  We introduce a finite volume scheme to solve a special case of isotropic
3-wave kinetic equations. We test our numerical solution against theoretical
results concerning the long time behavior of the energy and observe that our
solutions verify the energy cascade phenomenon. To our knowledge, this is the
first numerical scheme that can capture the long time asymptotic behavior of
solutions to those isotropic 3-wave kinetic equations, where the energy cascade
can be observed. Our numerical energy cascade rates are in good agreement with
previously obtained theoretical results. The finite volume scheme given here
relies on a new identity, allowing one to reduce the number of terms needed in
the collision operators.
