  Modeling the intermittent behavior of turbulent energy dissipation processes
both in space and time is often a relevant problem when dealing with phenomena
occurring in high Reynolds number flows, especially in astrophysical and space
fluids. In this paper, a dynamical model is proposed to describe the
spatio-temporal intermittency of energy dissipation rate in a turbulent system.
This is done by using a shell model to simulate the turbulent cascade and
introducing some heuristic rules, partly inspired by the well known $p$-model,
to construct a spatial structure of the energy dissipation rate. In order to
validate the model and to study its spatially intermittency properties, a
series of numerical simulations have been performed. These show that the level
of spatial intermittency of the system can be simply tuned by varying a single
parameter of the model and that scaling laws in agreement with those obtained
from experiments on fully turbulent hydrodynamic flows can be recovered. It is
finally suggested that the model could represent a useful tool to simulate the
spatio-temporal intermittency of turbulent energy dissipation in those high
Reynolds number astrophysical fluids where impulsive energy release processes
can be associated to the dynamics of the turbulent cascade.
