Rotordynamic effects of pocket damper seals /
Experiments are presented for labyrinth seals and pocket damper seals (PDS) with four and eight partition wails on a specially designed test rig. The experiments shown on this report include non-rotating tests and rotating tests which have the objective to determine the seal's characteristics a...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=731686401&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Experiments are presented for labyrinth seals and pocket damper seals (PDS) with four and eight partition wails on a specially designed test rig. The experiments shown on this report include non-rotating tests and rotating tests which have the objective to determine the seal's characteristics and will allow comparisons between them. Results from the non-rotating tests show very low damping values for the labyrinth seal, and even negative values for inlet pressures over 3.70 bar (40 psig). The non-rotating tests on the PDS show that the magnitude of the direct stiffness and direct damping increase with the inlet pressure. The PDS with eight partition wails shows more direct damping than the PDS with four partition wails, but probably also adds some non-linear characteristics to the system. The rotating tests, which consist of countdowns from 7000 to 300 rpm, are useful to corroborate the trend observed on the previous tests. They showed the ability of the PDS to suppress the critical speed amplitudes almost beyond recognition for inlet pressures 3.70 bar (40 psig) and above. The rotating tests also show that the journal's rotational speed (up to 7000 rpm) has very little effect on the dynamic coefficients of the seals and therefore, on the rotordynamics of the system. Based on the experimental data, a rotordynamic model was prepared for direct comparison of the extracted dynamic coefficients (from the non-rotating tests) with coefficients from the countdown plots (from the rotating tests). For all the experiments, it was observed that the journal was statically offcentered in a magnitude dependant on the inlet pressure. A mathematical model is prepared to predict the offcenter effect of the journal on the dynamic coefficients of the system. Comparisons with previous codes are made for the four-bladed PDS's. |
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| Item Description: | Vita. "Major Subject: Mechanical Engineering". |
| Physical Description: | xvii, 211 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 113-115). |