Arbitrary Surface Flank Milling and Flank SAM in the Design and Manufacturing of Jet Engine Fan and Compressor Airfoils

2012 ◽  
Author(s):  
Chung Y. Wu
Keyword(s):  
Axial Compressor ◽  
General Concept ◽  
Centrifugal Impeller ◽  
Flank Milling ◽  
Jet Engines ◽  
The Past ◽  
Software Methodology ◽  
Domain Of Applicability ◽  
Design And Manufacturing ◽  
Nickel Based Alloy

A pragmatic and versatile airfoil design and fabrication system, named the Arbitrary Surface Flank Milling (ASFM) system, has been continuously developed and applied to the design and manufacturing of fan and axial compressor airfoils — in the form of integrally bladed rotors (IBR) and centrifugal impeller blades — for jet engines at Pratt & Whitney over the past 28 years. In a previous paper 18 years ago, we gave an account of the general concept and methodology of the system, illustrated with a number of actual production engine applications. We have since then greatly expanded the domain of applicability of the system to successfully handle blades of unusual geometric complexity. We have made strides in the area of design for flank mill-ability with conventional cutters, and cutters shaped according to blade geometry. Based on the same concept and software methodology, we have also successfully demonstrated the superior quality and cost effectiveness of Flank Super Abrasive Machining (Flank SAM) of blades in nickel-based alloy IBRs.

Ale na razie tu cisza” – fotografie sprzed katastrofy w wybranych zapisach literackich (Stefan Chwin, Ryszard Kapuściński, Wisława Szymborska)

2020 ◽  
pp. 65-80
Author(s):  
Magdalena Strąk
Keyword(s):  
Time Perspective ◽  
Terrorist Attack ◽  
First World War ◽  
General Concept ◽  
Literary Texts ◽  
World War ◽  
The Past ◽  
The First World War ◽  
History Of ◽  
First World

The work aims to show a peculiar perspective of looking at photographs taken on the eve of the broadly understood disaster, which is specified in a slightly different way in each of the literary texts (Stefan Chwin’s autobiographical novel Krótka historia pewnego żartu [The brief history of a certain joke], a poem by Ryszard Kapuściński Na wystawie „Fotografia chłopów polskich do 1944 r.” [At an exhibition “The Polish peasants in photographs to 1944”] and Wisława Szymborska’s Fotografia z 11 września [Photograph from September 11]) – as death in a concentration camp, a general concept of the First World War or a terrorist attack. Upcoming tragic events – of which the photographed people are not yet aware – become for the subsequent recipient an inseparable element of reality contained in the frame. For the later observers, privileged with time perspective, the characters captured in the photograph are already victims of the catastrophe, which in reality was not yet recorded by the camera. It is a work about coexistence of the past and future in the field of photography.

Review and Understanding on Sweep in Axial Compressor Design

2005 ◽  
Author(s):  
Lucheng Ji ◽  
Jiang Chen ◽  
Feng Lin
Keyword(s):  
Axial Compressor ◽  
Blade Design ◽  
The Past ◽  
Compressor Design ◽  
Compressor Performance ◽  
Historical Remarks ◽  
Present Understanding ◽  
Full Operation ◽  
Blade Element

As a means of improving axial compressor performance, sweep technique has been investigated for over half a century and gained wide uses, in the past one decade. However, there is still diverse controversy about the roles of sweep in axial compressor design. In this paper, historical remarks about the sweep are presented firstly. Then, an understanding about the role of sweep is put forward. That is, the sweep is a degree of freedom (DOF) of blade design that emphasizes on matching the aerodynamic loading of every blade element along the whole span within the full operation range. The present understanding about the role of sweep may lead it a more sophisticated use.

A novel tool-path generation method for five-axis flank machining of centrifugal impeller with arbitrary surface blades

2016 ◽  
Vol 231 (1) ◽  
pp. 155-166 ◽  
Author(s):  
Hong-Zhou Fan ◽  
Shang-Jin Wang ◽  
Guang Xi ◽  
Yan-Long Cao
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Ruled Surface ◽  
Centrifugal Impeller ◽  
Flank Milling ◽  
Path Generation ◽  
Rough Machining ◽  
Machining Time ◽  
Geometrical Structures ◽  
Five Axis

