急加速される回転円筒内の流れの実験的研究 : 流れのLDV測定と可視化による速度分布の測定

抄録

The purpose of this study was to clarify the flow pattern inside a rotating drum that was abruptly accelerated from rest to a constant steady speed of rotation. Observations were made by flow visualization using light sheet methods and by measuring the time history of the velocity using LDV for 24 cases with 3 sizes of drum, liquid with 4 different viscosities, and 4 speeds of rotation. The experimental results are expressed in terms of two nondimensional parameters : π₁, which is determined by the viscosity of the liquid, the speed of rotation, and the size of the drum ; and π₂, which indicates the time required to attain a constant steady speed. The relationship between these two nondimensional numbers is given by a single formula. Prior to an experiment, π₁ was fixed and the time required to attain a constant steady speed was estimated from this relationship using π₂.