scholarly journals Automatic generation of octree-based three-dimensional discretizations for Partition of Unity methods

2000 ◽  
Vol 25 (2-3) ◽  
pp. 296-304 ◽  
Author(s):  
O. Klaas ◽  
M. S. Shephard
2010 ◽  
Vol 88 (23-24) ◽  
pp. 1391-1411 ◽  
Author(s):  
Timon Rabczuk ◽  
Stéphane Bordas ◽  
Goangseup Zi

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Liqun Dong ◽  
Junwei Zhang ◽  
Liang Qin ◽  
Ping Xue ◽  
Yun Ma ◽  
...  

Abstract Owing to the existence of the cone angle, the size of a conical counter-rotating twin screw continuously changes along the axis, so it is not easy to model using SolidWorks. In this study, the parametric design of the modeling process is completed based on the Visual Basic language and a program-driven method. Finally, the SolidWorks program plug-in and user interface are developed to complete the automatic generation of the three-dimensional model of a conical counter-rotating twin screw.


Author(s):  
R. C. Schlaps ◽  
S. Shahpar ◽  
V. Gümmer

In order to increase the performance of a modern gas turbine, compressors are required to provide higher pressure ratio and avoid incurring higher losses. The tandem aerofoil has the potential to achieve a higher blade loading in combination with lower losses compared to single vanes. The main reason for this is due to the fact that a new boundary layer is generated on the second blade surface and the turning can be achieved with smaller separation occurring. The lift split between the two vanes with respect to the overall turning is an important design choice. In this paper an automated three-dimensional optimisation of a highly loaded compressor stator is presented. For optimisation a novel methodology based on the Multipoint Approximation Method (MAM) is used. MAM makes use of an automatic design of experiments, response surface modelling and a trust region to represent the design space. The CFD solutions are obtained with the high-fidelity 3D Navier-Stokes solver HYDRA. In order to increase the stage performance the 3D shape of the tandem vane is modified changing both the front and rear aerofoils. Moreover the relative location of the two aerofoils is controlled modifying the axial and tangential relative positions. It is shown that the novel optimisation methodology is able to cope with a large number of design parameters and produce designs which performs better than its single vane counterpart in terms of efficiency and numerical stall margin. One of the key challenges in producing an automatic optimisation process has been the automatic generation of high-fidelity computational meshes. The multi block-structured, high-fidelity meshing tool PADRAM is enhanced to cope with the tandem blade topologies. The wakes of each aerofoil is properly resolved and the interaction and the mixing of the front aerofoil wake and the second tandem vane are adequately resolved.


2013 ◽  
Vol 13 (1) ◽  
pp. 18-28 ◽  
Author(s):  
Chao-Hung Lin ◽  
Jyun-Yuan Chen ◽  
Shun-Siang Hsu ◽  
Yun-Huan Chung

Tourist maps are designed to direct tourists to tourist attractions in unfamiliar areas. A well-designed tourist map can provide tourists with sufficient and intuitive information about places of interest. Thus, providing up-to-date information on places of interest and selecting their representative icons are fundamental and important in automatic generation of tourist maps. In this article, approaches for determining places of interest and for determining their representative icons are introduced. In contrast to general digital tourist maps that use text, simple shapes, or three-dimensional models, we use photos that offer abundant visual features of places of interest as icons in tourist maps. The photos are automatically extracted from a repository of photos downloaded from photo-sharing communities. Tourist attractions and their corresponding image icons are determined by means of photo voting and photo quality assessment. Qualitative analyses, including a user study and experiments in several areas with numerous tourist attractions, indicated that the proposed method can generate visually pleasant and elaborate tourist maps. In addition, the analyses indicated that the map produced by our method is better than maps generated by related methods and is comparable to hand-designed tourist maps.


Author(s):  
Olga Petrenko ◽  
Mateu Sbert ◽  
Olivier Terraz ◽  
Djamchid Ghazanfarpour

Flowers belong to one of the natural phenomena that cannot be captured completely, as there is enormous variety of shapes both within and between individuals. The authors propose a procedural modeling of flowering plants using an extension of L-Systems – a model based on three-dimensional generalized maps. Conventionally, in order to build a model the user has to write the grammar, which consists of the description of 3Gmaps and all the production rules. The process of writing a grammar is usually quite laborious and tedious. In order to avoid this the authors propose new interface functionality: the inverse modeling by automatic generation of L-systems. The user describes the flower he wants to model, by assigning the properties of its organs. The algorithm uses this information as an input, which is then analyzed and coded as L-systems grammar.


Author(s):  
D. J. Zhang ◽  
M. Zeng ◽  
Q. W. Wang

Recuperator in a microturbine system, which has to work under a high temperature and high pressure condition, is a key component to improve the electricity efficiency of the system. High temperature and pressure may cause high stress inside the Cross-Wavy Primary Surface (CWPS) sheet, and it is essential to analyze the stress distribution to ensure the security while the recuperator is working. In this paper the combined thermomechanical design of a CWPS recuperator for a 100kW microturbine system is presented. With the ANSYS Parametric Design Language (APDL), calculation procedures for heat transfer and stress analysis are combined in order to perform a reliable strength prediction of the recuperator. A program has been generated, which allows the automatic generation of the numerical model, the mesh and the boundary conditions. Also with the energy minimum principle, an optimal configuration of the air and gas passages is obtained. The results show that the material of the primary sheet (0Cr18Ni11Nb) is reliable. The stress distribution changes with the different configuration of the passages. Since the air pressure is much higher than that of the exhaust gas, the configuration of the primary sheet is much better when the sectional area of the gas passage is larger than that of the air passage. If the pitch of the sheet is maintained at 2mm, the best configuration is obtained when the dimension of passage is at r = 0.35–0.42mm, R = 0.55–0.48mm.


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