Browsing by Author "Warburton, T."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    A short note on a Bernstein-Bezier basis for the pyramid
    (Society for Industrial and Applied Mathematics, 2016) Chan, Jesse; Warburton, T.
    We introduce a Bernstein--Bezier basis for the pyramid, whose restriction to the face reduces to the Bernstein--Bezier basis on the triangle or quadrilateral. The basis satisfies the standard positivity and partition of unity properties common to Bernstein polynomials and spans the same space as nonpolynomial pyramid bases in the literature. Procedures for differentiation and integration of these basis functions are also discussed.
  • Thumbnail Image
    Item
    A Comparison of High Order Interpolation Nodes for the Pyramid
    (Society for Industrial and Applied Mathematics, 2015) Chan, Jesse; Warburton, T.
    The use of pyramid elements is crucial to the construction of efficient hex-dominant meshes [M. Bergot, G. Cohen, and M. Duruflé, J. Sci. Comput., 42 (2010), pp. 345--381]. For conforming nodal finite element methods with mixed element types, it is advantageous for nodal distributions on the faces of the pyramid to match those on the faces and edges of hexahedra and tetrahedra. We adapt existing procedures for constructing optimized tetrahedral nodal sets for high order interpolation to the pyramid with constrained face nodes, including two generalizations of the explicit warp and blend construction of nodes on the tetrahedron [T. Warburton, J. Engrg. Math., 56 (2006), pp. 247--262]. Comparisons between nodal sets show that the lowest Lebesgue constants are given by warp and blend nodes for order $N\leq 7$ and Fekete nodes for $N>7$, though numerical experiments show little variation in the conditioning and accuracy of all surveyed nonequidistant points.
  • Thumbnail Image
    Item
    Reduced storage nodal discontinuous Galerkin methods on semi-structured prismatic meshes
    (Elsevier, 2017) Chan, Jesse; Wang, Zheng; Hewett, Russell J.; Warburton, T.
    We present a high order time-domain nodal discontinuous Galerkin method for wave problems on hybrid meshes consisting of both wedge and tetrahedral elements. We allow for vertically mapped wedges which can be deformed along the extruded coordinate, and present a simple method for producing quasi-uniform wedge meshes for layered domains. We show that standard mass lumping techniques result in a loss of energy stability on meshes of vertically mapped wedges, and propose an alternative which is both energy stable and efficient. High order convergence is demonstrated, and comparisons are made with existing low-storage methods on wedges. Finally, the computational performance of the method on Graphics Processing Units is evaluated.