LIFD Early Career Researcher Spotlight: Ahmad Mohamadiyeh

Thesis title: Erosion of sediment beds using impinging jets: Application to nuclear waste mixing.

School/ Faculty: CDT in Fluid Dynamics, School of Computing

Supervisors: Dr Timothy Hunter, Professor Michael Fairweather, Professor Jeff Peakall and Martyn Barnes (Sellafield Ltd)

Tell us a bit about yourself:

I am currently in my third year of the CDT in Fluid Dynamics program, which is the second year of my PhD. I completed my undergraduate degree in mechanical engineering in the American University of Sharjah, UAE. Throughout my studies, I developed an interest in subjects related to fluid dynamics, which motivated me to pursue an MSc in thermal power and fluid engineering (TPFE) at the University of Manchester.  My MSc project focused on studying and comparing the flow behaviour in several ribbed channels numerically using CFD. My interests in research and fluid dynamics led to me pursue a PhD and join the Fluids CDT.

What is your research about?

Impinging jets are utilized in various industrial applications; one of the relevant applications is the nuclear waste management industry. They are used inside the storage tanks in Sellafield Ltd to erode the precipitated nuclear particles and keep them in suspension. Experimentally, the focus of the project is to investigate the effect of particle properties on the erosion. The erosion of particles with different size distributions, particle shapes, cohesion, and densities is tested. These include spherical soda lime particles, Barium Sulphate, and Calcium Carbonate. Ultrasonic velocity profiler (UVP) and image analysis are used to study and track erosion profiles, measure the crater and the clearance sizes. Numerically, the aim is to perform high-fidelity CFD simulations to understand the hydrodynamics of impinging jet flow such as turbulence, recirculation, and their effects on erosion. This includes simulations of a single-phase jet impinging on a flat surface and other various crater shapes as well as several jet conditions (speed, height). Studying these fundamentals of impinging jet erosion aids Sellafield in further understanding and optimizing the post operational clean out.

What did you wish you knew before starting a PhD?

In research, it is important to be adaptable and flexible, as the nature of research is inherently non-linear and open-ended. It is crucial to approach new or unexpected findings with flexibility, trying to find possible explanations and exploring different methods. As you progress in research, you gain a deeper understanding of what is realistic, and you can adjust your approaches based on that. Also, be prepared for tasks to take longer than expected, such as setting up experiments or writing code, and for things to go wrong, like equipment breakdowns during experiments. Patience and flexibility are key when dealing with the ups and downs of research.

What are your plans for the future?

I would like to continue developing the technical and researcher skills I have gained during the PhD and apply my skills and knowledge for further research. I am open to exploring research and development (R&D) positions in industry. Additionally, I am keen to investigate postdoctoral positions closely related to my area of research, as I find it enjoyable.