描叙了圆柱壳与声耦合系统建模技术的基本概念。根据WB法(Wave based method,简称WB法)的基本原理,将结构场变量和声压展开成波函数和特解函数的叠加。应用加权余量法将结构和声学边界条件以及结构与声耦合界面上的连续性条件转换成近...描叙了圆柱壳与声耦合系统建模技术的基本概念。根据WB法(Wave based method,简称WB法)的基本原理,将结构场变量和声压展开成波函数和特解函数的叠加。应用加权余量法将结构和声学边界条件以及结构与声耦合界面上的连续性条件转换成近似积分,推导出一组由代数方程表示的耦合模型。通过分析二维的算例表明这种预报技术计算量小且精度高,因此可应用到中频的分析。展开更多
This paper refers to the CNOP-related algorithms and formulates the practical method and forecast techniques of extracting predictable components in a numerical model for predictable components on extended-range scale...This paper refers to the CNOP-related algorithms and formulates the practical method and forecast techniques of extracting predictable components in a numerical model for predictable components on extended-range scales.Model variables are divided into predictable components and unpredictable chaotic components from the angle of model prediction error growth.The predictable components are defined as those with a slow error growth at a given range.A targeted numerical model for predictable components is established based on the operational dynamical extended-range forecast(DERF)model of the National Climate Center.At the same time,useful information in historical data are combined to find the fields for predictable components in the numerical model that are similar to those for the predictable components in historical data,reducing the variable dimensions in a similar judgment process and further correcting prediction errors of predictable components.Historical data is used to obtain the expected value and variance of the chaotic components through the ensemble forecast method.The numerical experiment results show that this method can effectively improve the forecast skill of the atmospheric circulation field in the 10–30 days extended-range numerical model and has good prospects for operational applications.展开更多
文摘描叙了圆柱壳与声耦合系统建模技术的基本概念。根据WB法(Wave based method,简称WB法)的基本原理,将结构场变量和声压展开成波函数和特解函数的叠加。应用加权余量法将结构和声学边界条件以及结构与声耦合界面上的连续性条件转换成近似积分,推导出一组由代数方程表示的耦合模型。通过分析二维的算例表明这种预报技术计算量小且精度高,因此可应用到中频的分析。
基金supported by the National Natural Science Foundation of China (Grant Nos. 40930952, 41105055)Global Change Study of Major National Scientific Research Plan of China (Grant No. 2012CB955902)Meteorological Special Project of China (Grant Nos. GYHY201106016, GYHY201106015)
文摘This paper refers to the CNOP-related algorithms and formulates the practical method and forecast techniques of extracting predictable components in a numerical model for predictable components on extended-range scales.Model variables are divided into predictable components and unpredictable chaotic components from the angle of model prediction error growth.The predictable components are defined as those with a slow error growth at a given range.A targeted numerical model for predictable components is established based on the operational dynamical extended-range forecast(DERF)model of the National Climate Center.At the same time,useful information in historical data are combined to find the fields for predictable components in the numerical model that are similar to those for the predictable components in historical data,reducing the variable dimensions in a similar judgment process and further correcting prediction errors of predictable components.Historical data is used to obtain the expected value and variance of the chaotic components through the ensemble forecast method.The numerical experiment results show that this method can effectively improve the forecast skill of the atmospheric circulation field in the 10–30 days extended-range numerical model and has good prospects for operational applications.
