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Bhai re Bhai No Sell No pani
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kopa sammiuskl nkks
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baal search a ashe na
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Magnetic bearing modelling
Hello ,
I m modelling radial magnetic bearing .Now for single pair of electromagnets with the bias current i have found the force.Now my question is hw to simulate the control current in the system??? whether it s possible to do this??
I m modelling radial magnetic bearing .Now for single pair of electromagnets with the bias current i have found the force.Now my question is hw to simulate the control current in the system??? whether it s possible to do this??
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Finding the Domain number/Creating an entity of a feature created with the Comsol Java API
Hi everyone,
I am using the Java API with Comsol and I really like it's abilities overall. I would like to be able to (in a for loop) create a 3D geometrical object (a cylinder) and then make that cylinder into it's own entity. This would be much like if you were to in the GUI create a cylinder, create an Explicit Entity, Change the geometric entity level to "Domain," click on the cylinder, then right click to select that domain, then change Output Entities to Adjacent Boundaries with either Exterior or Interior boundaries selected. Then create a Floating Potential, or really any other Boundary Condition, then set that Boundary Condition to be set to the Entity that was just made.
Here are some lines of the code:
model.geom("geom1").feature().create("cyl1", "Cylinder"); //creates the cylinder
model.geom("geom1").feature("cyl1").set("pos", new String[]{"0", "0", "0"}); // sets position
model.geom("geom1").feature("cyl1").set("h", "length"); // sets the length of the cylinder
model.selection().create("sel1", "Explicit");
model.selection("sel1").geom("geom1", 3, 2, new String[]{"exterior", "interior"});
model.selection("sel1").set(new int[]{5}); // HOW DO YOU FIGURE OUT WHAT DOMAIN TO PUT HERE.
// later in the code:
model.physics("ec").feature().create("fp1", "FloatingPotential", 2);
model.physics("ec").feature("fp1").selection().named("sel1");
Hopefully you got a pretty good idea of what I'm trying to accomplish above. Just trying to be able to find out what domain number "cyl1" is in this case. Eventually, this will be implemented into a code with 100-10000 cylinders and an individual floating potential can be assigned to each cylinder.
Thanks in advance for your help,
John
I am using the Java API with Comsol and I really like it's abilities overall. I would like to be able to (in a for loop) create a 3D geometrical object (a cylinder) and then make that cylinder into it's own entity. This would be much like if you were to in the GUI create a cylinder, create an Explicit Entity, Change the geometric entity level to "Domain," click on the cylinder, then right click to select that domain, then change Output Entities to Adjacent Boundaries with either Exterior or Interior boundaries selected. Then create a Floating Potential, or really any other Boundary Condition, then set that Boundary Condition to be set to the Entity that was just made.
Here are some lines of the code:
model.geom("geom1").feature().create("cyl1", "Cylinder"); //creates the cylinder
model.geom("geom1").feature("cyl1").set("pos", new String[]{"0", "0", "0"}); // sets position
model.geom("geom1").feature("cyl1").set("h", "length"); // sets the length of the cylinder
model.selection().create("sel1", "Explicit");
model.selection("sel1").geom("geom1", 3, 2, new String[]{"exterior", "interior"});
model.selection("sel1").set(new int[]{5}); // HOW DO YOU FIGURE OUT WHAT DOMAIN TO PUT HERE.
// later in the code:
model.physics("ec").feature().create("fp1", "FloatingPotential", 2);
model.physics("ec").feature("fp1").selection().named("sel1");
Hopefully you got a pretty good idea of what I'm trying to accomplish above. Just trying to be able to find out what domain number "cyl1" is in this case. Eventually, this will be implemented into a code with 100-10000 cylinders and an individual floating potential can be assigned to each cylinder.
Thanks in advance for your help,
John
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mphgetselection
how can i get only the entities field of mphgetselection and not the other fields?
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active magnetic levitation - single magnetic bearing
hello, as I am trying to design a controller for magnetic levitation, do you think COMSOL software will do the job, and any recommended documented or video to start with
Thanks
Thanks
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Question about Comsol
Good day.
