Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

something about EHD ( electro-hydro dynamics )

Please login with a confirmed email address before reporting spam

EHD is electro-hydro dynamics,i wanna know:In the 2D model, how to associate the electrostatic field with the space charge field, and set the volume force of the fluid to come from the electric field and the space charge at the same time


4 Replies Last Post 25 mag 2021, 04:09 GMT-4
Robert Koslover Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 3 years ago 21 mag 2021, 21:12 GMT-4
Updated: 3 years ago 25 mag 2021, 08:35 GMT-4

Sounds like you'll want to use/combine the basic electrostatics module (es) with one of the fluid module applications (either laminar flow or not, depending on your fluid & physics regime). The electrostatics model already has charge density in its formulation. And in many of the fluid models, you can specify a volume force density, you can use that to couple the physics between the two. For that, I presume the simplest way is that you would specify the x and y components of the force density by entering the x and y components of the electric field (es.Ex and es.Ey) times the charge density, locally. This is a multiphysics problem. If you want more suggestions, I recommend that you describe your problem to the forum in much more detail and explain what level of assistance you need. If you already have a preliminary model and need help with some specifics, you might want to post that model to the forum and identify where you need specific help. There are many, many questions one could ask, after all.

-------------------
Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
Sounds like you'll want to use/combine the basic electrostatics module (es) with one of the fluid module applications (either laminar flow or not, depending on your fluid & physics regime). The electrostatics model already has charge density in its formulation. And in many of the fluid models, you can specify a volume force density, you can use that to couple the physics between the two. For that, I presume the simplest way is that you would specify the x and y components of the force density by entering the x and y components of the electric field (es.Ex and es.Ey) times the charge density, locally. This is a multiphysics problem. If you want more suggestions, I recommend that you describe your problem to the forum in much more detail and explain what level of assistance you need. If you already have a preliminary model and need help with some specifics, you might want to post that model to the forum and identify where you need specific help. There are many, many questions one could ask, after all.

Please login with a confirmed email address before reporting spam

Posted: 3 years ago 25 mag 2021, 04:03 GMT-4

Sounds like you'll want to use/combine the basic electrostatics module (es) with one of the fluid module applications (either laminar flow or not, depending on your fluid & physics regime). The electrostatics model already has charge density in its formulation. And in many of the fluid models, you can specify a volume force density, you can use that to couple the physics between the two. For that, I presume the simplest way is that you would specify the x and y components of the force density by entering the x and y components of the electric field (es.Ex and es.Ey) times the charge density, locally. This is a multiphysics problem. If you want more suggestions, I recommend that you describe your problem to the forum in much more detail and explain what level of assistance you need. If you already have a preliminary model and need help with some specifics, you might want to post that model to the forum and identify where you need specific help. There are many, many questions one could ask, after all.

>Sounds like you'll want to use/combine the basic electrostatics module (es) with one of the fluid module applications (either laminar flow or not, depending on your fluid & physics regime). The electrostatics model already has charge density in its formulation. And in many of the fluid models, you can specify a volume force density, you can use that to couple the physics between the two. For that, I presume the simplest way is that you would specify the x and y components of the force density by entering the x and y components of the electric field (es.Ex and es.Ey) times the charge density, locally. This is a multiphysics problem. If you want more suggestions, I recommend that you describe your problem to the forum in much more detail and explain what level of assistance you need. If you already have a preliminary model and need help with some specifics, you might want to post that model to the forum and identify where you need specific help. There are many, many questions one could ask, after all.


Please login with a confirmed email address before reporting spam

Posted: 3 years ago 25 mag 2021, 04:06 GMT-4

Sounds like you'll want to use/combine the basic electrostatics module (es) with one of the fluid module applications (either laminar flow or not, depending on your fluid & physics regime). The electrostatics model already has charge density in its formulation. And in many of the fluid models, you can specify a volume force density, you can use that to couple the physics between the two. For that, I presume the simplest way is that you would specify the x and y components of the force density by entering the x and y components of the electric field (es.Ex and es.Ey) times the charge density, locally. This is a multiphysics problem. If you want more suggestions, I recommend that you describe your problem to the forum in much more detail and explain what level of assistance you need. If you already have a preliminary model and need help with some specifics, you might want to post that model to the forum and identify where you need specific help. There are many, many questions one could ask, after all.

As shown in picture 7c3c5, this is the simulation result of others. The flow field shown by the ion wind model he made is only between the corona electrode and the collector.

>>Sounds like you'll want to use/combine the basic electrostatics module (es) with one of the fluid module applications (either laminar flow or not, depending on your fluid & physics regime). The electrostatics model already has charge density in its formulation. And in many of the fluid models, you can specify a volume force density, you can use that to couple the physics between the two. For that, I presume the simplest way is that you would specify the x and y components of the force density by entering the x and y components of the electric field (es.Ex and es.Ey) times the charge density, locally. This is a multiphysics problem. If you want more suggestions, I recommend that you describe your problem to the forum in much more detail and explain what level of assistance you need. If you already have a preliminary model and need help with some specifics, you might want to post that model to the forum and identify where you need specific help. There are many, many questions one could ask, after all. As shown in picture 7c3c5, this is the simulation result of others. The flow field shown by the ion wind model he made is only between the corona electrode and the collector.

Please login with a confirmed email address before reporting spam

Posted: 3 years ago 25 mag 2021, 04:09 GMT-4

Sounds like you'll want to use/combine the basic electrostatics module (es) with one of the fluid module applications (either laminar flow or not, depending on your fluid & physics regime). The electrostatics model already has charge density in its formulation. And in many of the fluid models, you can specify a volume force density, you can use that to couple the physics between the two. For that, I presume the simplest way is that you would specify the x and y components of the force density by entering the x and y components of the electric field (es.Ex and es.Ey) times the charge density, locally. This is a multiphysics problem. If you want more suggestions, I recommend that you describe your problem to the forum in much more detail and explain what level of assistance you need. If you already have a preliminary model and need help with some specifics, you might want to post that model to the forum and identify where you need specific help. There are many, many questions one could ask, after all.

The following pictures 1 and 2 show the model I made. I found that after adding the volume force, the entire watershed will have a velocity field. I don't know how to make his effect.

>Sounds like you'll want to use/combine the basic electrostatics module (es) with one of the fluid module applications (either laminar flow or not, depending on your fluid & physics regime). The electrostatics model already has charge density in its formulation. And in many of the fluid models, you can specify a volume force density, you can use that to couple the physics between the two. For that, I presume the simplest way is that you would specify the x and y components of the force density by entering the x and y components of the electric field (es.Ex and es.Ey) times the charge density, locally. This is a multiphysics problem. If you want more suggestions, I recommend that you describe your problem to the forum in much more detail and explain what level of assistance you need. If you already have a preliminary model and need help with some specifics, you might want to post that model to the forum and identify where you need specific help. There are many, many questions one could ask, after all. The following pictures 1 and 2 show the model I made. I found that after adding the volume force, the entire watershed will have a velocity field. I don't know how to make his effect.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.