It is considered that there is an annular layer of a non newtonian liquid, whose behavior follows the powerlaw model, adjacent to the inside wall of the capillary, which in turn surrounds an inner flow of a second conducting liquid that is driven by electroosmosis. In the solid part of the heat exchanger the velocity vector, u u, v, w, is set to zero in all directions. Changes in piping pressure, flow rate, gas density and velocity. Creating new physics interfaces that you can save and share, modifying the underlying equations of a model, and simulating a wider variety of devices and processes. Porescale modeling of nonisothermal two phase flow in 2d.
See whats new in the cfd module in comsol multiphysics version 5. Typical multiphysics couplings flow with heat transfer. The node settings define the nonisothermal flow properties. Nonisothermal plugflow reactor comsol multiphysics. If you have the cfd module, the nonisothermal flow multiphysics interface is available.
Nonisothermal flow in a 2d mixer comsol multiphysics. It shows the coupling of heat transport conduction, radiation and convection to momentum transport non isothermal flow induced by density variations caused by temperature. Nonisothermal pipe flow is fully coupled to the heat transfer simulation of the mold and polyurethane part. For example, when the option to compensate for the hydrostatic pressure is. This heat transfer module model library provides details about a large number of. The ideal schottky, thermionic emission, and continuous quasifermi level boundary conditions have been enhanced to improve the accuracy of your semiconductor models, while saving. Lets have a closer look at the steps for modeling evaporation.
To enable simulation of nonisothermal phenomena, this system of equations is coupled with a heat equation, similar to that used by other authors for modeling gasliquid slug flow in capillary tubes fukagata et al. This example considers the thermal cracking of acetone, which is a key step in the production of acetic anhydride. Another example of nonisothermal flow illustrates forced convection in an. Comsol series non newtonian fluid modeling in comsol youtube. This type of study is traditionally done using a computational fluid dynamics. Pipe flow module model transport phenomena and acoustics in pipe systems with the pipe flow module. This way you can follow along with the printed discussion as well as use them as a jumpingoff point for your own modeling needs. The following example builds and solves a conduction and convection heat transfer problem. Selecting the fluid flow interface node in the model builder shows the settings window below. Thermomagnetic siphoning on a bundle of currentcarrying. Comsol approach to modeling fluid flow chemical reactions electromagnetic fields acoustics heat transfer structural mechanics user defined equations. Time dependent flow in pipe coupled with heat transfer in arabic. In particular the basic and the chemical engineering modules of comsol multiphysics are employed.
This will open up comsol library where you see many comsol files to solve chemical reaction engineering problems. The combined mole balance, rate law, and stoichiometry yield. For bubbly flow, bubble concentration must be small 0. Click on run in browser to start the application you will see that the following window opens which has input parameters, description, graphical features and a few buttons. Under the study node a stationary, fluid study step was introduced to. Compressible flow with comsol multiphysics, how to model. In this work, a nonisothermal electroosmotic flow of two immiscible fluids within a uniform microcapillary is theoretically studied. Both laminar and turbulent flow are supported and can be modeled with natural and forced convection. If you have the cfd module, the non isothermal flow multiphysics interface is available. The dependent variables for the fluid flow and the temperature field were computed with the non isothermal flow interface nitf. For example i dont see much difference when varying the flow rate which i would expect. Steady state nonisothermal reactor design energy balances, rationale and overview calculate the volume necessary to achieve a conversion, x, in a pfr for a firstorder, exothermic reaction carried out adiabatically.
Heat transfer modeling software for analyzing thermal effects. For users of the heat transfer module, comsol multiphysics version 5. We discuss methods that involve simple approximations, highfidelity nonisothermal flow coupling, modeling heat transfer at fluidsolid interfaces, boundary approximations using heat transfer coefficients, techniques to fully resolve the flow and temperature fields, and more. U flow modifications of mod flow, for example kuiper, 1983, do not solve the energy equation and, hence, can only give the first approximation to the reality.
Comsol series non newtonian fluid modeling in comsol. In this work, a non isothermal electroosmotic flow of two immiscible fluids within a uniform microcapillary is theoretically studied. The dependent variables for the fluid flow and the temperature field were computed with the nonisothermal flow interface nitf. As the cracking chemistry is endothermic, control over the temperature in the reactor.
Flow of co 2, or any fluid, and its mixtures in non isothermal wells is modeled according to the approach of lu and connell 2014, in which the flow equations are based on the averaged flow model. Compressible flow has often been an undereducated aspect of chemical engineering, but is important to many different careers in which piping systems are used. The numerical modeling with comsol multiphysics was divided into two steps. What is the best way to start with comsol multiphysics. Move to the physics menu and select boundary settings. The gas phase reaction takes place under nonisothermal conditions in a plug flow reactor. Non isothermal pipe flow is fully coupled to the heat transfer simulation of the mold and polyurethane part.
