Comparison of Classic and Finned Piston Reciprocating Linear Air Compressor Using COMSOL Multiphyics®
M. Heidari, P. Barrade, A. Rufer
LEI, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
The current work is dedicated to develop a FEM model for compressors using moving mesh. An analytical model is already developed for a classic compressor based on mass and energy balance and is extended to a finned piston compressor. COMSOL Multiphysics® is employed to verify the analytical results and to provide an insight to detailed modeling of the system in desired areas. Moving mesh is ...
B. Baumann, J. Schwieger, M. Wolff, F. Manders, J. Suijker
Hamburg University of Applied Sciences, Hamburg, Germany
Philips Lighting, Turnhout, Belgium
High-intensity discharge lamps will in the foreseeable future be important light sources despite a growing market share of LEDs. Cost and energy efficient high frequency (300 kHz) operation is hampered by the excitation of acoustic resonances inside the arc tube, which results in low frequency (10 Hz) light flicker. Our aim is to calculate the acoustic streaming velocity field, which is related ...
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 ...
N. Mahmoodi, C. J. Anthony
University of Birmingham, Birmingham, UK
Viscous damping has a significant effect on dynamic performance of the resonators operating within fluid. This work is aimed to find the viscous damping for MEMS torsional paddle operating in air. Interaction of moving structure with the fluid requires a complicated and challenging analysis. The Fluid-Structure Interaction interface of COMSOL Multiphysics® software is used to study the 2-D ...
Design and Simulation of an Orbiting Piezoelectric MEMS Gyroscope Based on Detection of Phase-Shift Signals
S. Gorelick, J. R. Dekker, B. Guo, H. Rimminen
 VTT Technical Research Centre of Finland, Espoo, Finland
The feasibility of phase-sensitive detection of angular-rates using bi-directional orbiting piezoresonators suspended by thick annular springs with thin-film aluminium nitride piezoactuators on top of them was investigated. The ring-shaped flexures are more suitable for supporting the orbiting motion due to their angle-dependent spring constant. The response of the orbiting resonators to angular ...
H. T. Mengistu, A. García-Cristóbal
Material Science Institute, University of Valencia, Valencia, Spain
The possibility to dispose of two-dimensional (2D) approaches to problems originally posed in a three-dimensional (3D) geometry is always desirable since it reduces significantly the computing resources needed for numerical studies. In this work we report on a new 2D approach called Generalized Plane Piezoelectric (GPP) problem  and apply it to the calculation of the strain and electric fields ...
Investigation of Mean-Flow Effects on Tubular Combustion Chamber Thermoacoustics Using a Burner Transfer Matrix Approach
A. Andreini, B. Facchini, A. Innocenti, D. Pampaloni
University of Florence, Florence, Italy
The paper presents a methodology to account for local mean-flow effects on thermo-acoustic instabilities to improve typical calculations performed under the zero-Mach number assumption. A 3D FEM model of a simplified combustor is solved with COMSOL Multiphysics® Pressure Acoustics interface. The Helmholtz equation is used to model the combustor and the classical k-τ model for the Flame Transfer ...
V. Pini, J. J. Ruz Martinez, E. Gil, M. Calleja, and J. Tamayo
Instituto de Microelectrónica de Madri
The detection back-action phenomenon has received little attention in physical, chemical, and biological sensors based on nanomechanical systems. We show that this effect is very significant in ultrathin bimetallic cantilevers, in which the laser beam that probes the picometer scale vibration largely modifies the resonant frequencies of the system. The light back-action effect is nonlinear, ...
EMD Millipore Corporation, Bedford, MA USA
Membrane-based tangential flow filtration (TFF) cassettes are used for the clarification, concentration and purification of fluid streams containing macromolecules of proteins. In TFF, the protein fluid is pumped tangentially along the surface of the membrane. The feed flow along the length of channel between two membranes causes a pressure drop from the feed to the retentate end of the channel. ...
Thermal Modeling in a Historical Building - Improving Thermal Comfort Through the Siting of a Passive Mass of Phase Change Material
D. Groulx, F. Herbinger, L. Desgrosseilliers
Mechanical Engineering, Dalhousie University, Halifax, NS, Canada
A model of an office room was created in the COMSOL Multiphysics® software to simulate heat transfer and study the impact of siting a mass of phase change material (PCM) in a room to increase thermal comfort. This study determined that incorporating the selected PCM, butyl stearate, in the ceiling and in the floor did not alter the temperature of the room significantly after one hour. ...