The centrifugal impeller with arbitrary surface blades is a very important component in automobile, ships, and aircraft industry, and it is one of the most difficult parts to process. Focusing on the machining efficiency improvement, combining the geometric advantages of ruled surface and arbitrary surface, and utilizing the efficient and accurate advantages of flank machining and point machining, this article presents a novel and targeted tool-path generation method and algorithm for five-axis flank machining of centrifugal impeller with arbitrary surface blades. In light of specific characters of different surfaces, the analyses of two different impeller blades are proposed first, the more characteristic and complex geometrical structures of the arbitrary blade are achieved. In rough machining, an approximate ruled surface blade is obtained, and a simple channel is achieved; the flank milling of the centrifugal impeller with ruled surface blades is achieved relative to the point milling of the centrifugal impeller with arbitrary surface blades; and the triangle tool path planning method is added in this process to save the machining time and cost collectively. Furthermore, in semi-finish machining, the approximate sub-ruled blade surfaces are calculated, and a new flank milling method of the sub-ruled blade surfaces is achieved; a new solution for tool interference is achieved in this process and the generation of non-interference tool paths becomes easy. Machining experiments of two different impellers are presented as a test of the proposed methods.

A Numerical Study on Performances of Centrifugal Compressor Stages With Different Radial Gaps

2000 ◽  
Author(s):  
K. Sato ◽  
L. He
Keyword(s):  
Centrifugal Compressor ◽  
Stokes Equations ◽  
Numerical Study ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Centrifugal Impeller ◽  
Vaned Diffuser ◽  
Navier Stokes Equations ◽  
Performance Predictions ◽  
Radial Gap

A numerical study of 3D unsteady flows in centrifugal compressor stages solving the Navier-Stokes equations is presented. The emphasis is on the effect of the radial gap between blade rows on the aerodynamic performance. In the numerical tests, Krain’s centrifugal impeller was combined with a DCA (Double Circular Arc) type radial vaned diffuser. The compressor stages with three settings of radial gap ranging from 5 to 15 percent of the impeller trailing edge radius are configured and unsteady flow simulations are carried out to compare the time-averaged efficiencies. The performance predictions show that the efficiency is deteriorated if the radial gap between blade rows is reduced with intensified blade row interaction, which is in contradiction to the general trend for axial compressor stages. In the centrifugal compressors tested, wake chopping by diffuser vanes, which usually benefits efficiency in axial compressor stages, causes unfavourable wake compression through the diffuser passages to deteriorate the efficiency.

OVERVIEW OF MANUFACTURING STRATEGY IN JAPAN

1996 ◽  
Vol 03 (03) ◽  
pp. 187-202
Author(s):  
JAY LEE
Keyword(s):  
Automotive Industry ◽  
Semiconductor Industry ◽  
Manufacturing Strategy ◽  
Environmentally Conscious ◽  
Substantial Impact ◽  
The Past ◽  
Design And Manufacturing ◽  
The Status ◽  
Manufacturing Technologies ◽  
Environmentally Conscious Design

Japan has been a world leader in manufacturing in the past several decades. Undoubtedly, this leadership will persist well into the 21st century. It is, therefore, very important to understand the status of Japan's manufacturing technologies as well as its projected manufacturing strategies for the future, especially those technologies which would generate substantial impact on the manufacturing industries in the next five years. This paper highlights current Japanese manufacturing strategies. Examples on several major industries including the industrial machinery industry, the semiconductor industry, and the automotive industry will be given. In addition, major initiatives on emerging technologies, including micromachine, environmentally conscious design and manufacturing, and manufacturing globalization support are described.

scholarly journals Unrealism in russian prose of early 20th century

2020 ◽  
Vol 6 (Extra-C) ◽  
pp. 75-85
Author(s):  
Elena V. Astashchenko
Keyword(s):  
20Th Century ◽  
Social Pressure ◽  
General Concept ◽  
Early 20Th Century ◽  
Second Person ◽  
The Third ◽  
The Past ◽  
Third Person ◽  
The Third Person ◽  
Imperative Mood

  The aim of the article is to analyze the multilevel manifestation of the text modality - from grammatical to aesthetic and build a general concept of unrealism as a peripheral, but permanent, constant of the modernist era. However, the ubiquity and dominant delimitation, necessary of structures with conjunctions of unreal comparison, with the predominance of those derived from future forms over those derived from the imperfect, also serves to strengthen the independence of the artwork from social pressure. Subsequently, the characteristic structures of modernity, analogous to the European "future in the past", building an alternative reality, are supplanted by the imperative mood of the second person, with the illocutionary act of calling for a change in the existing reality, in the primitive vanguard and the third person with the "pust" particle [let] in the middle of the 20th century, gradually degenerating into the imperative mood with the "puskai" particle [May], whose motivating pathos is extremely low.  

