Abstract
Complex flow structures in optical disc drives compatible for Blu-ray disc, were investigated by numerical flow simulation based on the Cartesian grid method. From the simulation results, we found that additional hole on the tray outside of the disc induced the secondary upward flow which was caused by asymmetric pressure and velocity distribution. And the experimental results showed that the cooling effect of the laser diode increased and the disc vibration was not influenced by the additional hole on the tray.