Mechanisms for the generation of self-excited traveling waves in thermoacoustic engines

2014 Fiscal Year Final Research Report

• Project/Area Number: 25820044
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Fluid engineering
• Research Institution: Fukui University of Technology (2014); Osaka University (2013)
• Principal Investigator: SHIMIZU DAI 福井工業大学, 工学部, 准教授 (40448048)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 熱音響自励振動 / 境界層理論 / 臨界条件 / 進行波 / スタック / 空隙率

Outline of Final Research Achievements

Numerical simulations of self-excited thermoacoustic oscillations in a looped tube are performed based on the one-dimensional theory in the boundary-layer approximation. Effects of porosity and other sub-parameters of the so-called stack on the generation of traveling waves are studied. It is found that the generation of traveling waves is enhanced as the porosity decreases when the wall thickness of the stack is constant. Thinner wall thickness of the stack is also effective for the generation of traveling waves when the porosity is constant. It is also found that these results become opposite for the porosity below around 0.5. It is unveiled that not only the common parameter omega tau but also the porosity of the stack and other sub-parameters are important for the specification of marginal temperature ratios and for the generation of traveling waves. The boundary-layer theory has turned out to be applicable even to the case with apparently narrow pores in the stack.

Free Research Field

熱流体力学