S. Marai, E. Ferrari, R. Civelli
DiSAA, University of Milan, Milan, Italy
This paper presents heat transfer 3-D models of a passive refrigeration system used to improve the shelf life and the quality of the perishable fruits. Passive refrigerator system uses the changing phase to keep temperature close to the melting temperature. A multi-step study was performed: a 3-D heat transfer model on the empty box; a 3-D heat transfer model on the box containing a slab with ...
N. Badi, R. Mekala
Department of Physics, Center for Advanced Materials, University of Houston, Houston, TX, USA
Department of Electrical & Computer Engineering, University of Houston, Houston, TX, USA
Thermally conducting but electrically insulating materials are needed for heat-sink LED lighting applications. We report on a cost effective and innovative method based on creating core-shell nanoparticles in polymer with aluminum (Al) nanoparticles as the high thermal conductivity core and ultrathin aluminum oxide (Al?O?) as a capping shell. The solid oxide shell around the Al core prevents ...
E. Tempfli, F.P. Schmidt
Karlsruhe Institute of Technology (KIT), Fluid Machinery (FSM), Karlsruhe, Germany
The paper investigates the hydrodynamic performance of a hierarchical parallel channel network for the objective of optimal thermal coupling to heat released in the adsorption processes, as in adsorption heat pumps. More specifically, the uniformity of the fluid flow over the network is improved by optimizing the topology of the manifold channels of the two hierarchical levels. For this purpose ...
Heat Propagation Improvement in YBCO-Coated Conductors for Superconducting Fault Current Limiters - new
D. M. Djokic, L. Antognazza, M. Abplanalp, M. Decroux
DPMC, University of Geneva, Geneva, Switzerland
ABB Corporate Research Centre, Dättwil, Switzerland
YBCO Coated Conductors (CCs), used for applications in Resistive Superconducting Fault Current Limiters (RSFCLs), are known to have insufficiently high Normal Zone Propagation Velocity (NZPV) during quench events. The improvement can be made by enhancing the thermal conductivity of YBCO-CCs with no decrease in the electrical resistivity. We studied the advantage of multilayered structures grown ...
A. D'Orazio, C. Agostini, S. Fiacco
Dipartimento di Ingegneria Astronautica, Elettrica ed Energetica - Sapienza University of Rome, Rome, Italy
Fundamental component of the NMR tomograph is the magnet. By using the property of superconductivity it is possible to achieve an induction field extremely homogeneous, stable and high. To maintain the material below the superconducting critical temperature (7.2K), the coils are immersed in liquid helium at 4K, within a cryostat. In this paper, we present the preliminary results related to the ...
H. Zhu, T. Gulati, K. Huang, A.K. Datta
Sichuan University, Chengdu, Sichuan, China
Cornell University, Ithaca, NY, USA
Mathematical description of microwave drying requires the solution of two different physics: electromagnetics in the microwave oven cavity and food material and, transport process (mass, momentum and heat transport) in the food material. Maxwell’s equations for electromagnetics were solved using the RF Module using the GMRES iterative solver with the GeometricMultigrid preconditioner. Mass, ...
C. Hurt, P. Angelo, R. Pevey
Department of Nuclear Engineering, University of Tennessee, Knoxville, TN, USA
Y-12 National Security Complex, Safety Analysis Engineering, Oak Ridge, TN, USA
Simulation of criticality accident transients offers the ability to confirm understanding of critical configurations, bound accident scenarios and aid comprehensive emergency planning. Computational ability to recreate excursion power histories in fissile solution is sought due to the predominance of solutions in process criticality accidents. Applicable solution transient physics methodologies ...
E. Salomatova, D. Trushnikov, V. Belenkiy, V. Tsaplin
Perm National Research Polytechnic University, Perm, Russia
In this paper describes an original method for indirect measurement of the vapor pressure and temperature in the keyhole in electron beam welding. This method is based on the determination of the concentration of chemical elements in the vapor above the welding zone. Taking into account these data model is built 2D diffusion processes with heat and mass transfer elements in the melt, which ...
Simulation of Helmholtz Resonators for Optical Gas Sensing: Comparison Between Pressure Acoustics and Thermoacoustics - new
B. Parvitte, C. Risser, R. Vallon, V. Zéninari
Université de Reims, Reims, France
Among optical gas sensing methods, photoacoustic (PA) spectroscopy combined with a laser source has proven to be a very robust and sensitive method for trace gas detection. COMSOL Multiphysics® software was used to calculate the frequency response of differential Helmholtz resonator cells in order to optimize the detection limit of PA sensors. Two different kind of simulation were performed: ...
J. Rivenc ,
 Airbus Group Innovations, Toulouse Cedex, France
The purpose of this study is to predict, with a multiphysics model, the degradation area of a composite material when a current is injected into the material. The main physical phenomenon is an exothermic reaction, with an irreversible nonlinear variation of the electrical conductivity. The strategy is presented, in order to perform a computation that correctly takes the physics into account. In ...