An Experimental Study on Active Control of Leakage-Flow-Induced Vibrations: Experiments for Translational One-Degree-of-Freedom System

This paper describes the active feedback control of leakage-flow-induced vibrations in translational one-degree-of-freedom system. In this paper, suppression of the leakage-flow-induced vibrations by the active feedback control technique is demonstrated experimentally. A rigid plate, as a controlled object, is elastically supported in a narrow tapered passage by using two flat-springs. The leakage-flow-induced vibrations occur to the plate in the translational motion due to the fluid flow in the narrow passage. The leakage-flow-induced vibrations are suppressed by the active feedback to the injection (and drawing) of the fluid at the inlet or outlet of the passage. The critical flow rate under controlled condition is examined with varying the controller gain and phase-shift between the injection (and drawing) of the fluid and the vibration strain (displacement) signal of the plate. As a result, it is indicated experimentally that the active feedback control technique increases the critical flow rate, and suppress the leakage-flow-induced vibrations effectively. Further, the control performance is examined and stabilization mechanism by the active feedback control is discussed.