Modeling of Ultrasonic Transducers and Ultrasonic Wave Propagation for Commercial Applications Using Finite Elements with Experimental Visualization of Waves for Validation - new
D. R. Andrews
Cambridge Ultrasonics, Over, UK
Finite element (FE) modelling of ultrasonic propagation using COMSOL Multiphysics® simulations can be used to create images of waves. Unfortunately, in time-stepping solutions, it is possible for numerical instabilities to grow large and dominate the solution adversely. Any design of transducer that is based upon poorly-configured FE models is unlikely to perform as expected and will almost ...
T. Gasch , A. Ansell ,
 KTH Royal Institute of Technology, Stockholm, Sweden
An extension of the Solid Mechanics interface in COMSOL Multiphysics® is presented to analyze localized deformations of quasi-brittle materials, for example cracking in concrete. This is achieved by implementing an isotropic damage mechanics constitutive law, which is combined with both a local and a non-local regularization technique to ensure mesh objectivity. The implementation is made using ...
Y. T. Habtemichael, R. T. Kiflemariam, H. R. Fuentes
Department of Civil & Environmental Engineering, Florida International University, Miami, FL, USA
Department of Mechanical & Materials Engineering, Florida International University, Miami, FL, USA
Seawater intrusion into coastal aquifers is usually modeled by using transport models that include account for the effect of variable-density on flow. Variable-density models can be validated with the Henry and Elder benchmark problems. However, when mixed convective flow is simulated under variable density conditions, it is susceptible to physical and numerical instabilities. The purpose of ...
Multiphysics Modelling of Standing Column Well and Implementation of Heat Pumps Off-Loading Sequence
A. Nguyen, P. Pasquier, D. Marcotte
 Department of Civil, Geological and Mining Engineering, École Polytechnique de Montréal, Montréal, QC, Canada
A fully coupled multiphysics model involving heat transfer and groundwater flow within a SCW and its surrounding ground was implemented in COMSOL Multiphysics 4.2a with MATLAB to simulate a 24-hour heating operation. The heat pumps were modeled using interpolation functions thereby allowing the effect of the pumped water temperature on the capacity and coefficient of performance of the heat ...
Full Coupling of Flow, Thermal and Mechanical Effects in COMSOL Multiphysics® for Simulation of Enhanced Geothermal Reservoirs
D. Sijacic, P. Fokker
TNO, Utrecht, The Netherlands
The effective modeling of enhanced geothermal systems (EGS) requires the coupling of geomechanics, fluid flow and thermal processes. An understanding of the complete system with these coupled processes is vital, not just for reservoir stimulation targeted at enhancing reservoir performance, but also for the understanding, prediction and prevention of induced seismicity. Thermal effects however ...
C. K. C. Arruda , A. A. Silveira , L. C. R. Vieira , F. C. Dart ,
 CEPEL, Rio de Janeiro, RJ, Brazil
High Voltage Direct Current transmission (HVDC) is a suitable alternative for long distance transmission. During the years, the use of this technology has been increasing, which is one of the several reasons to improve methodologies in HVDC grounding systems. Unlike the usual approach in AC, a HVDC grounding system is distinguished by its operating procedures, which is, when it is configured ...
R. Caulk, J. McCartney, E. Ghazanfari
University of Vermont, Burlington, VT, USA
University of Colorado, Boulder, CO, USA
In this study, a model of in-situ geothermal energy piles was constructed using COMSOL Multiphysics® software. Geothermal energy piles serve two purposes, first to transfer building load into the subsurface, but also to extract thermal heat from surrounding soils. This is achieved using a heat pump coupled with embedded heat exchangers. As a result, a multiphysics problem is introduced - heat ...
The Use of COMSOL Multiphysics® Software to Explore Flooding and Rising Dampness Problems Related to Cultural Heritage
H.L. Schellen , A.W.M. van Schijndel ,
 Eindhoven University of Technology, Eindhoven, Netherlands
In The Netherlands rising dampness problems due to flooding of rivers and high groundwater levels form an essential treat for monumental buildings and heritage. A number of cases exists where rising dampness problems lead to the deterioration of wall finishes but also of valuable wall paintings in churches and castles. To explore the problem and to look for solutions like drying regimes, ...
R. Hu , Q. Liu ,
 School of Earth Science and Engineering, Hohai University, Nanjing, China
Based on the heat transfer and seepage theory in porous media, a 2D cross section of a horizontal AGF project is selected and a numerical model is set up, which is based on full coupling of temperature and flow fields by combining physical interfaces of Darcy's Law and Heat Transfer in Porous Media. The simulation results show that freezing wall appears in an asymmetrical shape as the ...
R. Eze , G. Sivulka , ,
 City University of New York - LaGuardia Community College, Long Island City, NY, USA
 Regis High School, New York, NY, USA
The detection, characterization, and classification of underground environmental hazardous objects [mines, IEDs, and other unexploded military hardware] is a worldwide problem that needs urgent attention and solution. While electromagnetic sensor technologies have been applied to identify these hazards, increasingly low dielectric contrast between newer, sophisticated landmines, and complex ...