  We consider a particle diffusing inside a wedge with absorbing boundaries and
driven by a radial flow of incompressible fluid generated by a source at the
apex. The survival probability decays as (time)^{-b} with exponent depending on
the opening angle of the wedge and the Reynolds number associated with the
hydrodynamic flow. The computation of the decay exponent reduces to finding the
ground state energy of the quantum particle in an infinitely deep potential
well with shape determined by the radial flow velocity.
