Flow Induced Force by Compressible Fluid in the Narrow Gap around Rotating Shaft : 1st Report, Flow Induced Force of Cylindrical Narrow Parallel Gap in No-Rotating Condition

• Published in: Transactions of the Japan Society of Mechanical Engineers Series C Vol. 67; no. 659; pp. 2143 - 2150
• Main Authors: HISA, Shoichi, SHIODA, Kazunori
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society of Mechanical Engineers 25.07.2001
• Subjects: Compressible Fluid; Flow Induced Force; Rotor Vibration; Steam Whirl
• ISSN: 0387-5024; 1884-8354
• DOI: 10.1299/kikaic.67.2143

This paper describes the numerical evaluation of flow induced force by compressible fluid around rotating shaft with narrow gap. This flow induced force may cause shaft vibration namely flow induced vibration. Governing equations of fluid are composed of conservation equations of mass, momentum and energy respectively, and equation of state. Validity of compressibility in the numerical procedure proposed here gives fairly good agreement with isentropic theory of acoustic wave. This numerical procedure clarifies followings. (1) This procedure is available for analysis of swirling flow in the narrow gap with eccentricity around shaft in a simple manner. (2) Gap concept which is introduced into governing equations as variable makes it possible to evaluate, the effect of rotor tilt and time response of shaft whirl as well as eccentricity of shaft. (3) Swirling flow induces asymmetrical circumferential distribution of pressure around the narrowest point of gap, which may generate the shaft vibration. This procedure also provides available way to evaluate the flow induced force, which interacts with many parameters in the narrow gap by simple manner.