1999 年 65 巻 629 号 p. 44-47
Experimental study was conducted to examine applicability of Pyragas' Delayed feedback control theory for active control of fluid flow. Although many attempts of turbulence active control have been made, most of those experimental studies experience "out of control" state in the case of using larger feedback gain. In the present study, we assume this "out of control" state as Chaos, and apply chaos control theory to prevent the flow field from falling into "out of control" state. Experiments were carried out for low Reynolds number oil flow in a rectangle thin container, whose aspect ratio is 6 : 1 : 0.5. Two pulsed jets were used as actuator in order to keep the circulation of the flow in container constant. Fluid flow was observed using Particle Image Velocimetry (PIV) technology and the flow state was estimated by moving least square (MLS) method. As a result, we found that Pyragas Control was effective to prevent Chaos for active control of fluid flow.