Axial Inlet Conversion to a Centrifugal Compressor With Magnetic Bearings

1992 ◽  
Author(s):  
Tom Novecosky
Keyword(s):  
United States ◽  
British Columbia ◽  
Natural Gas ◽  
Centrifugal Compressor ◽  
Axial Compressor ◽  
Magnetic Bearings ◽  
Operating Costs ◽  
Eastern Canada ◽  
The Past ◽  
Compressor Efficiency

NOVA’s Alberta Gas Transmission Division transports natural gas via pipeline throughout the province of Alberta, Canada, exporting it to eastern Canada, United States and British Columbia. It is a continuing effort to operate the facilities and pipeline at the highest possible efficiency. One area being addressed to improve efficiency is compression of the gas. By improving compressor efficiency, fuel consumption and hence operating costs can be reduced. One method of improving compressor efficiency is by converting the compressor to an axial inlet configuration, a conversion that has been carried out more frequently in the past years. Concurrently, conventional hydrodynamic bearings have been replaced with magnetic bearings on many centrifugal compressors. This paper discusses the design and installation for converting a radial overhung unit to an axial inlet configuration, having both magnetic bearings and a thrust reducer. The thrust reducer is required to reduce axial compressor shaft loads, to a level which allows the practical installation of magnetic bearings within the space limitations of the compressor (Bear and Gibson, 1992).

Effect of Stator Variability on Axial Compressor Performance

2019 ◽  
Author(s):  
Kirubakaran Purushothaman ◽  
N. R. Naveen Kumar ◽  
Vidyadheesh Pandurangi ◽  
Ajay Pratap
Keyword(s):  
Guide Vane ◽  
Flow Analysis ◽  
Axial Compressor ◽  
Axial Flow ◽  
Low Pressure ◽  
Inlet Guide Vane ◽  
Jet Engines ◽  
Stator Blade ◽  
And Performance ◽  
Flow Compressor

Abstract Variability in stator vanes is a widely used technique to improve the stability and efficiency of axial flow compressor in gas turbine engines. Most of the modern aircraft jet engines use variable stator vanes in both low pressure and high pressure compressors primarily for off-design performance. This study discusses in detail about the effect of stator variability in a three stage low pressure axial compressor at design and off-design conditions. Computational flow analysis were carried out for the three stage low pressure compressor with variability in inlet guide vane and first stage stator blade. Detailed investigation on flow physics was carried out in rotor blade passages with stator variability. At off-design speeds, the reduction in flow velocity is lower than the reduction in blade tip speed. This leads to mismatch in flow angles and inlet blade angles causing high incidence and large flow separation in blade passage. This results in poor aerodynamic stability of the axial compressor at off-design speeds. In this study, aerodynamic performance of compressor is evaluated from 70% to 100% design speeds with different stagger angle setting of inlet guide vane at each speed. Further, to improve 2nd stage rotor performance, variability was introduced in 1st stage stator blade and performance was evaluated. Compressor test results are compared with CFD data for design and off-design speeds.

Evaluation Method for the Topological Synthesis of Sheet Metal Components

2004 ◽  
Author(s):  
Swapnil Padhye ◽  
Matthew I. Campbell
Keyword(s):  
Sheet Metal ◽  
Evaluation Method ◽  
Raw Material ◽  
Spatial Constraints ◽  
Optimal Sequence ◽  
Manufacturing Costs ◽  
The Past ◽  
Modern Engineering ◽  
Design And Manufacturing ◽  
Automated Tool

The popularity of sheet metal in modern engineering artifacts is due to the fact that it is both inexpensive as a raw material and inexpensive to form into components. In comparison to forging or machining components, sheet metal can produce lightweight and inexpensive design solutions. The main shortcomings of sheet metal are that resulting components have a limited rigidity and the feasibility of the parts is constrained by the inherent two-dimensionality of the initial sheet. Furthermore, design and manufacturing engineers are challenged by finding a shape that satisfies all spatial constraints and by deciding the optimal sequence of operations for making this product that minimizes both time and associated manufacturing costs. In the past two years, we have been working towards an automated tool that creates candidate sheet metal topologies and optimizes them for spatial constraints as well as time and cost objectives. While we have yet to complete this goal, we have to date developed a representation capable of creating a wide variety of sheet metal topologies (see DETC2002/DAC-34087) and have recently created a thorough evaluation method which is presented in this paper along with some preliminary results.

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