This is a simulation of the flow inside a 2D section of a turbomachine. The flow is resolved with the finite elements method. The software can render the 2D section, the elements inside it and the resulting streamlines.
The script splits the section in iso-parametric elements, that again are splitted in two to create triangular elements. The flow is then determined by resolving a linear system. Since triangular elements are used, calculations are straight forward as no integral need to be resolved. The choosen streamline is then rendered.