  The emergence of a submerged vortex upstream of a pump can reduce pump intake
efficiency and cause structural damage. In this study, we consider the use of
active flow control with steady blowing to increase the pressure distribution
within a single-phase pump-induced wall-normal vortex model, which is based on
the Burgers vortex with a no-slip boundary condition prescribed along its
symmetry plane. The goal of our control is to modify the vortex core velocity
profile. These changes are sought to increase the core pressure such that
detrimental effects on the pump are alleviated. Three-dimensional direct
numerical simulations (DNS) are performed to examine the dynamics of the vortex
with the application of axial momentum injection at and around the root of the
vortex. We find that the active flow control approach can effectively modify
the wall-normal vortical structure and significantly increase the low-core
pressure by up to 81% compared to that of the uncontrolled case. The result
shows that the control setup is also effective when it is introduced in an
off-centered manner. Compared to the unsteady blowing and suction based
actuation from our previous work (Liu et al. 2018), the current steady control
technique offers an effective and simple flow control setup that can support
robust operations of pumps.
