Simulating a non newtonian fluid flow from a bottle. It allows you to solve these equations in two ways. For newtonian fluids, the viscous stress is proportional to the deviatoric stress tensor. Using comsol multiphysics to model viscoelastic fluid flow bruce a. Excerpt from the proceedings of the comsol users conference. A fluid viscosity may be dependent on the local composition and temperature or any other field that is modeled in combination with fluid flow. Pipe flow software comsol multiphysics modeling software. First of all, it is not prepared in comsol to select non newtonian fluid in eulereuler model. There are a number of common rheology models or methods often used to characterise non newtonian fluids. In this model, the frozen rotor feature is used to simulate the mixing of a non newtonian fluid. As of update 2, the new rotordynamics module is available as. This is the viscosity of the fluid as a newtonian fluid 2.
Aside from air and water, most of the fluids we encounter in physical and industrial processes are non newtonian meaning that there is no simple relationship between the stress and the rate of strain. Due to rotational symmetry, it is possible to reduce the model dimensions from 3d to axisymmetric 2d. Nonnewtonian fluids, between solids and fluids comsol blog. Comsol series non newtonian fluid modeling in comsol youtube. Using comsol compiler, applications created with the application builder can be compiled and distributed as executable. First, i must say that when the fluid has non newtonian behavior, the shear thickening and shear thinning are divided.
They discovered that the newtonian model is a good approximation for modeling wall shear stress at high. Lets look at how to setup the material properties of blood as a nonnewtonian fluid. Aug 16, 2019 computational fluid mechanics with ansys fluent and comsol multiphysics. The most commonly used nonnewtonian models that are available on the simscale platform are described in brief detail. For more information on these other advancements visit comsols release highlights. Three yieldstress viscosity models have been added to the non newtonian viscosity models. What are some of the softwares that can be used for the. A commercial software comsol multiphysics was used to describe the non newtonian behaviors of the cement fluid using a single phase yield stress model. Watch this archived webinar to learn how to model non newtonian flow in comsol multiphysics and accurately predict pressure distribution, flow rate, and shear stress. In this paper non newtonian material models were compared for the calculation of viscous dissipation. This module explores boundary layer flow over a flat plate using nonnewtonian fluids. Both the transient and steadystate velocity and pressure profiles of. According to literature, a common shearthinning model used to replicate blood is the carreauyasuda model, which takes the form of. Nonnewtonian fluid dynamics and applications in geophysics.
A knowledge of nonideal effects is important for the design of equipment and interpretation of any derived parameters, such as fluid viscosity and. Hi i have a question about the nonnewtonian fluid behavior in cmg software. To calculate the output mass flow rate and the operating point of. I would like to modify the fluid property by defining my own equation.
In a non newtonian fluid, the local shear stresses and the local shear rates in the fluid have a non linear relation, where a proportionality constant can not be defined. The nonisothermal pipe flow interface sets up and solves the equations for the temperature and fluid flow. Apr 11, 20 simulating a nonnewtonian fluid flow from a bottle. A fluid is characterized by, among other things, its viscosity. This is what is called a shear thinning fluid, the exact opposite of shear thickening. Pulsatile flow of nonnewtonian blood fluid inside stenosed. The strain rate at which the fluid becomes non newtonian. The isosurfaces show the dynamic viscosity in the nonnewtonian aluminum flow. First of all, it is not prepared in comsol to select nonnewtonian fluid in eulereuler model.
Cfd software for simulating fluid flow applications. Eulereuler modeling of nonnewtonian fluid in which software. The viscous effects are contained in the viscous stress tensor. After coefficient matching the nonlinear material models can be easily implemented into the software. There are a number of common rheology models or methods often used to characterise nonnewtonian fluids. Fluid mechanics for chemical engineers 3rd edition download.
