J.A. Ospina and E. Canuto
Politecnico di Torino, Torino, Italy
The research project under which the COMSOL simulations are performed deals with multilayer and fine thermal control of an optical reference cavity for space applications. The cavity, made of Ultra Low Expansion glass (Corning ULE), must be kept close to the zero expansion temperature of the glass (close to room temperature). The target can only be met by active control, while leaving the cavity ...
A. Pellegrini, A. Beucci, and F. Costa
ALTRAN Italia, Pisa, Italy
In this paper a methodology for calculating the infrared signature of complex objects is presented. The transient thermal analysis allows us to evaluate the temperature distribution on the investigated object, pointing out which parts tend to be warmer. These temperature values are handled in the post processing phase in order to evaluate the zero range radiance distribution and the radiance of ...
Bourouga, B.1, Le Meur, G.1, Garnier, B.1, Michaud, J.F.2, Mohammed-Brahim, T.2
1 Laboratoire de Thermocinétique de Nantes
2 IETR – Groupe de Microélectronique-Université Rennes I
Development of new handling microsystems needs integration of field effect thin film transistors made directly on various low temperature substrates, as glass for example, with other functions. Argon laser is used to melt completely and then to crystallize 400 nm thick amorphous silicon films. However, the implementation of this process generates cracking and destruction of the silicon thin film ...
V. Le Sant, and G. Failleau
Laboratoire National d'Essais, Paris, France
Within the framework of its thermal metrology activities and, in particular, in the context of a European project, LNE has recently developed a new device for the realization of the ITS-90 fixed-points with the aim of reducing uncertainties.Concurrently with this new device, a numerical thermal model has been developed, using COMSOL, to study heat transfer in temperature fixed points. This ...
J. D. Freels
Oak Ridge National Laboratory, Oak Ridge, TN, USA
The only known supercritical hydrogen heat transfer data, at similar conditions to the HFIR CS, was taken by NASA in the 1960s. This rocket-engine test data did not compare well with any computer simulation results.It was hypothesized that the reason for this discrepancy was due to the large heat fluxes in the NASA rocket engines and unique hydrogen fluid properties. Therefore, a need existed to ...
B.W. Reed, T.B. LaGrange, G.H. Campbell, and N.D. Browning[1,2]
Lawrence Livermore National Laboratory, Livermore, CA, USA
University of California Davis, Davis, CA, USA
The Dynamic Transmission Electron Microscope (DTEM) at Lawrence Livermore National Laboratory is a unique instrument able to capture images of fast-evolving microstructure with exposure times of only 15 ns. This is more than six orders of magnitude faster than conventional in situ electron microscopy and has enabled new insights into phase transformations, chemical reactions, and materials ...
Homogeneous and Inhomogeneous Model for Flow and Heat Transfer in Porous Materials as High Temperature Solar Air Receivers
O. Smirnova, T. Fend, P. Schwaryboezl, and D. Schoellgen
German Aerospace Center, Institute of Technical Thermodynamics, Koeln, Germany
Results of simulations on flow and heat transfer in a porous Silicon Carbide honeycomb structure applied as a solar air receiver are presented. In this application porous materials are put in concentrated solar radiation. Flux densities of up to 1000 MW/m² are reached. Simultanously, ambient air flows through the material to be heated up to temperatures of app. 800°C. This hot air is then used ...
M. Bachmann, V. Avilov, A. Gumenyuk, and M. Rethmeier
BAM Federal Institute for Materials Research and Testing
The article deals with the magnetically-supported high-power full-penetration laser beam welding of aluminum. A stationary simulation was conducted accounting for the effects of natural convection, Marangoni convection and solid-liquid phase transition as well as an electromagnetic volume source term. An ac magnet below the weld specimen induces eddy currents. Consequently, Lorentz forces occur ...
Three-Dimensional Thermal Modeling of Temperature Variation in Concrete Box-Girders Using COMSOL Multiphysics®
S. Abid[1,2], N. Tayşi, M. Özakça
Gaziantep University, Gaziantep, Turkey
Wasit University, Kut, Iraq
The COMSOL's Heat Transfer module was used in this study to evaluate the temperature distribution in concrete box-girders subjected to exterior thermal conditions. The included thermal loads were air temperature, wind speed in addition to solar radiation. Moreover, the reflected radiation from the ground and other surroundings in addition to the mutual radiation between the different surfaces of ...
G. Petrone, C. Balocco
BE CAE & Test, Catania, Italy
Department of Industrial Engineering, University of Firenze, Firenze, Italy
High levels of Indoor Air Quality (IAQ) in Operating Theatres (OT) is an important issue in order to contribute in prevention of Surgical Site Infections (SSI). Despite of specific plant layouts are applied for OT ventilation (e.g. unidirectional flow), the effective use conditions can heavily modify the design microclimate and air quality levels. Medical staff presence and movements and sliding ...