2026-09-21T14:42:15Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/132697 2026-03-24 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

application/pdf en text Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-12-01 The student, Joshua Yoon, accepted the attached license on 2025-12-05 at 21:44. The student, Joshua Yoon, submitted this Thesis for approval on 2025-12-05 at 21:47. This Thesis was approved for publication on 2025-12-08 at 08:26. DSpace SAF Submission Ingestion Package generated from Vireo submission #23092 on 2026-02-19 at 18:46:50 Flame front imaging and ignition performance of ultra-compact trapped-vortex combustor Yoon, Joshua 2025-12-08 Lee, Tonghun Flame Dynamics, Compact Combustor, Flame Imaging eng In this study, the flame dynamics and ignition performance of a novel ultra-compact trapped-vortex combustor, the ARC-S1, is investigated. Time-averaged OH* chemiluminescence was used to visualize flame anchoring and distribution inside the combustor. High-speed OH* PLIF imaging was conducted at two spanwise locations along the combustor cavity at 1∼3 atm, revealing an axial shift in flame distribution along the cavity vortex as pressures increased. The ignition performance of the ARC-S1 was investigated at atmospheric pressure, with air injection temperatures of 25° and 10°C, using a conventional spark igniter and an experimental plasma igniter. At lean operating conditions, plasma ignition exhibited up to a 45% reduction in Eign, although negligible improvements were observed from nominal to rich operating conditions. 2025-12 Thesis https://hdl.handle.net/2142/132697 Copyright 2025 Joshua Yoon Mechanical Sci & Engineering Mechanical Engineering University of Illinois Urbana-Champaign M.S. Thesis