Plane Thermoelastic Deformation of a Multilayer Foundation with Non-Ideal Thermal Contact between its Layers

2019 ◽  
Vol 968 ◽  
pp. 486-495
Author(s):  
Nina Antonenko ◽  
Iryna Tkachenko
Keyword(s):  
Thermal Resistance ◽  
Recurrence Relations ◽  
Thermal Contact ◽  
Lower Boundary ◽  
Stationary Problem ◽  
Two Dimensional ◽  
Thermoelastic Deformation ◽  
Ideal Thermal Contact ◽  
Elastic Layers ◽  
Distribution Of Stresses

We proposed the method of the compliance function for the solution of two-dimensional stationary problem of thermoelasticity for a multilayer foundation (stack of elastic layers coupled with a half plane) with a non-ideal thermal contact between its layers. We constructed the recurrence relations for the auxiliary functions and the compliance functions of neighboring layers of the foundation. We analyzed the influence of thermal resistance on the distribution of stresses and temperature at the points of the lower boundary of the upper layer for a two-layer foundation subjected to the action of thermal loads.

scholarly journals Thermal condition of cohesion in a two-layer roll of a rolling mill

2019 ◽  
pp. 45-48
Author(s):  
Olga Panteleivna Demyanchenko ◽  
Viktor Lyashenko
Keyword(s):  
Heat Exchange ◽  
Temperature Distribution ◽  
Heat Conductivity ◽  
Rolling Mill ◽  
Thermal Condition ◽  
Thermal Contact ◽  
Homogeneous Equation ◽  
Target Setting ◽  
Radial Section ◽  
Ideal Thermal Contact

A condition of heat exchange between the layershaving different thermalphysic properties in a two-layercylindrical roll of a rolling mill is analyzed foe an ideal thermalcontact. It can be realized with application of the condition ofheat balance of one of the layers in the cylindrical area for ahomogeneous equation of heat conductivity. Analyzed was asimplified target setting in the radial section with a supposition,regarding an averaged in radius temperature distribution in theouter layer. By applying the condition of the thermal balance andby integrating the homogeneous equation of heat conductivity inthe two-layer area a condition of cohesion of an impedance typein case of an ideal thermal contact between the layers wasconstructed.

scholarly journals Theoretical Gravity Anomalies of Glaciers Having Parabolic Cross-Sections

1964 ◽  
Vol 5 (38) ◽  
pp. 255-257 ◽  
Author(s):  
Charles E. Corbató
Keyword(s):  
Cross Sections ◽  
Lower Boundary ◽  
Gravity Anomalies ◽  
Vertical Axis ◽  
Two Dimensional ◽  
Axis Of Symmetry ◽  
Upper Boundary

AbstractEquations and a graph are presented for calculating gravity anomalies on a two-dimensional glacier model having a horizontal upper boundary and a lower boundary which is a parabola with a vertical axis of symmetry.

scholarly journals Modelling of the processes of impact of a projectile with elements of individual defence

2019 ◽  
Vol 221 ◽  
pp. 01021
Author(s):  
Aleksandr Kraus ◽  
Evgeny Kraus ◽  
Ivan Shabalin
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Heterogeneous Media ◽  
Three Dimensional ◽  
Stationary Problem ◽  
Heterogeneous Structure ◽  
Plate Steel ◽  
Two Dimensional ◽  
Human Bones ◽  
Armor Plate

A two-dimensional and three-dimensional non-stationary problem of the interaction of a homogeneous impactor and a heterogeneous structure made of steel and ceramics and placed in a Kevlar pocket is considered. The model of the human body is a plate of gelatine with cylindrical inserts-imitators of human bones. The results of numerical simulation using different approaches for describing heterogeneous media are compared. On the basis of direct numerical simulation, it is shown that the gradient armor plate (steel + B4C) has the best weight and size parameters.

Modeling and solving the two-dimensional non-stationary problem in an elastic body with a rectangular hole

2016 ◽  
Author(s):  
Nurgali Ashirbayev ◽  
Zhansaya Ashirbayeva ◽  
Turlybek Sultanbek ◽  
Raina Bekmoldayeva
Keyword(s):  
Elastic Body ◽  
Stationary Problem ◽  
Two Dimensional ◽  
Rectangular Hole

Four-Probe Measurement of Thermal Transport in Suspended Few-Layer Graphene With Polymer Residue

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Eric Ou ◽  
Xun Li ◽  
Sangyeop Lee ◽  
Kenji Watanabe ◽  
Takashi Taniguchi ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Thermal Transport ◽  
Thermal Contact ◽  
Experimental Studies ◽  
Phonon Transport ◽  
Contact Thermal Resistance ◽  
Layer Graphene ◽  
Scattering Rate ◽  
Transport Measurements ◽  
Polymeric Residue

The presence of unknown thermal contact thermal resistance has limited prior two-probe thermal transport measurements of suspended graphene samples. Here, we report four-probe thermal transport measurements of suspended seven-layer graphene. By isolating the thermal contact resistance, we are able to attribute the observed reduced thermal conductivity primarily to polymeric residue on the sample instead of the contact thermal resistance, which resulted in ambiguity in the prior experimental studies of the effect of polymer reside. The extrinsic scattering rate due to the polymer residue is extracted from the measurement results based on a solution of the Peierls-Boltzmann phonon transport equation.

