Unsteady flow control using synthetic jet actuators

CFD Analysis for Industrial Applications using xGrid Environment

“…; nondimensionalizations were performed for the reduced frequency [2,4,6,8]. The flow induced by the actuator is supposed to have a low level of turbulence, so the same conditions for the viscous variables are considered as for free stream boundary conditions ( i.e.…”

“…This makes the resulting code to be so huge, and a cure for this problem is to rewrite some of the initial code and to use AD in an incremental way under global internal loops on the vertices. Also, from numerical results on small domains for some classical aerodynamic configurations [8], a well known poor dependency of the global state with respect to global flow perturbations was found . This also means that any global coefficient based on a surface integral on the shape is little influenced by the flow variations induced by the controls in the whole domain.…”

“…This also means that any global coefficient based on a surface integral on the shape is little influenced by the flow variations induced by the controls in the whole domain. This is materialized in a week dependence of the gradient with the state [8,16]. This means that for quick aerodynamic optimizations, one may neglect the state derivative in the gradient, so only derivatives with respect to the controls will be considered.…”

“…The controls used are SJ devices that have individual characteristics for the frequency and velocity profile. Several numerical studies for the actuator simulation using CFD analysis were performed in order to asses the effect of their operational characteristics [2,6,8]. From these results, for a complex analysis of their influence on a body, only the top speed and the frequency for a sinusoidal operating mode were selected.…”

Design of Adjoint-Based Laws for Wing Flutter Control

“…3 Flow control, for aerodynamics, using synthetic jets has been studied experimentally by Amitay, 4 Tuck and Soria, 5 and Nishizawa et al 6,7 Numerical investigations were performed by Nae. 8 It should be noted that in all these experiments, the location and frequencies of the actuators were chosen apriori. The control implemented, therefore, is open loop.…”