非一様な熱カウンター流に追従する微小粒子の速度分布に関する研究

抄録

Lagrangian trajectories of small particles in a fully developed turbulent state are studied in a rectangular duct based on thermal counterflow. Small particles made of solid hydrogen are visualized by high-speed camera and their trajectories are recorded. The liquid helium temperature was set to two temperatures, 1.90 K and 2.00 K, and the applied heat flux was 800 W/m2. In order to studying the influence of the wall on the flow field, a total of five visualized cross sections were set up at different distances from the wall. In this research, the original algorithm of image processing and particle tracking was developed. At each visualized cross section, Particle Tracking Velocimetry (PTV) was used to measure the instantaneous velocity in fluids using tracer particle. And we statistics the velocity distribution of the tracer particles to study the wall influence on the flow field.