If the Level Set Model node is a domain feature under the The Level Set Interface, it adds the following transport equation governing a level set function

If it is a domain subfeature under the Porous Medium domain feature, it adds the following equation

In both cases the Level Set Model node provides the options to define the associated level set parameters and the velocity field.

Enter a value or expression for the Reinitialization parameter γ (SI unit: m/s). The default is 1 m/s.

Enter a value or expression for the Parameter controlling interface thickness εls (SI unit: m). The default expression is ls.hmax/2, which means that the value is half of the maximum mesh element size in the region through which the interface passes.

Enter values or expressions for the components (u, v, and w in 3D, for example) of the Velocity field u (SI unit: m/s). The applied velocity field transports the level set function through convection.