Please use this identifier to cite or link to this item:
http://hdl.handle.net/1983/909
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| Title: | Nonlinear dynamics of torsional waves in a drill-string model with spatial extent |
| Author(s): | Barton, DAW
Krauskopf, B
Wilson, RE |
| Publication or creation date: | 28-Feb-2007 |
| Abstract: | In this paper we investigate the dynamics and bifurcations of an oil-well drill-string model that takes the form of a neutral delay differential equation (NDDE). We consider the torsional mode of the drill-string and investigate the associated stick-slip motion. To analyse the model we develop numerical continuation routines based on Fourier-methods since existing routines based on polynomial approximations are unable to cope with the presence of arbitrarily weakly damped modes. We find `resonance peaks' in the dynamics where a high-frequency mode is superimposed on the underlying periodic behaviour causing large torsional waves in the drill-string. We show that the resonance peaks are robust to small perturbations in the friction parameters but disappear if static friction forces are neglected completely |
| Subject keywords: | delay differential equation
bifurcation
numerical continuation
Cosserat |
| Sponsors: | David A.W. Barton is a research fellow funded by the Lloyds Tercentenary Foundation |
| Document type: | Preprint |
| Appears in Collections: | Bristol Centre for Applied Nonlinear Mathematics
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