Abstract
This study was performed in order to investigate flow patterns around a control rod and flow-induced vibration characteristics of that in HTTR (High Temperature engineering Test Reactor). The control rod used in the experiment is a full-sized partial model of HTTR and consists of four control rod elements and a shock absorber. The simulated control rod was suspended vertically in circular duct. The experiment carried out up to Rein=22000 using water. Water flowed downward inside and outside paths of the simulated control rod. Flow patterns were visualized by the pearl pigment method and vibration amplitudes were measured by a noncontact displacement sensor. Fundamental flow characteristics around the control rod were observed, such as a counter flow in narrow passage and an oscillory flow in outer channel.
