high hartmann flow

The Hartmann number (ratio of MHD force to viscous force) is often used to quantify the relative importance of MHD effects. HIMAG demonstrated for the first time in published literature the feasibility of very high Hartmann number (>10,000) calculations on complex geometries, validated against experiments and analysis.

HIMAG has been extremely successful at modeling problems that were not even attampted thus far using full flow-field solutions. Semi-analytical approaches based on core-flow assum reduced dimension models are in popular usage. However, none of these methods will be able to provide a complete, self-consistent solution to MHD flows in realistic geometries, to the extent that even the relevant qualitative flow features are largely unknown prior to gaining more knowledge via detailed testing.

The primary issue facing computer simulations based on full Navier-Stokes equations with appropriate MHD effects revolve around the extreme demands placed on the accuracy of numerical schemes in fusion relevant MHD and the computational time that can run into several months at times for realistic problems. Given that there is an enormous scope for applications and improvements in contemporary numerical methods in this area, we set out to improve upon the code structure in HIMAG. HIMAG has thus far been applied to internal and external flows.

Figure above shows Ha = 10,000 flow in a square duct computed with a completely unstructured mesh.