In all cases the model is a set of equations that describe the physical laws that the system will have to obey. In our case we use the Magneto Hydro-Dynamic equations (MHD equations). The MHD equations are a set of very complicated equations that describe how a plasma and a magnetic field behaves. If the parts of the equations that describes the effects of the magnetic field are removed, then the remaining set of equations (the Hydro-Dynamic equations) are used in the process of designing the surface shape of such different products as cars, ships and air planes and also in predicting the weather for tomorrow!

The equations are so difficult to solve that they can only be solved analytically (using pen and paper) in very simplified situations. To solve the MHD equations for more complicated situations we have to use other methods. Since the 60's computers have started to play an increasing role in solving these types of problems. The complexity of the MHD equations means that computer models are a very attractive way of investigate different ideas.

Like banks have computer programs that take care of all of the transactions done on their customers accounts, by following a few simple rules, we can write computer programs that can solve the MHD equations. To do this good and efficient is a science in itself.

A computer simulation is started from an initial condition. The MHD equations are then used to calculate the solution at a later time and this solution is then saved in a file. After the calculation is finished, we have to analyse the data output to try and understand the physics described by the data.

Even though computers have increased significantly in power over the last 30 years, it is still only possible to solve the MHD equations in simple cases.

There will be a lot of tasks waiting for you to work on in the future!