183 results found
Long CA, Childs PRN, 2006, The effect of inlet conditions on the flow and heat transfer in a multiple rotating cavity with axial throughflow, 1st International Symposium on Jet Propulsion and Power Engineering, Pages: 321-328
This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig. Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70 % full scale version of a high pressure compressor stack of an axial gas turbine engine. Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air. Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows (Reφ up to 5 x 106 and Rez up to 2 x 105). Two different builds have been tested. The most significant difference between these two build configurations is the size of the annular gap between the (non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method. The velocity measurements were made using a two component, LDA system. The heat transfer results from the discs show differences between the two builds. This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity. There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig. For the narrow annular gap, there is an increase of non-dimensional tangential velocity Vφ / Ωr with radial location to solid body rotation Vφ / Ωr = 1. For the wider annular gap, the non-dimensional velocities show a decrease with radial location to solid body rotation.
Peng Z, New P, Long CA, et al., 2006, Operating characteristics of a high radius pre-swirl cooling system, 1st International Symposium on Jet Propulsion and Power Engineering, Pages: 235-241
An experimental investigation into pre-swirl effectivenessand receiver hole discharge coefficient characteristics for ahigh radius injection pre-swirl cooling systems was carried outon a physically representative experimental rig with a 450 mmdiameter rotor. The receiver holes and pre-swirl nozzle werelocated at a radius of 181 mm and 180 mm respectively. Theexperimental work was mainly conducted at 5000-12000 rpm,4 bar absolute pressure and 1.132 kg/s air supply. Themaximum air supply temperature was 190ºC.Pressure and temperature distributions in the pre-swirlsystem were examined with an emphasis on the velocityeffectiveness of the pre-swirl system as a whole and on thedischarge coefficients of the rotating 'receiver holes' in therotor. The results showed that the velocity effectivenessincreased with increasing swirl ratio resulting in reduced bladecooling flow temperature. Different seal flow configurationscaused very different effectiveness at different speeds, butoutflow through the inner and outer seals always gave thehighest effectiveness compared other configurations.Increasing the seal flow rate reduced the effectiveness. For thecoefficient of discharge, except for the low speed range, itincreased with increase in swirl ratio for most speeds.
Childs PRN, Robinson LA, Stobart RK, 2005, Escaping the Straightjacket of Engineering Education, E&PDE 2004: 2nd International Engineering and Product Design Conference, Publisher: Design Society, Pages: 299-306
Childs PRN, 2004, Mechanical Design, Publisher: Elsevier Butterworth Heinemann, ISBN: 9780750657716
Childs PRN, Stobart RK, 2004, Total Vehicle Technology: Finding the radical, implementing the practical, Publisher: Professional Engineering Publications, ISBN: 9781860584602
All of the principal design methods require the vehicle producer to consider the applications, the users, available technologies and the context. Such processes are useful in providing the mantle within which design can occur. It is often stated how important initial conceptual design work is as this dictates the greater proportion of subsequent costly detailed design and developmental work. It is at this stage that all the elements relating to the design need to be broadly brought together. This may result, as is the case with the latest Landrover Defender, in a vehicle embracing available technologies and adhering to its core brand values to produce a praiseworthy vehicle. An alternative approach may be to push newer technologies as illustrated by the number of concept cars appearing utilising independent electric motor wheel drives. Of note, the former example relies on a traditional fuel, while the latter alludes to the possibility of widespread use of alternative energy sources. These examples illustrate the breadth of variation in design outcome and therein lies the challenge to engineers and designers who need to operate effectively within a changing and competitive market.The Total Vehicle Technology conference was conceived as an opportunity for consideration of the full scope of vehicle related issues. Although we may consider our professional decisions to be broad-minded, and that we do attempt to address and optimise the issues concerned, the realities of many working lives and practices dictate fast and all too often narrow expert approaches. The resulting solutions, although expedient, may inhibit a more creative approach. The Total Vehicle Technology 2004 conference has resulted in papers and presentations across a broad base ranging from energy issues, traffic infrastructure, human factors, powertrain, safety, to vehicle dynamics and control. It is possible that such a taxonomy of subjects, with its sub-division of activities is in its very nature co
Long CA, Childs PRN, Greenwood JR, et al., 2004, Manufacture and calibration of robust heat flux sensors for rotating turbomachinery, EXPERIMENTAL HEAT TRANSFER, Vol: 17, Pages: 181-197, ISSN: 0891-6152
Morris RD, Thomas AL, Childs PRN, 2004, Cabin and passenger environment design for the Airbus A380 – A case study for education, The 6th International Conference on Engineering and Product Design Education (E&PDE2003)
Robinson LA, Childs PRN, Stobart RK, 2004, Escaping the straitjacket of engineering education, The Changing Face of Design Education 2nd Int Engineering and Product Design Education Conference, Publisher: Design Society, Pages: 299-306
Engineering education in the United Kingdom might be characterised by a conservative andpragmatic approach. It has developed from the approaches developed during the age ofenlightenment and industrial revolution and has since been subject to a number of reviews andevolutionary changes. Engineering degrees in some cases have been taught by a combinationof distinctly identifiable modules, which, despite good intentions and encouragement byaccreditation bodies, are rarely explicitly interlinked or interrelated.The use of a virtual learning environment to support a problem based learning approach tofacilitate the acquisition of a wide range of interdisciplinary skills is explored within thispaper. Students are asked to design a transmission system for a compressor by an OEM(original equipment manufacturer). The activity requires marketing, business planning,project management, specification, conceptual design, detailed design, preparation formanufacture, team-work and liaison with a number of individuals and organisations. Themechanism of running the project is described here along with the methods employed forpersuading sceptical colleagues to embrace newer ways of providing education.
