Abstract
This paper describes non-proprietary rotating high-pressure turbine (HPT) blade thermal imaging results taken in a transient, full-scale, short-duration turbine blowdown facility as part of a larger instrumentation development program for operational aeroengine applications. While thermal imaging of stationary parts is routine, and several institutions use thermal imaging in turbine rig operations, the leap to capture HPT rotor blade transients inside operational aeroengines entail unique challenges. This paper describes an approach that inverts the traditional development path with early exposure to the real engine environment first, followed by turbine rig testing in the AFRL Turbine Research Facility (TRF) for cost-effective system improvement and enhancement between engine tests. Due to the TRF’s transient, short duration, and relatively low temperature operation, results show it is ideal for testing extreme limits of temporal, thermal, and spatial resolution needed for capturing fast engine transients. This demonstrated a new role for the TRF later in the development cycle; specifically, improving instrumentation hardware and software for engine use, while continuing its role as a design validation rig for turbomachinery research and development. Since the first thermal imaging of full speed rotating HPT blades in an operational aeroengine in 2008, the “inverted” instrumentation development path described in this paper provides lessons for future gas turbine sensing developments supporting integrated prognostic health monitoring, digital twin/digital thread, and fleet sustainment.