Dear all,
Using the 2D general PDE form within COMSOL, I'm trying to solve four coupled differenial equations, in order to obtain the velocity profile of an magnetohydrodynamic flow.
One PDE for the vorticity equation (in the 2D plane)
One PDE for the stream function (in the 2D plane)
One PDE for the velocity of the fluid, perpendicular to the 2D plane
One PDE for the electric potential (in the 2D plane)
These equations are solved for the following geometry:
A container, with a channel cut out of the bottom of the container
As a result this goemetry contains two sharp edges of 270 degrees: at the position where the side walls of the channels are in contact with the bottom of the container.
The walls of the channels have a defined electric potential, and the bottom of the channel, as well as the bottom of the container, have an undefined potential, but must satisfy that the derivative of the potential with respect to the normal must be zero (no electrical current through these walls).
After solving the model, the result of comsol shows an unexpected result around the sharp edges:
The electric current (which can be obtained from the electric potential) at these edges show an exceptional high electric current at the side wall of the channel, close to the edge, and an exceptional low current at the container bottom, close to the edge.
Is there some explanation for this result? To me it looks like a non physical phenomenon. If it is, can someone tell me how to solve this problem?
With kind thanks in advance, Anna
Using the 2D general PDE form within COMSOL, I'm trying to solve four coupled differenial equations, in order to obtain the velocity profile of an magnetohydrodynamic flow.
One PDE for the vorticity equation (in the 2D plane)
One PDE for the stream function (in the 2D plane)
One PDE for the velocity of the fluid, perpendicular to the 2D plane
One PDE for the electric potential (in the 2D plane)
These equations are solved for the following geometry:
A container, with a channel cut out of the bottom of the container
As a result this goemetry contains two sharp edges of 270 degrees: at the position where the side walls of the channels are in contact with the bottom of the container.
The walls of the channels have a defined electric potential, and the bottom of the channel, as well as the bottom of the container, have an undefined potential, but must satisfy that the derivative of the potential with respect to the normal must be zero (no electrical current through these walls).
After solving the model, the result of comsol shows an unexpected result around the sharp edges:
The electric current (which can be obtained from the electric potential) at these edges show an exceptional high electric current at the side wall of the channel, close to the edge, and an exceptional low current at the container bottom, close to the edge.
Is there some explanation for this result? To me it looks like a non physical phenomenon. If it is, can someone tell me how to solve this problem?
With kind thanks in advance, Anna