[School of Natural Sciences PhD Scholarships] The Fluid Mechanics of Granular Flow

About the project

About the Project Granular materials are the second most abundant material used by mankind, but our ability to model their flow lags far behind that of fluids. This is mainly because we do not have a complete rheological description of how granular materials flow and deform. Indeed, sometimes they behave as (i) a solid, (ii) a liquid or (iii) a gas, and all three states can simultaneously coexist in the same flow. Finding a rheology to describe all of this behaviour is still a challenge, but significant progress has been made by describing the liquid-like flow of grains with a non-Newtonian rheology that is pressure and shear-rate dependent. In this project we will investigate the development of secondary vortices that form as a granular material flows down an inclined plane. It is thought that these are responsible for the development of longitudinal ridges in long-runout landslides on Earth and Mars, as well as the formation of visually striking transversely-segregated striped patterns in small-scale experiments using bidisperse mixtures of particles of different sizes. The project will extend the non-Newtonian viscous-like rheology for granular flows to include second-normal-stress differences to drive the secondary flow. A numerical method will then be developed to solve the resulting equations, and the predictions will be tested against Discrete Element Method (DEM) simulations and small-scale experiments performed in our granular laboratory located in the Department of Physics & Astronomy. This project is fundamental in nature and will advance our knowledge of how granular materials flow and segregate. Since granular materials are the second most abundant material used by man, there are many potential applications to the construction, pharmaceutical, bulk chemical, mining, food and agricultural industries, which process vast amounts of grains to make the food that we eat and the products that we use every day. This project is expected to start in September 2027. Before you apply: We strongly recommend that you contact the supervisors for this project before you apply. How to apply: To be considered for this project you must complete a formal application through our online application portal. If you already have an applicant account this link will directly open an application for PhD School of Natural Sciences Scholarships . If you don’t already have an applicant account, please follow the instructions here . When applying, please specify the full title and supervisor/s of the project, details of your previous study, and names and contact details of two referees. You must also upload a Supporting Statement describing your motivation to apply to the project, your CV and transcripts of awarded and in-progress university qualifications . Please note late or incomplete applications will not be considered. Equality, diversity and inclusion are fundamental to the success of The University of Manchester and central to all our activities. A diverse research community strengthens creativity, productivity and quality, while increasing the societal and economic impact of our work. We welcome applicants from all career paths, backgrounds and sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation or transgender status. We welcome applications from candidates returning to study after a career break or experience in other roles. Flexible study arrangements may be available, including part-time study at 50%, 60% or 80%, subject to the requirements of the project and funder. Eligibility : The standard academic entry requirement for this PhD is an upper second-class (2:1) honours degree (or international equivalent) in Mathematics, Physics, Engineering OR any upper-second-class (2:1) honours degree and Master's degree (or international equivalent) at Merit in Mathematics, Physics or Engineering. This project will remain open until filled. If your application is submitted by 1st November 2026, you can expect a decision by 18th December 2026. If your application is submitted by 15th January 2027, you can expect a decision by 30th March 2027. Self or externally funded students can also be considered for this project. FSESoNS

Research areas