoor wind pressures. The models are solved numerically via finite volume method in order to estimate the necessity of additional heating at a design stage of a courier logistic storage hall, situated in the temperate climate zone, at the hardest winter conditions of the region. Recommendations about the organization of the heating and the cargo input are done based on the analyses of the fluid flow and thermal fields at the modelled scenarios.

scholarly journals Entropy Generation Analysis of Natural Convection in Square Enclosures with Two Isoflux Heat Sources

2017 ◽  
Vol 7 (2) ◽  
pp. 1486-1495
Author(s):  
S. Z. Nejad ◽  
M. M. Keshtkar
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Local Heating ◽  
Heat Sinks ◽  
Temperature Fields ◽  
Entropy Generation Rate ◽  
Heat Sources ◽  
Minimum Entropy ◽  
Adiabatic Flow ◽  
Heater Length

This study investigates entropy generation resulting from natural convective heat transfer in square enclosures with local heating of the bottom and symmetrical cooling of the sidewalls. This analysis tends to optimize heat transfer of two pieces of semiconductor in a square electronic package. In this simulation, heaters are modeled as isoflux heat sources and sidewalls of the enclosure are isothermal heat sinks. The top wall and the non-heated portions of the bottom wall are adiabatic. Flow and temperature fields are obtained by numerical simulation of conservation equations of mass, momentum and energy in laminar, steady and two dimensional flows. With constant heat energy into the cavity, effect of Rayleigh number, heater length, heater strength ratios and heater position is evaluated on flow and temperature fields and local entropy generation. The results show that a minimum entropy generation rate is obtained under the same condition in which a minimum peak heater temperature is obtained.

The Microelectronics Cooling Impact and Comparison of 2D and 3D Unsteady Effects of a Pair of Opposed Confined Angled Impinging Air Jets

2011 ◽  
Author(s):  
Victor Adrian Chiriac ◽  
Jorge Luis Rosales
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Temperature Fields ◽  
Heat Sources ◽  
Air Jets ◽  
Nusselt Numbers ◽  
Target Wall ◽  
Third Dimension ◽  
Vortex Patterns ◽  
2D And 3D

The unsteady laminar flow and heat transfer characteristics for a pair of angled confined impinging air jets centered in a channel were studied numerically. The time-averaged heat transfer coefficient for a pair of heat sources centered in the channel was determined, as well as the oscillating jet frequency for the unsteady cases. The present study is a continuation of the authors’ previous investigations, identifying the similarities and differences arising from the expansion to the third dimension. It examines the interaction between the angled jets and the associated impact on the cooling of the heat sources placed on the board at a jet Reynolds number of 100 and 600. Maintaining the inlet jet width, W, at 1 cm, as in the previous studied cases, the interaction between the 45° angled jets leads to the formation of unsteady symmetrical jets that impinge on the two heat sources placed on the board at a Reynolds number of 100. A second case investigates the hydrodynamic interaction between the 45° angled jets at a Reynolds number of 600. In this case the jets interact and form a region of unsteady shear causing the jets to sweep the target board and the heated components placed on it. The nature of this unsteadiness depends on the proximity of the jet inlets, the channel dimensions and the jet Reynolds number. The jet unsteadiness causes the stagnation point locations to sweep back and forth over the impingement region causing the jets to “wash” a larger surface area on the target wall. The relevant trends for the 2D and 3D jet hydrodynamic and thermal fields are further documented by comparing the field plots and the Nusselt numbers on the target walls for the cases under evaluation. Although similar in nature, the unsteady 3D opposite jets produce results that deviate from the 2D unsteady opposite jets. The complex vortex patterns resulting from the jet interaction at various jet inlet locations, as well as the velocity, vorticity and temperature fields for both 2D and 3D cases are thoroughly evaluated.

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