1 If I have more physics in the model together so do not cooperate and give me different results for the same quantity.
2,If I have the model used by electric or magnetic object eg. coil field lines are not all visible.
And if I put in a magnetic or electric field somehow metal or insulator, there are no more moves.
3.Missing there simulation of gas ionization by an electric field or temperature.
Thank you very much for your willingness.
Goodbye.
1 If I have more physics in the model together so do not cooperate and give me different results for the same quantity.
2,If I have the model used by electric or magnetic object eg. coil field lines are not all visible.
And if I put in a magnetic or electric field somehow metal or insulator, there are no more moves.
3.Missing there simulation of gas ionization by an electric field or temperature.
Thank you very much for your willingness.
Goodbye.
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Thermal coupling in hydro-mechanical analysis for a saturated soil
Hi everybody,
I would have some very important questions for you.
I am modeling a saturated soil deposit with the poro-elasticity interface and I would like to couple thermal effects. For this reason, I am also using the heat transfer in porous media interface. However, I would like to ask you if:
1. The solely poroelastocity interface takes into account the thermal induced effects on the mechanical behavior of the soil matrix, i.e., does the tensorial formulation of this interface takes into account thermal induced stress? I have seen that the poroelasticity interface is a sub-module of the solid mechanics one (which can be coupled with thermal effects through the multiphysics interface, both referring to temperature -for the flow in the porous media- and the stress calculation), however, anything is specified about this coupling with this specific module (Ii.e., the multiphysics interface is no more applicable to link the heat transfer and poroelasticity interfaces). May I use all the aforementioned three modules?
2. I have seen that the mass conservation formulation of the poroelasticity interface does not consider the term which expresses the time derivative of temperature multiplied by the relation which expresses the volume filled by water and solid phase through the porosity of the considered soil matrix. Do you know how could I implement this formulation?
Many thanks for your help in this matter,
Alessandro
I would have some very important questions for you.
I am modeling a saturated soil deposit with the poro-elasticity interface and I would like to couple thermal effects. For this reason, I am also using the heat transfer in porous media interface. However, I would like to ask you if:
1. The solely poroelastocity interface takes into account the thermal induced effects on the mechanical behavior of the soil matrix, i.e., does the tensorial formulation of this interface takes into account thermal induced stress? I have seen that the poroelasticity interface is a sub-module of the solid mechanics one (which can be coupled with thermal effects through the multiphysics interface, both referring to temperature -for the flow in the porous media- and the stress calculation), however, anything is specified about this coupling with this specific module (Ii.e., the multiphysics interface is no more applicable to link the heat transfer and poroelasticity interfaces). May I use all the aforementioned three modules?
2. I have seen that the mass conservation formulation of the poroelasticity interface does not consider the term which expresses the time derivative of temperature multiplied by the relation which expresses the volume filled by water and solid phase through the porosity of the considered soil matrix. Do you know how could I implement this formulation?
Many thanks for your help in this matter,
Alessandro
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When is the release date for comsol 5 ?
When is the release date for comsol 5 ?
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Magnetic field of magnetic bar
I want to dosimulation of magnetic field of conical as well as pyramidal shape magnet with properties of neodymium magnet. Please help me how to do
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calculate Nusselt number
Hi all,
i study a cooling of electronique component by natural convection, i want to plot the Nusselt number and local Nusselt number profiles using my simulation results (the components are fixed on a vertical plate).
wich formula must i use, and how can i use comsol to plot this profiles.
someone have a idea ?
sorry for my bad english !
txs
i study a cooling of electronique component by natural convection, i want to plot the Nusselt number and local Nusselt number profiles using my simulation results (the components are fixed on a vertical plate).
wich formula must i use, and how can i use comsol to plot this profiles.
someone have a idea ?
sorry for my bad english !
txs
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Nano Optics - Single dipole near infinite interface
I am trying to reproduce far field radiation patterns for single emitters close to an infinite dielectric interface. Namely, I place an emitter in air, in the vicinity of a glass substrate (10[nm] above). The dipole moment is oriented toward the interface.
