Two-phase flow including both incompressible and compressible fluids
Hello! I've been struggling to construct a Comsol model that simulates two-phase flow, in which one fluid is water(incompressible), the other is air(compressible), which can reach Mach number of around...
View ArticleTime Steps
While simulating our case, we have used strict time step with maximum as 1800 seconds. But still, it is taking a time step of 0.1 sometimes. This is making our simulation quite slow during the middle...
View ArticleDiscrepancy between particle trajectory and streamline?
Hello, I'm trying to teach myself how to use the particle tracing module, so I'm modeling a simple T-junction microfluidic channel. I get an unexpected result, however, when I trace the particles....
View Articlecone-jet mode in electrostatic field
Hi, Here is my problem. I want to simulate a electrohydrodynamic (EHD) phenomenone , a nozzle with full water (or electrolyte) in a electrostatic field, the the water is polarized and deformed the...
View Articlesimulating a rotating and moving blade
hi, i want to simulate a blade that is both moving up, down, front and back and also pitching at the same time mostly with time varying velocities. i know i have to use mesh deformation but i dont know...
View ArticleError - Failed to evaluate variable jacobian
Hello, I am currently working with the batteries and fuel cells module and I am attempting to create a model of a micro-scale PEM fuel cell. Right now I am starting by just trying to solve a free and...
View ArticleNeed Help: Solder Joint Estimation of Flip Chip
Dear All I'm a new for COMSOL. the case that i'm facing is a flip chip process. after read several samples, still could not figure it out what model/physics should to be used. hope to get some help...
View ArticleHow can I find the flow velocity of a specific coordinate point
Dear all, I would like to ask how can I find the flow velocity of a specific point (x=105, y=2.5) in my channel (it is shown in the picture). In the graph, if I click at any random point I got 3...
View ArticleTime Dependent Study of an Airfoil- Lift Coefficient
Hi, I am trying to learn how to calculation the lift and drag coefficient of an airfoil running a time-dependent study. Below are the boundary conditions. Re ~2000 Inlet- Inlet U*step1(t[1/s]) Top and...
View ArticleFixed time steps
While simulating our case, we have used strict time step with maximum as 1800 seconds. But still, it is taking a time step of 0.1 sometimes. This is making our simulation quite slow during the middle...
View ArticleAttempting to find total drag force on an object
I'm fairly new to COMSOL and haven't been able to find any really detailed guides on how to go about this. I've currently got two problems that I can't figure out how to solve. 1) When I solve the...
View Articleionisation air
Hey. I can not seem to model the ionization of air just using electro magnetism, temperature and pressure. Can anyone advise me or send process? Thank you.
View ArticleSessile droplet
I want to put a sessile droplet inside a channel. How to create a droplet of a specific material ? and how do I choose the model ? As a reference I was wondering about the model in one the Paper - A...
View ArticleWall condition (no slip or sliding), fluid outlet condition
Hi all, I am modeling a sphere moving in a moving laminar fluid domain (2D). The sphere is moved by the motion of the fluid, through boundary load on the sphere surface. I am wondering what kind of...
View Articlecan we bound a dependant variable?
Hello, I use laminar flow plus adding a convection-diffusion equation as a pde one to NV and continuity equations(time- dependant) to solve my simulation. The problem that I have is that the magnitude...
View ArticleHow to simulate the water boiling by Level-Set method
There is a good example simulating water boiling by phase field. I am trying to use the Level-Set method. However, I was frustrated by many times of failure. My problem is how to deal with the...
View ArticleFlow in a pipe with a very large aspect ratio
I'm trying to solve what should be a very simple problem as part of a larger project I'm working on. It's just laminar flow in a pipe of length 14,000 feet and radius 0.04 feet. I'm just trying to find...
View ArticleVelocity gradient expression in 2D-axisymmetric
Hello, the velocity gradient tensor for a 2D-axisymmetric problem presents, for the phiphi component, the following expression chns.graduDGphiphi = if(abs(r)<0.0010*h,d(u,r),u/r) does anyone know...
View ArticleAdding a weak contribution to a fluid domain
Hello, Can anyone please help me to add a modified continuity equation in fluid domain, I came to understand that by adding a weak contribution node, it is possible to modify equations.....Has someone...
View ArticleUnknown heat source in heat transfer-laminar flow coupled model
Hi all, I am modeling a volcanic conduit (5 m wide) moving up through a "host rock." I want to analyze the thermal budget of this situation. The conduit is a rectangle (Heat Transfer in Fluids, Laminar...
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