Numerical study of geometry and rotation dependence on the flow in labyrinth seals /
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| Other Authors: | |
| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2011]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | A computational study was conducted on the flow, both compressible and incompressible, in a labyrinth seal at various geometries and rotation rates. The computations were performed using the commercial software Fluent®, which solves the k-ε model to predict the flow field in the seal. Various clearance-pitch ratios were used to study the effect of clearance on the flow. The aspect ratio, which is defined as the pitch-height ratio was varied to study the influence of the depth of the cavity on the flow as a whole. These studies span a range of Taylor's number that is defined accordingly, while fixing the Reynolds number at 1000. The effects of clearance, aspect ratio and rotational rates were studied using carry-over coefficient and discharge coefficient. It was observed that a secondary recirculation zone (SRZ) occurs inside a seal cavity above certain Taylor's number. This significantly changes the flow field in the seal and the cavity, which results in an increase in pressure drop across the seal for a given flow boundary condition. This formation of SRZ's was more evident in incompressible flow (water) and occurred at prohibitively high rotational speeds in case of air (compressible flow). It was also observed that flow with teeth on rotor was characterized by SRZ's, while it is not the case with teeth on stator. A flow map which shows the onset and presence of SRZ's is presented. The ratio of tangential velocity of the shaft to the average of the swirl velocity in a cavity at various geometries of the cavities is presented. They seemed to be decreasing with decreasing depth and followed a linear pattern with the aspect ratios of the cavity. |
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| Item Description: | "Major Subject: Mechanical Engineering" Title from author supplied metadata (automated record created 2011-11-01 09:04:20). Electronic resource. |
| Physical Description: | 1 online resource. |
| Bibliography: | Includes bibliographical references. |