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| Investigation into leakage characteristics of honeycomb seals for water |
| WANG Wen-Quan, ZHANG Li-Xiang, YAN Yan |
| (Faculty of Civil Engineering and Architecture, Kunming University of Science and Technology, Kunming, Yunnan 650504, China) |
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Abstract A honeycomb seal installed between two parallel flat plates was used as an analytical model; the threedimensional flow in the seal was solved numerically according to the Navier-Stokes equations and Vreman subgrid stress model to investigate the leakage characteristics and sealing mechanism in honeycomb seals for water. The finite volume method was used to discretize the Navier-Stokes equations and the secondorder upwind scheme and the secondorder central scheme are applied to the convection and diffusion terms in the equations, respectively. The leakage flow rates through the honeycomb with different sizes of cells were obtained by means of numerical computation and compared with those in a corresponding labyrinth seal; eventually, the leakage characteristics and sealing mechanism were discussed. The results show that the honeycomb seal has better sealing performance than the labyrinth seal, a honeycomb with cells of 6 mm radius and 4 mm depth achieves the lowest leakage flow rate, causing the best sealing effect. Also, the leakage flow rate increases approximately linearly with increasing pressure difference across the inlet and outlet of the seal; however, the leakage flow rate remains nearly constant when the plate moving speed varies. Through further exploring the flow pattern in the honeycomb seal, it was observed that strong vortices have been generated in the honeycomb cell and consume the kinetic energy of stream. Such a flow pattern is mainly responsible for pressure drop and throttling effect in the seal.
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Received: 18 June 2011
Published: 31 March 2013
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