This article is cited in 3 papers

MODELS IN PHYSICS AND TECHNOLOGY

Mathematical model of hydride phase change in a symmetrical powder particle

S. V. Manicheva^a, I. A. Chernov<sup>b

a</sup> Karelian State Pedagogical Academy, 17 Pushkinskaya street, Petrozavodsk, 185035, Russia
^b Institute of Applied Math Research, 11 Pushkinskaya street, Petrozavodsk, 185910, Russia

Abstract: In the paper we construct the model of phase change. Process of hydriding/dehydriding is taken as an example. A single powder particle is considered under the assumption about its symmetry. A ball, a cylinder, and a flat plate are examples of such symmetrical shapes. The model desribes both the “shrinking core” (when the skin of the new phase appears on the surface of the particle) and the “nucleation and growth” (when the skin does not appear till complete vanishing of the old phase) scenarios. The model is the non-classical boundary-value problem with the free boundary and nonlinear Neumann boundary condition. The symmetry assumptions allow to reduce the problem to the single spatial variable. The model was tested on the series of experimental data. We show that the particle shape’s influence on the kinetics is insignificant. We also show that a set of particles of different shapes with size distribution can be approxomated by the single particle of the “average” size and of a simple shape; this justifies using single particle approximation and simple shapes in mathematical models.

Keywords: hydriding, dehydriding, phase change, mathematical modelling, shape symmetry.

UDC: 51-73

Received: 30.04.2012

DOI: 10.20537/2076-7633-2012-4-3-569-584