Flows around us in air and water are almost exclusively turbulent. This is also true for many applications in industry, energy technology and mobility. Our turbulence research program focuses on fundamental aspects of turbulence, as lack of fundamental understanding hinders the possibility to control and to predict flow behaviors. Additionally, in many applications, turbulent flows are often characterized by additional complexity, such as: density stratification in environmental flows, buoyancy or rotation in geophysical and astrophysical contexts, or the addition of particles to the turbulent flow, ranging from particulate matter to multiphase flows.
State-of-the-art, massively parallel, direct numerical simulation is the primary and most flexible tool to investigate the fundamental statistical properties of fluid dynamics turbulence. By mathematically and numerically manipulating the Navier-Stokes equations it is possible to perform numerical studies that help shedding light on the physics of turbulence.
Rotation and density effects on turbulence are considered in canonical model flow systems ideally suited for laboratory realization and direct numerical simulation. These two methods bring detailed and complementary insights into the physical mechanisms at work in these flows, which we then translate into models that can be used for the study of larger, more complex geophysical and astrophysical systems.
The study of particles in turbulence has applications as diverse as rainfall prediction (raindrop growth by collisional coalescence), enhancing performance of bioreactors or even shaping the properties of turbulence to our needs by adding smart particles. Also on this topic there is a fruitful exchange between laboratory experiments and simulations, involving simple low-level point-particle models or even the full resolution of flow around such particles.