  In this paper we briefly discuss the ways in which angular momentum transport
is included in simulations of non-self-gravitating accretion disks,
concentrating on disks in close binaries. Numerical approaches fall in two
basic categories; particle based Lagrangian schemes, and grid based Eulerian
techniques. Underlying the choice of numerical technique are assumptions that
are made about disk physics, in particular about the angular momentum transport
mechanism. Grid-based simulations have generally been of hot, relatively
inviscid disks whereas particle-based simulations are more commonly of cool,
viscous disks. Calculations of the latter type have been instrumental in
developing a model for the superhump phenomenon. We describe how we use an
artificial viscosity term to introduce angular momentum transport into our
smoothed particle hydrodynamics (SPH) disk code.
