Parametric Study of Vortex Generator Jets by Direct Numerical Simulation

Direct numerical simulations are used to gain insight into the effect of pitch and skew angle variations of vortex generator jets. The skew is investigated for a range from 30 \(^{\circ }\) to 150 \(^{\circ }\) for a pitch of 30 \(^{\circ }\) and 45 \(^{\circ }\) . The baseline consists of a laminar wall shear flow at a low Reynolds number of 165 based on the displacement thickness and freestream velocity. The resulting compound flows have been classified by integral values such as the friction coefficient and the momentum gain coefficient. The dependency on the pitch is small except at a small region close to the jet exit. Transition to turbulence occurs for skew angles above 90 \(^{\circ }\) . The jet trajectories are extracted from the data and a polynomial model that characterizes the trajectories as a function of skew and pitch is proposed.