The chemical reaction engineering module is useful for engineers and scientists working for example within the chemical, process, electric power, pharmaceutical, polymer, and food industries where material transport and chemical reaction are integral to the process you are working with. We explain what you need to know in this blog post. However, the pnp model has limited validity due to its meanfield approximation and its nature of continuum approximation. Comsol provides an ide and unified workflow for electrical, mechanical, fluid, acoustics and chemical applications. The nernst planck equation describes transport of copper ions in the electrolyte by. Numerical simulation of electricallydriven flows using. The alternating potential is applied by two metal electrodes placed in the solution. To start a new discussion with a link back to this one, click here.
For users of the electrochemistry module, comsol multiphysics version 5. Concentration overpotential may also be estimated by using nernst equations for the contribution of the concentration overpotential. I have a problem in coupling poissons equation and nernst planck equation. These models have been typically solved by using iterative procedures based on the rungekutta method. Comsol is one of the best software to date for multiphysics applications. Shreya mukherjee phd candidate university at buffalo. Solving poisson, nernstplanck and navierstokes for a nanopore in. In my problem, i focus on the concentration in the dilute solution with applied electric field.
The ion distribution within the il film is considered using the poisson nernst planck pnp model. In comsol multiphysics, i notice that using the generalized alpha with strictintermediate time steps is the best way to converge my structural based nonlinear solution. Outside the approximations defined above, the tertiary current distribution, nernstplanck interface can be used to solve the nernstplanck equations subject to the approximation of electroneutrality eqs. These release notes provide information regarding new functionality in existing products. Diffuse double layer with charge transfer comsol multiphysics. Noting the increased use of this product in analytical electrochemistry, the authors. To find substitute for nanopumps or other complicated means of transport in microfluidic devices which are used for lab on a chip devices for the healthcare industry have theoretically.
Comsol software users who are onsubscription should submit their questions via the support center for a more comprehensive. The electrochemistry module provides an interface for tertiary current distributions that utilizes the nernstplanck equation to describe the transport of chemical species in the electrolyte. The proposed modeling tool, npphreeqcek, is a coupling between comsol multiphysics, which is used to solve fluid flow and solute transport in saturated porous media based on a nernstplanckpoisson formulation, and phreeqcrm, used to solve geochemical reactions. The most successful nanofiltration models are those based on the combination of the extended nernst planck equation with the donnan steric equilibrium. Interfaces for modeling laminar and porous media flow are also available in the electrodeposition module, through navierstokes, darcys law, and the brinkman equations. Nernst planck comsol multiphysics modeling software. Browse the threads and share your ideas with the comsol community. Read about all of the electrochemistry module updates in further detail below. This example shows how to couple the nernstplanck equations to poissons equation, in order to consider this deviation from electroneutrality.
Nernst planck equation with excel which turns out to be interesting. Definition of species within the nernst planck application in chem eng module. Comsol multiphysics is a crossplatform finite element analysis, solver and multiphysics simulation software. Warning your internet explorer is in compatibility mode and may not be displaying the website correctly. Yet, such procedures present convergence problems in some cases. Read more about these electrochemistry module updates below. Utilizing the unparalleled capabilities in comsol multiphysics, this interface can be seamlessly coupled to other interfaces that describe fluid flow and. The comsol discussion forum covers a wide variety of simulation topics. Solving poisson, nernstplanck and navierstokes for a nanopore in comsol. Nonlinear poissonnernst planck equations for ion flux through con. The proposed modeling tool, npphreeqcek, is a coupling between comsol multiphysics, which is used to solve fluid flow and solute transport in saturated porous media based on a nernst planck poisson formulation, and phreeqcrm, used to solve geochemical reactions. Finlayson, university of washington, seattle, wa, usa abstract this paper shows how undergraduates are introduced to computational fluid dynamics cfd in research projects. Nonlinear poissonnernst planck equations for ion flux.
It allows conventional physicsbased user interfaces and coupled systems of partial differential equations pdes. It extends ficks law of diffusion for the case where the diffusing particles are also moved with respect to the fluid by electrostatic forces. This tutorial example shows how to couple the nernstplanck equations to the poisson equation, in order to describe diffuse double layer according to a. The application gallery features comsol multiphysics tutorial and demo. Sep 20, 2010 compared to the pure diffusion, or the nernst planck equation also called smoluchowski equation which characterizes diffusional drift by a given fixed potential, the poisson nernst planck model is able to generate a selfconsistent electrostatic potential and the nonequilibrium densities. See all of the electrodeposition module updates in more detail below. White paper modeling corrosion and corrosion protection. Nanofiltration modeling based on the extended nernstplanck. This model overcomes the lack of assuming very large and small electrical diffuse layer, as essential elements in the perfect dielectric pd and the leaky dielectric ld models, respectively.
