Abstract: Under certain specific conditions, a zone of recirculation may be formed in confined jet. Confined jets are often used for tubular reactors, evolution of recirculation will creat backmixing of fluids disturbing reactor performance. The authors of this paper conducted experiments involving recirculation phenomena in confined jets. Factors affecting the occurence of recirculation were studied. The initial and ending points of recirculation were identified. Based on the model for free turbulent round jets, a correlation formula was derived for estimating the initial point of recirculation in confined jets.

摘要： <正>在一定条件下,约束射流内会出现大规模环流,如将约束射流用于管式反应器,环流的产生不但造成物料返混而且改变了物料的停留时间分布及混和状况,从而影响反应器性能.作者对约束射流中环流现象进行观测研究,测定了环流起始与终止位置,同时分析了影响产生环流的因素,并应用自由湍流园射流模型导出了计算约束射流中环流起始位置的关联式.x_b/d_l=2.93(1+Q_(ao)/Q_(fo)