Acoustic control of instability waves in a turbulent jet

A theoretical study of the efficiency of instability wave excitation in a two-dimensional nozzle edge model

“…The form of the model perturbation should be chosen so as to reflect the characteristic features of the effect of an actual actuator on the jet. It is the special choice of the external action that makes the statement of the prob lem under study different from the problems studied in other publications [10,[16][17][18][19][20][21], where the diffraction of either plane or cylindrical waves by the edge was considered.…”

“…In the general form (without specifying the form of the perturbation), the solution to the problem of exter nal action on a jet is given in, e.g., [10]. Perturbations in regions I and II are represented as (5) where ϕ i1 is the perturbation potential, which is assumed to be known; the potentials ϕ 1 (in region I)…”

“…In our previous publications [10,11], we justified the basic possibility of implementing the active control of instability waves by solving relatively simple model problems. We showed that an instability wave excited by a time harmonic external action can be suppressed by a plane sound wave with properly chosen amplitude and phase.…”

“…At the same time, the presence of the nozzle edge con siderably complicates the problem of the action on the mixing layer. This difficulty can be overcome by replacing the mixing layer with a tangential disconti nuity [10,[16][17][18][19][20][21], which makes it possible to obtain an exact analytic solution to the problem, e.g., by the Wiener-Hopf method [22].…”

Instability wave control in turbulent jet by acoustical and plasma actuators

“…The TR PIV diagnostic technique described in the previous section was used in the experiments. The idea of the experiment is based on the theory of acoustic instability wave control described in [10,17]. In these papers, the instability wave is excited by a plane acoustic wave coming from semiin¦nite cylindrical nozzle, and then this instability wave is cancelled by an external acoustic wave with properly chosen amplitude and phase according to the analytical solution of the control problem.…”