Figure 1 from fluid motion between rotating concentric. Anyone who has tried to pour ketchup out of a bottle has encountered a yieldstress fluid. You will get a stepbystep demonstration on how to simulate non newtonian flows in comsol multiphysics and the cfd module. Interface solid edge with comsol multiphysics via livelink for solid edge fluidstructure interaction fsi in the cast and mold of an aluminum extrusion process. In this work we assume that the shear rate is proportional to the flow velocity. It can do this for incompressible and weakly compressible flows up to mach 0. A shooting method numerical solution agrees with the results found for newtonian fluids and is able to capture both shearthinning and shearthickening fluids. This model shows the influence of shear rate dependent viscosity on the flow of a. More research has been conducted on the behavior of the droplets of newtonian and low viscous fluids in dripping, and dropondemand jetting. The most commonly used non newtonian models that are available on the simscale platform are described in brief detail. There are also some big improvements to the cfd module in comsol 4. Engineering software solution for thermal elastohydrodynamic. Non newtonian fluids on the other hand typically exhibit either shear thinning or shear thickening behaviour and in some cases, exhibit a yield stress, i.
Watch this archived webinar to learn how to model nonnewtonian flow in comsol multiphysics and accurately predict pressure distribution, flow rate, and shear stress. Nonnewtonian power law cfd autodesk knowledge network. How can i simulate the nonnewtonian fluid behaviour for bingham fluid and herschel bulkley fluid in comsol multiphysics. A commercial software comsol multiphysics was used to describe the nonnewtonian behaviors of the cement fluid using a single phase yield stress model. Most commonly encountered fluids, such as water, gases, and ethanol, are newtonian. After coefficient matching the non linear material models can be easily implemented into the software. Viscoelastic fluids have first normal stress differences even in rectilinear flow. How can i simulate the nonnewtonian fluid behaviour for bingham. The pipes are coiled in a slinky shape and grouped onto sleds. Aside from air and water, most of the fluids we encounter in physical and industrial processes are nonnewtonian meaning that there is no simple relationship between the stress and the rate of strain. Can you recall other fluids exhibiting a nonnewtonian behavior.
The chemical engineering module university of michigan. Figure 9 from fluid motion between rotating concentric. How can i simulate the nonnewtonian fluid behaviour for. As a nonnewtonian fluid, ketchups viscosity and consequently its. Nearly 100 completely worked practical examples include 12 new comsol 5 examples. The following equation describes the non newtonian power law property variation. Combine the comsol multiphysics software and the addon cfd module. Often shear thinning of polymer is observed, which reduces the viscosity of the aqueous phase. In a nonnewtonian fluid, the local shear stresses and the local shear rates in the fluid have a nonlinear relation, where a proportionality constant can not be. First, in what we refer to as pde modes, you enter the equations from scratch at the keyboard. I am trying to simulate a nonnewtonian fluid which transfers solid particles by comsol and i have several problems.
Comsol is the developer of comsol multiphysics software, an interactive environment for modeling and simulating scientific and engineering problems. The complexity of thermal elastohydrodynamic lubrication tehl problems has led to a variety of specialised numerical approaches ranging from finite difference based direct and inverse iterative methods such as multilevel multiintegration solvers, via differential deflection methods, to finite element based fullsystem approaches. We investigated the effects of the stirrer of the rheometer and the fluid properties yield stress and plastic viscosity on both the flow pattern and the total torque required at. Jul 30, 2019 an important characteristic of the cfd module is its capability of precise multiphysicsflow simulations such as conjugate heat transfer with non isothermal flow, fluid structure interactions, non newtonian flow with viscous heating, and fluids with concentrationdependent viscosity. A similarity solution to taylors paint scraper problem for the flow of a non newtonian powerlaw fluid is presented. For this type of flow, you can use the carreau viscosity model. Hi i have a question about the non newtonian fluid behavior in cmg software. Comsol multiphysics for solving fluid mechanics problems 720. Additive manufacturing of 3d structures with nonnewtonian. Computational fluid mechanics with ansys fluent and comsol multiphysics.
Excerpt from the proceedings of the comsol users conference 2006 boston method was introduced to solve the stress equations, using either the streamwise upwinding petrovgalerkin method supg or the inconsistent petrovgalerkin method su. Particular functionality may be common to several products. In comsol equation based modeling is available to use custom equations. Enhance your solid edge designs in comsol multiphysics. In the plots, arrows represent the direction of flow in the mixer and streamlines represent the velocity. Fluid motion between rotating concentric cylinders using. I want to simulate the non newtonian fluid behaviour for bingham fluid using the binghampapanastasious model, but to compute the shear dependent viscosity for a given point i need to obtain the shear rate value at that point. The following equation describes the nonnewtonian power law property variation. This includes a specific one for laminar flow, which is used for modeling mixing flows of low to intermediate reynolds numbers by solving the navierstokes equations.
