INTELLIGENT AIRFOIL FOR PREVENTING FLOW SEPARATION

点击翻译按钮获取中文摘要

An intelligent airfoil was designed to incorporate sensor, prcessor and actuator for preventing the flow separation from airfoilsurface. The original airfoil was cut in two, and thus the airfoil consists of the leading and trailing parts, which are connected by shape memory alloys (SMA) rods. The airfoil shape was changed by actuating the SMA actuators so that its incidence angle can be decreased for the suppression of the flow separation, once flow separation from the airfoil surface were detected by sensor. Various sensors were tested to detect the flow separation from airfoil surface effectively ; optical fiber sensor to detect the flow at the clearance between the leading and trailing parts of developed airfoil, pressure distribution sensor using pressure sensitive rubber, liquid crystal paint, hot film sensor allay, and piezo-electric crystal. The responses of these sensors to flow separation were tested, but there are problems on the reliability of sensors characteristics. Output signal from sensor is processed for the judgment of flow separation, and then control signal is sent to the actuator once now separation were detected after the judgments. The developed intelligent airfoil was tested in wind tunnel, and it was found to be effective for preventing the flow separation.