scholarly journals A Computer Aided Design Method for Vaned Diffusers in Centrifugal Compressors

1984 ◽  
Author(s):  
F. S. Bhinder ◽  
M. M. H. Al-Modafar
Keyword(s):  
Computer Aided Design ◽  
Design Method ◽  
Pressure Recovery ◽  
Two Dimensional ◽  
Centrifugal Compressors ◽  
Optimum Pressure ◽  
Computer Aided ◽  
Geometrical Data ◽  
Aided Design

A procedure for designing the vaned diffusers incorporating wedge type vanes has been described. By transforming the geometrical data into the usual parameters for straight two-dimensional diffusers, the influence of some of the important variables on pressure recovery can be investigated. The results can then be used to select the values of these variables for optimum pressure recovery.

scholarly journals Design Method of Circular Weft-Knitted Jacquard Fabric Based on Jacquard Module

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Peixiao Zheng ◽  
Gaoming Jiang ◽  
Honglian Cong
Keyword(s):  
Mathematical Modeling ◽  
Computer Aided Design ◽  
Theoretical Basis ◽  
Design Method ◽  
Two Dimensional ◽  
Design Procedures ◽  
Rapid Design ◽  
Computer Aided ◽  
Aided Design

Abstract Recently, there is an increasing interest in design of circular weft jacquard because of the pursuit of fashion and comfort. Aiming at the complexity of the computer-aided design method of the existing circular weft-knitted jacquard fabrics, which is not conducive to the rapid design and intelligible for designers, a design method was proposed to transform pattern notation into knitting diagram efficiently, which was based on knitting rules and its creation as a set of jacquard modules. Knitting characteristics of jacquard fabrics were studied as a precondition. On this basis, the design procedures of jacquard modules were analyzed and illustrated by taking tricolor bird's eye backing jacquard as an example. Jacquard modules with various jacquard effects were designed and stored in a jacquard module database. To mathematically describe pattern notation, knitting diagram, and jacquard module, two-dimensional matrixes were established by the method of mathematical modeling, and a corresponding algorithm for the transformation of the pattern to knitting information according to the knitting rules of jacquard modules, which can be applied to ordinary jacquard fabrics was summarized. The project of tricolor circular weft-knitted jacquard with bird's eye in the reverse and four-color air-layer jacquard were taken for instance to verify the models and algorithm. The results obtained show that the approach can efficiently and conveniently realize the designation and machine-knitting of weft-knitted jacquard fabric, which provide a theoretical basis and notation of modeling for the computer-aided design of circular weft-knitted jacquard fabrics.

scholarly journals Computational wrapping: A universal method to wrap 3D-curved surfaces with nonstretchable materials for conformal devices

2020 ◽  
Vol 6 (15) ◽  
pp. eaax6212 ◽  
Author(s):  
Yu-Ki Lee ◽  
Zhonghua Xi ◽  
Young-Joo Lee ◽  
Yun-Hyeong Kim ◽  
Yue Hao ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Reliable Method ◽  
Design Method ◽  
Universal Method ◽  
Curved Surfaces ◽  
Two Dimensional ◽  
Steel Sheets ◽  
Computer Aided ◽  
Conformal Structures ◽  
Aided Design

This study starts from the counterintuitive question of how we can render conventional stiff, nonstretchable, and even brittle materials sufficiently conformable to fully wrap curved surfaces, such as spheres, without failure. Here, we extend the geometrical design method of computational origami to wrapping. Our computational wrapping approach provides a robust and reliable method for fabricating conformal devices for arbitrary curved surfaces with a computationally designed nonpolyhedral developable net. This computer-aided design transforms two-dimensional (2D)–based materials, such as Si wafers and steel sheets, into various targeted conformal structures that can fully wrap desired 3D structures without fracture or severe plastic deformation. We further demonstrate that our computational wrapping approach enables a design platform that can transform conventional nonstretchable 2D-based devices, such as electroluminescent lighting and flexible batteries, into conformal 3D curved devices.

Design of Longitudinal Beam Layout on a Curved Shell Based on the Production-Oriented Design Concept

1994 ◽  
Vol 10 (04) ◽  
pp. 217-222
Author(s):  
Kohji Honda ◽  
Noriyuki Tabushi
Keyword(s):  
Crude Oil ◽  
Computer Aided Design ◽  
Design Method ◽  
Three Dimensional ◽  
Design System ◽  
Two Dimensional ◽  
Skilled Workers ◽  
System A ◽  
Computer Aided ◽  
Aided Design

A VLCC (very large crude oil carrier) has approximately 1000 curved longitudinal beams, many of which have three-dimensional complicated curvatures. Due to the shortage of highly skilled workers and the need to keep costs down, production and structural designers have worked to reduce the number of such beams. In order to meet the requirements of production, the authors' company has attempted several design approaches for the longitudinal beam layout to reduce the number of beams that have complicated curvature. Recently, through the application of a computer-aided design system, which has been improved for shipbuilding based on the Calma's system, a new design method for the longitudinal beam layout has been successfully developed. A significant number of beams with a twisted configuration have been eliminated and replaced with beams of simpler, two-dimensional shapes. This paper shows the transition of these design approaches, and the application of the new design to building a VLCC.

