The University of Sheffield
Department of Mechanical Engineering

Dr Roger Lewis

MEng, PhD, CEng, MIMechE

Dr Roger Lewis

Senior Lecturer in Mechanical Engineering Design

Director of Resources

Department of Mechanical Engineering
Sir Frederick Mappin Building
Mappin Street
Sheffield
S1 3JD
UK

Telephone: +44 (0) 114 222 7838
Fax: +44 (0) 114 222 7890

email : Roger.Lewis@sheffield.ac.uk

Profile

Dr Roger Lewis became a lecturer in the Department in 2002 and was promoted to Senior Lecturer in 2006. He graduated from the University of Sheffield in 1996 with an MEng in Mechanical Engineering and continued to work at Sheffield towards a PhD in the Tribology Research Group. He then had posts as a Research Associate and Teaching Fellow in the Department.

In 2001 he was awarded the Tribology Trust Bronze Medal and in 2003 received a Brian Mercer Award for Innovation from the Royal Society. He is a Chartered Engineer and Fellow of the IMechE. He is also currently Chairman of the IMechE Tribology Group.

Roger has regularly edited an esential guide to wheel/rail contacts issues, 'The Wheel/Rail Interface Handbook' which is published by Woodhead.

Areas of Research

Roger´s research interests are split into three areas, solving industrial wear problems; application and development of a novel ultrasonic technique for machine element contact analysis and design of engineering components and machines. The research themes are wide ranging and include:

• Transportation tribology (railway, automotive and aerospace)
• Oral tribology
• Skin tribology
• Tribology in food sorting applications
• Design for sustainability
• Inclusive design

Areas of Research

Wear is a major problem for UK and worldwide industry. Most components end their usable life by wearing out. Unlike most other branches of engineering, there are no design codes for wear resistance. Roger's work is aimed at providing those codes for industrial applications. This will involve basic and applied component research to develop tools, such as software, databases, semi-empirical models, flow charts or wear maps, for industry to solve/avoid wear problems.

Wheel/rail tribology is a major research theme. This is an area of critical concern especially after recent accidents. The operation of both wheel and rail is safety critical and important to quality of life (noise emission and ride comfort). However, it is expensive to maintain or renew wheels and rails and problems with delays to trains can be caused. A fine balance exists between running a safe and comfortable railway while still keeping costs down. Research is aimed at the provision of wear prediction tools to be used to help optimise maintenance schedules and improve designs and materials to maintain this balance.

Roger's group is also working on a number of automotive tribology issues. Lubrication and friction models for car engines are well established but models for wear resistance do not exist. Engine developers therefore frequently only find wear problems during engine testing. Research is aimed at providing tools for wear analysis at the design stage. Work is also being carried out to study the abrasive cleaning of teeth. This is focused on understanding how abrasive particles in toothpaste interact with toothbrushes. The aim of the research is to optimise the cleaning process. Recently work has begun studying finger friction and grip of sports equipment and packaging. This is in an attempt to improve the handling of rugby balls and the openability of packaging.

Another area of Roger's work is the development of a non-invasive ultrasonic technique for characterising contact pressures and areas in component interfaces. This is important information needed in engineering design for fatigue and wear life calculations. Applications of the technique have included a wheel/rail contact, constant velocity joints, interference fits, bolted joints and whisky bottle caps.

Research Projects

Transportation Tribology

• Tribology of new Electro-mechanical Actuators for aircraft primary flight controls (EC IP MOET, with Airbus, Goodrich and Rollvis)
• Finger friction and grip of sports equipment and packaging
• Railway wheel wear modelling (EC funded KTN project, in collaboration with Alstom)
• Wheel and rail wear mechanisms and transitions (in collaboration with KTH, Stockholm)
• Contact pressure measurement in wheel hub/axle press fits (sponsored by Valdunes)
• Wheel/rail contact measurement (in collaboration with Voestalpine)
• Wheel/rail isolation due to contaminant films (funded by Kelsan and Interfleet Technology Ltd.)
• Wheel/rail adhesion enhancers to overcome the leaf problem (sponsored by Kelsan)

Human Tribology

• Particle/fluid interactions in abrasive teeth cleaning (sponsored by Unilever)
• Optimisation of wax strips for hair removal (KTP with Reckitt Benckiser)

Automotive Tribology

• Diesel engine valve and seat wear (sponsored by Ford and Perkins)
• Wear of engine components due to soot (sponsored by Ford and Perkins)
• Surface coatings to reduce valve recession (sponsored by Ford and Keronite)

General

• Wear of rice sorting equipment (sponsored by Sortex)
• Rubbish compactor design (KTP with Bergmann Direct Ltd)

Research Grants

As Principal Investigator :

• MOET, EC funded FP6 IP, wear and friction in electro-mechanical actuators for primary flight controls (July 2006 – June 2009) - £172,040
• KTP with Bergmann Direct Ltd. To redesign a rubbish compactor (June 2006 – Feb 2009) - £145,062
• Perkins research grant to investigate valve recession issues in diesel engines (Jan 2005 – March 2008) - £9,000
• Ford Motor Company research grant to support an EPSRC CASE Award to investigate surface coatings to reduce engine component wear (Oct 2004 – March 2008) - £19,000
• Royal Society Brian Mercer Award for Innovation for the development of an ultrasonic contact pressure measurement tool (Sept 2003 – March 2006) - £22,000

As Co-Investigator:

• EC Marie Curie ToK to model railway wheel wear (Aug 2006 – July 2008) (with R.S. Dwyer-Joyce) - £169,425
• Unilever research grant to study abrasive particle and brush filament interaction in teeth cleaning (Oct 2003 – Sept 2006) (with R.S. Dwyer-Joyce) - £45,000

Current Teaching

MEC115 Design and Manufacturing course (module leader)

MEC425 Design for a Sustainable Environment (module leader)

MEC411 Tribology of Machine Elements course

MEC416 Computer Simulation and Validation course

Part of team organising Engineering Applications

Part of team organising MEC 307 Group Design Project

Selected Publications