Search results for "Heat Transfer"
showing 10 items of 442 documents
The modeling of dissimilar welding of immiscible materials by using a phase field method
2013
A multiphysical model of high power beam welding of immiscible materials is developed to explain the influence of operational parameters and materials properties on resulting morphology by simultaneous solving of heat transfer, fluid flow and mass transfer problems. The introduction of phase field description of the interface motion between two immiscible liquids allows obtaining the cartography of melted zone in function of two key-parameters: the position of heat source relatively to joint line and the welding speed. Due to the short thermal cycle limiting mass transfer, high power beam welding techniques may result in very inhomogeneous melted zones. In this study, the interest is paid t…
Experimental Investigation on the Use of Argon to Improve FMEP Determination through Motoring Method
2019
In the ever increasing challenge of developing more efficient and less polluting engines, friction reduction is of significant importance and its investigation needs an accurate and reliable measurement technique. The Pressurized Motoring method is one of the techniques used for both friction and heat transfer measurements in internal combustion engines. This method is able to simulate mechanical loading on the engine components similar to the fired conditions. It also allows measurement of friction mean effective pressure (FMEP) with a much smaller uncertainty as opposed to that achieved from a typical firing setup. Despite its advantages, the FMEP measurements obtained by this method are …
High-pressure Raman investigation of high index facets bounded alpha-Fe2O3 pseudocubic crystals
2021
[EN] High index facet bounded alpha-Fe2O3 pseudocubic crystals has gained the attention of the scientific community due to its promising electrochemical sensing response towards aqueous ammonia. The structural stability of alpha-Fe2O3 pseudocubic crystals is investigated through high-pressure Raman spectroscopy up to 22.2 GPa, and those results are compared with our ab initio theoretical calculations. The symmetry of the experimental Raman-active modes has been assigned by comparison with theoretical data. In addition to the Raman-active modes, two additional Raman features are also detected, whose intensity increases with compression. The origin of these two additional peaks addressed in t…
Friction and wear testing of multilayer coatings on carbide substrates for dry machining applications
2002
Abstract The principle aim of this paper is to investigate three wear-protective coatings with multilayer structures, which are frequently used in the cutting tool industry and to assess their frictional behaviour under the test conditions equivalent to those for the cutting of medium carbon steel. A modified pin-on-disc tester was used to conduct experiments in which both the friction coefficient and the linear wear of the tribo-pair were recorded vs. sliding distance. The volumetric wear rate was proposed as a parameter for quantitative comparison of the wear resistance of the tribo-pairs tested. It was found that the principle stage of the specimen wear takes place during the first 200–2…
Thermal Characterization of the Chip-Tool Interface When Using Coated Turning Inserts
2000
Abstract This paper reports some results of extensive experimental investigations of the thermal interactions between the coating/substrate and the moving surface of the chip. Semi-orthogonal cutting when bar turning a medium carbon steel and an austenitic stainless steel was carried out. Both flat-faced and grooved inserts coated with TiC, TiC/TiN, and TiC/Al 2 O 3 /TiN were tested. A standard K-type thermocouple embedded in the workpiece was used to convert measured efm's to the interfacial temperatures. In addition, the chiprake contact length and the area of contact were determined by using computer processing of scanned contact images. The minimum steady-state temperature at the interf…
Conjugate heat transfer analysis within in lattice-filled heat exchanger for additive manufacturing
2020
Compact heat exchangers for heat removal has become one of the most effective cooling techniques. In this paper, numerical scheme to simulate conjugated heat transfer using additively manufactured ...
Dynamics of crystallization in hard-sphere suspensions.
1996
Density fluctuations are monitored by small-angle light scattering during the crystallization of 0.22-\ensuremath{\mu}m-radius, hard colloidal spheres. Measured structure factors show an intensity maximum at finite-scattering vectors. The shape of the intensity distribution scales at early times during nucleation and growth and again at large times during ripening. At intermediate times there is a crossover region where scaling ceases to be valid. Both the amplitude and the position of the maximum intensity show quasi-power law behavior in time. The values of the observed exponents are within the range expected for classical growth models. The breadth of the intensity distribution increases…
<title>Structure-relaxation-induced peculiarities of the holographic recording in amorphous As<formula><inf><roman>2</roma…
1997
The results of the experimental study of holographic recording in a-As2S3 films are reported such as exposure and intensity dependencies, spatial frequency dependence. Several peculiarities are found including recording intensity threshold, nonmonotonical intensity dependencies, nonlinear exposure curves, the change of the spatial frequency response due to films aging. These peculiarities are explained in terms of phenomenological model which is based on the simultaneous action of the photostructural changes and the relaxational structural changes.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Thermal–mechanical and thermal–hydraulic integrated study of the Helium-Cooled Lithium Lead Test Blanket Module
2010
Abstract The Helium-Cooled Lithium Lead Test Blanket Module (HCLL-TBM) is one of the two TBM to be installed in an ITER equatorial port since day 1 of operation, with the specific aim to investigate the main concept functionalities and issues such as high efficiency helium cooling, resistance to thermo-mechanical stresses, manufacturing techniques, as well as tritium transport, magneto-hydrodynamics effects and corrosion. In particular, in order to show a DEMO-relevant thermo-mechanical and thermal–hydraulic behavior, the HCLL-TBM has to meet several requirements especially as far as its coolant thermofluid-dynamic conditions and its thermal–mechanical field are concerned. The present paper…
A physical description of fractional-order Fourier diffusion
2014
In this paper the authors introduce a physical picture of anomalous heat transfer in rigid conductor. The analysis shows that a fractional-order Fourier transport is obtained by the analysis of the heat transport in a functionally graded conductor. The order of the fractional-type operator obtained is related to the grading of the physical properties of the conductor.