王威 , 周超 ,
微纳米马达是一种能将周围环境的能量转化为自身自主运动的新型智能仿生材料，其在药物的运输与释放，低维材料的合成以及软物质研究中有着重要的应用。基于自电泳的双金属棒马达是研究时间最长的一类马达，它有着与自然界中类似的自组装和群体行为的特性。但是其运动机理复杂且涉及到多个物理场的紧密耦合，这就为其进一步的研究和应用带来了一定的困难。 COMSOL Multiphysics® 可以方便地进行多物理场的模拟。图(1)展示了双金属棒的自电泳机理， 由于棒两端的化学反应造成了带电离子浓度的分布不均匀，进而产生自生电场驱动马达运动。其中传质过程、流体流动以及电场形成相互影响，环环相扣。基于以上物理过程，我们对 COMSOL 中稀物质传递，静电和蠕动流接口进行了有效的耦合，从而实现了马达周围离子场，电场和流场的模拟(图2)，在此基础之上，我们研究了马达的运动速度(图3) ...
S. K. Nayaka,, S. Roya ,, K. Ghosha ,, S. Aroshb ,, S. Prakashb,, S. P. Duttaguptaa 
 Center for Research in Nanotechnology and Science, IIT Bombay, Mumbai, Maharashtra, India.
 Dept. of Electrical Engineering, IIT Bombay, Mumbai, Maharashtra, India.
Methane detection and quantification is of great importance due to its natural abundance, potential to cause explosions and known greenhouse effect. Leak detection and concentration monitoring at source is highly challenging as CH4 is odorless and colorless. This can be performed mounting sensor network over a potential diffusion area. It requires optimal positioning of those sensor nodes to ...
F. Wittbrach, A. Weddemann, A. Auge, and A. Hütten
Department of Physics, Bielefeld University, Germany
It is possible to control the motion of magnetic beads using a combination of hydrodynamic and electromagnetic forces. In this work, we investigate the possibility to manipulate the motion of beads with different magnetic moments in a special microfluidic structure so as to separate them. We also experimentally prove that this structure is a suitable device to separate beads and show that the ...
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 Finite Element Analysis on the Modeling of Heat Release Rate, as Assessed by a Cone Calorimeter, of Char Forming Polycarbonate
D. Statler, and R. Gupta
Mid-Atlantic Technology, Research and Innovation Center, South Charleston, WV, USA
Department of Chemical Engineering, West Virginia University, Morgantown, WV, USA
During the pyrolysis and combustion of polymers, heat is released and is typically measured with a cone calorimeter to better assess the polymer’s flammability. Modeling heat release rate, as assessed by cone calorimetry, has not been extensively studied for char-forming polymers, such as, polycarbonate. Here we determine the heat release rate with the help of a one-dimensional transient finite ...
J. Park, T. Bjornara, H. Westerdahl, and E. Gonzalez
Norwegian Geotechnical Institute (NGI), Oslo, Norway
StatoilHydro Research Center, Norway
In this study, we propose an absorbing boundary domain (or condition), which is really simple but still efficient for the 2.5D finite element (FE) analysis. The main application is to simulate the electromagnetic (EM) waves related to the marine controlled source electromagnetic (CSEM) method, where the EM wave propagates with extremely low frequency in the conductive media. In the near future, ...
A. Nyman, M. Behm, and G. Lindbergh
Applied Electrochemistry, School of Chemical Science and Engineering, Royal Institute of Technology Stockholm, Sweden
Modeling of mass transport is an important step in evaluating lithium-ion battery electrolytes and understanding cell performance. For high-power applications, concentration gradients in the electrolyte lead to limiting currents, which limit the power-density of the battery. The model has been used for determining a complete set of transport and thermodynamic properties for LiPF6 dissolved in an ...
Designing the Actuator for the Next-Generation Astronomical Deformable Mirrors: a Multidisciplinary and Multiphysics Approach
C. Del Vecchio, R. Biasi , D. Gallieni, and A. Riccardi
INAF-OAA, Fierenze, Italy
Microgate Srl, Bolzano, Italy
ADS International Srl, Valmadrera, Italy
The actuation system of the deformable mirror is one of the crucial components of an Adaptive Optics unit. One possible implementation comprehends a linear force motor and a capacitive sensor providing the feedback measure signal. Choosing a magnetic circuit that makes optimum use of the magnetic force delivered by a current and properly arranging the electrostatic geometry allows to obtain very ...
A. Haas, M. Scholle, A. Aksel, H.M. Thompson, R.W. Hewson, and P.H. Gaskell
Department of Applied Mechanics and Fluid Dynamics, University of Bayreuth, Bayreuth, Germany
School of Mechanical Engineering, University of Leeds, Leeds, United Kingdom
Heat transfer in a plane shear flow configuration consisting of two infinitely long parallel plates is considered. In laminar flows over undulated substrates eddies can be generated due to the kinematical constraints. A closed form analytical solution for the velocity field, based on lubrication theory as well as a semi-analytic solution for the temperature field is derived for the creeping ...
T.I. Bjørnarå, E. Aker, and E. Skurtveit
NGI, Oslo, Norway
Safe short term storage of CO2 depends mainly on structural and solubility trapping. On longer term, mineral trapping is also contributing to the trapping of CO2. To be able to investigate the importance of these different storage mechanisms, a finite element model for simulation of CO2 injection has been developed in COMSOL Multiphysics®. The model describes and solves for two-phase flow ...