About the project
This PhD project will investigate how roughness geometry alters turbulent boundary layers and drag. Using advanced wind-tunnel experiments, 3D PTV and direct drag measurements, the project will expand an internationally used roughness database and develop new geometry-dependent drag models, in collaboration with Johns Hopkins University and complementary high-fidelity simulations.
Surface roughness can dramatically alter turbulent boundary layers, increasing drag and affecting the performance of a wide range of engineering and environmental systems. Examples include marine hulls affected by coatings and biofouling, pipelines transporting fluids, and natural surfaces such as river beds. Despite its importance, reliably predicting the drag generated by complex rough surfaces remains a major challenge.
This PhD project will investigate turbulent boundary layers developing over a range of carefully designed and realistic rough surfaces. The aim is to determine how surface geometry modifies near-wall turbulence, momentum transport and drag, and to translate this understanding into improved predictive models.
The experimental programme will use state-of-the-art wind-tunnel facilities and advanced three-dimensional diagnostics. 3D Particle Tracking Velocimetry (PTV) will resolve the turbulent flow above the roughness, while a custom-built drag balance will provide direct measurements of the forces generated by different surfaces. These measurements will establish detailed links between surface morphology, turbulent structure and aerodynamic drag.
The new datasets will contribute to our internationally used roughness database, expanding its range of geometries and flow conditions and providing an important resource for the wider rough-wall turbulence community. A key objective will be to develop new surface-geometry-dependent models capable of predicting roughness-induced drag directly from measurable characteristics of the surface.
The project is a collaboration with Johns Hopkins University in the United States, where complementary high-fidelity simulations will provide quantities difficult to access experimentally. Together, the experiments and simulations will provide an unusually detailed description of rough-wall turbulence and support the development of broadly applicable drag-prediction tools.
You will receive extensive training in wind-tunnel experimentation, Particle Image and tracking Velocimetry as well as Direct Drag measurements. You will also develop skills in experimental design, uncertainty analysis, scientific programming and data-driven modelling, while gaining experience of collaborative research with academic partners and presenting results to international audiences.
The School of Engineering is committed to promoting equality, diversity inclusivity as demonstrated by our Athena SWAN award. We welcome all applicants regardless of their gender, ethnicity, disability, sexual orientation or age, and will give full consideration to applicants seeking flexible working patterns and those who have taken a career break. The University has a generous maternity policy, onsite childcare facilities, and offers a range of benefits to help ensure employees’ well-being and work-life balance. The University of Southampton is committed to sustainability and has been awarded the Platinum EcoAward.
