Centres of expertise on tribology and related sciences in the UK

Citation

Hammond, G.P. (1998), "Centres of expertise on tribology and related sciences in the UK", Industrial Lubrication and Tribology, Vol. 50 No. 4. https://doi.org/10.1108/ilt.1998.01850dab.004

Centres of expertise on tribology and related sciences in the UK

Centres of expertise on tribology and related sciences in the UK

Keywords: Research, Tribology, University of Bath

University of Bath

School of Mechanical Engineering, University of Bath, Bath BA2 7AY

Professor G.P. Hammond. Msc, CEng, MIMech.E, MInst.R. Tel: + 44 (0) 1225 826168; Fax: + 44 (0) 1225 826 928; E-mail: ensgph@bath.ac.uk

The Fluid Power Centre has been providing post-experience modular courses in fluid power, instrumentation and control since 1970. The modules range from an introduction to fluid power systems to specialist courses on design, control and instrumentation. They have a strong industrial and practical emphasis.

Further details of the activities may be found on the WWW at: http://www.bath.ac.uk/ Departments/Eng/pfc/home.html

Current research projects are listed as follows:

Fluid power systems and design

The Engineering Design Centre (EDC) in Fluid Power Systems was established at the university in 1992, to develop computer-based techniques to improve the design of fluid power systems. The EDC is funded by the EPSRC on a four-year rolling grant which is reviewed every two years. The projects are concerned with the:

(1) development of an industrially generic design methodology for fluid power systems;

(2) integration of design software packages;

(3) design of circuit spatial layout to minimise vibration and noise;

(4) strategic configuration design for hybrid domains using the axiomatic approach and machine learning;

(5) structured system design using computer techniques;

(6) life-cycle design of alternative fluid power systems.

Hydraulic control valves using pulse width modulated magnetostrictive actuation

This project is investigating the feasibility of combining the magnetostrictive properties of an amorphous ferromagnetic alloy for the actuation of a hydraulic control valve, driven from a pulse width modulated (PWM) electrical input signal.

Hydraulic system synthesis ­ an integrated approach

This research is concerned with the integrated design of hydraulic machinery and controllers to achieve required dynamic performance criteria, in the context of flexible complex loads. The main tasks of the project include design of a hydraulic system for the specified load and performance, design of a kinematic mechanism with flexible members to deliver the generated forces and torques to the external load, and design of a robust controller to achieve the required dynamic performance.

The use of numerical optimisation techniques for the selection and sizing of fluid power components

This project is concerned with an investigation into the use of numerical optimisation techniques in conjunction with the Bathfp dynamic-simulation package to assist the fluid power engineer with the parameter definition stage of the circuit design process. The aim is to automate the task of defining the component sizes, settings and electrical gains that enable a fluid power system to perform as required.

Modelling of transient flows in hydraulic hoses and pipelines

There is a variety of ways of modelling pipelines but problems can occur in a number of situations, and existing knowledge is inadequate. The objective is to develop a modelling technique that is applicable both to pipelines when properties and conditions are varying and also to hoses.

Automated failure modes and effects analysis (FMEA) for aerospace applications of electro-hydraulic systems

Since the time scale to conduct a normal FMEA is such that the analysis time often exceeds the design and development phase, methodology which manipulates qualitative values is being developed which can automate and speed up the FMEA.

Adaptive control of pressure and flow

In a number of hydraulically-controlled processes, such as plastic- injection moulding, it is necessary to control injection speed while limiting pressure in the initial stage, while in the later phase, it is only necessary to have direct control of pressure. Such control valves are termed PQ valves, and the object of the project is to find a method of controlling a PQ valve with the need for hands-on tuning.

Adaptive control of energy-efficient hydraulic systems

This joint project, with the University of Bristol, is concerned with a study of the application of model reference adaptive control schemes for the control of electro-hydraulic load-sensing systems. Through the use of adaptive control, it should be possible for the controller to tune itself in a manner which achieves consistent transient performance, regardless of operating conditions of the circuit, while achieving high energy efficiency.

Control of a two-axis servosystem

The objective is the study of a two-axis servo-hydraulic manipulator with the aim of achieving good tracking performance for a wide range of payloads and for different configurations, by controlling each axis independently.

Control methods to decouple axes interaction in animated figures

In a complex structure of this type interactions occur between reaction forces from the movement of one member causing parasitic oscillations in other members. The overall aim was to improve the speed of operation without introducing oscillations to enable the animated figure to emulate human-type movements in other members.

Automotive group

Elastomeric hydraulic mounts for secondary suspension applications

The performance characteristics of elastomeric hydraulic mounts, such as those used for engine vibration isolation, are being studied through experimental testing and computer simulation after having developed a six-degrees of freedom vehicle ride simulator.

Modelling and prediction of diesel injector systems for enhanced performance

The high pumping pressures necessary to achieve reduction in emission particulates is causing deformation of pump components. A technique has been developed to predict the distortion in an efficient manner. The next phase of the investigation will be to couple the elasticity problem to the fluid flow problem, so that leakage flows can be predicted.

Suction characteristics of power steering vane pumps

The object of this investigation into the suction behaviour of positive displacement vane pumps, as are used in automobile power steering pumps, is to minimise the effects of cavitation and to improve pump design methodology

CFD analysis of unsteady flows in hydrodynamic bearings

This investigation used computational fluid dynamics techniques to perform a thermo-hydrodynamic analysis of a stationary bearing, an oscillating film, and an orbiting and rotating journal. The resulting dynamic thermal equilibrium has enabled an assessment to be made of the thermal state of the journal.

Algorithms for vehicle switchable dampers

Novel and superior algorithms for the control of semi-active suspension systems with switchable dampers are being examined, along with the design of hydraulic and pneumatic systems to achieve this aim.

Vehicle powertrain control to maximise efficiency and minimise harmful emissions

The project is aimed at integrating the control of the Torotrak infinitely variable transmission and a spark ignition engine with the object of developing robust tuneable controllers able to significantly reduce fuel consumption compared with a manual vehicle, over defined drive cycles, involving both transient and steady state operation.

Loss mechanisms in automotive belt drive transmissions

Most production continuously variable transmissions are unable to match the vehicle efficiencies of comparable vehicles fitted with manual transmissions, owing to belt torque losses, bearing and gear friction losses, and pumping losses in the hydraulic control system. This project aims to use experimental and analytical methods to develop an understanding of the power losses, and to develop a test rig which will allow the losses to be measured accurately at a range of controlled speeds, loads and operating temperatures.

The driveability of vehicles with continuously variable transmissions

There are a number of transmission designs which involve a split-power configuration, with a multiple range or mode change facility, either to improve efficiency or provide a geared neutral.

However, the dynamics of the range change provide unsatisfactory driveability characteristics and are detectable by the driver. Models of the powertrain and control hydraulics have been written, allowing the stability of the system to be investigated, with the object of being able to predict the effect of design modifications to improve the shift quality.

G.P. HammondSchool of Mechanical EngineeringUniversity of Bath