I expect a far field angular pattern similar to the one attached (expected_behavior.jpg where they put the dipole in water instead of air). Instead I get something like the other picture (dipole_near_interface.png).
Light should be directed along the critical angle (in Air/Glass case -> 41 degrees). Instead of that, I find an extremum at around 50 degrees.
I define the dipole as a point dipole. I have PML, but I guess that have two different materials touching could be a problem here. Therefore i want to know if I am indeed limited to finite systems, or if I can model a dipole with two infinite materials .
Thanks for reading,
Jean-Christophe
ps : Model made with C.4.3
I expect a far field angular pattern similar to the one attached (expected_behavior.jpg where they put the dipole in water instead of air). Instead I get something like the other picture (dipole_near_interface.png).
Light should be directed along the critical angle (in Air/Glass case -> 41 degrees). Instead of that, I find an extremum at around 50 degrees.
I define the dipole as a point dipole. I have PML, but I guess that have two different materials touching could be a problem here. Therefore i want to know if I am indeed limited to finite systems, or if I can model a dipole with two infinite materials .
Thanks for reading,
Jean-Christophe
ps : Model made with C.4.3
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Graded Index Waveguide
Hi all,
I'm trying to model a graded Index Waveguide (for instance a diffused waeguide) in Comsol 4.4.
I'm was more familiar with Comsol 3.5 where I could enter the expression for my graded index profile and then simulate my modes.
I've tried to do the same thing in 4.4 defining a new material and entering the expression in the refractive Index tab.
But I can see that it doesn't work.
Do you have any clue on how to do it?
Moreover is there any way to open the file generated with 3.5?
Thank you.
Best,
Domenico
I'm trying to model a graded Index Waveguide (for instance a diffused waeguide) in Comsol 4.4.
I'm was more familiar with Comsol 3.5 where I could enter the expression for my graded index profile and then simulate my modes.
I've tried to do the same thing in 4.4 defining a new material and entering the expression in the refractive Index tab.
But I can see that it doesn't work.
Do you have any clue on how to do it?
Moreover is there any way to open the file generated with 3.5?
Thank you.
Best,
Domenico
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Buoyancy Force
Hello everyone,
I know that there was a discussion about buoyancy forces acting on a rigid body but i spent some time for solving this problem and I will appreciate if you help me about my situation.
First of all I need to model and graph all the forces acting on an arbitrary body in a closed cube of stationary water . The density of my particle will be close to the density of water.
From that i have to make an animation for observing the movement of my arbitrary body.
I followed instruction for the example terminal velocity of falling sand grain. But i have some question which i dont understand in that example's instruction pdf.
1) What is Xdott, Xdot?? and where do you define those?
2) What does reacf() operator stand for? Does it include all acting forces like for example in vertical movement drag and buoyancy forces?
Thank you
I know that there was a discussion about buoyancy forces acting on a rigid body but i spent some time for solving this problem and I will appreciate if you help me about my situation.
First of all I need to model and graph all the forces acting on an arbitrary body in a closed cube of stationary water . The density of my particle will be close to the density of water.
From that i have to make an animation for observing the movement of my arbitrary body.
I followed instruction for the example terminal velocity of falling sand grain. But i have some question which i dont understand in that example's instruction pdf.
1) What is Xdott, Xdot?? and where do you define those?
2) What does reacf() operator stand for? Does it include all acting forces like for example in vertical movement drag and buoyancy forces?
Thank you
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converting a 3D helix to a 2D spiral
Hello,
I'm trying to define a spiral geometry in 2D (actually 5 co-centric spirals) by converting five 3D helices. I have defined Helix1, Helix2.... Helix5 and in the Work Plane I have created a cross-section at z=0 and converted to solid. Then I've exported a geometry file and saved it in the .mphbin format.
In the same model I added Component 2, this time in 2D, and imported there the .mphbin file. I have a problem now with specifying the materials, each helix (spiral) is made of different material. I cannot select different domains, to me it looks like the geometry is not a solid surface but just the contour lines that distinguish various spirals. If anyone had a similar problem and could give me an advice on how to solve it, I would very much appreciate it.
