Imperial College London

ProfessorPeterChilds

Faculty of EngineeringDyson School of Design Engineering

Head of the School of Design Engineering
 
 
 
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Contact

 

+44 (0)20 7594 7049p.childs Website CV

 
 
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Location

 

10 Princes Gardens10-12 Prince's GardensSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

176 results found

Farahani A, Childs P, 2009, VALIDATION AND COMPARISON OF STRIP SEAL DESIGNS FOR GAS TURBINE ENGINE NOZZLE GUIDE VANES, ASME International Mechanical Engineering Congress and Exposition, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 1185-1192

CONFERENCE PAPER

Hall A, Childs P, 2009, Innovation design engineering: Non-linear progressive education for diverse intakes, Pages: 312-317

This paper discusses the non-linear progressive educational techniques developed and adopted by the Innovation Design Engineering (IDE) masters degree at the Royal College of Art and Imperial College, London. In particular a focus is applied to the development of creative processes for diverse intakes without recourse to overt systems presentation. Innovation design engineering is viewed as a cutting-edge product design, experimentation and enterprise discipline with applicants drawn from three areas including engineering, industrial design and other art, design and business disciplines. The co-education of such a diverse intake requires careful balancing of an academic programme to ensure that all parties are stimulated and enabled to expand their knowledge and skills base while also contributing to a communal environment via team-based activities. Designers work at the centre of complex, demanding projects, juggling creatively in teams, to generate great ideas, designs and successful products. In order to achieve such goals it is critical for students to attain high levels of selfreflection, social networking, work-collaboration and interdisciplinarity. This is achieved by surrounding the students with experts and leaders in their fields to support them in their design ventures. Through reflection and theorising, a conceptual base for educating innovative design engineers is explored. One of the techniques described provided evidence to suggest running a design enterprise strand in the programme, a proposal that has now been implemented. Students elect from three learning strands: experimental design; design for manufacture; and design enterprise. The design enterprise strand addresses product, idea and service launching, finance, marketing, commercialisation, designing service support infrastructures and establishing production and supplier relationships. Design for manufacture is the traditional core industrial design activity associated with advanced manufactur

CONFERENCE PAPER

McGlashan NR, Childs PRN, Heyes AL, Marquis AJet al., 2009, PRODUCING HYDROGEN AND POWER USING CHEMICAL LOOPING COMBUSTION AND WATER-GAS SHIFT, 54th ASME Turbo Expo 2009, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 177-188

CONFERENCE PAPER

Patounas DS, Long CA, Childs PRN, 2009, DISC HEAT TRANSFER IN GAS TURBINE COMPRESSORINTERNAL AIR SYSTEMS, 8th European Conference on Turbomachinery, Pages: 377-386

Experimental disc heat transfer measurements were obtained from the internal air systemin high-pressure compressor cavities of gas turbine engines with axial throughflow using a rigbased on real aero-engine components. Tests were carried out over a range of non-dimensionalparameters representative of real engine conditions (Re up to 10000000 and Rez up to 110000).The heat transfer data were obtained from surface temperature measurements through a2D tapered disc numerical solution. Local values of heat transfer coefficient and Nusseltnumber showed a decreasing distribution with radius close to turbulent natural convection,similar to those found in past research. Study of the average Nusselt number showed that thisincreases with increasing axial Reynolds number and decreases with increasing rotationalReynolds number. These are consistent with increased action of the throughflow inside thecavity and an increase in the Coriolis force attenuating the flow inside the cavity.

CONFERENCE PAPER

Regan NJ, Atkins NR, Long CA, Childs PRN, Hutcheson PS, Hart KJet al., 2009, AN EXPERIMENTAL STUDY OF SPRAYS IN CROSS FLOW REPRESENTATIVE OF GAS TURBINE ENGINE SECONDARY AIR SYSTEMS, 54th ASME Turbo Expo 2009, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 133-143

CONFERENCE PAPER

Robb DA, Childs PRN, Flora H, 2009, Sketching to solid modelling skills for mechanical engineers, Pages: 275-280

Hand sketching skills remain an important part of aiding discussions in meetings and are, for example, an essential asset for brainstorming and other ideation activities. The tendency for novice students on entry to engineering and design degree programmes to produce naïve, laboured or'glitzy'sketches and inappropriate CAD representations has previously been identified. This paper describes the strategy implemented at Imperial College London for the MEng in Mechanical Engineering in order to develop key sketching skills across the diverse intake of students and in conjunction with the development of CAD solid modelling and technical drawing capabilities. The approach, based on use of visual diaries, museum and site visits, design, make and test and conceptual exercises has ensured that all students are able to sketch and produce solid models in their first year, although the production of naïve and laboured sketches continues to some extent.

