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Full-Text Articles in Engineering
Helios And Tenasi Results For The Workshop For Integrated Propeller Prediction, Aaron Crawford
Helios And Tenasi Results For The Workshop For Integrated Propeller Prediction, Aaron Crawford
Honors Theses
Beginning in 2018, the AIAA began the workshop for integrated propeller prediction. This effort was intended to bolster the CFD prediction capabilities of the aerospace community due to a resurgent interest in propeller driven vehicles for electric applications. The test bed for this workshop is the NASA X-57, a model of which was experimentally tested in the Lockheed Martin Low Speed Wind Tunnel in January 2019. Using the 3D scanned geometry provided by the workshop a mesh was created and all priority one simulations were performed using two flow solvers. The flow solvers used were Helios, developed by the ADD …
Mesh Generation Using A Correspondence Distance Field, Nicholas Szapiro
Mesh Generation Using A Correspondence Distance Field, Nicholas Szapiro
Masters Theses and Doctoral Dissertations
The central tool of this work is a correspondence distance field to discrete surface points embedded within a quadtree data structure. The theory, development, and implementation of the distance field tool are described, and two main applications to two-dimensional mesh generation are presented with extension to three-dimensional capabilities in mind. First is a method for surface-oriented mesh generation from a sufficiently dense set of discrete surface points without connectivity information. Contour levels of distance from the body are specified and correspondences oriented normally to the contours are created. Regions of merging fronts inside and between objects are detected in the …
Comparison Of Two Methods For Two Dimensional Unstructured Mesh Adaptation With Elliptic Smoothing, Matthew David O'Connell
Comparison Of Two Methods For Two Dimensional Unstructured Mesh Adaptation With Elliptic Smoothing, Matthew David O'Connell
Masters Theses and Doctoral Dissertations
A new mesh adaptation method for unstructured grids is presented. The technique uses virtual control volumes that are iteratively manipulated to conform the mesh to match either a Riemannianmetric tensor field or an equal distribution of scalar weights. Forcing functions similar to those used for structured grids are employed such that the resulting meshes can be compared with those generated using the new adaptation method. Several test cases using analytic functions to drive the mesh adaptation are also presented and compared with the new method. Mesh adaptation results driven by computed flow field information are also compared to those adapted …
An Adaptive Hybrid Mesh Generation Method For Complex Geometries, Cameron Thomas Druyor
An Adaptive Hybrid Mesh Generation Method For Complex Geometries, Cameron Thomas Druyor
Masters Theses and Doctoral Dissertations
An adaptive hybrid mesh generation method is described to automatically provide spatial discretizations suitable for computational fluid dynamics or other 2D solver applications. This method employs a hierarchical grid generation technique to create a background mesh, an extrusion-type method for inserting boundary layers, and an unstructured triangulation to stitch between the boundary layers and background mesh. This method provides appropriate mesh resolution based on geometry segments from a file, and has the capability of adapting the background mesh based on a spacing field generated from solution data or some other arbitrary source. By combining multiple approaches to the grid generation …
Generation And Optimization Of Spacing Fields, Max David Collao
Generation And Optimization Of Spacing Fields, Max David Collao
Masters Theses and Doctoral Dissertations
Meshes are used to discretize space for computational fluid dynamics (CFD) simulations. Mesh adaptation through refinement and smoothing can improve the accuracy of the CFD solution. In order to perform adaptive refinement or smoothing a spacing field is needed to define the desired edge sized in mesh. The objectives of this research are to generate spacing fields from existing CFD solutions and optimize this spacing information for efficient use by programs to perform adaptive refinement or smoothing. All work was done on 2D meshes with the intention of gaining knowledge and experience for later application to 3D meshes. The program …
Unstructured Grid Technologies For Hydrodynamic Applications With Bodies In Relative Motion And Mesh Deformation, Lei Ji
Masters Theses and Doctoral Dissertations
Unstructured grid technologies for hydrodynamic applications with bodies in relative motion and mesh deformation are presented. A parallel universal mesh deformation scheme is developed to manage deforming surface and volume grids for both aerodynamic and hydrodynamic applications. The approach is universal and independent of grid type. Also, it requires minimal inter-processor communication and is thus perfectly suitable to a parallel platform. The original scheme of Allen (2006) has difficulty deforming volume grids in regions near concave geometry features and for abrupt grid resolution changes. Several modifications are proposed to overcome these problems. Grid quality can be improved significantly by adding …
Winslow Elliptic Smoothing Equations Extended To Apply To General Regions Of An Unstructured Mesh, James Steven Masters
Winslow Elliptic Smoothing Equations Extended To Apply To General Regions Of An Unstructured Mesh, James Steven Masters
Masters Theses and Doctoral Dissertations
In any engineering endeavor, it is important to have the ability to efficiently and intelligently break up a region of interest in order to explore and investigate the interesting and dynamic aspects of the system enclosed in the region. In the field of fluid mechanics - and, in particular, computational fluid dynamics - this region breakup (known as discretization) has traditionally been done using structured meshes but, because of their flexibility with capturing real-world geometry, unstructured meshes are being increasingly utilized. Not surprisingly, techniques that have traditionally been reserved for structured meshes are migrating to the world of unstructured meshing …