Paul M R, Cross M C, Fischer P F, Greenside H S
Department of Physics, California Institute of Technology 114-36, Pasadena, California 91125, USA.
Phys Rev Lett. 2001 Oct 8;87(15):154501. doi: 10.1103/PhysRevLett.87.154501. Epub 2001 Sep 25.
The origin of the power-law decay measured in the power spectra of low Prandtl number Rayleigh-Bénard convection near the onset of chaos is addressed using long time numerical simulations of the three-dimensional Boussinesq equations in cylindrical domains. The power law is found to arise from quasidiscontinuous changes in the slope of the time series of the heat transport associated with the nucleation of dislocation pairs and roll pinch-off events. For larger frequencies, the power spectra decay exponentially as expected for time continuous deterministic dynamics.
利用圆柱域中三维布辛涅斯克方程的长时间数值模拟，研究了低普朗特数瑞利 - 贝纳德对流在混沌起始附近功率谱中测得的幂律衰减的起源。发现幂律源于与位错对的形核和滚动夹断事件相关的热传输时间序列斜率的准不连续变化。对于更高频率，功率谱按时间连续确定性动力学预期呈指数衰减。
