RESUMO

A simple, inexpensive flow visualization technique for studying moderate-frequency oscillating flow field is described. The technique involves performing planar Mie-scattering visualization in a phase-sensitive fashion using a conventional CCD camera equipped with a built-in electronic shutter. The periodic nature of the flow field is utilized making it possible to study a rapidly oscillating flow field without the use of high-speed film. It allows the use of video camera in studying the oscillatory phenomena with the period much shorter than the video display period. In this article the technique was used to study periodic fuel injection into a forced flow field. Real-time phase-resolved acquisition and computerized processing of planar Mie-scattering images were performed with a simple setup and at a reasonable cost. While a copper-vapor laser was used as the light source in the work, the technique can also be employed with other less-expensive light sources, including continuous as well as spark-based types.