CONFERENCE PAPER

Tsai S, Childs P, 2009, TRIZ Incorporating the BRIGHT Process in Design, TRIZ Journal

The theory of inventive problem solving (TRIZ) is widely acclaimed by adoptees and in the academic literature. An apparent disparity exists, however, between the low reported industrial take-up of TRIZ and perceptions in the TRIZ community which indicate more widespread use. A review of TRIZ, design processes and creative problem solving processes are reported, showing differences in the emphasis on creative thinking and the use of iteration. The advantages of a procedure related to the aspects of usability, creative thinking and iteration within the TRIZ environment has been recognised and addressed by the development of a new process named BRIGHT.

JOURNAL ARTICLE

Hounsam S, Stobart RK, Cooke AO, Childs PRNet al., 2008, Energy Recovery Systems for Engines. SAE Paper 2008-01-0309, SAE World Congress 2008

Energy recovery from IC engines has proved to be ofconsiderable interest across the range of vehicleapplications. The motivation is substantial fuel economygain that can be achieved with a minimal affect on the“host” technology of the vehicle.This paper reviews the initial results of a research projectwhose objective has been to identify system conceptsand control methods for thermal recovery techniques. Avapour power cycle is the means of energy transfer. Thearchitecture of the system is considered along withsupport of the fuel economy claims with the results ofsome hybrid vehicle modelling. An overview of the latestexperimental equipment and design of the heatexchanger is presented. The choice of controlarchitecture and strategy, whose goal is overall efficiencyof the engine system, is presented and discussed. Someinitial control results are presented. One importantproject aim is to identify and implement an optimalcontrol method that allows an explicit balance, betweenthe IC engine output and the recovered work from thevapour power cycle.Initial simulation work shows that there are significant,potential, fuel economy advantages, between 6% and31%, and that high efficiencies can be achieved atpractical operating pressures. Conclusions point to theneed to investigate and develop the system controldynamics.

CONFERENCE PAPER

Hounsham S, Stobart R, Cooke A, Childs Pet al., 2008, Energy recovery systems for engines, SAE Technical Papers

Energy recovery from IC engines has proved to be of considerable interest across the range of vehicle applications. The motivation is substantial fuel economy gain that can be achieved with a minimal affect on the "host" technology of the vehicle. This paper reviews the initial results of a research project whose objective has been to identify system concepts and control methods for thermal recovery techniques. A vapour power cycle is the means of energy transfer. The architecture of the system is considered along with support of the fuel economy claims with the results of some hybrid vehicle modelling. An overview of the latest experimental equipment and design of the heat exchanger is presented. The choice of control architecture and strategy, whose goal is overall efficiency of the engine system, is presented and discussed. Some initial control results are presented. One important project aim is to identify and implement an optimal control method that allows an explicit balance, between the IC engine output and the recovered work from the vapour power cycle. Initial simulation work shows that there are significant, potential, fuel economy advantages, between 6% and 31%, and that high efficiencies can be achieved at practical operating pressures. Conclusions point to the need to investigate and develop the system control dynamics. Copyright © 2008 SAE International.

