ペットボトルロケット背後に生じる剥離渦の可視化

抄録

In our laboratory, manufacture and flight tasts of PET bottle rocket in the first semester of 2nd grade have been carrying out as introductive education of fluid engineering. The objective of this paper is to investigate a stall phenomenon arising in the PET bottle rocket at the optimum launching angle, which is calculated computationally. The separated vortex patterns over the PET bottle rocket at the attack incidence range 45 to 70 deg have been visuallized by hydrogen bubble method and tungsten halogen lamp in the improved water channel experiment. Reynolds number in the visualization experiments is 4.7 × 1,000 referred to the base diameter. It was confirmed that the uniformity of velocity profile at the test section of the water channel was better than ±20% over the whole main flow velocity range measured. It was found that the separated vortices become asymmetric with an increase in angle of incidence, and the vortex shedding such as karman vortex street performs at attack angle larger than about 65 deg.