COMSOL: Simulation Drives Understanding

COMSOL Multiphysics® is a general-purpose simulation software used in all fields of engineering, manufacturing, and scientific research. The software offers fully coupled multiphysics and singlephysics modeling capabilities, simulation data management, and user-friendly tools for building simulation applications. Spread the value of simulation to your design teams, manufacturing departments, test labs, customers, and other collaborators by distributing your apps using COMSOL Compiler™ and COMSOL Server™. Add-on modules provide specialized functionality for chemical reaction engineering, fluid flow, heat transfer, electromagnetics, structural mechanics, and acoustics. Interfacing products are available for CAD and other third-party software

COMSOL Multiphysics GmbH

COMSOL: Simulation Drives Understanding COMSOL Multiphysics® is a general-purpose simulation software used in all fields of engineering, manufacturing, and scientific research. The software offers fully coupled multiphysics and single-physics modeling capabilities, simulation data management, and user-friendly tools for building simulation applications. Spread the value of simulation to your design teams, manufacturing departments, test labs, customers, and other collaborators by distributing your apps using COMSOL Compiler™ and COMSOL Server™. Add-on modules provide specialized functionality for chemical reaction engineering, fluid flow, heat transfer, electromagnetics, structural mechanics, and acoustics. Interfacing products are available for CAD and other third-party software

Optimal modelling and experimentation for the improved sustainability of microfluidic chemical technology design

Optimization of the dynamics and control of chemical processes holds the promise of improved sustainability for chemical technology by minimizing resource wastage. Anecdotally, chemical plant may be substantially over designed, say by 35-50%, due to designers taking account of uncertainties by providing greater flexibility. Once the plant is commissioned, techniques of nonlinear dynamics analysis can be used by process systems engineers to recoup some of this overdesign by optimization of the plant operation through tighter control. At the design stage, coupling the experimentation with data assimilation into the model, whilst using the partially informed, semi-empirical model to predict from parametric sensitivity studies which experiments to run should optimally improve the model. This approach has been demonstrated for optimal experimentation, but limited to a differential algebraic model of the process. Typically, such models for online monitoring have been limited to low dimensions. Recently it has been demonstrated that inverse methods such as data assimilation can be applied to PDE systems with algebraic constraints, a substantially more complicated parameter estimation using finite element multiphysics modelling. Parametric sensitivity can be used from such semi-empirical models to predict the optimum placement of sensors to be used to collect data that optimally informs the model for a microfluidic sensor system. This coupled optimum modelling and experiment procedure is ambitious in the scale of the modelling problem, as well as in the scale of the application - a microfluidic device. In general, microfluidic devices are sufficiently easy to fabricate, control, and monitor that they form an ideal platform for developing high dimensional spatio-temporal models for simultaneously coupling with experimentation. As chemical microreactors already promise low raw materials wastage through tight control of reagent contacting, improved design techniques should be able to augment optimal control systems to achieve very low resource wastage. In this paper, we discuss how the paradigm for optimal modelling and experimentation should be developed and foreshadow the exploitation of this methodology for the development of chemical microreactors and microfluidic sensors for online monitoring of chemical processes. Improvement in both of these areas bodes to improve the sustainability of chemical processes through innovative technology. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved

Heat transfer simulation of evacuated tube collectors (ETC): An application to a prototype

Since fossil fuels shortages are predicted for the forthcoming generations, the use of renewable energy sources is playing a key role and is strongly recommended worldwide by national and international regulations. In this scenario, solar collectors for hot water preparation, space heating and cooling are becoming an increasingly interesting alternative, especially in the building sector because of population growth. Thus, the present paper is addressed to numerically investigate the thermal behaviour of a prototypal evacuated tube by solving the heat transfer differential equations using the Finite Element Method. This is to reproduce the heat transfer process occurring within the real system, helping the industry improve the prototype

Sensitivity analysis modelling for microscale multiphysics robust engineering design

Sensitivity Analysis (SA) plays an important role in the development of any practical engineering model. It can help to reveal the sources and mechanisms of variability that provide the key to understanding system uncertainty. SA can also be used to calibrate simulation models for closer agreement with experimental results. Robust Engineering Design (RED) seeks to exploit such knowledge in the search for design solutions that are optimal in terms of performance in the face of variability. Microscale and multiphysics problems present challenges to modelling due to their complexity, which puts increased demands on computational methods. For example, in developing a model of a piezoelectric actuator, the process of calibration is prolonged by the number of parameters that are difficult to verify with the physical device. In the approach presented in this paper, normalised sensitivity coefficients are determined directly and accurately using the governing finite element model formulation, offering an efficient means of identifying parameters that affect the output of the model, leading to increased accuracy and knowledge of system performance in the face of variability

Theoretical and Numerical Investigation of Liquid-Gas Interface Location of Capillary Driven Flow During the Time Throughout Circular Microchannels

The main aim of this study is to find the best, most rapid, and the most accurate numerical method to find the liquid-gas interface of capillary driven flow during the time in circular Microchannels by using COMSOL Multiphysics software. Capillary driven flow by eliminating micropumps or any physical pressure gradient generators can make the microfluidic devices cheaper and more usable. Hence, by using this two-phase flow, the final costs of lots of microfluidic devices and lab-on-a-chip can significantly be decreased and help them to be commercialized. The first step to employing the capillary flow in these devices is the simulation of this flow inside the microchannels. One of the most common and valid software for this work is COMSOL Multiphysics; this fact reveals the importance of this study. In this research study, simulation results obtained by using two possible numerical methods in this software, for capillary flows of water and ethanol in two different circular microchannels, verified and compared with four other methods, which verified experimentally before. Finally, the most accurate and time-saving numerical method of this software will be specified. This appropriate technique can contribute to simulate microfluidic and lab-on-a-chip devices, which are made of different mechanical and electrical parts, in COMSOL Multiphysics software by choosing the best method.Comment: 7 pages, 13 figures, 7 tables, 2017 5th International Conference on Robotics and Mechatronics (ICROM

Finite element analysis of non-isothermal multiphase porous media in dynamics

This work presents a mathematical and a numerical model for the analysis of the thermo-hydro-mechanical (THM) behavior of multiphase deformable porous materials in dynamics. The fully coupled governing equations are developed within the Hybrid Mixture Theory. To analyze the THM behavior of soil structures in the low frequency domain, e.g. under earthquake excitation, the u-p-T formulation is advocated by neglecting the relative acceleration of the fluids and their convective terms. The standard Bubnov-Galerkin method is applied to the governing equations for the spatial discretization, whereas the generalized Newmark scheme is used for the time discretization. The final non-linear and coupled system of algebraic equations is solved by the Newton method within the monolithic approach. The formulation and the implemented solution procedure are validated through the comparison with other finite element solutions or analytical solutions