Correlated and uncorrelated particle fluctuations

Both in industrial processes and in nature, many different particle-laden flows can be encountered. From sedimentation in rivers and landslides to polymer and steel production, all these flows have one thing in common: solid particles move inside a fluid. In doing so, the particles interact with the fluid and can generate or dampen turbulence. Additionally, the solid particles collide with each other and, therefore, move in different directions. This project places particular emphasis on the relationship between the motion of the particles due to collisions in different directions and the collective motion of the particles caused by turbulent eddies. This relationship is derived using mathematical equations and predicted and assessed through high-resolution numerical simulations. In these simulations, the equations of motion for both the particles and the fluid are solved on supercomputers. The goal of the project is to describe the relationship between the correlated and uncorrelated movements of the particles with simplified mathematical models, thereby reducing the computational cost of the simulations by more than a factor of 100. This enables industry to gain a deeper insight into their processes through faster simulations. As a result, new, more efficient, and thus more environmentally friendly processes can be implemented. This accelerates the transition from fossil fuels to more environmentally friendly alternatives such as hydrogen.