In silico evaluation of manufacturing concepts for non-Newtonian products

The main aim of the work is to establish the optimal geometric configuration for a particular configuration of process mixer
(a Controlled Deformation Dynamic Mixer (CDDM)). The project will seek to understand the unique flow dynamics found
inside the mixer itself and, through that understanding, improve the quality of the mixture that the device produces. At the
same time, the work will establish changes to the mixer geometry such that the overall mixture is improved, while
simultaneously reducing the power required. The analysis of the mixer is made more complex because the flow within is
typically non-Newtonian, and demonstrates a viscosity that is dependent (in the first instance) on the shear rate and (in the
second instance) on the processing history of the fluid itself. The physics of the process material, coupled with the
competing influences of high angular velocities (the mixer typically runs at approximately 50000rpm), high pressure drops
and extremely small flow geometries preclude easy characterisation of the flow. In addition, the channels through the mixer
are sinuous and change with the mixer rotor position. In the light of these, the flow will be studied initially in the laminar
flow mode and static configuration; as understanding develops, increasingly complex dynamics will be introduced---either
through the mixer motion itself, through the action of the viscosity, through turbulent flow physics or some combination of all
three. The work is of considerable interest to the academic partner, as the evolving rheology represents an application of
multiphysics; it couples together CFD, rheology and (in the longer term) meso-scale modelling. The wider goal of the
project is to accelerate the introduction of new & better products into the market by the simulation of manufacturing
processes for complex multiphase liquid products for fast moving consumer goods (FMCG), and unifies computational fluid
dynamics (CFD), rapid prototyping (RP) and experimental evaluation.

The work will increase the competitiveness of the UK by improving innovation and introducing shorter channels between
supply and demand. The work is estimated to have economic benefits of the order of £15-30M to the UK and to Europe.
The strategic goal of the project is directed towards on-site manufacture and distribution, which will also impact directly on
the general public through increased consumer choice and a more attractive pricing structure. In addition, by reducing the
length of the supply chain, the work will have an indirect effect on the quality of UK life. This will be achieved by the
reduction in carbon footprint resulting from reduced storage and -particularly-from reduced domestic transportation of end
product.
Outside of the fast moving consumer goods envisage by the industrial partners, mixing is ubiquitous in many industries,
and the energy costs of mixing is increasingly studied (see, for example
http://www.grundfos.com/content/dam/Global%20Site/Industries%20%26%20solutions/waterutility/pdf/Energy_saving_potential_for_mixing_of_horizontal_flow_systems.pdf, http://mixing14.eu/p/mixing14eu_35.pdf or
http://www.chopperpumps.com/pdfs/brochure_rotamix.pdf for examples of how CFD and experiment are increasingly used
to reduce energy costs associated with mixing). Through CDDMtec, this project has a natural conduit to other industries
where mixer design development-refined by the work undertaken here- will be able to contribute to the overall reduction in
mixer power costs.
In terms of wider public engagement, non-Newtonian flows are of considerable general interest; blood flow is an important
application (see, for example
http://www2.imperial.ac.uk/ssherw/physflow/pfn/Meetings/Edinburgh/Presentations/Ieuan%20Owen.pdf). Also, there are
well known examples (such as the corn starch and water mixture commonly referred to as 'Oobleck') which provide an
excellent introduction to aspects of fluid dynamics for young scholars or the interested public (examples for the non expert
audience can be found, for example, at http://www.sciencelearn.org.nz/Science-Stories/Strange-Liquids/Non-Newtonianfluids).
We anticipate providing a number of examples of non-Newtonian flows (both simulated and experimental - refer to
the pathways to impact document), through which we will demonstrate the importance of the work to the wider audience.