VOFTools - A software package of calculation tools for volume of fluid methods using general convex grids

The VOFTools library includes efficient analytical and geometrical routines for (1) area/volume computation, (2) truncation operations that typically arise in VOF (volume of fluid) methods, (3) area/volume conservation enforcement (VCE) in PLIC (piecewise linear interface calculation) reconstruction and(4) computation of the distance from a given point to the reconstructed interface. The computation of a polyhedron volume uses an efficient formula based on a quadrilateral decomposition and a 2D projection of each polyhedron face. The analytical VCE method is based on coupling an interpolation procedure to bracket the solution with an improved final calculation step based on the above volume computation formula. Although the library was originally created to help develop highly accurate advection and reconstruction schemes in the context of VOF methods, it may have more general applications. To assess the performance of the supplied routines, different tests, which are provided in FORTRAN and C, were implemented for several 2D and 3D geometries.VOFTools库包含高效的分析与几何运算程序，涵盖四大类功能：(1) 面积与体积计算；(2) 通常在流体体积（VOF, Volume of Fluid）方法中出现的界面截断操作；(3) 分段线性界面重构（PLIC, Piecewise Linear Interface Calculation）中的面积/体积守恒约束（VCE）；(4) 给定点到重构界面的距离计算。多面体体积计算采用基于四边形分解与各多面体面二维投影的高效计算公式。解析式VCE方法将用于限定解区间的插值过程，与基于上述体积计算公式的改进最终计算步骤相结合。尽管该库最初是为在VOF方法框架下开发高精度平流与重构方案而构建，但它亦可应用于更广泛的场景。为评估所提供运算程序的性能，研究团队针对多种二维与三维几何结构，开发了分别以FORTRAN和C语言实现的多组测试用例。