Department of Mechanical Engineering

Enquiries and bookings

For prices and dates, please visit the Course Overview

Mrs Gillian Elsworth
Centre for Power Transmission and Motion Control
Department of Mechanical Engineering
University of Bath
Claverton Down
Bath BA2 7AY


Tel: +44 (0)1225 386371

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This course is run in conjunction with the IMechE.


FP3 - Hydraulic Systems and Efficiency

This module covers system design for efficiency. It introduces inherent losses of common systems, loss characteristics of components and methods to recover energy. A part of the course is dedicated to new technologies that are not yet standard in the field. Worked examples, case studies, design exercises, computer simulation classes, and lab sessions demonstrate how to combine hydraulic components into efficient systems.

Who should apply

The course is suitable for engineering professionals and graduates concerned with the design, development or simulation of fluid power systems and components. It is essential that participants have taken the FP1 module or have some work experience and knowledge of hydraulic systems equivalent to CETOP Level 3 before taking the course. Reasonable mathematical and computational skills are needed and knowledge of the FP2 module (or similar content) will be beneficial.

Please be aware that there might be some changes to the course content while we finalise it.


Further details

Upon completion, participants should be able to do the following:

  • Have a thorough understanding of the inherent losses in common hydraulic circuits
  • Be able to evaluate systems with regards to their efficiency
  • Appreciate causes for losses on a component level
  • Be able to identify potential for energy recovery and suitable approaches
  • Understand technical specifications of components and use this information to combine components into efficient systems.
  • Know the principles of system design taking into account duty cycles and system efficiency
  • Apply computer simulation methods for predicting the efficiency of hydraulic systems.
  • Use experimental methods for measuring the efficiency of hydraulic systems.
  • Be aware of upcoming technology

Fundamental principles

  • Causes, effects, and quantitative description of losses in power transmission
  • Noise generation in hydraulic systems
  • Thermodynamic properties of accumulators
  • Measurement and control

Valve-based vs displacement-based control

  • Recap of essential content from FP1 and FP2 with focus on efficiency
  • Comparison of typical system layouts
  • Advantages and disadvantages

Variable speed prime movers

  • Recap of essential content from ED with a focus on efficiency and relevant electric machines
  • Efficiency of power electronics
  • Efficiency of internal combustion engines
  • Electrohydrostatic actuation

Combination of different methods for speed control

  • Possible combinations
  • Transient responses
  • Challenges for controlling a multi-input-single-output system

Energy Recovery

  • Recap of essential accumulator content from FP1 and FP2
  • Use of accumulators for energy recovery
  • Redirecting "wasted" flow to other functions
  • Recovery in systems with electric prime movers

Future technologies

  • Valves with individual control edges
  • Digital hydraulics
  • Switched inertance for hydraulic pulse width modulation
  • Hydraulic transformers

Determining efficiency of hydraulic systems

  • Duty Cycles
  • Hand calculations
  • Simulation (Matlab/Simulink, AMESim, Hopsan freeware)
  • Experimental measurements
  1. Case study: Electrohydrostatic actuation
  2. Design exercise: System design
  3. Hand calculation of different system configurations
  4. Computer simulation exercises
We try to use current research rigs where possible for these lab exercises, so some lab content might vary.
  1. Switched inertance
  2. Switchable area actuator
  3. Measuring static efficiency
  4. Dynamic measurements