How to properly consider the impacts of non-hydrostatic perturbations is one of the challenging issues in developing non-hydrostatic dynamics solvers（NHDSs） for high-resolution atmospheric models. To overcome the dr...How to properly consider the impacts of non-hydrostatic perturbations is one of the challenging issues in developing non-hydrostatic dynamics solvers（NHDSs） for high-resolution atmospheric models. To overcome the drawbacks of current approaches to tackling this issue, this study analyzed the differences between hydrostatic dynamics solvers（HDSs） and their non-hydrostatic counterparts.The analysis then motivated a flexible approach to adjusting existing hydrostatic atmospheric models,especially those adopted in climate simulations for the impacts of non-hydrostatic perturbations.In this approach, the impacts of non-hydrostatic perturbations, reflecting the differences between HDSs and NHDSs, were encapsulated into a single term in the vertical momentum equation for the atmosphere. At each time step, this term was estimated by a separate sub-model, and then it was used to adjust the dynamics of the atmosphere. The adjustment was optional, and could be turned on and off flexibly by utilizing different initial conditions. The approach was illustrated using the Weather Research and Forecasting（WRF） model as an example, and was preliminarily validated by running the 3D baroclinic-wave test case in the model. Results showed that the modified dynamics solver produced simulation results that were very close to those given by the standard NHDS in the WRF model, implying that the approach was basically effective in capturing the non-hydrostatic features of the atmosphere.展开更多
This work deals with a description of a parametric tool for elastic analysis of wind turbine tower, incorporating all analysis steps （preprocessing, processing and post-processing）. The tower geometry is approximate...This work deals with a description of a parametric tool for elastic analysis of wind turbine tower, incorporating all analysis steps （preprocessing, processing and post-processing）. The tower geometry is approximated by fiat elements in which the membrane effects are evaluated using the FF （free formulation） finite element and the flexure effects are calculated using DKT （discrete shear triangle） finite element. The user-friendly system is implemented using OpenGL library to provide the graphical construction for geometry, mesh orientation, and other requirements of the finite element model. For the processing stage is built a specific dll library implemented in C＋＋ language for the analysis using the FF and DKT finite elements. The post-processing stage is build using specific dialogs box to present all results. The displacement results are visualized in the graphic interface to show the static and dynamic deformations of the tower. Some examples are presented to show all the tasks of the parametric tool.展开更多
基金supported by the National Key Research and Development Program[grant number 2016YFB0200805]the National Natural Science Foundation of China[grant number 41622503]
文摘How to properly consider the impacts of non-hydrostatic perturbations is one of the challenging issues in developing non-hydrostatic dynamics solvers（NHDSs） for high-resolution atmospheric models. To overcome the drawbacks of current approaches to tackling this issue, this study analyzed the differences between hydrostatic dynamics solvers（HDSs） and their non-hydrostatic counterparts.The analysis then motivated a flexible approach to adjusting existing hydrostatic atmospheric models,especially those adopted in climate simulations for the impacts of non-hydrostatic perturbations.In this approach, the impacts of non-hydrostatic perturbations, reflecting the differences between HDSs and NHDSs, were encapsulated into a single term in the vertical momentum equation for the atmosphere. At each time step, this term was estimated by a separate sub-model, and then it was used to adjust the dynamics of the atmosphere. The adjustment was optional, and could be turned on and off flexibly by utilizing different initial conditions. The approach was illustrated using the Weather Research and Forecasting（WRF） model as an example, and was preliminarily validated by running the 3D baroclinic-wave test case in the model. Results showed that the modified dynamics solver produced simulation results that were very close to those given by the standard NHDS in the WRF model, implying that the approach was basically effective in capturing the non-hydrostatic features of the atmosphere.
文摘This work deals with a description of a parametric tool for elastic analysis of wind turbine tower, incorporating all analysis steps （preprocessing, processing and post-processing）. The tower geometry is approximated by fiat elements in which the membrane effects are evaluated using the FF （free formulation） finite element and the flexure effects are calculated using DKT （discrete shear triangle） finite element. The user-friendly system is implemented using OpenGL library to provide the graphical construction for geometry, mesh orientation, and other requirements of the finite element model. For the processing stage is built a specific dll library implemented in C＋＋ language for the analysis using the FF and DKT finite elements. The post-processing stage is build using specific dialogs box to present all results. The displacement results are visualized in the graphic interface to show the static and dynamic deformations of the tower. Some examples are presented to show all the tasks of the parametric tool.
