[yaoxy]

From the mhd help, the induced electric current and the Lorentz force tend to oppose the fluid of ferrofluid.
In MHD model, the direction of magnetic field B and the initial velocity of fluid shoulud be perpendicular(or a certain angle), that means when increas the B,the velocity of fluid will be decrease. In other words, the magnetic force is the resistance of fluid.
Now,my question is that can the magnetic force be the driving force of fluid?The velocity increases when the B is increased.
My geometric model is a 3D cylinderical.
The question is as following:
From the theoretical analysis, the magnetic force is along the z axis, the direction of velocity as well. That means: the fluid velocity v is increased with increasing magnetic field B.
But in Fluent, when B and v both are applied along Z axis, the velocity will not be any change. While given a initial velocity along x axis, and the magnetic field B is along Y axis, then the induced magnetic force is along Z axis, what we mainly pay attention is the velocity along z axis.
Theoretically, the velocity along z axis should be increase when increase the magnetic B, but the simulate results is not like that, the velocity along z axis is decrease.

The results I want to realise is that the velocity along z axis is increased with increasing the magnetic field B.
Does this be realised in fluent? If it is ok, how can do it?
thanks