SIMPLIFIED APPROACH FOR CONTROL OF ROTATING STALL .2. EXPERIMENTAL RESULTS

The primary objective of this article is to provide experimental valid ation of the simplified approach to control of rotating stall presente d in Part 1 of this article. The experimental rig utilized is a low-sp eed, single-stage axial compressor rig, It is shown that the controlle r based on this approach has significant ability to reject persistent disturbances that cause the uncontrolled system to enter rotating stal l. in addition, it is shown that the effective stable axisymmetric flo w range of the compressor has been extended by this controller. This i s a consequence of the fact that the controller enlarges the domains o f attraction of linearly stable axisymmetric equilibria, A secondary o bjective of this article is the investigation of the presence of rotat ing stall precursors in this rig. Our motivation here is to determine the most appropriate signal processing to apply to sensor data prior t o using it in the controller. In this rig, two first-mode rotating sta ll precursors traveling at different speeds are found when appropriate spectral separation of measured data is performed.