Publications

Actuating transverse jets via nozzle-edge vortical perturbations

Marzouk, Youssef M.; Ghoniem, Ahmed F.

The trajectory and entrainment properties of a transverse jet are important to a variety of engineering applications. This study seeks to develop actuation strategies that manipulate the penetration, spread, and vortical structures of the tranverse jet, based on simple vorticity perturbations at the nozzle edge. We use three-dimensional vortex simulations of a transverse jet at high Reynolds number to examine four prototypical actuations, all at a jet-to-crossflow velocity ratio of r = 7. These actuations include a delta-tab on the windward edge of the jet nozzle as well as periodic modulations and inversions of wall-normal vorticity in the shear layer. Small modifications to the vorticity on nascent shear layer are found to have a significant impact on the jet evolution - creating jets that remain confined and penetrate further into the crossflow, or, alternately, jets that quickly spread in the spanwise direction and bend downstream. Vorticity perturbations also hasten or delay the formation of counter-rotating vorticity by modifying the folding of shear-layer segments.