著者

肥爪 彰夫 倉田 健二 中村 優一 松田 隆男

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集C編 (ISSN:03875024)

巻号頁・発行日

vol.58, no.554, pp.2869-2876, 1992

被引用文献数

1

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Excessively large transient torsional vibration is induced on the rotor system of modern large turbine-generators. This paper reveals that the coupling connecting the adjacent rotors acts as a hysteresis damper, and discusses the effect. First, a model is presented for the damping mechanism of typical shaft coupling. Second, the time-dependent nonlinear transient torsional vibration of the rotor system is investigated, using this model. Third, an improved coupling of higher damping capacity is introduced and investigated in the same way. Thus, the proper direction of the optimal design of coupling is clearly specified.

著者

富山 明男 平野 雅司 松田 隆男 坂口 忠司

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.58, no.551, pp.2177-2183, 1992-07-25

被引用文献数

1

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Computational time for numerical simulation of transient incompressible viscous flow is governed by numerical methods to solve the Poisson equation of the pressure. In order to improve the computational efficiency of the SOR method, a mathematical analysis was conducted in the present study to derive the spectral radius, i. e., the maximum modulus of the eigenvalues of the iteration matrix for a discrete Poisson equation in staggered mesh system. The derived spectral radii for the point, line and area Jacobi iteration matrices are applicable to the Dirichlet, the mixed boundaryvalue and the Neumann problems in an n-dimensional rectangular region. The validity of the optimum relaxation parameter of the SOR method, which was calculated by the derived spectral radii, was confirmed by numerical experiments. Furthermore, a simple estimation method of the optimum relaxation parameter for the non-rectangular region was presented for transient flow analyses.