Author：Daisuke SHIMOKURI
Affiliation：Hiroshima university
Abstract：The four‑region shock tube has been proposed as a technique capable of suppressing the severe pressure noise phenomenon (bump) encountered in ignition delay measurements. Although it has been confirmed that the bump can be suppressed, the underlying mechanism remains unclear, and elucidation of this mechanism is essential for efficient operation. In this study, detailed numerical simulations were conducted to investigate the gas dynamics inside the four‑region shock tube, which are difficult to capture experimentally.