氧相变换热器内压力波动的混沌特性分析

摘要

采用非线性分析方法对氧相变换热器的入、出口压力脉动时间序列进行分析,提取关联维数、Ko1omogrov熵,并对重构10维相空间矩阵的协方差矩阵进行最大奇异值分解.验证了该热力学系统是具有混沌特征的非线性系统.针对物质在临界点附近的特性,考察了各混沌特性参数和普朗特数的关联性,结果表明：压力脉动信号蕴含了与系统相关的大量物理信息;各混沌特性参数与普朗特数这一物性参数之间存在明显关联性;说明各参数反映物质本身的物理本质,可以作为考察物质相变物理特性的重要参数.%Pressure fluctuation signals at the inlet/outlet of an oxygen phase-change heat exchanger are analyzed using non-linear method. Chaotic characteristic parameters such as correlation dimension,Kolomogrov entropy and the largest singular value decomposition （SVD） for the covariance matrix of an established 10-dimensional phase space are analyzed.Results prove that the heat exchanger is a non-linear system with chaotic characteristics.Correlations between these parameters and Prantl Number are also examined for the thermal behavior of oxygen in the critical region.The strong dependence of these characteristic parameters on Pr indicates that they can be used to investigate effectively the phase change behavior of pure substance.