JOURNAL ARTICLE

Tsai SK, Childs PRN, 2008, TRIZ incorporating the BRIGHT process in design, 8th ETRIA World TRIZ Future Conference

CONFERENCE PAPER

Childs PRN, 2007, Temperature measurement: resistance thermometry, Publisher: ESDU, ISBN: 978 186 246 595 4

BOOK

Childs PRN, 2007, FLOW IN ROTATING COMPONENTS - DISCS, CYLINDERS AND CAVITIES, Publisher: ESDU, ISBN: 978 1 86246 605 0

ESDU 07004 introduces the subject of flow in applications where rotating machinery components induce flow rotation. There are many examples of rotating and swirling flow in engineering such as the flow between a stationary disc and a rotating disc, in a gas turbine engine or turbocharger, and the flow in an annulus with a rotating inner cylinder, between the armature and stator of an electric motor. In ESDU 07004, the phenomena involved in rotating flows are introduced and guidance on the techniques for modelling specific rotating flow applications involving discs, cylinders and cavities is provided. Emphasis within ESDU 07004 has been placed on presenting correlations based on analytical, experimental and the computational fluid dynamics (CFD) models for parameters such as mass flow, boundary layer thickness, swirl speed, pressure distribution and moment used in parametric design studies and optimisation. ESDU EngineerIssue 17FLOW IN ROTATING COMPONENTS - DISCS, CYLINDERS AND CAVITIESIssue Table of Contents Jane's Information GroupFlow in Rotating Components Aircraft Cabin Noise Interactive Graphs - updateTransverse Rupture of Lugs Temperature Measurement ESDU 07004 introduces the subject of flow in applications where rotating machinery components induce flow rotation. There are many examples of rotating and swirling flow in engineering such as the flow between a stationary disc and a rotating disc, in a gas turbine engine or turbocharger, and the flow in an annulus with a rotating inner cylinder, between the armature and stator of an electric motor. In ESDU 07004, the phenomena involved in rotating flows are introduced and guidance on the techniques for modelling specific rotating flow applications involving discs, cylinders and cavities is provided. Emphasis within ESDU 07004 has been placed on presenting correlations based on analytical, experimental and the computational fluid dynamics (CFD) models for parameters such as mass flow, boundary layer thickness, sw

BOOK

Childs PRN, 2007, Temperature measurement: thermocouples, ISBN: 9781862465947

ESDU 06018 is one of a series of Data Items concerned with temperature measurement and provides background information and practical guidance on designing temperature measuring systems using thermocouples. The nominal temperature range covered is -272 to 2000 degrees C but the comments will apply, in general terms, to all thermocouple systems. It is aimed at the user who wishes to design and install a practical thermocouple system using improved techniques that will allow temperatures to be measured within known tolerances. ESDU 06018 considers the selection, preparation, and installation of thermocouples, the use of compensating or extension cables, and methods of referencing to a known temperature. The requirements for reliable systems operating to commercial tolerances are also described. Various factors that might impair the accuracy and stability of thermocouples are identified together with methods of reducing their effect. A check list for the design of a thermocouple system is given and a flowchart procedure for selecting appropriate thermocouple materials is provided. The employment of the techniques described will ensure that the temperature of the measuring junction is within known tolerances.

BOOK

Childs PRN, Hamilton T, Morris RD, Johnston Get al., 2007, Centre For Technology Enabled Creativity, the 8th International Conference on Engineering and Product Design Education, Publisher: The Design Society, Pages: 367-372

CONFERENCE PAPER

Cooke A, Childs P, Long C, 2007, Investigation into the effect of uncertainty in thermal properties on turbomachinery disc heat transfer using both a Monte Carlo simulation technique and a Taylor series uncertainty propagation method, 52nd ASME Turbo Expo 2007, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 1179-1188

CONFERENCE PAPER

Farahani A, Childs P, 2007, Characterisation of static strip seal flow, 52nd ASME Turbo Expo 2007, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 1169-1177

CONFERENCE PAPER

Georgakis C, Whitney C, Woollatt G, Stefanis V, Childs Pet al., 2007, Turbine stator well CFD studies: Effect of upstream egress ingestion, 52nd ASME Turbo Expo 2007, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 1623-1637

CONFERENCE PAPER

Hamilton T, Morris R, Childs PRN, 2007, 'Learning from Higher Arts Education in Designing Constructivist Learning Spaces: A Case Study of InQbate: The Centre of Excellence in Teaching and Learning in Creativity, Cambridge, 3rd ELIA Teachers' Academy, Publisher: Burlington Press, Pages: 105-108

The aims of ‘InQbate: The Centre of Excellence in Teaching and Learning in Creativity’ aretwofold: to increase the creativity of our teaching, and to improve our teaching of creativity [Childset al, 2006]. This case study outlines how we have addressed these twin goals by drawing on theexperience of the creative disciplines in order to design physical learning spaces that supportcreation-, construction-, performance-, installation- and exhibition-based activities within a socialconstructivist pedagogical model. We hope that this will act as a bridge for increased dialogueand collaboration between Higher Arts Education and non-Arts subjects.

