An axial-flow turbine is one of the main components of aircraft jet engines. It is important to suppress the leakage flow at the blade tip to improve the aerodynamic performance of the turbine blades. To achieve this, a unique ring-type plasma actuator was developed as an active flow control device. This plasma actuator consists of a high-frequency−high-voltage electrode installed in the outer casing of the turbine rotor. The metallic turbine rotor blades act as the grounded electrode. Dielectric barrier discharge (DBD) plasma is generated between the outer casing and tip of the turbine blade; this plasma interrupts the leakage flow. In this study, the effect of the plasma actuator in reducing the tip leakage flow of a linear turbine cascade was demonstrated using particle image velocimetry (PIV) to obtain velocity measurements at two planes, namely, the blade mid-passage and blade exit. The turbulence intensity and vorticity were also analyzed. The blade mid-passage measurements showed that the low-velocity region caused by the tip leakage flow was reduced by the plasma actuator and the blade exit measurements clarified the vortex structure. The operation of the plasma actuator successfully reduced or eradicated the tip leakage vortex. Contrarily, the passage vortex at the tip side became clearer and stronger. The plasma actuator reduced the tip leakage vortex even when the Reynolds number was changed.

轴流式涡轮机是飞机喷气发动机的主要部件之一。抑制叶尖漏流对提高涡轮叶片的气动性能具有重要意义。为实现这一目标，开发了一种独特的环形等离子体致动器作为主动流量控制装置。该等离子致动器由安装在涡轮转子外壳中的高频-高压电极组成。金属涡轮转子叶片充当接地电极。在涡轮叶片的外壳和尖端之间产生介质阻挡放电 (DBD) 等离子体；这种等离子体中断了泄漏流。在这项研究中，使用粒子图像测速仪 (PIV) 在两个平面上获得速度测量值，证明了等离子体致动器在减少线性涡轮级联的尖端泄漏流量方面的效果，即，叶片中间通道和叶片出口。还分析了湍流强度和涡度。叶片中间通道测量表明，等离子致动器减少了尖端泄漏流引起的低速区域，叶片出口测量阐明了涡流结构。等离子体致动器的运行成功地减少或消除了尖端泄漏涡流。反之，尖端侧的通道涡流变得更加清晰和强烈。即使改变雷诺数，等离子体致动器也减少了尖端泄漏涡流。叶片中间通道测量表明，等离子致动器减少了尖端泄漏流引起的低速区域，叶片出口测量阐明了涡流结构。等离子体致动器的运行成功地减少或消除了尖端泄漏涡流。反之，尖端侧的通道涡流变得更加清晰和强烈。即使改变雷诺数，等离子体致动器也减少了尖端泄漏涡流。叶片中间通道测量表明，等离子致动器减少了尖端泄漏流引起的低速区域，叶片出口测量阐明了涡流结构。等离子体致动器的运行成功地减少或消除了尖端泄漏涡流。反之，尖端侧的通道涡流变得更加清晰和强烈。即使改变雷诺数，等离子体致动器也减少了尖端泄漏涡流。