Development of 3D Pocket Tracking Algorithm from Volumetric Measured Turbulent Flames

The flame pocket formation, including reactant pocket, product pocket, soot pocket, and fluid parcel, is a common phenomenon in turbulent combustion occurred as a response of the flame to flow straining and shearing. Understanding pocket behavior is vital to study the flames in such a regime. This work addresses the research need to experimentally measure and track multiple flame pockets in 3D. For this purpose, volumetric measurements were performed to measure the high-speed turbulent flame structure at 15 kHz based on emission tomography. With the 3D flame structures, a new tracking algorithm was developed to identify and track the multiple flame pockets simultaneously in 3D. The instantaneously tracked 3D flame pockets enabled the extraction of key properties of pocket dynamics, including the favorable formation location, 3D3C movement speed, and pocket expanding/shrinking speed. The developed methods were evidently able to resolve the detailed behavior of flame pockets in highly turbulent flames.