Experimental Study on Compound Swirl Jet

This paper concerns the fundamental study on the push-pull type ventilator, especially applied to the smoking table. In order to achieve more effective cleaning of the dirty air, a compound swirl jet, which consists of a round free jet having thick rim and a coaxial annular swirl jet was proposed by the authors. It was found that the compound flow is very useful for the push flow of the push-pull type ventilator selecting the suitable flow rate ratio of the annular swirl jet to the free jet. As a fundamental study on the compound swirl jet, the flow visualization was also carried out using the smoke method. At the same time, the mean velocity components were measured using the cobra Pitot tube. It was found from the results of these experiments that the unique flow structure by the interaction of two jets is created in the compound swirl jet choosing the adequate flow rate ratio, which is suitable for the push flow of the push-pull type ventilator.