Measurements of energy flux density in thermoacoustic synchronization

2015 Fiscal Year Final Research Report

• Project/Area Number: 25400398
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: Aichi University of Education
• Principal Investigator: Yazaki Taichi 愛知教育大学, 教育学部, 教授 (20144181)
• Co-Investigator(Renkei-kenkyūsha): UEDA Yuki 東京農工大学, 工学研究科, 准教授 (00447509)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 同期現象 / 振動抑制 / 熱音響振動 / 音響強度 / 共鳴管のQ値

Outline of Final Research Achievements

We address a basic question in synchronization phenomena, “Where is the power source necessary to sustain synchronized oscillations?” Very little experimental research exists that has specifically focused on synchronization from the viewpoint of the power source or power flux density. To find the power source may be easy if a system has just one source, but is never trivial in the case of synchronization phenomena involving multiple power sources.
Self-sustained oscillations in a gas column induced by a temperature gradient are periodically perturbed by external forcing. The power source required to sustain synchronized oscillations is identified using sound intensity measurements. We demonstrate that, even if small forcing entrains the natural frequency or strong forcing completely suppresses the natural dynamics, the external forcing device is never the source of power; this source resides in the temperature gradient, which creates natural-frequency oscillations.

Free Research Field

音響物理学