Before you start (or after you started), it’s good idea to know a little bit of basics of how we simulate a flow field. Suppose Fig. 1 is the flow field we want to solve.

There are 3 steps to simulate the flow.

**First**, we discretise the field into *NX* x *NY* mesh points as in Fig. 2 (NX and NY are numbers of mesh points in horizontal and vertical directions).

**Second**, we calculate many Many MANY equations on each mesh point (in space) to obtain the instantaneous solution. The equations are explained in the Users’ Guide.

**Third**, we advance the solution little (*dt*) by little (*dt*) in time to obtain temporal change of the flow. Here, *dt* is the physical time increment per time step and typically this has an order of microseconds.

This is how Flowsquare simulates flows. Easy peasy!