Effects of Geometry on the Performance of a Downhole Orbital Vibrator
Author:
Reynolds Robert R., Cole Jack H., Yuan Zhen1
Affiliation:
1. Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701
Abstract
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.
Publisher
ASME International
Subject
Geochemistry and Petrology,Mechanical Engineering,Energy Engineering and Power Technology,Fuel Technology,Renewable Energy, Sustainability and the Environment
Reference8 articles.
1. Yang, C.-I., and Moran, T. J., 1979 September, “Finite Element Solution of Added Mass and Damping of Oscillation Rods in Viscous Fluids,” ASME J. Appl. Mech., 46, pp. 519–523. 2. Garner, G., and Chandra, S., 1984 December, “Fluid-Structure Coupling Between a Finite Cylinder and a Confined Fluid,” ASME J. Appl. Mech., 51, pp. 857–862. 3. Chen, S. S., 1987, Flow-Induced Vibration of Circular, Cylindrical Structures, Hemisphere Pub. Corp., Washington, DC. 4. Brouwers, J. J. H., and Meijssen, T. E. M., 1985, “Viscous Damping Forces on Oscillating Cylinders,” J. Appl. Ocean Res., 7, pp. 118–123. 5. Hickox, C. E., and Dykhuizen, R. C., 1994, “Coupling of Acoustic Source Model With Exterior Domain,” Tech. Rep., Sandia National Laboratories. July.
|
|