## Electronics

#### ANSYS Maxwell – External Force fields, mainly Gravity?

• Devey
Subscriber

Hello,

I am working on a Linear Induction Motor simulation and I was interested in studying the levitation provided by it. I have been able to obtain realistic levitation forces (Y-direction) but I wanted to get the most comprehensive simulation by including gravity as an external force field. I have been looking for it in various places. There are options for other ANSYS Products but haven't found any resources for ANSYS Maxwell specifically.

I should mention that I am doing a 2D Transient sim right now but I plan on moving it to 3D Transient later on. I hope the solution would be the same for both.

Thanks!

• Karthik R

Hello,

Moving this question to the Electromagnetics thread for better visibility.

Thank you.

Best Regards,

Karthik

• Paul Larsen
Ansys Employee

If you are using Maxwell Transient solver and have motion defined (either 2D or 3D), then you would define gravity force as an additional Load Force.  For example, if the direction of gravity is -Y, and Y-direction is your linear motion direction, you would define the gravity force as "-9.8*Mass", where 9.8 is the mks gravity acceleration constant, and Mass would be the entire mass of the moving assembly.  If the linear motion is applied at some angle to gravity, then you would include the respective cosine angle.

• Devey
Subscriber

Awesome, I think that makes sense. I had done that before, not really sure why it didn't seem to make sense to me then. This also presents another question - Say I move to doing a 3D simulation, and now I will require the gravitational force to be in the y-direction, while the translational motion is in the x-direction. Would that be possible? If so, how? I ask because I don't see an option for putting in directional load forces in 3D.

• Paul Larsen
Ansys Employee

If the force is perpendicular to the direction of motion (and the motion is constrained along that one direction), then that perpendicular gravity force often shows up as an increased friction force or side-loading force (the Y-directed gravity would create an increased friction force in the X-direction).  This will depend on the types of constraints and mechanical assemblies within your system.  The motion in Maxwell by default assumes motion in a single direction, so all the forces, damping, and motion are with respect to that single direction only.