Thermal Resistance of Nanowire-Plane Interfaces

2005 ◽  
Vol 127 (6) ◽  
pp. 664-668 ◽  
Author(s):  
V. Bahadur ◽  
J. Xu ◽  
Y. Liu ◽  
T. S. Fisher
Keyword(s):  
Thermal Resistance ◽  
Thermal Contact ◽  
Surrounding Medium ◽  
Van Der Waals ◽  
Interface Resistance ◽  
Nanoelectronic Devices ◽  
Van Der Waals Theory ◽  
And Performance ◽  
Planar Substrates ◽  
Conductivity Medium

This paper employs continuum principles combined with van der Waals theory to estimate the thermal contact resistance between nanowires and planar substrates. This resistance is modeled using elastic deformation theory and thermal resistance relations. The contact force between a nanowire and substrate is obtained through a calculation of the van der Waals interaction energy between the two. The model estimates numerical values of constriction and gap resistances for several nanowire-substrate combinations with water and air as the surrounding media. The total interface resistance is almost equal to the gap resistance when the surrounding medium has a high thermal conductivity. For a low-conductivity medium, the interface resistance is dominated by the constriction resistance, which itself depends significantly on nanowire and substrate conductivities. A trend observed in all calculations is that the interface resistance increases with smaller nanowires, showing that interface resistance will be a significant parameter in the design and performance of nanoelectronic devices.

Design and Verification of a Low-Powered Pre-Programmable In-Package Temperature Controller

2006 ◽  
Author(s):  
Hyeun-Su Kim ◽  
Hsien-Hsin Liao ◽  
Byeong-hee Lee ◽  
Thomas W. Kenny
Keyword(s):  
Thermal Resistance ◽  
Contact Resistance ◽  
Temperature Change ◽  
Thermal Contact Resistance ◽  
Operating Temperature ◽  
Electrostatic Force ◽  
Thermal Contact ◽  
Temperature Regulator ◽  
Thermal Resistors ◽  
Device Test

A zero power passive temperature regulator has been studied and designed to maintain electric chip operating temperature using a variable thermal resistor. Apart from the passive temperature regulator design, we also present active variable thermal resistors using electrostatic force to actuate the device. Test samples were fabricated to verify these two designs and we observed the temperature change of a heated chip due to thermal resistance changes. This study estimated and measured the thermal contact resistance and the force required to remove it.

Thermal Properties of Thin Metallic Layer Deposited on Insulators: Effect of the Interface on the Independent Determination of the Thermal Diffusivity and Conductivity of the Layer

2008 ◽  
Author(s):  
Danie`le Fournier ◽  
Jean Paul Roger ◽  
Christian Fretigny
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Thermal Resistance ◽  
Thermal Contact ◽  
Heat Diffusion ◽  
Metallic Layer ◽  
Good Thermal Contact ◽  
Lateral Heat

Lateral heat diffusion thermoreflectance is a very powerful tool for determining directly the thermal diffusivity of layered structures. To do that, experimental data are fitted with the help of a heat diffusion model in which the ratio between the thermal conductivity k and the thermal diffusivity D of each layer is fixed, and the thermal properties of the substrate are known. We have shown in a previous work that it is possible to determine independently the thermal diffusivity and the thermal conductivity of a metallic layer deposited on an insulator, by taking into consideration all the data obtained at different modulation frequencies. Moreover, it is well known that to prevent a lack of adhesion of a gold film deposited on substrates like silica, an intermediate very thin (Cr or Ti) layer is deposited to assure a good thermal contact. We extend our previous work: the asymptotic behaviour determination of the surface temperature wave at large distances from the modulated point heat source for one layer deposited on the substrate to the two layers model. In this case (very thin adhesion coating whose thermal properties and thickness are known), it can be establish that the thermal diffusivity and the thermal conductivity of the top layer can still be determined independently. It is interesting to underline that the calculus can also be extended to the case of a thermal contact resistance which has often to be taken into account between two solids. We call thermal resistance a very thin layer exhibiting a very low thermal conductivity. In this case, the three parameters we have to determine are the thermal conductivity and the thermal diffusivity of the layer and the thermal resistance. We will show that, in this case, the thermal conductivity of the layer is always obtained independently of a bound of the couple thermal resistance – thermal diffusivity, the thermal diffusivity being under bounded and the thermal resistance lower bounded. Experimental results on thin gold layers deposited on silica with and without adhesion layers are presented to illustrate the method. Discussions on the accuracy will also be presented.

The effects of thermal conditions on the cell sizes of two-dimensional convection

1994 ◽  
Vol 281 ◽  
pp. 33-50 ◽  
Author(s):  
Masaki Ishiwatari ◽  
Shin-Ichi Takehiro ◽  
Yoshi-Yuki Hayashi
Keyword(s):  
Heat Flux ◽  
Lower Boundary ◽  
Thermal Conditions ◽  
Heat Fluxes ◽  
Internal Cooling ◽  
Two Dimensional ◽  
Numerical Integrations ◽  
The Difference ◽  
Convective Cells ◽  
Upper Boundary

The effects of thermal conditions on the patterns of two-dimensional Boussinesq convection are studied by numerical integration. The adopted thermal conditions are (i) the heat fluxes through both upper and lower boundaries are fixed, (ii) the same as (i) but with internal cooling, (iii) the temperature on the lower boundary and the heat flux through the upper boundary are fixed, (iv) the same as (iii) but with internal cooling, and (v) the temperatures on both upper and lower boundaries are fixed. The numerical integrations are performed with Ra = 104 and Pr = 1 over the region whose horizontal and vertical lengths are 8 and 1, respectively.The results confirm that convective cells with the larger horizontal sizes tend to form under the conditions where the temperature is not fixed on any boundaries. Regardless of the existence of internal cooling, one pair of cells spreading all over the region forms in the equilibrium states. On the other hand, three pairs of cells form and remain when the temperature on at least one boundary is fixed. The formation of single pairs of cells appearing under the fixed heat flux conditions shows different features with and without internal cooling. The difference emerges as the appearance of a phase change, whose existence can be suggested by the weak nonlinear equation derived by Chapman & Proctor (1980).

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