Boundary layers with embedded streamwise vortices
The key research questions in this project are:
- To investigate how boundary layers with specific perturbations evolve in the downstream direction and respond to streamwise pressure gradients.
- To focus on the detailed physics of the embedded vortex flow evolution.
- To gain insights on how to efficiently model such effects in the RANS or hybrid RANS simulations that are useful to industry.
While the past decades have seen substantial advancements in our capacity to numerically model wall-bounded turbulent flows, wall-flows encountering additional perturbations remain a significant challenge. Such flows include the effects of heterogeneous roughness, pressure gradients and additional strain rates, or a combination of these factors. For many aerodynamic and hydrodynamic applications, a prevalent circumstance is the presence of organised streamwise vortices that evolve as a secondary flow embedded within a boundary layer.
The experiments focus on high-resolution PIV of the streamwise vortex system that forms in a laminar boundary layer junction flow. These experiments will be conducted in a small water channel at Melbourne. To complement these experiments, high resolution direct numerical simulations (DNS) will be conducted at Aachen. Accordingly, the PhD student’s efforts will focus on the analysis of the DNS in Germany and conducting and analysing the experiments in Australia.
Graduate researcher profile: Weiqi Sun
I achieved my masters degree at Zhejiang University, majoring in fluid mechanics. I love observing, recording and exploring interesting flow phenomena in nature (e.g. the flight of dandelion). My research in my graduate stage focuses numerical simulation of evaporating and atomising behavior of precursor droplets in plasma gas, especially addressing the relation between evaporation and atomisation of droplets in the thermal flow field of plasma gas.
My research interest in the following PhD stage focuses on elucidating the role of the various complicated vortices in nature and industry, and uncovering the underlying physical mechanism behind them (e.g. the leading-edge vortex and the separated vortex ring utilized by wind-dispersed seeds).
I see this joint project as a continual opportunity of my long-term research goal on more directly exploring significant flow phenomenon in nature and industrial applications (often involved with complicated vortex flow) with accurately numerical too, such as DNS (Direct Numerical Simulation) and reliable experimental observation.