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.


2013 ◽  
Vol 561 ◽  
pp. 559-563
Author(s):  
Hai Ming Hu ◽  
Hui Li ◽  
De Bao Yin

This paper introduces vectorization technology fromTrueType font for the text on the sidewall plate of the tire mold. TrueTypefont processing technology is the extraction of Windows functions and datatypes of the font outline. Call the API function to process the text in orderto achieve the CNC Machining of the text. It completes the tire mold word-processingsoftware on this basis. The software enables a variety of functions includingtext layout, font zoom, font spacing adjustment, font choice. It also providesa rapid tool for the quickly arranged and CNC machining of the text on thesidewall plate of the tire mold.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Parsa Omidi ◽  
Mohamadreza Najiminaini ◽  
Mamadou Diop ◽  
Jeffrey J. L. Carson

AbstractSpatial resolution in three-dimensional fringe projection profilometry is determined in large part by the number and spacing of fringes projected onto an object. Due to the intensity-based nature of fringe projection profilometry, fringe patterns must be generated in succession, which is time-consuming. As a result, the surface features of highly dynamic objects are difficult to measure. Here, we introduce multispectral fringe projection profilometry, a novel method that utilizes multispectral illumination to project a multispectral fringe pattern onto an object combined with a multispectral camera to detect the deformation of the fringe patterns due to the object. The multispectral camera enables the detection of 8 unique monochrome fringe patterns representing 4 distinct directions in a single snapshot. Furthermore, for each direction, the camera detects two π-phase shifted fringe patterns. Each pair of fringe patterns can be differenced to generate a differential fringe pattern that corrects for illumination offsets and mitigates the effects of glare from highly reflective surfaces. The new multispectral method solves many practical problems related to conventional fringe projection profilometry and doubles the effective spatial resolution. The method is suitable for high-quality fast 3D profilometry at video frame rates.


2013 ◽  
Vol 670 ◽  
pp. 202-207 ◽  
Author(s):  
Jun Ting Cheng ◽  
C. Zhao ◽  
W.L. Zhao ◽  
W.H. Wu

In the development of a three-dimensional measurement system, binocular stereo matching is the most important and difficult. In the basis of introducing selective principles of matching algorithm, a new stereo matching algorithm for binocular vision is put forward that is named noncoded difference measuring distance. The algorithm effectively grapples with the problem of searching for the coincidence relation of raster and can efficiently and accurately obtain three-dimensional world coordinates of the entities. Experiment results show that this 3D measuring machine can effectively measure the 3D solid profile of free surface. During the evaluation test for accuracy, scan a standard plane. Fit all 3D points in one plane, and then the flatness value of this plane is obtained. The flatness value of the standard plane has been ultimately measured as: ± 0.0462mm, this measuring accuracy can completely satisfy the requirements of rapid prototyping or CNC machining, it as well as achieves the stated accuracy (± 0.05mm).


ACTA IMEKO ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 142
Author(s):  
Giuseppe Schirripa Spagnolo ◽  
Lorenzo Cozzella ◽  
Fabio Leccese

<p class="Abstract">The relief of form is undoubtedly one of the most topical topics in the field of cultural heritage. Physical access to historic and artistic manufactures can be limited by a lot of factors. For example, the access to the collection of the ancient coins is difficult, especially for students. Indeed, for coins digital archive of high-quality three-dimensional model and remote fruition is of great interest. The use of projected fringes for the measurement of surface profile is a well-developed technique. In this paper, we present a surface profile measurement system for small objects of cultural heritage where it is important not only to detect the shape with good accuracy but also to capture and archive the signs due to ageing. The illustrated equipment is simple, reliable, and cheap. Furthermore, some examples of acquisitions are presented to demonstrate the potentiality of the proposed scheme for recovering 2.5D shape of cultural heritage objects.</p>


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