| Harmonic Regelation | ||
| Joe D. Goddard, Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0411 The early works of Faraday and the Thomson brothers mark the beginning of a sustained scientific fascination with "regelation", the pressure-induced thawing and refreezing of ice at solid boundaries. This phenomenon has been invoked to explain various processes such as basal melting of glaciers and a well-known classroom experiment involving the passage without trace of a solid wire through a block of ice. Nye [1] provides an elegant mathematical theory for the movement of a circular wire, with speed controlled by a lubrication-type flow in an interfacial liquid layer, together with conduction of heat through wire, layer and surrounding ice. Nye derives an analytical solution to the problem, based on the angular symmetry of the associated harmonic temperature and pressure fields, Subsequent careful experiments, e.g. of [2], show close agreement with Nye's theory in some cases but not in others. After a brief review of the theory and experiment, it is shown here that Nye's is a special case of a more general theory which admits solutions for the translation and rotation of symmetrical bodies such as elliptic cylinders and general ellipsoids. This provides a generalization of the "Stokes-law" drag proposed by Nye for the motion of one rigid body through another. The current theory also suggests a simpler regelation experiment with measurement of torque required for the slow rotation of an elliptic cylinder in ice. [1] J.F. Nye, "Theory of regelation". Phil. Mag.,16,1249-66,1967. [2] L.D. Drake and R.L. Shreve,"Pressure melting and regelation of ice by round wires" Proc. Roy. Soc. A,, 332, 51-83, 1973. Extended Abstract Status: Not Uploaded | ||