Parameter Identification in Partial Integro-Differential Equations for Physiologically Structured Populations
S. Moenickes, O. Richter, and K. Schmalstieg
Institut für Geoökologie, Abt. Umweltsystemanalyse, Technische Universität Braunschweig, Germany
Continuous dynamic models, e.g. COMSOL based simulations, play – besides statistical or iterative methods – a mayor role in theoretical ecology; in forecasting and management, but also in systems analysis. Ecological issues generally comprise highly interacting agents and/or unknown side effects. Here we show how combining direct simulation with COMSOL with simple optimization tools ...
A. Weddemann, D. Kappe, and A. Hütten
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA, USA
Department of Physics, Thin Films and Physics of Nanostructures, Bielefeld University, Bielefeld, Germany
In principal, the calculation of the magnetic state inside a magnetic object requires the evaluation of the field in the entire unbounded space. With finite element methods restricted to finite domains, commonly auxiliary domains are employed which result in a non-physical cut-off. Not only that these additional domains result in an increased number of degrees of freedom which are strictly ...
Finite Element Convergence and Speed-Up Studies Using COMSOL Multiphysics and LiveLink™ for MATLAB® with Large Assembly Models
H. Pourzand, A.H. Aziz, A. Singh
Pennsylvania State University, State College, PA, USA
COMSOL Multiphysics along with its LiveLink™ for MATLAB® is used to investigate the needed number of elements and the required order of Lagrangean p element for a number of different simulation models. For this task, convergence study, speed up testing and interactive meshing is performed on a large assembly model which is also imported using the LiveLink™ for SolidWorks®. As a test bench, the ...
Reliable Full-Wave EM Simulation of a Single-Layer SIW Interconnect with Transitions to Microstrip Lines - new
J. L. Chavez-Hurtado, J. E. Rayas-Sanchez, Z. Brito-Brito
ITESO - Universidad Jesuita de Guadalajara, Tlaquepaque, Jalisco, Mexico
We present a procedure to obtain reliable EM responses for a SIW interconnect with microstrip line transitions. The procedure focuses on two COMSOL® configuration settings: meshing size and simulation bounding box. Once both are properly configured, the implemented structure is tested by perturbing the simulation bounding box to ensure it has no effect on the EM responses.
H. Karakuzu, M. Dubov, S. Boscolo
 Aston University, Birmingham, UK
We present an optimization procedure to improve the propagation properties of the depressed-cladding, buried micro-structured waveguides formed in a z-cut lithium niobate (LN) crystal by high repetition rate femtosecond (fs) laser writing. It is shown that the propagation wavelength for which the confinement losses of ordinary (O) and extraordinary ordinary (E) polarizations are below 1 dB/cm ...
3D COMSOL Multiphysics® Model of a Plate Heat Exchanger to Support a Laboratory Teaching Environment - new
N. Medeiros, W. Clark
Worcester Polytechnic Institute, Worcester, MA, USA
Chemical engineering students and practitioners need an understanding of fluid flow and heat transfer inside heat exchangers. Because the flow within plate heat exchangers is difficult to visualize, we developed COMSOL Multiphysics® simulations of plate heat exchangers for students to study alongside a physical heat exchanger in a laboratory setting. Simulative experiments allow students to ...
COMSOL Multiphysics Models for Teaching Chemical Engineering Fundamentals: Absorption Column Models and Illustration of the Two-Film Theory of Mass Transfer
Chemical Engineering Department, Worcester Polytechnic Institute, Worcester, MA, USA
COMSOL® models have been developed for teaching gas absorption fundamentals. Model results are compared to environmentally significant experimental results for removing CO2 and SO2 from air using water as solvent. For concentrated gas mixtures, the models are shown to be equivalent to but easier to use than the traditional graphical integration method and to a solution method developed with ...
I. Neitzel, U. Prüfert, and T. Slawig
DFG priority program SPP 1253, Technische Universität Berlin, Berlin, Germany
DFG research center Matheon, Technische Universität Berlin, Germany
DFG Cluster of Excellence The Future Ocean, DFG priority progam SPP 1253, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
We use COMSOL Multiphysics to solve time-dependent optimal control problems for partial differential equations whose optimality conditions can be formulated as a PDE. For a class of linear-quadratic model problems we summarize known analytic results on existence of solutions and first order optimality conditions that exhibit the typical feature of time-dependent control problems, namely the fact ...
Atomic Energy of Canada Limited, Mississauga, Ontario, Canada
RFSP-IST (Reactor Fueling Simulation Program) is a computer code used for the full-core neutronics design and analysis of CANDU® reactors. RFSP-IST calculates the static flux and power distributions in the core by solving the neutron diffusion equation in two energy groups. For validation purposes, results from RFSP-IST are often compared with those from other codes. This paper documents the ...
N. Petra, and M.K. Gobbert
Department of Mathematics and Statistics, University of Maryland, Baltimore County, Baltimore, Maryland, USA
The graphical user interface (GUI) of COMSOL Multiphysics offers an effective environment to get started solving problems. For reproducibility of the results, it is often desirable to explore the script-based modeling capabilities of COMSOL with MATLAB. There are also potential benefits of running COMSOL in parallel, specifically by running several computational threads in shared-memory ...