Open Access

ARTICLE

Study on 3D Unsteady Swirling Recirculating Flow in a Nozzle with a Slotted-tube

Hui-Fen Guo^1,2, Bin-Gang Xu^1,3, Sheng-Yan Li¹, Chong-Wen Yu²

1 Institute of Textiles and Clothing, the Hong Kong Polytechnic University, Kowloon, Hong Kong
2 College of Textile, Donghua University, Shanghai 201620, China
3 Corresponding author, E-mail: tcxubg@inet.polyu.edu.hk

Computer Modeling in Engineering & Sciences 2011, 80(2), 87-112. https://doi.org/10.3970/cmes.2011.080.087

Abstract

Three-dimensional transient simulation is presented for swirling recirculating flow in a nozzle with a slotted-tube (different grooves) and the effect of the groove number is also investigated. The numerical results on the streamline angles are validated by experimental visualization using the surface oil flow technology. In the downstream center of the injectors, the vortex breakdown experiences a transition from bubble- to spiral- breakdown as time is increased. For all cases under study, as the sizes of two recirculation zones near the injector upstream wall and the step retain almost constant, the spiral breakdown shows a periodic development. The more the groove number is, the longer the computing time is to reach a periodic solution. For the case with four grooves, due to geometry symmetry, the vortex breakdown occurs earlier with axis, and the size and strength of the vortices are larger compared with that in two other cases with three and five grooves. Different from the results of the four grooves, which the breakdown point moves downward over time, the breakdown position is almost fixed for three and five grooves.

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Keywords

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