D. Testi, P. Conti
University of Pisa, Department of Energy and Systems Engineering, Pisa, Italy
The use of foundation piles as ground heat exchangers coupled to a geothermal heat pump is considered of interest for possible savings in installation costs, compared to conventional borehole heat exchangers. We refer to them as “geothermal piles” or “energy piles”. The main purpose of the foundation structure is to transmit the load of the building to the lower layers of the soil, best suited ...
H. Zhu, T. Gulati, A. K. Datta, K. Huang
Institute of Applied Electromagnetics, Sichuan University, Chengdu, China
Department of Biological and Environment Engineering, Cornell University, Ithaca, NY, USA
Microwave drying of fruits and vegetables in a domestic oven has been found to result in large textural changes in the product such as puffing, crack formation and even burning due to the inhomogeneous heating of the microwaves. Microwave drying of potatoes is a complex interplay of mass, momentum and energy transport. Three phases are considered in the system: solid (skeleton), liquid (water) ...
M. Wei, S. Grossman, J. Speck
Institute of Electrical Power Systems and High Voltage Engineering, Technische Universität Dresden, Dresden, Germany
The job of designing end-winding corona protection (ECP) system is one of the very important and complex phases for insulation configuration of high voltage rotating machines. This complexity stems on one hand from the highly nonlinear characteristics of the ECP material and on the other hand from the coupled multiphysics phenomena of the involved performance evaluation. Simulation based ECP ...
OSRAM SYLVANIA, Beverly, MA, USA
COMSOL Multiphysics is used to simulate natural convection and its impact on peak operating temperatures of solid-sate lighting in thermally adverse conditions. PDE modes in the general form are used in conjunction with a thin-surface conduction formulation in the weak form. COMSOL is used to predict both temperatures and heat flows through numerous components of the configuration. Model ...
P.A. Koski and M.S. Mikkola
Department of Applied Physics, Helsinki University of Technology, Espoo, Finland
A 3D FEM (Finite Element Method) model for predicting the internal pressure distribution of a fuel cell stack is presented. The model includes contact pair boundary conditions between the most critical components, thermal expansion and Young's moduli as a function of temperature. The model is used to investigate the changes in pressure distribution inside a PEM fuel cell at realistic ...
Multiphase, Dual Polymer Injection Molding and Cooling of an Open Cavity to Form both Distinct and Graduated Material Properties within a Complex Three-Dimensional Body
Continuum Blue Ltd, Forest Row, United Kingdom
With the advancement of medical devices and implants, many now require more advanced nonlinear, hyper-elastic materials such as elastomers to be extensively utilized in the body. This combined with the need to allow for considerably different, varying and graduated material responses within the three-dimensional device, poses a difficult challenge to manufacturing an elastomeric implant in a ...
M. Hackert-Oschätzchen, R. Paul, M. Penzel, M. Zinecker, A. Schubert
Professorship Micromanufacturing Technology, Technische Universität Chemnitz, Chemnitz, Germany
Evaporative cooling is a promising cooling method for dissipating high heat fluxes in high power density applications. One possibility to enhance heat flux is a generation of microstructures into the cooler surface. This enlarges the cooler surface and systematically affects the fluid flow as well as the boiling process. In this study the geometric arrangement of cylindrical pin microstructures ...
Numerical Modeling of the Near-Subsurface Temperature Distributions in the Presence of Time Varying Air Temperature in the Boundary Condition and Space Varying Temperature for the Initial Condition - new
M. Ravi, D. V. Ramana, R. N. Singh
CSIR - National Geophysical Research Institute, Hyderabad, Telangana, India
The subsurface thermal structure in presence of groundwater recharge/discharge has been obtained by applying the Robin type boundary condition at the earth’s surface. The Robin type boundary condition involves the effect air temperatures at the surface which are taken as exponentially varying with time and the initial condition which is taken as exponential function of depth. The numerical ...
COMSOL Multiphysics® as a Tool to Increase Safety in the Handling of Acetylene Cylinders Involved in Fires
F. Ferrero, M. Beckmann-Kluge, and K. Holtappels
BAM Federal Institute for Materials Research and Testing Division II.1 “Gases, Gas Plants”, Berlin, Germany
In this paper a mathematical model for predicting the heating-up of an acetylene cylinder involved in a fire is presented. In the simulations polynomial functions were used to describe the temperature dependency of the thermal properties of the cylinder interior, which is a complex system composed by a solid porous material, a solvent and acetylene dissolved in it. Model equations covered heat ...
A. Priarone, S. Lazzari, and E. Zanchini
Dipartimento di Ingegneria Energetica, Nucleare e del Controllo Ambientale, Alma Mater Studiorum - Università di Bologna, Bologna, Italy
The long-term performance of double U-tube Borehole Heat Exchangers (BHEs) is studied numerically by considering three different time-dependent heat fluxes exchanged between each BHE and the ground. Since the temperature distribution along the vertical direction has a negligible influence on long-term BHE performance, the problem is studied by means of a 2D conduction model, where the energy ...