S. Lazzari, A. Priarone, and E. Zanchini
DIENCA, University of Bologna, Bologna, Italy
A numerical investigation of the long-term performance of double U-tube borehole heat exchanger (BHE) fields, in the case of non-negligible effects of groundwater movement, is performed by means of COMSOL Multiphysics. Two time periodic heat loads, with a period of one year, are studied: Q1, with a partial compensation between winter heating (principal load) and summer cooling; Q2, with no summer ...
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 ...
Finite Element Modeling of Coupled Heat and Mass Transfer of a Single Maize Kernel Based on Water Potential Using COMSOL Multiphysics Simulation
A.J. Kovács, E. Lakatos, G. Milics, and M. Neményi
University of West Hungary, Institute of Biosystems Engineering, Mosonmagyarovar, Hungary
Finite element modeling of agricultural materials is very often used for describing physical processes. However, exact physical measurements are needed as input parameters for the models. Knowing the driving forces (potentials) during heat and mass transfers is necessary for an accurate model. Water potential gradients as the driving force are used in contrast with the conventional practice ...
Finite Element Approach for Optimizing the Cooling of the Metallic Bipolar plates for Fuel Cell Applications
E. Firat[1,2], C. Siegel[1,2], L. Kühnemann[1,2], P. Beckhaus, and A. Heinzel[1,2]
Zentrum für Brennstoffzellentechnik (ZBT) GmbH, Duisburg, Germany
University of Duisburg Essen, Duisburg, Germany
Metallic bipolar plates promise several advantages for fuel cell applications. On the other hand, cooling of these plates is a critical task regarding design optimization. The high thermal conductivity of the material and the complex geometry of these plates affect directly the cooling performance. To analyze this phenomenon, a 3D model is set-up and solved using a FEM (finite element method) ...
S. Francois, and P. Namy
Nexans Research Center, Lyon cedex, France
SIMTEC, Grenoble, France
Power over Ethernet (PoE/PoE+) is a technology allowing to transmit data and power over the same data cable. The major concern for this technology is the degradation of data transmission performances due to the temperature increase in the cable. To have a better quantitative and qualitative knowledge of the temperature field in the cables, Nexans has developed a 2D finite element thermal model ...
A. Plana-Fattori[1,2], E. Chantoiseau[1,2], C. Doursat[1,2], and D. Flick[1,2]
AgroParisTech, Massy, France
INRA, Massy, France
Many liquid food processes involve coupled phenomena of fluid flow, heat transfer and product transformation. A typical example is the heat treatment of a starch suspension inside a tubular heat exchanger. Fluid flow influences heat transfer which determines temperature evolution along fluid trajectories. Temperature locally influences the food product transformation. The latter influences ...
G. Petrone, G. Cammarata, and L. Cammarata
Department of Industrial and Mechanical Engineering, University of Catania, Italy
This study aims to numerically investigate on a passive solar system for indoor heating called as \"Trombe wall\". The transient buoyancy driven flow characterizing that system and the thermal distribution are solved by numerically integrating the governing equations in COMSOL Multiphysics environment. Simulations are carried-out for a time range corresponding to 12 days. The results are ...
B. Watzke, H. Deyber, and H. Limbach
Nestlé Research Centre, Lausanne, Switzerland
Research Centre, Lausanne, Switzerland
The freezing curve of the food material was extracted from Differential Scanning Calorimetry experiments. A heat conductive model was generated in COMSOL, including the thermo-physical characteristics and the phase transition behavior. The resulting temperature-time evolutions at different positions in space were in excellent agreement with our experimental data. Changing scale, the variation ...
P-O. Johansson, and J. Wollerstrand
Lund University, Lund, Sweden
In a hydronic space heating system the heat output arises from natural convection and radiation from the radiators. In order to increase the heat output, without replacing the radiators with larger ones, or increasing the temperature level, the radiator can be equipped with add-onfan blowers. In the latter case, the heat output from the radiator will increase due to increased convection. This ...
Thermal Modelling For The Implementation Of An Energetic Efficiency Control System In A Room Of Meetings Of Singular Geometry
M. Martínez, V. Fuster, J. Fernández, and I. Benítez
Instituto Tecnológico de la Energía (ITE), Paterna, Valencia, Spain
The aim of this Project is to obtain a temporary and spatial evolution model of the temperature into a meeting room with the aim to develop an efficient energy mechanism which can improve the air conditioner control system. The project has considered two extremes cases: on the one hand a typical summer day and on the other hand a winter day. From annual data of the Institute weather station a ...