The influence of geometry on the pressure field within the confined, water-filled annulus between a central, vibrating cylinder and an outer, rigid enclosure is determined. A two-dimensional model is constructed using the finite element (FE) method and parameters are identified to characterize the eccentricity of the nominal cylinder position, the size of the annulus relative to the inner cylinder and the degree to which the annulus is not circular (i.e., it is elliptic). The FE solution is verified using a closed-form solution for the special case of a concentric cylinder and annulus. It is shown that the system acts as a force multiplier. Analyses of the asymmetrical geometries indicate that while the pressure field on the surface of the cylinder and enclosure can be highly asymmetric, the system is relatively insensitive to minor variations in annulus shape except when the vibrating cylinder is not centrally located within the fluid region or the annulus size itself is small.
Effects of Geometry on the Performance of a Downhole Orbital Vibrator
Contributed by the Petroleum Division and presented at the International Mechanical Engineering Congress and Exposition, the Winter Annual Meeting of THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS, New York, New York, November 11–16, 2001. Manuscript received by the Petroleum Division, June 26, 2001; revised manuscript received January 30, 2002. Editor: A. K. Wojtanowicz.
Reynolds, R. R., Cole, J. H., and Yuan, Z. (May 28, 2002). "Effects of Geometry on the Performance of a Downhole Orbital Vibrator ." ASME. J. Energy Resour. Technol. June 2002; 124(2): 77–82. https://doi.org/10.1115/1.1467600
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