scholarly journals Computer-Aided Sketching: Incorporating the Locus to Improve the Three-Dimensional Geometric Design

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1181 ◽  
Author(s):  
José Ignacio Rojas-Sola ◽  
David Hernández-Díaz ◽  
Ricardo Villar-Ribera ◽  
Vicente Hernández-Abad ◽  
Francisco Hernández-Abad
Keyword(s):  
Computational Geometry ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Geometric Design ◽  
Curved Surfaces ◽  
Two Dimensional ◽  
Technical Design ◽  
Computer Aided ◽  
Aided Design

This article presents evidence of the convenience of implementing the geometric places of the plane into commercial computer-aided design (CAD) software as auxiliary tools in the computer-aided sketching process. Additionally, the research considers the possibility of adding several intuitive spatial geometric places to improve the efficiency of the three-dimensional geometric design. For demonstrative purposes, four examples are presented. A two-dimensional figure positioned on the flat face of an object shows the significant improvement over tools currently available in commercial CAD software, both vector and parametric: it is more intuitive and does not require the designer to execute as many operations. Two more complex three-dimensional examples are presented to show how the use of spatial geometric places, implemented as CAD software functions, would be an effective and highly intuitive tool. Using these functions produces auxiliary curved surfaces with points whose notable features are a significant innovation. A final example provided solves a geometric place problem using own software designed for this purpose. The proposal to incorporate geometric places into CAD software would lead to a significant improvement in the field of computational geometry. Consequently, the incorporation of geometric places into CAD software could increase technical-design productivity by eliminating some intermediate operations, such as symmetry, among others, and improving the geometry training of less skilled users.

A Computational Geometry for the Blades and Internal Flow Channels of Centrifugal Compressors

1983 ◽  
Vol 105 (2) ◽  
pp. 288-295 ◽  
Author(s):  
M. V. Casey
Keyword(s):  
Computational Geometry ◽  
Computer Aided Design ◽  
Design Procedure ◽  
Internal Flow ◽  
Geometrical Shape ◽  
Parametric Form ◽  
Centrifugal Compressors ◽  
Flow Channels ◽  
Computer Aided ◽  
Aided Design

A new computational geometry for the blades and flow passages of centrifugal compressors is described and examples of its use in the design of industrial compressors are given. The method makes use of Bernstein-Bezier polynomial patches to define the geometrical shape of the flow channels. This has the following main advantages: the surfaces are defined by analytic functions which allow systematic and controlled variation of the shape and give continuous derivatives up to any required order: and the parametric form of the equations allows the blade and channel coordinates to be very simply obtained at any number of points and in any suitable distribution for use in subsequent aerodynamic and stress calculations and for manufacture. The method is particularly suitable for incorporation into a computer-aided design procedure.

A Review on Fabricating Procedures in Rapid Prototyping

2016 ◽  
Vol 6 (2) ◽  
pp. 23-40 ◽  
Author(s):  
Ganzi Suresh ◽  
K. L. Narayana
Keyword(s):  
Rapid Prototyping ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Rapid Manufacturing ◽  
Two Dimensional ◽  
Computer Aided ◽  
Aided Design ◽  
Crude Material

Rapid prototyping (RP) advancements are in light of the rule of making three-dimensional geometries straightforwardly from computer aided design (CAD) by stacking two-dimensional profiles on top of one another. Rapid manufacturing (RM) is the utilization of rapid prototyping advancements to make end-utilize or completed items. Aside from the ordinary assembling methods which are utilized for quite a while assembling of an item, added substance assembling methodologies have picked up force in the late years. The explanation for this is that these techniques don't oblige extraordinary tooling and don't evacuate material which is exceptionally advantageous really taking shape of a segment. Rapid manufacturing is the developing innovation in assembling commercial ventures with a specific end goal to create the model inside the less time and expense effective. In this paper we talked about a portion of the fast assembling advancements in light of the sort of crude material is utilized for the procedures, applications, preferences and limits.

A Method of Determining the Direction of Two Dimensional Curves

2014 ◽  
Vol 980 ◽  
pp. 159-164
Author(s):  
F. Wang ◽  
R.K.F. Abdelmaguid ◽  
H.M.A. Hussein
Keyword(s):  
Computer Aided Design ◽  
Tangent Vector ◽  
Two Dimensional ◽  
Linear Algorithm ◽  
Complete Cycle ◽  
Angular Change ◽  
Computer Aided ◽  
Aided Design ◽  
Relationship Of

Two-dimensional curves are represented by a list of vertices and other parameters that control the shape or curvature of the segments. In computer programming to deal with closed two-dimensional curves, it is often required to know the direction of the curve, which is reflected by the sequence of the vertex data. It can be anticlockwise or clockwise. This paper presents a robust, linear algorithm to determine the direction of a closed two-dimensional curve, by computing the total angular change of a tangent vector travelling along the curve for a complete cycle. A new, robust linear algorithm is proposed for the determination of the positional relationship of a point to a two-dimensional curve. For curves that consist of line and arc segments, which are most commonly used in engineering applications in computer aided design, the paper presents algorithms and procedures for solving the above problems.

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