Abstract
Recently a high speed pulsed light generator system has been developed for the optical analysis or imaging of fast processes in mechanical oscillations, turbulent velocity fluctuations in gaseous or liquid flows and plays an important role in visualizing the time dependency of rapidly changing states and processes. In this paper, a pulsed light system for stroboscopic photography that makes use of superbright LED has been developed. The maximum light power obtained from the developed system using a single superbright LED (TLRA 190P, λc=660nm) was approximately 1.5 watt at pulse width 24nsec and the pulse light intensity was stable over 30 hours, corresponding to 1×107 shots running at a pulse repetition frequency of 100Hz. The pulse light generator is especially suited for the observation of high speed moving objects by stroboscopic methods due to its high power light output, incoherence, pulse width and temporal stability. The stroboscopic method of imaging has been successfully applied e.g., to the microscopic investigation of the breakup of a liquid fuel jet discharging from a nozzle into the atmosphere chamber which has cylindrical space and to the observation of the droplets produced during this breakup process. The results show that the fuel flows have very distinctive shapes just after the start of injection.
