How to evaluate time-domain Green function and its gradients efficiently is the key problem to analyze ship hydrodynamics in time domain.Based on the Bessel function,an Ordinary Differential Equation(ODE)was derived f...How to evaluate time-domain Green function and its gradients efficiently is the key problem to analyze ship hydrodynamics in time domain.Based on the Bessel function,an Ordinary Differential Equation(ODE)was derived for time-domain Green function and its gradients in this paper.A new efficient calculation method based on solving ODE is proposed.It has been demonstrated by the numerical calculation that this method can improve the precision of the time-domain Green function.Numerical research indicates that it is efficient to solve the hydrodynamic problems.展开更多
This work presented the development and validation of an analytical method to predict the transient temperature field in the asphalt pavement.The governing equation for heat transfer was based on heat conduction radia...This work presented the development and validation of an analytical method to predict the transient temperature field in the asphalt pavement.The governing equation for heat transfer was based on heat conduction radiation and convection.An innovative time-dependent function was proposed to predict the pavement surface temperature with solar radiation and air temperature using dimensional analysis in order to simplify the complex heat exchange on the pavement surface.The parameters for the time-dependent pavement surface temperature function were obtained through the regression analysis of field measurement data.Assuming that the initial pavement temperature distribution was linear and the influence of the base course materials on the temperature of the upper asphalt layers was negligible,a close-form analytical solution of the temperature in asphalt layers was derived using Green's function.Finally,two numerical examples were presented to validate the model solutions with field temperature measurements.Analysis results show that the solution accuracy is in agreement with field data and the relative errors at a shallower depth are greater than those at a deeper one.Although the model is not sensitive to dramatic changes in climatic factors near the pavement surface,it is applicable for predicting pavement temperature field in cloudless days.展开更多
Novel exact solutions of one-dimensional transient dynamic piezoelectric problems for thickness polarized layers and disks, or length polarized rods, are obtained. The solutions are derived using a time-domain Green’...Novel exact solutions of one-dimensional transient dynamic piezoelectric problems for thickness polarized layers and disks, or length polarized rods, are obtained. The solutions are derived using a time-domain Green’s function method that leads to an exact analytical recursive procedure which is applicable for a wide variety of boundary conditions including nonlinear cases. A nonlinear damper boundary condition is considered in more detail. The corresponding nonlinear relationship between stresses and velocities at a current time moment is used in the recursive procedure. In addition to the exact recursive procedure that is effective for calculations, some new practically important explicit exact solutions are presented. Several examples of the time behavior of the output electric potential difference are given to illustrate the effectiveness of the proposed exact approach.展开更多
为板鳍热的精确分析与在预设以内控制电子设备设备的温度的能力下沉可控制的温度范围在电路设计并且为监视目的即时温度的过程两个都被要求。为了提供卓见进一个板鳍热水池的温度的行为，在表面上使不一致的热密度遭到了，获得产出在电...为板鳍热的精确分析与在预设以内控制电子设备设备的温度的能力下沉可控制的温度范围在电路设计并且为监视目的即时温度的过程两个都被要求。为了提供卓见进一个板鳍热水池的温度的行为，在表面上使不一致的热密度遭到了，获得产出在电子设备设备的任何点联系驱散的力量到温度上升的明确的公式的精确分析答案是必要的。这份报纸用源于一个适当的板鳍热水池的三维的热方程的一个分析答案为一个板鳍热水池的热模拟论述一个方法短暂热模型。全部答案方法论在板鳍热水池的特别例子上详细被说明表面上的使遭到的不一致的热密度。短暂温度侧面在板鳍热水池的表面为不同位置被获得。分析结果与在冷板的表面上做的大小相比，他们在对不到 3 K 的一个错误的好同意，这被发现。展开更多
基金This work was financially supported by Key Program of the National Natural Science Foundation of China(No.50639020)the National High Technology Research and Development Program of China(863Program)(No.2006AA09Z332)
文摘How to evaluate time-domain Green function and its gradients efficiently is the key problem to analyze ship hydrodynamics in time domain.Based on the Bessel function,an Ordinary Differential Equation(ODE)was derived for time-domain Green function and its gradients in this paper.A new efficient calculation method based on solving ODE is proposed.It has been demonstrated by the numerical calculation that this method can improve the precision of the time-domain Green function.Numerical research indicates that it is efficient to solve the hydrodynamic problems.
基金Project(2012zzts019)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(201306370121)supported by State Scholarship Fund of ChinaProject(51248006)supported by the National Natural Science Foundation,China
文摘This work presented the development and validation of an analytical method to predict the transient temperature field in the asphalt pavement.The governing equation for heat transfer was based on heat conduction radiation and convection.An innovative time-dependent function was proposed to predict the pavement surface temperature with solar radiation and air temperature using dimensional analysis in order to simplify the complex heat exchange on the pavement surface.The parameters for the time-dependent pavement surface temperature function were obtained through the regression analysis of field measurement data.Assuming that the initial pavement temperature distribution was linear and the influence of the base course materials on the temperature of the upper asphalt layers was negligible,a close-form analytical solution of the temperature in asphalt layers was derived using Green's function.Finally,two numerical examples were presented to validate the model solutions with field temperature measurements.Analysis results show that the solution accuracy is in agreement with field data and the relative errors at a shallower depth are greater than those at a deeper one.Although the model is not sensitive to dramatic changes in climatic factors near the pavement surface,it is applicable for predicting pavement temperature field in cloudless days.
文摘Novel exact solutions of one-dimensional transient dynamic piezoelectric problems for thickness polarized layers and disks, or length polarized rods, are obtained. The solutions are derived using a time-domain Green’s function method that leads to an exact analytical recursive procedure which is applicable for a wide variety of boundary conditions including nonlinear cases. A nonlinear damper boundary condition is considered in more detail. The corresponding nonlinear relationship between stresses and velocities at a current time moment is used in the recursive procedure. In addition to the exact recursive procedure that is effective for calculations, some new practically important explicit exact solutions are presented. Several examples of the time behavior of the output electric potential difference are given to illustrate the effectiveness of the proposed exact approach.
基金Aeronautical Science Foundation of China （2008ZC52024）
文摘为板鳍热的精确分析与在预设以内控制电子设备设备的温度的能力下沉可控制的温度范围在电路设计并且为监视目的即时温度的过程两个都被要求。为了提供卓见进一个板鳍热水池的温度的行为，在表面上使不一致的热密度遭到了，获得产出在电子设备设备的任何点联系驱散的力量到温度上升的明确的公式的精确分析答案是必要的。这份报纸用源于一个适当的板鳍热水池的三维的热方程的一个分析答案为一个板鳍热水池的热模拟论述一个方法短暂热模型。全部答案方法论在板鳍热水池的特别例子上详细被说明表面上的使遭到的不一致的热密度。短暂温度侧面在板鳍热水池的表面为不同位置被获得。分析结果与在冷板的表面上做的大小相比，他们在对不到 3 K 的一个错误的好同意，这被发现。
