|
The spatial twist continuum is a dual representation of an all hexahedral mesh that defines the global connectivity constraint. Discovered by Dr. Peter Murdoch on 16 September 1993, the spatial twist continuum is a method that can be used in automatic and semi-automatic mesh generation methods to create all hexahedral meshes for both computational fluid dynamics and finite element method applications. The name is derived from the description of the surfaces that define the connectivity of the hexahedral elements. The surfaces are arranged in the three principal dimensions such that they form orthogonal intersections that conicide with the centroid of the hexahedral element. They are arranged predominately coplanar to each other in their respective dimensions yet they can twist into the other dimensional planes through transitions. The surfaces are unbroken throughout the entire volume of the mesh hence they are continuums. One of the areas where the STC finds application is CFD computational fluid dynamics which is a field of Science and analysis that involves simulating the flow of fluids such as air over and through bodies defined by boundary surfaces. The procedure involves building a mesh and solving the same on a computer using a finite volume approach. An analyst has many choices available for creating a mesh that can be used in a CFD or CAE simulation, one is to use a Tetrahedral, Polyhedral, Trimmed Cartesian or Mixed of Hybrid of Hexahedra called hex dominate, these are classified as non-structured meshes, which can all be created automatically, however the CFD and FEA results are both inaccurate and prone to solution divergence, (the simulation fails to solve). The other option for the analyst is to use an all-hexahedral mesh that offers far greater solver stability and speed as well as accuracy and the ability to run much more powerful turbulence solvers like Large eddy simulation LES in transient mode as opposed to the non-structured meshes that can only run a steady state RANS model. The difficulty with generating an all-hexahedral mesh on a complex geometry is that mesh needs to take into consideration the local geometric detail as well as the global connectivity constraint. This is the STC, and it is only present in an all-hexahedral mesh. This is the reason why it is relatively easy to automate a non-structured mesh, the automatic generator only needs to be concerned with the local cell size geometry. The tradeoffs and relative benefits of using either mesh method to build and solve a CFD or CAE model are best explained by looking at the total work flow. 1) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Spatial twist continuum」の詳細全文を読む スポンサード リンク
|