【摘要】 实验研究了管外换热状况对振荡管最佳射流激励频率及管内振荡流特性的影响。采用自然对流及强制对流（轴向水冷却）两种不同的管外换热形式，并用管外平均对流换热系数α来定量评价管外换热状况。研究表明，自然对流（α＝１４．５Ｗ／ｍ２·℃）时，最佳射流激励频率ｆｏｐｔ随膨胀比的增大而显著增大；强化管外传热后（α＝１１４０Ｗ／ｍ２·℃），振荡管的制冷效率明显提高且受射流激励频率的影响变小，同时，ｆｏｐｔ显著降低且几乎不随膨胀比而变化，本文将这一现象称为“钳制效应”。文中对钳制效应的机理及应用前景进行了分析与讨论更多还原

【Abstract】 The influences of the heat transfer condition outside an oscillatory tube on the optimum exciting frequency and the characteristics of the oscillatory flow inside the tube have been experimentally investigated. Two kinds of heat transfer type, the natural convection and the forced ones, are adoptted in the experiments and the heat transfer effect is quantitatively evaluated by the average heat transfer coefficient ( ). The results show that in case of natural convection( =14.5W/m 2·℃), f opt is increased by 20% as the expansion ratio ε is changed from 2.0 to 6.0. When the heat transfer is intensified ( =1 140 W/m 2·℃), the value of f opt is significantly decreased and is hardly influenced by ε , and this effect of f opt is called “clamping effect” in this paper. The mechanism and application prospect of the clamping effect are also discussed.更多还原