Influence of plasma actuators as a flow separation control device was investigated experimentally. Hump model was used to demonstrate the effect of plasma actuators on external flow separation, while for internal flow separation a set of compressor cascade was adopted. In order to investigate the modification of the flow structure by the plasma actuator, the flow field was examined non-intrusively by particle image velocimetry measurements in the hump model experiment and by a hot film probe in the compressor cascade experiment. The results showed that the plasma actuator could be effective in controlling the flow separation both over the hump and in the compressor cascade when the incoming velocity was low. As the incoming velocity increased, the plasma actuator was less effective. It is urgent to enhance the intensity of the plasma actuator for its better application. Methods to increase the intensity of plasma actuator were also studied.
Rotary disc is a key part in aero engine, HPT rotor disc due to its highest thermal load as well as mechanical load, always suffers from thermal or mechanical failure. In this paper, the authors initiate a new kind of novel fin-like structure which is presented on both surfaces of the rotating disc. The presence of the fin-like structure acts like a turbulence & vortex generator and hence increases the heat transfer effectiveness between the cooler cavity flow and the higher temperature disc surface. This paper deals with a numerical investigation of the new kind of fin-like structure which is tending to be applied on the high pressure turbine rotor's rotating disc. Numerical results revealed that with this novel structure thermal load of the disc reduced noticeably ranging from 10℃ to 20℃. This can be explained by the vortex structure generated by the disturbance of the cavity's cooling flow, thus enhancing the convective heat transfer rates between the disc surface and the cavity flow.
