scholarly journals Application of Additively Manufactured Pentamode Metamaterials in Sodium/Inconel 718 Heat Pipes

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3016
Author(s):  
Longfei Hu ◽  
Ketian Shi ◽  
Xiaoguang Luo ◽  
Jijun Yu ◽  
Bangcheng Ai ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Alkali Metal ◽  
Inconel 718 ◽  
Thermal Stresses ◽  
Engineering Application ◽  
Thermal Response ◽  
Heat Pipes ◽  
Uniform Temperature ◽  
Temperature Distributions ◽  
Stress Accommodation

In this study, pentamode metamaterials were proposed for thermal stress accommodation of alkali metal heat pipes. Sodium/Inconel 718 heat pipes with and without pentamode metamaterial reinforcement were designed and fabricated. Then, these heat pipes were characterized by startup tests and thermal response simulations. It was found that pentamode metamaterial reinforcement did not affect the startup properties of sodium/Inconel 718 heat pipes. At 650–950 °C heating, there was a successful startup of heat pipes with and without pentamode metamaterial reinforcement, displaying uniform temperature distributions. A further simulation indicated that pentamode metamaterials could accommodate thermal stresses in sodium/Inconel 718 heat pipes. With pentamode metamaterial reinforcement, stresses in the heat pipes decreased from 12.9–62.1 to 10.2–52.4 MPa. As a result, sodium/Inconel 718 heat pipes could be used more confidently. This work was instructive for the engineering application of alkali metal heat pipes.

Analysis of the Thermal Stress and Strain on Arrigo Fiammingo’s Artistic Window in the Cathedral of Perugia

2001 ◽  
Vol 123 (6) ◽  
pp. 1173-1180 ◽  
Author(s):  
Cinzia Buratti
Keyword(s):  
Thermal Stress ◽  
Thermal Stresses ◽  
Actual State ◽  
Stress And Strain ◽  
Work Of Art ◽  
Temperature Distributions ◽  
Software Program ◽  
Thermal Stress And Strain

Thermal stress can damage fragile materials such as glass. It is a worrisome problem if the glass is a work of art, such as the polychromatic window of Arrigo Fiammingo (1565), in the Cathedral of Perugia, the topic of this paper. The window surface, irradiated by sunlight, suffers different thermal stresses, according to the color of the glass elements. In the present paper a calculation of stresses and strains on the window is carried out, for different temperature distributions due to sunlight, by using the ANSYS 5.3 software program. Results are compared with the actual state of the fissures on the window.

Multidimensional Modeling of Temperature Distribution in Engine Combustion Chamber

2011 ◽  
Author(s):  
Yuanhong Li ◽  
Song-Charng Kong
Keyword(s):  
Heat Conduction ◽  
Combustion Chamber ◽  
Thermal Stresses ◽  
Combustion Process ◽  
Numerical Procedure ◽  
Heat Fluxes ◽  
Operating Conditions ◽  
Uniform Temperature ◽  
Temperature Distributions ◽  
Engine Combustion

Heat conduction calculations are coupled with in-cylinder combustion modeling for engine simulation in this study. Heat transfer on the fluid-solid interface will affect the in-cylinder combustion process, emissions formation, and thermal loading on the combustion chamber surface. Full knowledge of heat fluxes on the interface is important in helping improve engine efficiency, reduce exhaust emissions, and reduce combustion chamber thermal stresses. To account for the unsteady, non-uniform temperature distributions on the combustion chamber surface, a fully coupled numerical procedure was developed and applied to calculate in-cylinder flows and heat conduction in solids simultaneously. The current approach was first validated against analytical heat conduction solutions. The model was then applied to simulate diesel engine combustion under different operating conditions. Unsteady, non-uniform temperature distributions on the piston surface were successfully predicted. Global engine parameters including in-cylinder pressure, heat release rate, and emissions were also comparable to the experimental data.

Thermal Stress Analysis of MCM Package Using Diamond Material

2007 ◽  
Vol 353-358 ◽  
pp. 2904-2907
Author(s):  
Kuo Jun Xie ◽  
Chang Shun Jiang ◽  
Lin Zhu ◽  
Hai Feng Xu
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Geometrical Structure ◽  
Integrate Circuit ◽  
Stress Model ◽  
Temperature Distributions ◽  
Thermal Stress Distribution ◽  
On Chip ◽  
Quantity Of Heat

With the increasing of packaging integration the power and the quantity of heat of integrate circuit will increase, it will bring more and more temperature distributions and problems about thermal stresses in package. In this paper a finite element thermal stress model of substrate-adhesive-chip is established, thermal stress distribution of substrate-chip interfaces and the affects of geometrical structure on thermal stresses are analyzed by finite element method, especially discuss interfacial thermal stresses distributions on chip-adhesive interface and adhesinve-substrate interface.

Thermal Stresses in the SS Boulder Victory

1958 ◽  
Vol 2 (03) ◽  
pp. 55-71
Author(s):  
J. L. Meriam ◽  
P. T. Lyman ◽  
R. F. Steidel ◽  
G. W. Brown
Keyword(s):  
Thermal Stress ◽  
Thermal Stresses ◽  
Transverse Section ◽  
Beam Theory ◽  
Temperature Changes ◽  
Strain Measurements ◽  
Temperature Distributions ◽  
Hull Structure ◽  
Stress Patterns ◽  
Marine Engineers

The lack of comprehensive experimental measurements of thermal stresses induced in a ship's hull structure by diurnal temperature changes prompted the present study. Its essential purpose is to provide reliable prototype measurements of thermal stress patterns around a complete transverse section. These results are compared with stresses computed by the theory of simple beams under arbitrary temperature distributions across their section. The research was conducted under direct sponsorship of The Society of Naval Architects and Marine Engineers at the Maritime Reserve Shipyard in Richmond, Cal. The SSBoulder Victory was supplied as the test vessel by the Maritime Administration. The ship was instrumented during June and July, 1957, and tests run during August. Various temperature conditions were observed and corresponding strain measurements taken. The results are consistent and give a reliable picture of thermal-stress conditions in the ship. They also verify the prediction of thermal stresses afforded by the simple beam theory.

