The Design and Evaluation of a High Frequency Fore-Aft Probe

Abstract

A high-frequency surge and stall sensing fore-aft probe was developed at the Turbomachinery Research Laboratory at Virginia Tech. The probe was designed to detect surge and stall based on changes in large regions of flow behind a turbofan engine compressor fan. The probe exhibited excellent frequency response capabilities and can accurately measure data with response well above anticipated surge frequencies. A CFD analysis was performed in order to gain more understanding about the flow around the probe. The results of the CFD analysis and the experimental testing were analyzed and presented. The probe worked as expected when the flow was aligned with the upstream pressure transducer. Thus, it can be used to determine the onset of surge and stall. However, the probe was found to be extremely sensitive to off-axis flows. Design improvements are suggested in order to increase its capabilities.