Volume CAD—CW-complexes based approach

A three‐dimensional Cartesian cut cell method for incompressible viscous flow with irregular domains

“…Moreover, the conventional CAD is incapable of providing input mesh data for the numerical analysis because it only yields the surface expression of an object. To overcome the above problems and bridge the gap between CADs and various computer simulation methods, a previously proposed VCAD system is adopted here to generate the Cartesian cut cells for the object. The two major characteristics of the VCAD system are as follows: Three‐dimensional voxel (cell) is used to decompose the boundary and inner space of an object.…”

“…Therefore, in practical applications, significant effort is still required to bridge the gap between CADs and various computer simulation methods, such as CFD and FEM, and to implement mesh generation for the object on the basis of its CAD expression. To satisfy the above demands of the Cartesian cut cell method in practical applications, Kase et al presented a three‐dimensional cut cell method for the approximate description of the curved surface and a general shape and volume attribute handling the platform for the direct application of CAD expressions to numerical simulations. However, the millions of cut cell shapes baffle the extension of this cut cell method and platform to CFD applications.…”

The construction of sets made by Bézier curves

“…In terms of a CAD system, an automatic feature extraction module constitutes a characteristic that facilitates design and process planning activity for the overall product realization process [7]. In conventional CAD, parametric surface such as NURBS (Non-Uniform Rational B-Spline) are used for their high degree of freedom of modeling surface shape with smooth continuity of differential geometric properties like curvature, tangents, and normal vectors [8]. As we known, the theory of NURBS was beginning from so called Bézier curve developed by Pierre Bézier [9].…”

Viscous micropump simulation by particle/continuum methods

“…In the case of liquid, the molecular length scale is small, and the continuum model may be still valid [10] . However, for a gas at the micro or nano scale, the rarefaction effect, the surface dominant effect and the compressibility effect may become significant, thus the flow solver must be able to accurately reflect the unique properties at this scale and the Navier-Stokes equations may not be available any more.The Volume-CAD (V-CAD) system as feature of Kitta Cube [11] can act as the platform for storing and handling both of the geometry data and volume data by representing them as attributes of a set of cells. The generated Cartesian background grids offer an efficient and elegant way of modeling complicated surface that cannot be described analytically.…”

“…The Volume-CAD (V-CAD) system as feature of Kitta Cube [11] can act as the platform for storing and handling both of the geometry data and volume data by representing them as attributes of a set of cells. The generated Cartesian background grids offer an efficient and elegant way of modeling complicated surface that cannot be described analytically.…”