Resumen de Lateral forces on a magnet falling in a conducting pipe

S. Dufour, G. Vinsard, J.-P. Brancher

• urpose – The purpose of this paper is to investigate the lateral forces during the fall of a magnet in a conducting pipe, when the direction of magnetization of the magnet is fixed. If the direction of magnetization is not parallel to the axis of the pipe, lateral forces occur and a decentration of the magnet happens.

  Design/methodology/approach – The problem is studied numerically, with a T − h 3D FE formulation well‐suited for the problem. Computational results are compared with experimental results.

  Findings – The physical model is given and the main force coefficients analyzed. The lateral forces and the decentration phenomenon are studied as a function of the main parameters (thickness and radius of the pipe).

  Originality/value – The direction of magnetization is a key parameter to analyze the dynamics of a magnet motion inside a conducting pipe, when the radii of the pipe and the magnet are not so close. This analysis with a fixed direction of magnetization allows one to quantify the lateral forces and the decentration, and is a first step to understand the complete motion which includes the rotation which can be linked to the decentration.