Childs PRN, 2003, Degree Design - Exploring Creativity from the Start, Sharing Experience in Engineering Design (SEED) 2002, Pages: 91-95
Morris RD, Thomas AL, Childs PRN, 2003, Cabin and passenger environment design for the Airbus A380 - a case study for education, International Engineering and Product Design Conference, Publisher: PROFESSIONAL ENGINEERING PUBLISHING LTD, Pages: 51-58
Atkins RD, Kennedy Ping R, Childs PRN, 2002, Idea transfer and company constraints in the design of a two-seater sports car, 2nd ADSC, IMechE Conference on Total Vehicle Technology
In 1992 the principal authors were contacted by Beans Industries, the owners of the ReliantCar Company of Tipton, Staffordshire, and asked to present a proposal for the design andproduct development of a lightweight sports car based upon Reliant parts bin components.This paper covers some highlights of the exercise and details some of the compromisesbetween engineering excellence, manufacturing practicability, cost constraints and pleasingdesign. Key aspects identified within the paper are the concepts of idea transfer, transferringtechnology, techniques and style from one design to another and the merits and process ofintegrating existing components into a design. The study illustrates the scope for two-seatersports cars in the market and postulates on near-term possibilities.
Childs P, 2002, Degree design - exploring creativity from the start, 24th Annual Conference on Engineering Design Education/9th National Conference on Product Design Education, Publisher: PROFESSIONAL ENGINEERING PUBLISHING LTD, Pages: 91-98
Childs PRN, 2002, Advances in heat transfer, Advances in heat transfer, Editors: Irvine, Hartnett, Publisher: Academic Pr, Pages: 111-181, ISBN: 9780120200368
Advances in Heat Transfer fills the information gap between regularly scheduled journalsand university level textbooks by providing in-depth review articles ...
Childs PRN, 2002, Temperature Measurement: Techniques, Publisher: ESDU, ISBN: 9781862461963
The purpose of this Item is to review the general techniques available for measuring temperature and toconsider specific instruments for particular applications. The issues of measurement criteria includinguncertainty, thermal disturbance and calibration are described. Based on the relative merits of differenttechniques, guidance for the selection of an appropriate temperature measurement technique is provided.
Childs PRN, Downie JH, Katz T, 2002, Design Models and Their Value in Education, Sharing Experience in Engineering Design (SEED) 2001, Pages: 179-186
Ozturk HK, Turner AB, Childs PRN, 2002, The effect of labyrinth seal clearance on stator-well flow and windage heating, INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES, Vol: 19, Pages: 219-231, ISSN: 0334-0082
Smout PD, Chew JW, Childs PRN, 2002, ICAS-GT: A European collaborative research programme on internal cooling air systems for gas turbines, Pages: 907-914
The Internal Cooling Air Systems for Gas Turbines (ICAS-GT) research programme, sponsored by the European Commission, ran from January 1998 to December 2000, and was undertaken by a consortium of ten gas turbine manufacturing companies and four universities. Research was concentrated in five discrete but related areas of the air system including turbine rim seals, rotating cavity flow and heat transfer, and turbine pre-swirl system effectiveness. In each case, experiments were conducted to extend the database of pressure, temperature, flow and heat transfer measurements to engine representative non-dimensional conditions. The data was used to develop correlations, and to validate CFD and FE calculation methods, for internal fluid flow and heat transfer. This paper summarises the outcome of the project by presenting a sample of experimental results from each technical work package. Examples of the associated CFD calculations are included to illustrate the progress made in developing validated tools for predicting rotating cavity flow and heat transfer over an engine representative range of flow conditions.
