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Control of Thermoacoustic Chaotic Oscillations

热声混沌振荡的控制

基本信息

批准号：
18J11951
负责人：
DELAGE REMI
金额：
$ 0.96万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for JSPS Fellows
财政年份：
2018
资助国家：
日本
起止时间：
2018-04-25 至 2020-03-31
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18J11951/
关键词：
Thermoacoustics Oscillator Chaos Coupling

项目摘要

In thermoacoustic oscillators, a temperature gradient imposed on a gas column induces self-sustained acoustic oscillations. For the development of next generation, highly efficient thermoacoustic engines, lots of efforts are made to increase the pressure oscillations amplitude, which will lead to encounter nonlinear phenomena such as chaotic oscillations. In order to maintain these systems energy efficient, control methods are becoming necessary. On the other side, thermoacoustic oscillations can occur in gas turbine or rocket engines exposed to extreme temperatures. While threatening the stability operation and increasing NOx particles emissions of these systems, high amplitude thermoacoustic oscillations can severely damage the engines.After introducing a local contraction in simple thermoacoustic systems, we previously observed chaotic oscillations at low temperature ratios. By dissipatively coupling two of our new systems, we successfully stabilized the oscillations into a periodic motion as well as completely stopping the oscillations depending on the coupling strength and detuning parameters.We also applied a passive delay feedback on one oscillator and observed a suppression of the modes in the route to chaos by setting the delay to half of the oscillation period. Different modes were stabilized by varying the delay feedback strength and we observed an increase of the onset temperature ratio.Both the stabilization into a periodic motion and oscillation suppression find application in the development of new thermoacoustic engines and combustion engines respectively.

在热声振荡器中，施加在气柱上的温度梯度引起自持声振荡。为了发展下一代高效热声发动机，人们一直在努力提高发动机的压力振荡幅度，这将导致发动机出现混沌振荡等非线性现象。为了保持这些系统的能量效率，控制方法变得必要。另一方面，热声振荡可发生在暴露于极端温度的燃气涡轮机或火箭发动机中。高振幅的热声振荡不仅会威胁系统的稳定运行，而且会增加NOx的排放。在简单的热声系统中引入局部收缩后，我们观察到了低温比下的混沌振荡。通过耗散耦合两个新系统，我们成功地将振荡稳定为周期运动，并根据耦合强度和失谐参数完全停止振荡，我们还对一个振荡器施加了被动延迟反馈，并观察到通过将延迟设置为振荡周期的一半来抑制通向混沌的模式。通过改变延迟反馈的强度，可以稳定不同的模态，并观察到起振温度比的增加，这两种方法分别在新型热声发动机和内燃机的发展中得到应用。