High-Speed RDC Data Averaging Through Dynamic Time Warping

Abstract

High-speed diagnostics are essential for understanding the unsteady parameter fluctuations in Rotating Detonation Combustors (RDCs). However, the experimental data from RDCs often exhibit significant stochasticity spatially and temporally due to factors such as lap-to-lap detonation wave fluctuations, measurement uncertainties, and sensor-induced artifacts. Traditional phase-averaging techniques, like the arithmetic mean, can distort the true detonation wave structure by smoothing out key features due to temporal misalignment. This study investigates the application of a soft-Dynamic Time Warping (soft-DTW) based averaging as a unique method for processing high-speed RDC data. Compared to conventional methods, soft-DTW has shown improved resilience to local time axis distortions, which may enable better alignment and preservation of the intrinsic wave structure, particularly by capturing the sharpness of the main peak and secondary features relevant to the detonation process. The study evaluates the capability of soft-DTW to capture essential physical characteristics of rotating detonation waves using dynamic pressure and video data. Additionally, a sensitivity analysis assesses the method’s effectiveness in accurately representing secondary features, such as reflected shock waves, highlighting its potential for more representative RDC data averaging.