M. Di Bari, and G. Zito
University of Bari, Italy
Many theoretical studies concerning lava tubes focus on the thermal disturbances generated on the earth surface. Recently a solution was suggested, where a lava tube located at a great depth h in the soil, where the ratio between h to the major axis of the ellipse a is higher than 10. However, lava tubes more frequently are located at shallower depths. In this work we ...
Numerical Analysis of the Impact of Geometric Shape Patterns on the Performance of Miniaturized Chromatography Systems
R. Winz, E. von Lieres, and W. Wiechert
Department of Simulation, University of Siegen, Siegen, Germany
Institute of Biotechnology, Research Centre Jülich, Siegen, Germany
We have implemented a two dimensional chromatography model for the analysis and optimization of structured micro pillar arrays. Dynamic surface interaction of solved molecules is taken into account by the kinetic Langmuir model. Variations of the pillar array geometry lead to deviations in the outlet concentration profiles. These deviations cannot be described by the one dimensional models that ...
Dinex Emission Technology A/S, Middelfart, Denmark
Exhaust noise must meet legislation targets, customer expectations and cost reduction which call for design optimization of the exhaust systems in the design phase. One solution is to use 3 dimensional linear pressure acoustics and calculate the transfer matrix of the muffler. The transfer matrix is the basis for calculating either the insertion loss or transmission loss of a muffler. The 3D ...
C. Gavrila, A. Ghiaus, and I. Gruia
Technical University of Civil Engineering Bucharest, Faculty of Building Services, Bucharest, Romania
University of Bucharest, Faculty of Physics, Bucharest, Romania
A dynamic mathematical model, based on physical and transport properties and mass and energy balances, was developed for the simulation of unsteady convective drying of agricultural products (fruits and vegetables) in static bed conditions. The model utilizes water sorption isotherm equations and the change in solid density due to the shrinkage phenomenon. The aim of this article is to describe ...
Benchmarking as Key Element of Confidence Building in Safety Assessments for Radioactive Waste Disposal
SCK-CEN (the Belgian Nuclear Research Centre), Mol, Belgium
Verification of the codes applied for assessment of the long-term repository safety is typically one of the quality assurance requirements demanded by regulatory bodies, in the disposal of radioactive waste. In this paper, an internationally organized benchmark exercise is presented, in which the comparison was carried out for a selection of key radionuclides. The examples presented in this ...
Simulation of Optical Properties of the Si/SiO2/Al Interface at the Rear of Industrially Fabricated Si Solar Cells
Y. Yang, and P. Altermatt[1,2]
Institute for Solar Energy Research Hamelin (ISFH), Emmerthal, Germany
Dep. Solar Energy Research, Inst. Solid-State Physics, Leibniz University of Hanover, Germany
The specular and diffuse reflection properties of sunlight at the rear surface of silicon solar cells with various degrees of roughness are computed by solving the Maxwell and material equations in two dimensions, using the COMSOL RF Module. The model is tested on planar Si/SiO2/air interfaces and planar Si/SiO2/Al interfaces. The simulations show that for wavelengths of 800 nm, (i) maximum ...
E. Holzbecher, and Hang Si
Weierstrass Institute for Applied Analysis and Stochastics (WIAS), Berlin, Germany
In the paper we examine the accuracy of various meshes for different model regions and simple differential equations in 2D and in 3D. We study the potential equation for a single irregular domain (2D testcase 1), for a simple domain with irregular sub-domains (2D testcase 2) and a 3D testcase. For testcase 1 we compare with the analytical solution, for testcases 2 with the best solution, ...
M. Darif, and N. Semmar
GREMI-UMR6606, CNRS-Universite d’Orleans, Orléans, France
A 2D transient heat conduction model was created in COMSOL Multiphysics to simulate temperature changes in material irradiated by a KrF laser beam confined on silicon’s surface. In this paper, the obtained results are shown and discussed in case of bulk Silicon. The heat source is distributed in time with ‘gate’ and ‘gaussian’ shapes. The thermal properties values ...
M. Zampolli, N. Malm, and A. Tesei
NURC NATO Research Centre, La Spezia, Italy
COMSOL AB, Stockholm, Sweden
Perfectly matched layers (PML) are an efficient alternative for emulating the Sommerfeld radiation condition in the numerical solution of wave radiation and scattering problems. The key ingredient of the PML formulation is the complex scaling function, which controls the anisotropic damping of the PML. The objective of this study is to propose a modified complex scaling function capable of ...
H. Bakhtiary, F. Hayer, H. Venvik, A. Holmen
Norwegian University of Science and Technology Trondheim
Methanol synthesis is a typical reaction in heterogeneous catalysis. In this work, we have studied a laboratory fixed-bed reactor packed with a Cu/Zn/Al2O3 catalyst in both adiabatic and isothermal tubular operational modes. A methanol synthesis kinetic model was implemented in COMSOL Reaction Engineering Lab. Both 1D and 2D pseudo-homogeneous dispersion models were applied to describe the mass ...