Thank you!
N
I'm trying to define a spiral geometry in 2D (actually 5 co-centric spirals) by converting five 3D helices. I have defined Helix1, Helix2.... Helix5 and in the Work Plane I have created a cross-section at z=0 and converted to solid. Then I've exported a geometry file and saved it in the .mphbin format.
In the same model I added Component 2, this time in 2D, and imported there the .mphbin file. I have a problem now with specifying the materials, each helix (spiral) is made of different material. I cannot select different domains, to me it looks like the geometry is not a solid surface but just the contour lines that distinguish various spirals. If anyone had a similar problem and could give me an advice on how to solve it, I would very much appreciate it.
Thank you!
N
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inductive heating - moving mesh problem
Hi,
i try to simulate a 3D model with a rigid coil over a moving metal-part. The simulation consists of three physics: moving mesh (ale), magnetic and electric fields (mef) and heat transfer (ht).
I implemented all three studies and particularly they work fine, but the problem is that the electromagnetic heat source moves with the partboundary and does not remain under the coil.
I have three single studies:
1. time-dependent: ale
2. time-dependent: mef
3. time-dependent: ht
So can anybody tell me where is my mistake?
Thank you
Robert
i try to simulate a 3D model with a rigid coil over a moving metal-part. The simulation consists of three physics: moving mesh (ale), magnetic and electric fields (mef) and heat transfer (ht).
I implemented all three studies and particularly they work fine, but the problem is that the electromagnetic heat source moves with the partboundary and does not remain under the coil.
I have three single studies:
1. time-dependent: ale
2. time-dependent: mef
3. time-dependent: ht
So can anybody tell me where is my mistake?
Thank you
Robert
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ICP torh
Hello, I'm new user of Comsol .
Can i modeling atmosphere pressure ICP plasma torch using Comsol?
Typical value of pressure 1-2 atm.
Typical value of power 10-500 kW
Typical working area (geometry): 70 (horizontal)x600(vertical) mm in 2d axisymmetric case???
Can i modeling atmosphere pressure ICP plasma torch using Comsol?
Typical value of pressure 1-2 atm.
Typical value of power 10-500 kW
Typical working area (geometry): 70 (horizontal)x600(vertical) mm in 2d axisymmetric case???
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reduced magnetic vector potential formulation in eddy current testing
hello every one ,
Can any one of you please guide that how to model Reduced magnetic vector potential of Eddy current testing in comsol.
I will be grateful
Can any one of you please guide that how to model Reduced magnetic vector potential of Eddy current testing in comsol.
I will be grateful
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Effect of the heating rate on thermal stresses induced by dilatations
Dear community,
I'm trying to modelize the thermal stresses induced in a sandwich structure composed of materials with different coefficients of thermal expansion (CTE). The stresses are induced by the large difference of CTE, during heating.
I would like to study the effect of the heating rate on the thermal stresses (the stresses should be lower with a lower heating rate).
However, the dilatations are always calculated from a reference temperature (Tref=25°C). Even with a time dependant study, the dilatations, at each temperature, are calculated from the reference temperature. Thus, the heating rate is not taken into account.
So, do you know which parameter i have to change to take into account the heating rate in the calculation of the dilatations ? (time dependant Tref....).
Thank you,
Emilien
I'm trying to modelize the thermal stresses induced in a sandwich structure composed of materials with different coefficients of thermal expansion (CTE). The stresses are induced by the large difference of CTE, during heating.
I would like to study the effect of the heating rate on the thermal stresses (the stresses should be lower with a lower heating rate).
However, the dilatations are always calculated from a reference temperature (Tref=25°C). Even with a time dependant study, the dilatations, at each temperature, are calculated from the reference temperature. Thus, the heating rate is not taken into account.
So, do you know which parameter i have to change to take into account the heating rate in the calculation of the dilatations ? (time dependant Tref....).
Thank you,
Emilien
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