Stobart RK, Childs PRN, 2002, Total Vehicle Technology: How do we get the innovation back into vehicle design, Publisher: Professional Engineering Publishing Limited, ISBN: 9781860583773
Early developments of passenger cars were fresh and radical and the popular imagination was firmly captured. The novelty of the early Ford Model T cars gave way to a low priced commodity version that, while cost effective, quickly lost popularity. It was the innovation promoted by Alfred Sloan of General Motors that forced Henry Ford to develop the Model A. Since then car manufacturers have frequently rung the changes to keep the buying public interested.Nearly a century after cars were first sold, their design has settled into a predictable form. Through this period the engineering progress has been staggering: passenger safety, exhaust emissions, passenger comfort, and driveability have all improved beyond recognition. Radical changes however are all too rare. The emergence of the MPV concept has made a big difference to family driving, and the arrival of the Fiat Multipla illustrates how far the concept can go in terms of spacious transport. The Smart car is a convenient town car of high utility and with its boosted downsized mid positioned engine represents a radical departure. We have seen radical progress with electronics and safety technologies.So where else have we been able to see innovation? There are big heavy vehicles, the retro look and “crossover” designs that give the impression of a desperate attempt to retain a fading market. Beneath the surface of the car innovation can be seen, but is by no means radical. Why does the truly radical so rarely emerge when we know it is possible? What is the key to releasing innovation at a faster rate?Much can be explained by history and the industry structure that has developed as a consequence. Where technology advance comes primarily through the convergence of several technologies an industry structure that keeps technologies separate is starting from a disadvantaged position. However there are hopeful signs where major (Tier 1) suppliers are looking to do more of their own innovation. In partnership
Childs PRN, 2001, Practical Temperature Measurement, Publisher: Elsevier, ISBN: 9780750650809
Childs PRN, Downie J, Katz T, 2001, Design models and their value in education, 23rd SEED Annual Design Conference and 8th National Conference on Product Design Education, Pages: 179-186
There are a number of models of the design process that are in relatively common use ineducation. Within industry the use of a unified design model seldom occurs and most companiesand individual designers tend to develop their own although these often have common themes.The design educator faces the challenge of assisting students to develop their design skills andyet be employable within a range of industries. Methods used to achieve this aim often includethe presentation of the more common design models. However when models are presented at theearly stages of their education students have not usually yet attained the interdisciplinary skillsdemanded by the design process. This paper reviews the approaches adopted at two universitiesto address the issues of the complexities of design models in education and suggests someapproaches to teaching design methodology, which are perceived by the students to be helpfuland not simply yet other design constraints.
Childs PRN, Stobart RK, 2001, Total Vehicle Technology: Challenging Current Thinking, Publisher: Professional Engineering Publishing, ISBN: 978-1-86058-324-7
Childs PRN, Stobart RK, 2001, Total Vehicle Technology: Challenging Current Thinking, Publisher: Professional Engineering Publishing, ISBN: 978-1-86058-324-7
In order to provide appropriate products for the market place any industry must innovate and improve. These requirements are acute in the automotive industry and the Total Vehicle Technology conference, 2001, provides an important contribution with the focus on the totality of vehicle technologies.The aim of this conference is to provide an opportunity for the presentation and discussion of the engineering and design tasks involved in the production of a vehicle. The underlying theme of the conference is the integration of technologies in vehicle and automotive engineering. The subtitle, challenging current thinking, stems from the thrust and diversity of the papers presented, combined with the realisation amongst some major players and commentators that current engineering, design and business strategies are inadequate within the projected automotive industry environment.The theme of the conference has resulted in the collection of articles presented here. Some striking themes have emerged:• Fast and furious introduction of new technology across the spectrum of vehicle engineering;• Challengers to the current perceived future direction for prime mover technology;• The criticality of customer perception and the reordering of the importance of design criteria;• The impact of advanced design tools has resulted in a redefinition of design standards;• The requirement for a transformation in the skills base for automotive designers.The proceedings presented here represents a diverse collection of approaches to the challenges facing product developers and will make an important contribution to the automotive sector.
Milburn C, Childs PRN, 2001, The Styling Process, Bury St Edmunds and London, Total Vehicle Technology Conference 2001, Publisher: Professional Engineering Publishing, Pages: 275-287
The automotive sector is a mature market with the consumer having increasingly more choice and as a result a greater influence on the design of new products. This paper outlines the complexity of the design process, the importance of image and branding and suggests, using an example, a possible way forward to meet the needs of the sophisticated consumer. In particular the trend for consolidation in the automotive sector is challenged as an avenue for success in favour of a leaner design process to meet the timescales of consumer interest.
Simons RW, Childs PRN, 2001, Estimating in Engineering Design, Sharing Experience in Engineering Design (SEED) 2000
Childs PRN, Brodhurst EK, 2000, Integrating Design Education Beyond 2000, Publisher: Professional Engineering Publishing, ISBN: 9781860582653
Childs PRN, Greenwood JR, Long CA, 2000, Review of temperature measurement, REVIEW OF SCIENTIFIC INSTRUMENTS, Vol: 71, Pages: 2959-2978, ISSN: 0034-6748
Childs PRN, Simons RW, 2000, Small priced tools and equipment case study, Sharing Experience in Engineering Design (SEED) 1999
Simons RW, Childs PRN, 2000, Estimating in engineering design, 22nd Sharing Experience in Engineering Design Conference/7th National Conference on Product Design Education, Publisher: PROFESSIONAL ENGINEERING PUBLISHING LTD, Pages: 261-266
Turner AB, Davies SJ, Childs PRN, et al., 2000, Development of a novel gas turbine driven centrifugal compressor, PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY, Vol: 214, Pages: 423-437, ISSN: 0957-6509
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