Bi-Dispersed Heavy Particles in Air Turbulence

In the first stage of the research, a homogeneous bi-dispersed distribution of particles is generated. Two species of particles, differing in size but with the same density, are placed in a system of sieves with varying grid spacings. This system is then attached to an automatic shaker that oscillates above the air chamber, where the particles are visualized. In this preliminary phase, the student will verify that both particle species are equally visible inside the observation volume under still air conditions, a necessary step to investigate how air turbulence will ultimately affect both particle species. In the second stage, the student will perform 3D tracking experiments in turbulent air, generated by two randomly actuated synthetic jet arrays within the air chamber. Once the particles settle in the observation volume, they will be imaged from a multicamera system, and their trajectories will be reconstructed with 3D Tracking techniques (3D-PTV). In post-processing, the data will be analyzed to investigate the effects of turbulence on the individual particle species. With highly resolved particle trajectories, the student will be able to address key physical questions about particle interactions in turbulence. How is the individual particle settling velocity affected by turbulence? How does turbulence redistribute them in space? How can this data improve our understanding of collective particle behaviours in nature, such as interactions between rain droplets in precipitating clouds?

In the first stage of the research, a homogeneous bi-dispersed distribution of particles is generated. Two species of particles, differing in size but with the same density, are placed in a system of sieves with varying grid spacings. This system is then attached to an automatic shaker that oscillates above the air chamber, where the particles are visualized. In this preliminary phase, the student will verify that both particle species are equally visible inside the observation volume under still air conditions, a necessary step to investigate how air turbulence will ultimately affect both particle species. In the second stage, the student will perform 3D tracking experiments in turbulent air, generated by two randomly actuated synthetic jet arrays within the air chamber. Once the particles settle in the observation volume, they will be imaged from a multicamera system, and their trajectories will be reconstructed with 3D Tracking techniques (3D-PTV). In post-processing, the data will be analyzed to investigate the effects of turbulence on the individual particle species. With highly resolved particle trajectories, the student will be able to address key physical questions about particle interactions in turbulence. How is the individual particle settling velocity affected by turbulence? How does turbulence redistribute them in space? How can this data improve our understanding of collective particle behaviours in nature, such as interactions between rain droplets in precipitating clouds?

The goal of this project is to investigate the dynamics of a bi-dispersed suspension of heavy particles in air turbulence. To achieve this, the student will first generate a homogeneous distribution of settling particles of equal densities and two different diameters. The particles will settle in turbulence generated by the air chamber at IFD, and data will be collected using a 3D multi-camera setup. Using 3D tracking techniques, the trajectories of individual particles will be reconstructed and, finally, the particle positions and settling velocities will be analyzed statistically. The project will evolve based on the interests of the students and will eventually contribute to future work to study the collision statistics between particles in turbulence.

The goal of this project is to investigate the dynamics of a bi-dispersed suspension of heavy particles in air turbulence. To achieve this, the student will first generate a homogeneous distribution of settling particles of equal densities and two different diameters. The particles will settle in turbulence generated by the air chamber at IFD, and data will be collected using a 3D multi-camera setup. Using 3D tracking techniques, the trajectories of individual particles will be reconstructed and, finally, the particle positions and settling velocities will be analyzed statistically. The project will evolve based on the interests of the students and will eventually contribute to future work to study the collision statistics between particles in turbulence.

You will collaborate with members from the Institute of Fluid Dynamics (IFD) in the Department of Mechanical Engineering and Process Engineering (D-MAVT). To apply, please send your full transcript (up to the current semester) and a short motivation letter to agambino@ethz.ch and fcoletti@ethz.ch. Proficiency in a programming language is required, and prior experience with imaging techniques is recommended. The project is planned to start in Spring 2025 and is open for semester projects, bachelor's and master’s thesis.

You will collaborate with members from the Institute of Fluid Dynamics (IFD) in the Department of Mechanical Engineering and Process Engineering (D-MAVT). To apply, please send your full transcript (up to the current semester) and a short motivation letter to agambino@ethz.ch and fcoletti@ethz.ch. Proficiency in a programming language is required, and prior experience with imaging techniques is recommended. The project is planned to start in Spring 2025 and is open for semester projects, bachelor's and master’s thesis.