The multidimensional modal theory proposed by Faltinsen, et al. （2000） is applied to solve liquid nonlinear free sloshing in right circular cylindrical tank for the first time. After selecting the leading modes and ...The multidimensional modal theory proposed by Faltinsen, et al. （2000） is applied to solve liquid nonlinear free sloshing in right circular cylindrical tank for the first time. After selecting the leading modes and fixing the order of magnitudes based on the Narimanov-Moiseev third order asymptotic hypothesis, the general infinite dimensional modal system is reduced to a five dimensional asymptotic modal system （the system of second order nonlinear ordinary differential equations coupling the generalized time dependent coordinates of free surface wave elevation）. The numerical integrations of this modal system discover most important nonlinear phenomena, which agree well with both pervious analytic theories and experimental observations. The results indicate that the multidimensional modal method is a very good tool for solving liquid nonlinear sloshing dynamics and will be developed to investigate more complex sloshing problem in our following work.展开更多
本文主要研究信号的归一化峰度及其在弱非线性系统辨识中的应用策略问题。首先简要介绍了几类常见的无记忆/有记忆非线性模型及其表示方法;给出了信号的归一化峰度定义及重要性质;在此基础上,分别针对非线性系统的记忆效应和非线性阶数...本文主要研究信号的归一化峰度及其在弱非线性系统辨识中的应用策略问题。首先简要介绍了几类常见的无记忆/有记忆非线性模型及其表示方法;给出了信号的归一化峰度定义及重要性质;在此基础上,分别针对非线性系统的记忆效应和非线性阶数对系统输出信号归一化峰度的影响进行了理论推导和仿真分析,揭示了该参数随系统特性的变化规律,表明归一化峰度具备精确辨识弱非线性系统的潜力。最后,针对SFDR(无杂散动态范围)高达85dBFS(dB Full Scale)的弱非线性系统,本文提出了一种分步辨识的方法,并结合所提出的方法阐明了此规律对于弱非线性系统盲辨识和失真补偿的潜在应用价值及其精度优势。展开更多
基金Project supported by the National Defense Pre-research Foundation of‘Tenth Five-Year-Plan’of China (No.41320020301)
文摘The multidimensional modal theory proposed by Faltinsen, et al. （2000） is applied to solve liquid nonlinear free sloshing in right circular cylindrical tank for the first time. After selecting the leading modes and fixing the order of magnitudes based on the Narimanov-Moiseev third order asymptotic hypothesis, the general infinite dimensional modal system is reduced to a five dimensional asymptotic modal system （the system of second order nonlinear ordinary differential equations coupling the generalized time dependent coordinates of free surface wave elevation）. The numerical integrations of this modal system discover most important nonlinear phenomena, which agree well with both pervious analytic theories and experimental observations. The results indicate that the multidimensional modal method is a very good tool for solving liquid nonlinear sloshing dynamics and will be developed to investigate more complex sloshing problem in our following work.
基金Supported by Key Scientific Research Project of Hunan Provincial Department of Education (No. 22A0484)National Natural Science Foundation of China (No. 12104150)。
文摘本文主要研究信号的归一化峰度及其在弱非线性系统辨识中的应用策略问题。首先简要介绍了几类常见的无记忆/有记忆非线性模型及其表示方法;给出了信号的归一化峰度定义及重要性质;在此基础上,分别针对非线性系统的记忆效应和非线性阶数对系统输出信号归一化峰度的影响进行了理论推导和仿真分析,揭示了该参数随系统特性的变化规律,表明归一化峰度具备精确辨识弱非线性系统的潜力。最后,针对SFDR(无杂散动态范围)高达85dBFS(dB Full Scale)的弱非线性系统,本文提出了一种分步辨识的方法,并结合所提出的方法阐明了此规律对于弱非线性系统盲辨识和失真补偿的潜在应用价值及其精度优势。
