  Drift ordered fluid models are widely applied in studies of low-frequency
turbulence in the edge and scrape-off layer regions of magnetically confined
plasmas. Here, we show how collisional transport across the magnetic field is
self-consistently incorporated into drift-fluid models without altering the
drift-fluid energy integral. We demonstrate that the inclusion of collisional
transport in drift-fluid models gives rise to diffusion of particle density,
momentum and pressures in drift-fluid turbulence models and thereby obviate the
customary use of artificial diffusion in turbulence simulations. We further
derive a computationally efficient, two-dimensional model which can be time
integrated for several turbulence de-correlation times using only limited
computational resources. The model describes interchange turbulence in a
two-dimensional plane perpendicular to the magnetic field located at the
outboard midplane of a tokamak. The model domain has two regions modeling open
and closed field lines. The model employs a computational expedient model for
collisional transport. Numerical simulations show good agreement between the
full and the simplified model for collisional transport.