Binghampapanastasiou, cassonpapanastasiou models, herschelbulkleypapanastasiou u u twophase flow with level set and phase field for all turbulence models u u interior wetted wall for twophase flow u u pipe connection for combining 1d pipe flow with 3d singlephase flow u u. 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 strain rate at which the fluid becomes nonnewtonian. A fluid dynamics analysis of the velocity and pressure fields that occur in the annular gap between two concentric cylinders with a stationary outer cylinder and a rotating inner cylinder is presented. Ponds and lakes can serve as thermal reservoirs in geothermal heating applications. Non newtonian fluid dynamics and applications in geophysics. Fluid mixing software creating fluid and chemical mixing. This model shows how to use simulations to predict power numbers with power law fluids. For nonnewtonian fluids, you can use the predefined rheology models for. To satisfy our curiosity, as well as our appetites, and come one step closer to perfecting our ketchuppouring technique, we have simulated ketchup flow from a bottle using the comsol multiphysics software and addon cfd module.
In this example, fluid circulates underwater through polyethylene piping in a closed system. For non newtonian fluids, you can use the predefined rheology models for viscosity, such as power law, carreau, and bingham for easy model setup. In this paper nonnewtonian material models were compared for the calculation of viscous dissipation. You will get a stepbystep demonstration on how to simulate nonnewtonian flows in comsol multiphysics and the cfd module. Three nonnewtonian models, as well as the newtonian model are used to.
Calculating the dissipation in fluid dampers with non. I am trying to simulate a non newtonian fluid which transfers solid particles by comsol and i have several problems. We also discuss rheological models, postprocessing techniques, and transforming a fluid flow model into a simulation app. Simulating a nonnewtonian fluid flow from a bottle.
Thus, they are more complicated than purely viscous nonnewtonian fluids. The non isothermal pipe flow interface sets up and solves the equations for the temperature and fluid flow. In this simulation, we have made a few simplifying assumptions. Newtonian and nonnewtonian blood flow over a backwardfacing.
In this model, the frozen rotor feature is used to simulate the mixing of a nonnewtonian fluid. Comsol series non newtonian fluid modeling in comsol. Comsol multiphysics software provides a platform for investigating various nonideal effects that can occur in this particular configuration under both transient and steadystate flow conditions. Eulereuler modeling of nonnewtonian fluid in which. For the binghampapanastasiou and cassonpapanastasiou models, the viscosity approaches a constant value for large strain rates. Nonnewtonian fluids on the other hand typically exhibit either shear thinning or shear thickening behaviour and in some cases, exhibit a yield stress, i. Warning your internet explorer is in compatibility mode and may not be displaying the website correctly. How can i simulate the non newtonian fluid behaviour for bingham fluid and herschel bulkley fluid in comsol multiphysics. We simulated cement fluid in rotational flows of a rheometer.
First, i must say that when the fluid has nonnewtonian behavior, the shear thickening and shear thinning are divided. Nearly 100 completely worked practical examples include ten new comsol 5 examples. In this work, the fluid flow over a 2d backwardfacing step is analyzed in order to. This model shows the influence of shear rate dependent viscosity on the flow of a linear polystyrene solution. An important characteristic of the cfd module is its capability of precise multiphysicsflow simulations such as conjugate heat transfer with nonisothermal flow, fluidstructure interactions, nonnewtonian flow with viscous heating, and fluids with concentrationdependent viscosity. Cfd software for simulating fluid flow applications comsol. A similarity solution to taylors paint scraper problem for the flow of a nonnewtonian powerlaw fluid is presented. Second, my geometry is two 3d concentric cylinder which only the interior one rotates. Comsol multiphysics is a modeling package that solves arbitrary systems of partial differential equations pdes. We also discuss rheological models, postprocessing techniques, and transforming a fluid flow model.