Hello everyone, I am simulating the magnetohydrodynamic,the flow region expans gradually with the specified boundary moves. As the flow field contributes little to the magnetic field, so the influence of flow field on magnetic field was ignored in the study. I have used a one-way coupling to solve this problems. In the first step, I have calculated the magnetic field and obtained the distribution of electromagnetic force, as can be seen in the figure 1 below. In the second step, I have used a deformed geometry to realize the enlargement of the flow region when the boundary moves down (black line in figure 1), the electromagnetic force has been added into the momentum equation by menas of body force in order to describe the flow behaviors under forced condition. However, I found that the distribution of electromagnetic force also expanded with the flow region, as can be seen in figure 2. Actually, during the second step, the distribution of electrpmagnetic force should be kept identical and be like what presents in figure 1. Hence I found the resulting calculated flow field was totally wrong. Is there any ways to overcome this problem?
Thank you Wenchao Duan