This project is part of a 4-year Dual PhD degree programme between the National Tsing Hua University (Taiwan) and the University of Liverpool (England). As part of the NTHU-UoL Dual PhD Award students are in the unique position of being able to gain 2 PhD awards at the end of their degree from two internationally recognised world-leading Universities. As well as benefiting from a rich cultural experience, students can draw on large-scale national facilities of both countries and create a worldwide network of contacts across two continents.
The latest set of projects targeted goal #11 from the UN Sustainable Development Goals: Sustainable Cities and Communities.
Turbulent flows inside a square duct are of considerable engineering interest, e.g. in heat exchangers or in district heating and cooling plants. Previous experimental studies have concentrated on the case of purely-pressure-driven flow (i.e. Poiseuille flow) and have shown that the flow is characterised by the existence of a secondary flow. Although this secondary flow is quite weak in magnitude, it has been shown to be able to enhance both momentum and heat transfer in different devices. For Newtonian fluids such as water, the combined effects of wall translation (the so-called “Couette” component) have hitherto only been studied experimentally and numerically for laminar flow and numerically for turbulent flow using Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES).
It is well known that the addition of minute amounts of polymers or surfactants can massively reduce the drag in turbulent wall-bounded flows. There have been thousands of experimental and numerical papers on the effect in recent decades. However, drag reduction by additives has not yet been investigated in duct flows with a moving wall. It is possible that the largely uncontrollable action of the additive combined with the controllable moving wall presents new possibilities for flow control and drag reduction techniques. An example application here would be reducing energy losses in a district heating and cooling system.
This PhD project aims to experimentally and numerically investigate the control of pressure-driven turbulent flow through a square duct using a moving wall, with and without drag-reducing additives. This will involve conducting experiments of turbulent Couette-Poiseuille (i.e. pressure driven flow plus a moving wall) of Newtonian and non-Newtonian (drag-reducing) fluids using the new moving-wall square-duct rig at UoL, and performing new simulations to model the Couette-Poiseuille flow with drag-reducing additives using existing codes at NTHU.
For academic enquires please contact Dr David Dennis firstname.lastname@example.org
For enquires on the application process or to find out more about the Dual programme please contact School of Engineering Postgraduate Office email@example.com
Applicants should apply via the University of Liverpool application form, for a PhD in the subject area listed above via: https://www.liverpool.ac.uk/study/postgraduate-research/how-to-apply/