Numerical Simulation Study on the Feasibility of Cyclone PIV Tracer Particle Seeder in Microgravity

The Particle Image Velocimetry (PIV) Unit in the Combustion Science Experimental System (CSES) aboard the China Space Station (CSS) is designed for flow field measurements in microgravity combustion experiments. However, the lack of a reliable microgravity-compatible tracer particle seeder has hindered its practical application. To address this issue, the cyclone PIV particle seeder was proposed and evaluated through steady and transient numerical simulations using the Reynolds Stress Model (RSM) and Eulerian multiphase model to assess the effects of geometric parameters, gravity, and particle accumulation on flow characteristics and particle seeding performance. Ground-based cold jet and premixed combustion PIV experiments were also conducted. Results show that while the flow field of the cyclone particle seeder is generally similar to conventional cyclone separators, localized differences exist. Traditional optimization strategies of cyclone separators may not be applicable, while a longer vortex finder improved particle seeding performance compared to the shorter configuration and the guide vane design. By combining numerical simulations and experiment results, this study demonstrates the feasibility of using the cyclone particle seeder under microgravity conditions, provides key theoretical support for optimizing cyclone seeders, and enables flow field measurements in future microgravity combustion experiments aboard the China Space Station.