Recently, a nonlocal (quasilinear)
renormalization scheme for turbulent transport of passive scalars has been
formulated that allows one to derive renormalized transport equations for
passive scalars in terms of fractional differential operators. As a result,
this provides a method for obtaining fractional transport exponents for
these problems by characterizing the statistics and correlations of the
Lagrangian velocities along the characteristics trajectories of the flow.
We will explore these methods to characterize tracer transport in fluid
simulations of simple (drift-wave) turbulence in different physics limits.
The simplified system allows us to concentrate on the role that the polarization
and E X B nonlinearities play in determining the value of the effective
fractional transport exponents.
In addition, we look at preliminary results from a gyro kinetic simulation
that has much more physics in it to explore the characteristics of the tracer
transport in that system.
(In other words...fun with turbulence simulations)