PIV application in He II forced flow research

We report an experimental approach for applying the PIV technique to measurements in He II forced flow. The forced flow of He II is created in a 3.5 m long experimental channel within the Liquid Helium Forced Flow Visualization Facility (LHFVF). We demonstrate that micron size solid hydrogen isotope particles are the best choice for tracing He II forced flow. A novel particle seeding device has been developed to form and seed such solid hydrogen isotope particles directly within He II flow. Velocity field measurements of forced flow He II subjected to a constant locally applied heat flux are presented. Results are compared to analysis based on the two-fluid model.