CONFERENCE PAPER

Long C, Childs P, 2007, The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow, Hangkong Dongli Xuebao/Journal of Aerospace Power, Vol: 22, Pages: 683-693, ISSN: 1000-8055

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 (Re φ up to 5 × 10 6 and Re z up to 2 × 10 5 ). 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 V φ /Ωr with radial location to solid body rotation V φ /Ωr=1. For the wider annular gap, the non-dimensional velocities show a decrease with radial location to solid body rotation.

JOURNAL ARTICLE

Long CA, Childs PRN, 2007, Shroud heat transfer measurements inside a heated multiple rotating cavity with axial throughflow, International Journal of Heat and Fluid Flow, Vol: 28, Pages: 1405-1417, ISSN: 0142-727X

Experimental measurements of heat transfer are made from the inner peripheral surface of a rotating test rig designed to be similar to a gas turbine high pressure compressor internal air system. The test rig comprises a number of annular discs sealed at their periphery by a shroud. An axial throughflow of cooling air enters the test rig and flows through the annular section between the disc bores and a central shaft. Tests were carried out for the following range of rotational speeds and axial throughflow rates: 540 < N R < 10,800 rev/min and 0.124 < over(m, ̇) < 0.85 kg / s (corresponding to the range of rotational and axial Reynolds numbers 4 × 10 5 < Re φ{symbol} < 7.7 × 10 6 and 3.3 × 10 4 < Re z < 2.2 × 10 5 ). The shroud Nusselt numbers are found to depend on the shroud Grashof number. They are relatively insensitive to changes in axial Reynolds number and two geometrically similar cavities give similar values of Nusselt number. The heat transfer from the shroud is governed by the mechanism of free convection. It is recommended that a modified form of a correlation for Rayleigh-Bénard convection in a gravitational force field be used, with appropriate modification, to predict shroud heat transfer. © 2007 Elsevier Inc. All rights reserved.

JOURNAL ARTICLE

Long CA, Miche NDD, Childs PRN, 2007, Flow measurements inside a heated multiple rotating cavity with axial throughflow, International Journal of Heat and Fluid Flow, Vol: 28, Pages: 1391-1404

This paper discusses experimental results from a multiple cavity test rig representative of a high pressure compressor internal air system. Measurements of the axial, tangential and radial velocity components are presented. These were made using a two component, laser doppler anemometry (LDA) system for a range of non-dimensional parameters representative of engine conditions (Re up to 4 × 106 and Rez up to 1.8 × 105). Tests were carried out for two different sizes of annular gap between the (non-rotating) drive shaft and the disc bores. The axial and radial velocities inside the cavities are virtually zero. The size of the annular gap between disc bore and shaft has a significant effect on the radial distribution of tangential velocity. For the narrow annular gap (dh/b = 0.092), there is an increase of non-dimensional tangential velocity V/Ωr with radial location from V/Ωr < 1 at the lower radii to solid body rotation V/Ωr = 1 further into the cavity. For the wider annular gap (dh/b = 0.164), there is a decrease from V/Ωr > 1 at the lower radii to solid body rotation further into the cavity. An analysis of the frequency spectrum obtained from the tangential velocity measurements is consistent with a flow structure in the r– plane consisting of pairs of contra rotating vortices.

