An Investigation of Axial Compressor Rotor Aerodynamics

Abstract

The detailed nature of the three-dimensional flow over the blading, and in the wake, of an isolated compressor rotor has been studied experimentally in a large scale rotating rig. A variety of flow properties were measured including (1) blade profile and endwall surface flow visualization, (2) radial-circumferential arrays of pneumatic wake data acquired in the rotating frame and (3) full-span blade pressure distribution data. Data have been obtained over a wide range of blade loading and downstream location. These results show a hub corner stall at lower blade loadings and full-span blade separation at higher blade loadings. Under both conditions there is strong radial flow on the airfoil. The radial flow in the wake, however, increases dramatically when the blade undergoes full-span separation. The impact of these flow phenomena on the blade pressure distribution is also illustrated.

Discussion: “Three-Dimensional Flows and Loss Reduction in Axial Compressors” (Dong, Y., Gallimore, S. J., and Hodson, H. P., 1987, ASME J. Turbomach., 109, pp. 354–361)

“…To summarize, the rotor flow described by Dong et al is very similar in many respects to those of [1,2]. The arguments that their rotor did not have corner separation are not convincing.…”

“…The authors conclude that the corner separation on the rotors of [1,2] is due to "excessive diffusion." In fact, however, the diffusion factors calculated in both the pretest design analysis and those calculated from the measured inlet and exit flow data were well within conventional limits for Manager, Gas Turbine Technology, United Technologies Research Center, East Hartford, CT 06108.…”

“…both of the rotors in [1][2][3]. These diffusion factors ranged from 0.5 to 0.6 at the hub to 0.45 in the core flow region.…”

Aircraft Propulsion Systems Technology and Design

“…) One final example of the mutual corroboration of theory and experiment will be discussed in this section. A series of unsteady aerodynamic experi- 97. The model is driven by a variable-speed electric motor and the downstream flow is throttled by a variable-vortex valve prior to passing through a constant-speed centrifugal blower.…”

Discussion: “Axial Compressor Stator Aerodynamics” (Joslyn, H. D., and Dring, R. P., 1985, ASME J. Eng. Gas Turbines Power, 107, pp. 485–492)

“…The suction surface corners of the present stator were stalled, as was the hub suction surface corner of the upstream rotor [7]. Corner stall has been observed on an isolated rotor over a wide range of incidence and inlet boundary layer thickness [2][3][4][5][6][7]. It has also been seen to occur on high solidity rotors and stators [15].…”