Flow Separation and Turbulence in Jet Pumps for Thermoacoustic Applications

详细信息    查看全文

• 作者：Joris P. Oosterhuis ; Anton A. Verbeek ; Simon Bühler…
• 关键词：Jet pumps ; Thermoacoustics ; Flow separation ; Turbulence ; Oscillatory flows ; Minor losses
• 刊名：Flow, Turbulence and Combustion
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：98
• 期：1
• 页码：311-326
• 全文大小：838KB
• 刊物类别：Engineering
• 刊物主题：Engineering Fluid Dynamics; Fluid- and Aerodynamics; Engineering Thermodynamics, Heat and Mass Transfer; Automotive Engineering;
• 出版者：Springer Netherlands
• ISSN：1573-1987
• 卷排序：98

文摘

The effect of flow separation and turbulence on the performance of a jet pump in oscillatory flows is investigated. A jet pump is a static device whose shape induces asymmetric hydrodynamic end effects when placed in an oscillatory flow. This will result in a time-averaged pressure drop which can be used to suppress acoustic streaming in closed-loop thermoacoustic devices. An experimental setup is used to measure the time-averaged pressure drop as well as the acoustic power dissipation across two different jet pump geometries in a pure oscillatory flow. The results are compared against published numerical results where flow separation was found to have a negative effect on the jet pump performance in a laminar flow. Using hot-wire anemometry the onset of flow separation is determined experimentally and the applicability of a critical Reynolds number for oscillatory pipe flows is confirmed for jet pump applications. It is found that turbulence can lead to a reduction of flow separation and hence, to an improvement in jet pump performance compared to laminar oscillatory flows.