scholarly journals Multiblock Grid Generation for Simulations in Geological Formations

Author(s):  
Sanjay Kumar Khattri
Author(s):  
Muting Hao ◽  
Feng Wang ◽  
Joshua Hope-Collins ◽  
Max E. Rife ◽  
Luca di Mare

Abstract This paper describes a multiblock grid generation method for turbine cooling geometries. The method is based on the observation that cooling films are essentially branches inserted on a large trunk, represented by the passage or by the cooling duct. The small size of the films compared to the overall size of turbine blades allows simplifications to be introduced with respect to general-purpose trunk and branch algorithms. The grid generation starts from an existing layout for the passage or cooling duct grid and operates on a Cartesian patch of the trunk surface. The patch is hollowed and a templated branch layout is inserted. Padding blocks are created to connect the two layouts into a single, boundary conforming layout. The resulting multiblock grid is then smoothed using a modification of Thompson’s Poisson system. The boundary mesh distribution is not prescribed. Instead, boundary orthogonality is enforced and elliptic smoothing is performed on the boundaries as well as inside the volume. The grid size control relies on a novel Newton-like update for the control functions of the Poisson system. The smoothing step is essential in achieving good grid quality throughout and determines, in part, the template for a given configuration. The algorithm is particularly suitable for large arrays of films or other cooling decoration and results show that the proposed method can produce grids of better quality than existing methods.


2017 ◽  
Vol 26 (1) ◽  
pp. 53-68
Author(s):  
Mark Byron

Scholarly research over the last twenty years has marked a profound shift in the understanding of Beckett's sources, his methods of composition, and his attitudes towards citation and allusion in manuscript documents and published texts. Such landmark studies as James Knowlson's biography, Damned to Fame (1996), and John Pilling's edition of the Dream Notebook (1999), and the availability of primary documents such as Beckett's reading notes at Reading and Trinity libraries, opened the way for a generation of work rethinking Beckett's textual habitus. Given this profound reappraisal of Beckett's material processes of composition, this paper seeks to show that Beckett's late prose work, Worstward Ho, represents a profound mediation on writing, self-citation, and habits of allusion to the literary canon. In its epic gestures, it reorients the heavenly aspiration of Dante's Commedia earthwards, invoking instead the language of agriculture, geology and masonry in the process of creating and decreating its imaginative space. Beckett's earthy epic invokes and erodes the first principles of narrative by way of philology as well as by means of deft reference to literary texts and images preoccupied with land, farming, and geological formations. This process is described in the word corrasion, a geological term referring to the erosion of rock by various forms of water, ice, snow and moraine. Textual excursions into philology in Worstward Ho also unearth the strata comprising Beckett's corpus (in particular Imagination Dead Imagine, The Lost Ones, and Ill Seen Ill Said), as well as the rock or canon upon which his own literary production is built. A close reading of Worstward Ho turns up a number of shrewd allusions to the King James Bible and Thomas Browne, as one might expect, but also perhaps surprisingly sustained affinities with the literary sensibilities of Alexander Pope and the poetry of S. T. Coleridge. The more one digs, the more Beckett's ‘little epic’ seems to become one of earthworks, bits of pipe, and masonry, a site and record of literary sedimentation.


AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 768-770 ◽  
Author(s):  
Reijo Lehtimaki

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