Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
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.
Point Evaluation using Biot-Savart Law.
Posted 2013年5月3日 GMT-4 16:26 Version 4.3 3 Replies
Please login with a confirmed email address before reporting spam
Hello everyone,
I am currently attempting to do a point evaluation with the expression for Biot-Savart Law.
The set up is like this:
I have an array of points that I would like to get the value at using this expression:
1/(4*pi)*intop1((ec.Jy*(z_P-z)-ec.Jz*(y_P-y))/r^3)
where:
intop1 is the integration operator,
z_P, y_P, x_P are the field points, and x.y.z are points within the domain
r = ((x_P-x)^2+(y_P-y)^2+(z_P-z)^2)^0.5
I can get the values with parameter sweeps, but this involves solving the model over and over again for each point I use. (No point in solving for the current density N times, when it only needs to be solved once.)
Ideally I would like the expression to be something like:
1/(4*pi)*intop1((ec.Jy*(z_coord_at_selected_point-z)-ec.Jz*(y_coord_at_selected_point-y))/r^3)
r = ((x_coord_at_selected_point-x)^2+(y_coord_at_selected_point-y)^2+(z_coord_at_selected_point-z)^2)^0.5
I have looked pretty extensively on the internet, and in manuals, but cannot seem to find a command for such a general function. I have seen dom==particular point, ie 7, but I need it to take a general selected point, as well as only taking the x, y, or z coordinate of the point.
Does anyone know of a command I may have missed? Or offer an alternative method to getting this information without having to input an insane amount of parameters into comsol?
I realize I can use the magnetic package to get the field from the current density, but I am needing to do it this way for now, so the magnetics package isn't an option for me.
Any and all help is much apprecated, thanks!
I am currently attempting to do a point evaluation with the expression for Biot-Savart Law.
The set up is like this:
I have an array of points that I would like to get the value at using this expression:
1/(4*pi)*intop1((ec.Jy*(z_P-z)-ec.Jz*(y_P-y))/r^3)
where:
intop1 is the integration operator,
z_P, y_P, x_P are the field points, and x.y.z are points within the domain
r = ((x_P-x)^2+(y_P-y)^2+(z_P-z)^2)^0.5
I can get the values with parameter sweeps, but this involves solving the model over and over again for each point I use. (No point in solving for the current density N times, when it only needs to be solved once.)
Ideally I would like the expression to be something like:
1/(4*pi)*intop1((ec.Jy*(z_coord_at_selected_point-z)-ec.Jz*(y_coord_at_selected_point-y))/r^3)
r = ((x_coord_at_selected_point-x)^2+(y_coord_at_selected_point-y)^2+(z_coord_at_selected_point-z)^2)^0.5
I have looked pretty extensively on the internet, and in manuals, but cannot seem to find a command for such a general function. I have seen dom==particular point, ie 7, but I need it to take a general selected point, as well as only taking the x, y, or z coordinate of the point.
Does anyone know of a command I may have missed? Or offer an alternative method to getting this information without having to input an insane amount of parameters into comsol?
I realize I can use the magnetic package to get the field from the current density, but I am needing to do it this way for now, so the magnetics package isn't an option for me.
Any and all help is much apprecated, thanks!
3 Replies Last Post 2013年5月6日 GMT-4 13:24