Department of Chemical Engineering


Contact details

Room: 9 West 2.08
Tel: +44 (0) 1225 386132

PhD supervision

Interested in supervising students studying;

  • Green cleaning
  • Surface fouling and cleaning
  • Sensors and instrumentation for surface measurement
  • Two-phase flow computational modelling
  • Membrane efficiencies.

Dr John Chew

BCom, BEng, PhD (Cantab), CEng, CSci, MIChemE


Dr John Chew studied for BCom (Accounting) and BEng Hons (Chemical and Process Engineering) at the University of Canterbury, New Zealand.

He obtained a PhD in Chemical Engineering at the University of Cambridge. He then worked at Cambridge as a Research Fellow of the Royal Academy of Engineering before joining Bath in 2010.  


John's research interests lie in the following two areas, with particular applications in the food and biotechnology industries.

Green Cleaning

Fouling of process surfaces is a major problem in many manufacturing and heat transfer operations.

The removal of fouling layers from process surfaces, i.e. cleaning, is a mundane but critically important task in many applications, particularly where hygiene is the key consideration.

John has been working on research related to fouling and cleaning of surface layers in the food, chemical, biological and medical sectors. His work has lasting positive impact on the ongoing issues of ‘greener’ environment and energy sustainability, in that both fouling and cleaning require extra energy to be expended, and cleaning requires the use of chemicals whose supply and disposal can be problematic.

John’s research activities are focused around:

  • Developing fluid dynamic gauging (FDG) into a surface engineering sensor for monitoring the thickness and strength of soft-solids (with University of Cambridge)
  • Fundamental studies of the formation and removal characteristics of soft deposits on porous (e.g. filter and membranes) and non-porous surfaces (e.g. steel, polymers and tailored surfaces)
  • Combine experimental studies with numerical modelling of the deformation of the surface layers to assess the performance of surface coatings and enhance cleaning and the effectiveness of environmentally friendly cleaning agen

Recent work includes:

  •  the application of FDG to investigate the deposition and removal of yeast and ballotini cake layers form on curved membranes, and biofilms formed on stainless steel and glass
  • The Green Cleaning Laboratory at Bath masters the application of FDG to porous surfaces.

There is strong collaboration with University of Cambridge, Technical University of Braunschweig, Germany and University of Canterbury, New Zealand.

Computational Fluid Dynamics

The rheology of soft fouling layer is rarely simply elastic or Newtonian. The deformation and flow behaviours are largely affected by its microstructure, and the microstructure is modified by the flow of surrounding fluid. Fusing FDG, CFD and microscopic (confocal, optical and atomic force microscopy) data sets will enable the characterisation of the material rheology and deformation behaviour more completely. John’s research work involves:

  • Modelling the fluid-structure interaction soft fouling layers
  • Modelling the flow behaviour of slurries and pastes
  • Design and optimisation of the fluid dynamic gauging system
  • Ongoing project includes combining FDG-CFD-optical imaging to study the deposition of food soils on fabrics and membranes.

Other computational interests are modelling the mass transfer characteristics in hollow fibre applications and heat transfer mechanisms of a spinning disk apparatus.


  • Transport Phenomena
  • Particle Technology
  • MEng Design Project
  • BEng Design Project.


Read publications by John Chew