Experimental jet control with Bayesian optimization and persistent data topology
arxiv(2024)
摘要
This study experimentally optimizes the mixing of a turbulent jet at
Re=10000 with the surrounding air by targeted shear layer actuation. The
forcing is composed of superposed harmonic signals of different azimuthal
wavenumber m generated by eight loudspeakers circumferentially distributed
around the nozzle lip. Amplitudes and frequencies of the individual harmonic
contributions serve as optimization parameters and the time-averaged centerline
velocity downstream of the potential core is used as a metric for mixing
optimization. The actuation is optimized through Bayesian optimization. Three
search spaces are explored - axisymmetric forcing, m=0, superposed
axisymmetric and helical forcing, m ∈{0,1}, and axisymmetric actuation
combined with two counter-rotating helical modes, m ∈{-1,0,1}.
High-speed PIV is employed to analyze the jet response to the optimized
forcing. The optimization processes are analyzed by persistent data topology.
In the search space of axisymmetric excitation, the routine identifies an
actuation at the natural frequency of the flow to be most efficient, with the
centerline velocity being decreased by 15%. The optimal solutions in both
the two-mode and three-mode search space converge to a similar forcing with one
axial and one helical mode combined at a frequency ratio of around 2.3.
Spectral analysis of the PIV images reveals that for the identified optimal
forcing frequencies, a non-linear interaction between forced and natural
structures in the jet flow is triggered, leading to a reduction in centerline
velocity of around 35%. The topology of the most complex search space from
the discrete data reveals four basins of attractions, classified into three
forcing patterns including axisymmetric, axisym.-helical, and axisym.-flapping.
Two deep basins are related to the optimal axisym.-helical pattern, and the
others are shallower.
更多查看译文
AI 理解论文
溯源树
样例
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要