In the channels the velocity field is defined by an analytical expression that approximates fullydeveloped laminar flow for a circular cross section. Comsol multiphysics in education chemical reactions, heat. Oct 31, 2014 fluid nonisothermal flow isothermal vs. Excerpt from the proceedings of the comsol conference 2008 hannover. The heat transfer module users guide comsol documentation. Boundary setting 1 laminar inflow 2 slipsymmetry 3 slipsymmetry 4 pressure 0 table 10 non isothermal flow physics boundary excerpt from the proceedings of the comsol conference 2007, boston. The first study step was the steadystate cfd simulation of the weld pool. Thermomagnetic siphoning on a bundle of currentcarrying wires. If you are reading the documentation as a pdf file on your computer. Intro to modeling heat transfer with comsol multiphysics.
For an ideal gas, density is inversely proportional to temperature. Learn about these heat transfer features and more below. This example describes an array of heating tubes submerged in a vessel with fluid flow entering at the bottom. In many engineering applications, we can assume that a fluids temperature will remain constant because variations are either very small or inconsequential in magnitude compared to other physical variations in the application. These steps do not require any additional modules as the model only includes joule heating without the previous thermal expansion analysis. For the isothermal reactor the t is set equal to t0. The equation set has been used in a comsol tutorial 4 and actual application 5. Nonisothermal flow and conjugate heat transfer multiphysics. Simulation of flow and heat transfer through packed beds.
This option also eliminates the description of pressure waves, which requires a dense mesh and small time steps to resolve, thus also a relatively long computation time. Microfluidics software for simulating microfluidics devices. Fluid flow and heat transfer in fixed beds with tube to particle diameter ratios of n3 and n5. Pipe flow software generating and analyzing pipe flow. The geometries of these models consisted of 55 and 400 spheres respectively. A rather common chemical system encountered in the process industry is the continuously stirred tank reactor cstr. Model highlights the motion of the gas within the bulb. Comsol multiphysics has wide range of functionalities. Comsol multiphysics in education chemical reactions. The pipe systems are modeled as geometrical 1d lines or curves embedded in 2d or 3d and are created using the existing drawing tools in comsol multiphysics.
Comsol lep tutorial for nonisothermal tubular reactor with. The coupled magnetic, fluid, and thermal interactions are highly complicated. The developed method is validated using nonisothermal poiseuille flow through a channel. Modeling, analysis and simulation, published by prenticehall, 1998. The multiphysics coupling to couple the heat transfer interface and the laminar flow interface was nonisothermal flow. Comsol lep tutorial for nonisothermal plug flow reactor.
Compressible gas flow experiment and assisted comsol. Laminar flow reactor with heat transfer effects spring 2007 objectives. Comsol, comsol multiphysics, comsol reaction engineering lab, and. Click on run in browser to start the application you will see that following window opens which has input parameters, description, graphical features and. It is considered that there is an annular layer of a nonnewtonian liquid, whose behavior follows the powerlaw model, adjacent to the inside wall of the capillary, which in turn surrounds an inner flow of a second conducting liquid that is driven by electroosmosis. Rather, than reading books on comsol, i suggest please start using comsol because when you will start, you will find many errors, may be physics. The combination of comsol products required to model your application depends on several factors and may include boundary conditions, material properties, physics interfaces, and part libraries.
The nonisothermal flow interface includes the weakly compressible flow option, which simplifies flow problems by neglecting density variations with respect to pressure. The following section provides a general description for all of the abovementioned. This is a multiphysics model because it involves fluid dynamics coupled with heat transfer. Compressible gas flow experiment and assisted comsol modeling. Comsol simulation application for thermoplastics viscosity. Dec 08, 2014 multiphysics node for nonisothermal flow.
Comsol lep tutorial for nonisothermal plug flow reactor with. The pressure and the velocity field are the solution of the navierstokes equations. Transfer modules turbulent nonisothermal flow multiphysics coupling, combining. We can find the settings for the weakly compressible flow option by selecting the nonisothermal flow interface or the conjugate heat transfer interface.
The heat transfer module contains features for modeling conjugate heat transfer and nonisothermal flow effects. Particular functionality may be common to several products. Watch this archived webinar to learn how to simulate heat transfer in fluids using the comsol multiphysics software. Boundary setting 1 laminar inflow 2 slipsymmetry 3 slipsymmetry 4 pressure 0 table 10 nonisothermal flow physics boundary excerpt from the proceedings of the comsol conference 2007, boston. Free convection in a light bulb comsol multiphysics. The following example demonstrates how to model a coupled fluidthermal interaction problem with comsol multiphysics, using the nonisothermal flow. Comsol multiphysics model makes it possible to determine the temperature distribution on the outer surface of the bulb, as well as the temperature and pressure. These capabilities can be used to model heat exchangers, electronics cooling, and energy savings, to name a few examples. By definition, isothermal means to have a constant temperature. If you have the heat transfer module, the conjugate heat transfer multiphysics interface is available. Introduction to modeling natural convection in comsol. The tutorial sections present the different application modes.
1333 1140 1123 444 601 1257 1196 117 1419 913 79 283 309 985 648 438 1345 378 808 922 1294 817 112 512 1097 1539 69 1421 1259 1035 373 361 61 1143 42 1152 407 181 1179 332 169 909 1377 1331