JOURNAL ARTICLE

Morris R, Childs P, Hamilton T, 2007, Sustainability by design: a reflection on the suitability of pedagogic practice in design and engineering courses in the teaching of sustainable design, European Journal of Engineering Education, Vol: 32, Pages: 135-142, ISSN: 0304-3797

JOURNAL ARTICLE

Peng Z, New P, Long CA, Childs PRNet al., 2007, An Experimental Investigation of A High Radius Pre-Swirl Cooling System, 8th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, Pages: 511-518

An experimental investigation into pre-swirl effectiveness and receiver hole discharge coefficient characteristics for a high radiusinjection pre-swirl cooling systems was carried out on an engine representative experimental rig with a 450 mm diameter rotor. Thereceiver holes and pre-swirl nozzles were located at a radius of 181 mm and 180 mm respectively. The experimental work was conductedat 5000-12000 rpm, 4 bar absolute pressure and 1.132 kg/s air supply. The maximum air supply temperature was 190ºC. Pressureand temperature distributions in the pre-swirl system were examined with an emphasis on the velocity effectiveness of thepre-swirl system as a whole and on the discharge coefficients of the rotating 'receiver holes' in the rotor. The results showed that thevelocity effectiveness increased with increasing swirl ratio resulting in reduced blade cooling flow temperature. Increasing the sealflow rate reduced the effectiveness. For the coefficient of discharge, it increased with increase in swirl ratio for most speeds. Thecoefficient of discharge also decreased with an increase in inner seal flow rate.

CONFERENCE PAPER

Peng Z, New P, Long CA, Childs PRNet al., 2007, Operating characteristics of a high radius pre-swirl cooling system, Hangkong Dongli Xuebao/Journal of Aerospace Power, Vol: 22, Pages: 849-858, ISSN: 1000-8055

An experimental investigation into pre-swirl effectiveness and receiver hole discharge coefficient characteristics for a high radius injection pre-swirl cooling systems was carried out on a physically representative experimental rig with a 450 mm diameter rotor. The receiver holes and pre-swirl nozzle were located at a radius of 181 mm and 180 mm respectively. The experimental work was mainly conducted at 5000-12000 r/min, 4 bar absolute pressure and 1.132 kg/s air supply. The maximum air supply temperature was 190°C. Pressure and temperature distributions in the pre-swirl system were examined with an emphasis on the velocity effectiveness of the pre-swirl system as a whole and on the discharge coefficients of the rotating 'receiver holes' in the rotor. The results showed that the velocity effectiveness increased with increasing swirl ratio resulting in reduced blade cooling flow temperature. Different seal flow configurations caused very different effectiveness at different speeds, but outflow through the inner and outer seals always gave the highest effectiveness compared other configurations. Increasing the seal flow rate reduced the effectiveness. For the coefficient of discharge, except for the low speed range, it increased with increase in swirl ratio for most speeds.

JOURNAL ARTICLE

Pett ADW, Coren DD, Childs PRN, 2007, Model validation for a shrouded rotor-stator system with superposed cooling and static protuberances, 52nd ASME Turbo Expo 2007, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 1379-1386

CONFERENCE PAPER

Childs P, Dullenkopf K, Bohn D, 2006, Internal air systems experimental rig best practice, 51st ASME Turbo Expo, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 1333-1343

CONFERENCE PAPER

Childs P, Hamilton T, Morris RD, Johnston Get al., 2006, Centre for technology enabled creativity, Pages: 367-372

The Higher Education Funding Council for England (HEFCE), has recently awarded over £4 million (ca. 6 million Euro) to the University of Sussex and the University of Brighton to set up the Centre of Excellence in Teaching and Learning (CETL) in Creativity. The principal activities are the effective use of technology in the creative process with a particular focus, reflecting the collaboration between the two Universities involved, on engineering and design. This paper describes the pedagogic rationale behind this initiative and provides details of its implementation.

CONFERENCE PAPER

Childs P, de la Fuente CP, 2006, An investigation of lock plate flow, 51st ASME Turbo Expo, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 1463-1471

CONFERENCE PAPER

Childs PRN, 2006, Gas turbine engine internal air systems, 1st International Symposium on Jet Propulsion and Power Engineering, Pages: 25-27

CONFERENCE PAPER

Cooke A, Childs P, Long C, 2006, An investigation into the uncertainty of turbomachinery disc heat transfer calculations using Monte Carlo simulation methods, 51st ASME Turbo Expo, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 1301-1311

CONFERENCE PAPER

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