In these environments, the presence of cavities or trenches are apparent. The electric potential allied on the two electrodes are stationary. The electric double layer is simulated using comsol multiphysics software. The electrochemistry module provides an interface for tertiary current distributions that utilizes the nernst planck equation to describe the transport of chemical species in the electrolyte. I am completely new to comsol and am trying to couple the nernstplanck equation with the poisson equation. The nernstplanckpoisson equations an ionexchange material is typically modeled as a porous medium consisting of a fixed matrix with the pores filled up with water and additional mobile ions. Nanofiltration modeling based on the extended nernst. The chemical engineering module includes two different application modes for this type of transport. Multiphysics moduleheat transferconduction and convection steady state analysis. Utilizing the unparalleled capabilities in comsol multiphysics, this interface can be seamlessly coupled to other interfaces that describe fluid flow and heat transfer. This example shows how to couple the nernst planck equations to poissons equation, in order to. Modeling the nernstplanckpoisson equation using the pde. It is very easy to learn provided one must know the underlying theory behind the simulation, i. The students first solve problems in their textbook, then solve.
Comsol white paper series modeling corrosion and corrosion protection 3 introduction almost every manmade structure involves the use of metals. This model demonstrates the use of moving meshes in the application of copper electrodeposition on circuit boards. The first accounts for the transport of every charged species and has to be solved in combination with the electroneutrality condition the nernst planck application mode. Modeling electrokinetic transport and biogeochemical. Do i need to solve the poison equation first and then feed the values in to the np equation. Modeling the nernst planck poisson equation using the pde solver.
The nernst planck poisson equations interface adds the electrostatics and transport of diluted species interfaces to a model, together with predefined couplings for potential and space charge. Use of comsol multiphysics in undergraduate research projects to solve reallife problems bruce a. Adham riad graduate research and teaching assistant. Built up the microfluidic fuel cell with comsol multiphysics based on fluid mechanics navier stokes equations, mass transfer nernst planck equation, and electrochemistry butlervolmer equation as a multidisciplinary model, associated with solidworks. The model makes use of the tertiary, nernst planck interface for electrodeposition to keep track of the deformation of the mesh. Solving poisson, nernstplanck and navierstokes for a nanopore in comsol i think i have all the settings in terms of boundary conditions right and i get a converged solution with reasonable. May 21, 2011 the poissonnernstplanck model is a wellestablished electrodiffusion model for a wide variety of applications in chemistry, physics, nanoscience, and biology. Solving poisson, nernstplanck and navierstokes for a. Now, with one species leaving, the concentration changes and therfore the space charge density, which over the poissonequation and and the defined space charge density should have influence on the migrationterm in the nernst planck equation as far as i understand. Electrochemistry module application gallery examples comsol. I have generated my geometry and have filled in the correct boundary conditions. In what concerns available software packages, comsol multiphysics. No external field or voltage is applied, my goal is to check whether these. I want to model ionic behavior in a conical nanopore and need to solve the nernst planck, poisson and navier stokes equations.
This includes electrolyte mass transport explicitly in the analysis, which is a computationally much more demanding problem since. The time dependent form of the nernstplanck equation is a conservation of mass equation used to describe the motion of a charged chemical species in a fluid medium. Solving the nernst planck equations for all species concentrations with concentration of current and electroneutrality makes the equation set nonlinear and very complicated for the tertiary current distribution, which results in more time and memory storage requirements for the simulation. The nernst planck equation is often used to describe the diffusion, convection, and migration of charged particles. Use of comsol multiphysics in undergraduate research projects. I am trying to simulate the electroosmotic flow in a nanochannel using the poisson nernst planck and navierstokes equations coupling them from the electrostatics,transport of dilute species and laminar flow modules respectively using stationary solver in comsol 4. Our group uses comsol multiphysics for numerical simulation to. The poisson equation and nernstplanck equations are coupled to simulate the timedependent potential and ion concentration in the solution 3. Nernstplanck equation system hermes examples guide. You will experience speedup by a factor of up to ten in software responsiveness, as well as new and improved features for solving, meshing, and the physicsbased addon modules. Learn how to model ionexchange membranes and donnan potentials using the comsol software. Trial licenses are automatically associated with your account. The new nernst planck poisson equations multiphysics interface can be used to investigate charge and ion distributions within an electrochemical double layer, where charge neutrality cannot be assumed.
Note that while comsol employees may participate in the discussion forum, comsol software users who are onsubscription should submit their questions via the support center for a more comprehensive response from the technical support team. Nu multiion charge regulation equation 2 2 n a b s total a s b s k k h f k h k h v comsol multiphysics p02 p u \u e u 0 stokes equation continuity equation highly coupled equations nonlinear partial differential equation. Typically, the diffuse double layer may be of interest when modeling very thin layers of electrolyte including those in electrochemical capacitors and microelectrodes. Materials and device considerations in electrophoretic. This tutorial example shows how to couple the nernstplanck equations to the. Comsol is the developer of comsol multiphysics software, an interactive environment for modeling and simulating scientific and engineering problems. Poissonnernstplanck equations for simulating biomolecular. Some of the distinct advantages i have experienced are. However i need the nernst planck without electroneutrality and comsol does not seem to offer that. You will need an onsubscription comsol license attached to your comsol access account or a software trial provided by your sales representative. This may sound completely wrong to anyone who has seen, for instance, a nafion membrane, one of the most common polymer electrolyte materials. The motion of charged ions is described by the nernst planck equation and combined with poissons equation, which relates the charge density to the external applied electric field, forms the. Now, you can also add film resistances and dissolvingdepositing species types to your simulation, which are useful for modeling porous and edge electrodes. The nernstplanck equation is used to describe the mass transport of species.
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