Blade Tip Clearance
Measurement of rotating blade tip to shroud clearances for fan, compressor, and turbine components are necessary to set operating clearances for best performance and efficiency of the rotating component. Diagnostic rotating clearance measurement systems are needed for both steady state correlations of clearances with engine operating conditions and also dynamic measurements. Clearance measurement systems with high enough bandpass frequency can be used to measure rotor dynamics and vibration. Past sensors have been optical, capacitance, eddy current, microwave, and contact.
Current Sensor Needs
Important to be compact and non-intrusive in size, 0.25 inch diameter for compressors and turbines. Need the capability to operate at high-pressure turbine temperatures. Required measurement range of 0 to 0.200 inches for compressors and turbines, and measurement range of 0 to 0.400 inches for large by-pass fans. Repeatable to within 0.0005 inches is needed. For use to record dynamic data, must measure individual blade clearance and have a frequency response of 1 Mega Hertz (Full Power Bandwidth). Tip Clearance System will need real time measurement and display.
Strategic Advisory Board (SAB) Members Addressing This Need
Aerodyn Engineering, Inc.
Cleveland Electric Laboratories Company, Inc.
Goodrich Sensor Systems