The Design of a Large Single-Screw Melt Extruder Using a Quasi Two-Dimensional Conducting Screw Computer Model

1997 ◽  
Vol 119 (4A) ◽  
pp. 644-648 ◽  
Author(s):  
D. R. Samuel Jones ◽  
P. S. Ghoshdastidar ◽  
M. K. Muju ◽  
Manab K. Das
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Computer Aided Design ◽  
Transfer Model ◽  
Two Dimensional ◽  
Newtonian Flow ◽  
Single Screw ◽  
Flow And Heat Transfer ◽  
Computer Aided ◽  
Aided Design

This paper describes a computer-aided design study for a large (5000 kg/hr) single-screw melt extruder processing 0.2 MFI LDPE using a quasi 2D steady-state non-Newtonian flow and heat transfer model that takes into account screw conduction. The effect of different screw materials has also been investigated.

Teaching computer-aided design of fluid flow and heat transfer engineering equipment

1979 ◽  
Vol 3 (2) ◽  
pp. 111-118 ◽  
Author(s):  
A.D. Gosman ◽  
B.E. Launder ◽  
F.C. Lockwood ◽  
P.A. Newton ◽  
G.J. Reece ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Computer Aided Design ◽  
Engineering Equipment ◽  
Flow And Heat Transfer ◽  
Computer Aided ◽  
Aided Design

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 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.

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.

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.

A Computer-Aided Design and Manufacturing Implementation of the Atomic Force Microscope Tip-Based Nanomachining Process for Two-Dimensional Patterning

2017 ◽  
Vol 5 (4) ◽  
Author(s):  
E. B. Brousseau ◽  
S. Thiery ◽  
B. Arnal ◽  
E. Nyiri ◽  
O. Gibaru ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Computer Aided Design ◽  
Two Dimensional ◽  
Atomic Force ◽  
Machining Errors ◽  
Computer Aided ◽  
Design And Manufacturing ◽  
Cad Cam ◽  
G Code ◽  
Aided Design

This paper reports a feasibility study that demonstrates the implementation of a computer-aided design and manufacturing (CAD/CAM) approach for producing two-dimensional (2D) patterns on the nanoscale using the atomic force microscope (AFM) tip-based nanomachining process. To achieve this, simple software tools and neutral file formats were used. A G-code postprocessor was also developed to ensure that the controller of the AFM equipment utilized could interpret the G-code representation of tip path trajectories generated using the computer-aided manufacturing (CAM) software. In addition, the error between a machined pattern and its theoretical geometry was also evaluated. The analyzed pattern covered an area of 20 μm × 20 μm. The average machined error in this case was estimated to be 66 nm. This value corresponds to 15% of the average width of machined grooves. Such machining errors are most likely due to the flexible nature of AFM probe cantilevers. Overall, it is anticipated that such a CAD/CAM approach could contribute to the development of a more flexible and portable solution for a range of tip-based nanofabrication tasks, which would not be restricted to particular customised software or AFM instruments. In the case of nanomachining operations, however, further work is required first to generate trajectories, which can compensate for the observed machining errors.

Temperature Stability of Heteropolytypic 6H/3C FETs

2007 ◽  
Vol 556-557 ◽  
pp. 843-846
Author(s):  
Chia Ching Chen ◽  
Alton B. Horsfall ◽  
Nicolas G. Wright ◽  
Konstantin Vassilevski
Keyword(s):  
Density Distribution ◽  
Computer Aided Design ◽  
Electron Density Distribution ◽  
Temperature Stability ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Electron Gases ◽  
Computer Aided ◽  
Band Profile ◽  
Aided Design

The formation of two-dimensional electron gases (2DEG) at the polytypic 6H/3C heterojunction is investigated. The main of study was to obtain the properties of the 3C/6H structure using Technology Computer Aided Design (TCAD) software. The electron-density distribution and conduction band profile in 6H/3C SiC heterojunction are calculated as a function of temperature. Simulation of these hetero-junctions has concentrated on the I-V behaviour over a range of temperatures between 350 and 650 K. We show that the device characteristics are substantially degraded at high temperatures and this will limit the use of these devices to moderate temperature applications.

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