表面テクスチャを有する非接触シールの動特性の推定法

抄録

In order to reduce the leakage flow rate and improve the precessing motion of non-contacting seals, seals with variously shaped concaves and grooves on the sliding surface of the seal have been proposed. In the numerical analysis of such non-contact seals with concavities and grooves, the grid points are set according to the concavities and grooves. On the other hand, with the recent progress in machining technology, the degree of freedom in machining the sliding surface shape has increased, and the shape is expected to become more complex. In other words, the conventional numerical analysis model that uses grid points to match the actual shape as described above is expected to become difficult to analyze, and a model that allows more flexible numerical analysis is required. In this study, a bulk flow model is used to analyze the effect of surface texture on the flow of a non-contact seal with a surface texture on the seal sliding surface. The effectiveness of the proposed analysis method is then compared with the static and dynamic characteristics obtained from conventional numerical analysis models and experiments. As a result, the following points were clarified. For a damper seal with irregularities on the seal side, the dynamic characteristics of the liquid film can be predicted relatively accurately by setting the value of the dimensionless empirical turbulence coefficients to match the leakage flow rate over a wide range of speeds. The best agreement with the experiment is obtained when the seal clearance is set to be the clearance at the land and the dimensionless empirical turbulence coefficients is set to be the same for the seal side and the rotor side.