Correlation of Theoretical and Photothermoelastic Results on Thermal Stresses in Idealized Wing Structures

1960 ◽  
Vol 27 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Herbert Tramposch ◽  
George Gerard
Keyword(s):  
Thermal Stress ◽  
Thermal Behavior ◽  
Experimental Evaluation ◽  
High Speed ◽  
Thermal Stresses ◽  
Initial Conditions ◽  
Temperature Distributions ◽  
Wing Structures ◽  
Simplifying Assumptions ◽  
Transient Thermal

After a rather complete exploratory program described in previous papers, the photothermoelastic method was applied to the experimental evaluation of thermal-stress theories. The new technique was correlated with several theories which analyzed the transient thermal stresses in idealized wing structures of high-speed aircraft. Various theories were investigated which represented the same idealized wing models and differed from each other only in the simplifying assumptions regarding the temperature distributions in skin and webs. The theories were evaluated by duplicating the boundary and initial conditions on plastic models and then by correlating the theories with the observed fringe orders in nondimensional form. A significant general conclusion was reached after correlating the available theories and experimental results. Owing to simplifying assumptions concerning the thermal behavior in the flanges, thermal stresses predicted by the available theories are all higher than the experimental observation. In some cases the discrepancy is as great as 30 per cent.

Three Turnaround Heat Treating Studies

2003 ◽  
Author(s):  
Jaan Taagepera ◽  
Marty Clift ◽  
D. Mike DeHart ◽  
Keneth Marden
Keyword(s):  
Heat Treatment ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Heat Treating ◽  
Element Analysis ◽  
Stress Profiles ◽  
Insight Into

Three vessel modifications requiring heat treatment were analyzed prior to and during a planned turnaround at a refinery. One was a thick nozzle that required weld build up. This nozzle had been in hydrogen service and required bake-out to reduce the potential for cracking during the weld build up. Finite element analysis was used to study the thermal stresses involved in the bake-out. Another heat treatment studied was a PWHT of a nozzle replacement. The heat treatment band and temperature were varied with location in order to minimize cost and reduction in remaining strength of the vessel. Again, FEA was used to provide insight into the thermal stress profiles during heat treatment. The fmal heat treatment study was for inserting a new nozzle in a 1-1/4Cr-1/2Mo reactor. While this material would ordinarily require PWHT, the alteration was proposed to be installed without PWHT. Though accepted by the Jurisdiction, this nozzle installation was ultimately cancelled.

Steady-State Thermal Stresses in Wedge-Shaped Cutting Tools

1975 ◽  
Vol 97 (3) ◽  
pp. 1060-1066
Author(s):  
P. F. Thomason
Keyword(s):  
Thermal Stress ◽  
Steady State ◽  
Metal Cutting ◽  
Thermal Stresses ◽  
Heat Conduction Problem ◽  
Equivalent Stress ◽  
Cutting Tools ◽  
Thermoelastic Stress ◽  
Plastic State ◽  
Steady State Heat

Closed form expressions for the steady-state thermal stresses in a π/2 wedge, subject to constant-temperature heat sources on the rake and flank contact segments, are obtained from a conformal mapping solution to the steady-state heat conduction problem. It is shown, following a theorem of Muskhelishvili, that the only nonzero thermal stress in the plane-strain wedge is that acting normal to the wedge plane. The thermal stress solutions are superimposed on a previously published isothermal cutting-load solution, to give the complete thermoelastic stress distribution at the wedge surfaces. The thermoelastic stresses are then used to determine the distribution of the equivalent stress, and this gives an indication of the regions on a cutting tool which are likely to be in the plastic state. The results are discussed in relation to the problems of flank wear and rakeface crater wear in metal cutting tools.

Modelling of Convective Melt Flow and Interface Shape in Commercial Bridgman-Stockbarger Growth of CdZnTe

2000 ◽  
Author(s):  
Toby D. Rule ◽  
Ben Q. Li ◽  
Kelvin G. Lynn
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Solute Transport ◽  
Latent Heat ◽  
Thermal Stresses ◽  
Radiation Detector ◽  
Time History ◽  
High Quality ◽  
Melt Convection ◽  
The Impact

Abstract CdZnTe single crystals for radiation detector and IR substrate applications must be of high quality and controlled purity. The growth of such crystals from a melt is very difficult due to the low thermal conductivity and high latent heat of the material, and the ease with which dislocations, twins and precipitates are introduced during crystal growth. These defects may be related to solute transport phenomena and thermal stresses associated with the solidification process. As a result, production of high quality material requires excellent thermal control during the entire growth process. A comprehensive model is being developed to account for radiation and conduction within the furnace, thermal coupling between the furnace and growth crucible, and finally the thermal stress fields within the growing crystal which result from the thermal conditions imposed on the crucible. As part of this effort, the present work examines the heat transfer and fluid flow within the crucible, using thermal boundary conditions obtained from experimental measurements. The 2-D axisymetric numerical model uses the deforming finite element method, with allowance made for melt convection, solidification with latent heat release and conjugate heat transfer between the solid material and the melt. Results are presented for several stages of growth, including a time-history of the solid-liquid interface (1365 K isotherm). The impact of melt convection, thermal end conditions and furnace temperature gradient on the growth interface is evaluated. Future work will extend the present model to include radiation exchange within the furnace, and a transient analysis for studying solute transport and thermal stress.

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