Abstract
Pulsating jets are very common and sometimes useful in industrial fields, due to some differences in basic characteristics from steady jets. In this research, the authors focuse upon the frequency effect of pulsation on a circular jet. Experiments are conducted at a Reynolds number of 5, 000, Strouhal numbers of 0.13, 0.20 and 0.27, and a velocity-amplitude ratio of 0.5. Using olive-oil smoke, the authors visualise the flow near a nozzle exit, and get quantitative information by a PIV technique. Measurements on the entrainment flow rate give us another specific flow information, on which we discuss the frequency effect.
