Rapid B-rep model preprocessing for immersogeometric analysis using analytic surfaces.
Rapid B-rep model preprocessing for immersogeometric analysis using analytic surfaces.
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DOI：
10.1016/j.cagd.2017.03.002
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发表时间：
2017-03
影响因子：
1.5
通讯作者：
Krishnamurthy A
中科院分区：
文献类型：
--
作者：
Wang C;Xu F;Hsu MC;Krishnamurthy A
复杂物体上的流动的计算流体动力学（CFD）模拟传统上使用符合物体形状的流体域网格来执行。然而，为复杂的几何形状（如汽车）创建形状一致的网格需要大量的几何预处理。这个过程通常是乏味的，需要修改几何体，包括专门的操作，如defeaturing和填充小间隙。开发了一种新的immersogeometric流体流动方法，不需要生成的边界拟合网格的流体域。然而，他们的方法使用了曲面的NURBS参数化来生成曲面求积点以强制边界条件，这需要在执行分析之前将B-rep模型完全转换为NURBS。此转换通常会导致参数化不佳的NURBS曲面，并可能导致修剪不佳或缺少曲面特征。此外，将简单几何体（如圆柱体）转换为NURBS会带来性能损失，因为这些几何体必须作为有理样条处理。因此，在转换后必须再次检查几何形状以确保分析兼容性，并且可能增加计算成本。在这项工作中，我们已经扩展了immersogeometric方法直接使用解析曲面生成曲面求积点。我们已经制定了所有四种解析曲面的求积规则：平面、圆锥、球面和圆环面。我们还开发了方法进行自适应正交修剪解析曲面。由于解析曲面经常用于构建实体模型，因此这种方法在现实世界的几何体上生成正交点的速度也比仅使用NURBS曲面更快。为了评估所提出的方法的准确性，我们进行了一个基准问题的流在鱼雷形状的分析表面的模拟，并比较这些相同的模型与NURBS曲面的immersogeometric模拟。我们还比较了我们的immersogeometric方法的结果与那些使用边界拟合CFD的镶嵌鱼雷形状，和感兴趣的量，如阻力系数是在良好的协议。最后，我们证明了我们的immersogeometric方法高保真工业规模的模拟的有效性，通过执行一辆卡车，有很大比例的分析表面的空气动力学分析。在NURBS上使用解析曲面可避免不必要的曲面类型转换，并显著减少模型预处理时间，同时为感兴趣的空气动力学量提供相同的精度。
Computational fluid dynamics (CFD) simulations of flow over complex objects have been performed traditionally using fluid-domain meshes that conform to the shape of the object. However, creating shape conforming meshes for complicated geometries like automobiles require extensive geometry preprocessing. This process is usually tedious and requires modifying the geometry, including specialized operations such as defeaturing and filling of small gaps. developed a novel immersogeometric fluid-flow method that does not require the generation of a boundary-fitted mesh for the fluid domain. However, their method used the NURBS parameterization of the surfaces for generating the surface quadrature points to enforce the boundary conditions, which required the B-rep model to be converted completely to NURBS before analysis can be performed. This conversion usually leads to poorly parameterized NURBS surfaces and can lead to poorly trimmed or missing surface features. In addition, converting simple geometries such as cylinders to NURBS imposes a performance penalty since these geometries have to be dealt with as rational splines. As a result, the geometry has to be inspected again after conversion to ensure analysis compatibility and can increase the computational cost. In this work, we have extended the immersogeometric method to generate surface quadrature points directly using analytic surfaces. We have developed quadrature rules for all four kinds of analytic surfaces: planes, cones, spheres, and toroids. We have also developed methods for performing adaptive quadrature on trimmed analytic surfaces. Since analytic surfaces have frequently been used for constructing solid models, this method is also faster to generate quadrature points on real-world geometries than using only NURBS surfaces. To assess the accuracy of the proposed method, we perform simulations of a benchmark problem of flow over a torpedo shape made of analytic surfaces and compare those to immersogeometric simulations of the same model with NURBS surfaces. We also compare the results of our immersogeometric method with those obtained using boundary-fitted CFD of a tessellated torpedo shape, and quantities of interest such as drag coefficient are in good agreement. Finally, we demonstrate the effectiveness of our immersogeometric method for high-fidelity industrial scale simulations by performing an aerodynamic analysis of a truck that has a large percentage of analytic surfaces. Using analytic surfaces over NURBS avoids unnecessary surface type conversion and significantly reduces model-preprocessing time, while providing the same accuracy for the aerodynamic quantities of interest.
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影响因子：
4.1
作者：
Hsu MC;Kamensky D;Xu F;Kiendl J;Wang C;Wu MC;Mineroff J;Reali A;Bazilevs Y;Sacks MS
通讯作者：
Sacks MS
DOI：
10.1016/j.cma.2008.11.020
发表时间：
2010-01-01
影响因子：
7.2
作者：
Bazilevs, Y.;Michler, C.;Hughes, T. J. R.
通讯作者：
Hughes, T. J. R.
DOI：
10.1016/j.cma.2008.02.036
发表时间：
2008-01-01
影响因子：
7.2
作者：
Duester, A.;Parvizian, J.;Rank, E.
通讯作者：
Rank, E.
DOI：
10.1016/j.cma.2007.07.016
发表时间：
2007-01-01
影响因子：
7.2
作者：
Bazilevs, Y.;Calo, V. M.;Scovazzi, G.
通讯作者：
Scovazzi, G.
影响因子：
1.5
作者：
Hsu, Ming-Chen;Wang, Chenglong;Krishnamurthy, Adarsh
通讯作者：
Krishnamurthy, Adarsh