The calculation of gear pump porting areas by mathematical means

2014 ◽  
Vol 229 (1) ◽  
pp. 180-188 ◽  
Author(s):  
Martin K Yates
Keyword(s):  
Computer Aided Design ◽  
Gear Pump ◽  
Fuel Delivery ◽  
Lumped Parameter ◽  
Pinion Gear ◽  
Computer Aided ◽  
Gear Pumps ◽  
Aero Engines ◽  
Definition Of ◽  
Aided Design

Twin pinion gear pumps are used widely in industrial hydraulics and as fuel-delivery pumps for aero engines. The kinematics of the pumping action leads to high-flow rates into and out of the meshing gears, and at the high speeds used with aerospace fuel pumps cavitation can occur. One-dimensional ‘lumped parameter’ models are often used to analyse this type of pump. These methods rely on an accurate description of the volume trapped by the meshing teeth and the flow areas during the meshing cycle. Typically, multiple computer-aided design models have to be created to calculate these values during the meshing cycle. This paper presents a mathematical method for calculating these parameters based on a parametric definition of the gear and inlet and outlet porting. Green's theorem is used to allow line integrals around the periphery of the tooth spaces to be used to calculate the volumes and flow areas. Winding numbers are used to calculate the inflow and outflow areas that are formed by the intersection of the trapped volume and the side area porting. The method is validated against computer-aided design model data. This method is well suited for incorporation in an optimisation algorithm since the geometry is defined parametrically.

Computer-Aided Design Synthesis Using Syntactic Solid Modeling

1994 ◽  
Author(s):  
Vassilios E. Theodoracatos ◽  
Xiaogang Guan
Keyword(s):  
Computer Aided Design ◽  
Solid Modeling ◽  
Large Set ◽  
Complex Structures ◽  
Design Synthesis ◽  
Computer Aided ◽  
Grammar Rules ◽  
Small Set ◽  
Definition Of ◽  
Aided Design

Abstract This paper presents a new Computer-Aided Design (CAD) synthesis model which uses Plex Grammar as structural relationship descriptors and NURBS surface representation for constructing standard and non-standard solid entities. Here, the designer uses a syntactic design methodology for early topological and geometrical definition of the structure of concept alternatives resulting from the design process. This syntactic scheme provides the capability of describing a large set of complex structures by using a small set of simple entities. The recursive nature of the grammar and the hierarchical representation of the structure makes the description of complex structures simple and under the direct control of the designer. An object structure constructive tree is generated and subsequently translated into Plex Grammar production rules in order to form an Interconnection Matrix (ICM) expressing. The resulting Plex structure defined in the ICM expresses the topological information among entities which form the specific types of objects. By modifying the Plex grammar rules, various objects with different geometry and topology can easily be reconstructed. Compared to conventional solid modeling techniques, this approach provides more systematic object generation, easy manipulation and modification, control over congruity and the ability to represent sculptured shapes. Several examples of syntactic solid modeling applied in design synthesis will be presented for further usage in downstream applications.

A Dual Environment for 3D Modeling With User-Defined Freeform Features

2009 ◽  
Vol 9 (2) ◽  
Author(s):  
Thomas R. Langerak ◽  
Joris S. M. Vergeest
Keyword(s):  
3D Modeling ◽  
Computer Aided Design ◽  
Target Surface ◽  
Feature Modeling ◽  
Dynamic Feature ◽  
Design Features ◽  
Computer Aided ◽  
Definition Of ◽  
High Level ◽  
Aided Design

Modeling with freeform features has become the standard in computer-aided design. Features offer a high-level approach to modeling shapes. However, in most commercial modeling packages, only a static set of freeform features is available. A new method for user-driven feature definition is presented, as well as a method to instantiate these user-defined features on a target surface. We propose the concept of a dual environment, in which the definition of a feature is maintained parallel to its instance on a target surface. This dual environment enables dynamic feature modeling, in which the user is able to change the definition of instantiated features on-the-fly.

scholarly journals Technological heredity at quality formation of parts manufactured

2018 ◽  
Vol 2018 (10) ◽  
pp. 27-32 ◽  
Author(s):  
Владимир Аверченков ◽  
Vladimir Averchenkov ◽  
Андрей Васильев ◽  
Andrey Vasilev ◽  
М. Хейфец ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Computer Aided ◽  
Technological Heredity ◽  
Definition Of ◽  
Aided Design ◽  
Quality Formation

The problems of a technological heredity impact upon quality formation and machinery operation properties are considered. The significance of the definition of quantitative dependences taking into account technological heredity manifestation is shown. Simulators for the computer-aided design of engineering ensuring parts quality required are offered.

Integrating Manufacturing and Life Cycle Information Into the Product Model

2004 ◽  
Vol 20 (04) ◽  
pp. 221-231
Author(s):  
Rolf Oetter ◽  
Christopher D. Barry ◽  
Lawrence A. DeCan ◽  
Paul F. Sorensen
Keyword(s):  
Life Cycle ◽  
Computer Aided Design ◽  
Production Engineering ◽  
Product Model ◽  
Computer Aided ◽  
Other Information ◽  
Cad Cam ◽  
Definition Of ◽  
Aided Design

The power of the integrated product model can be extended well beyond the mere definition of geometry, and this extension offers significant benefits to shipbuilders. The nature of computer-aided design/manufacturing (CAD/CAM) data allows use of arbitrarily extensible linked databases, which can contain any other information that might be useful for manufacture, production engineering, procurement, and even maintenance and operation of the ship throughout its life cycle.

New Non-Equidistant Optimum GM(1,1) of Line-Drawing Data Processing in Computer Aided Design

2010 ◽  
Vol 439-440 ◽  
pp. 1561-1566
Author(s):  
You Xin Luo
Keyword(s):  
Data Processing ◽  
Computer Aided Design ◽  
Line Drawing ◽  
Grey Model ◽  
Reconstruction Method ◽  
Computer Aided ◽  
Scope Of Application ◽  
Power Mutation ◽  
Definition Of ◽  
Aided Design

Based on the exponential trait of grey model and the definition of integral, the reconstruction method of GM(1,1) model’s background value of non-equal distance sequence was put forward and a kind of non-equidistant optimum grey model GM(1,1) to line-drawing data processing in computer aided design was proposed. The mean relative error is taken as the optimum objective function. The power mutation particle swarm optimization program PMPSO1.0 was compiled with Matlab 7.6 software to make optimization. Two examples were given, their results were compared with the results based other Grey models, respectively. The method can be used for model establishing on equal interval, as well as on non-interval. Moreover, GM(1,1) model’s fitting precision and prediction is advanced and the scope of application is enlarged. The model is simple and practical, and has a generalizing value in the field of CAD.

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