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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

History terms in the heat and mass transfer equations of particles

Get access (open in a dialog) DOI: 10.1615/IHTC12.4460
6 pages

摘要

It is well known that the lagrangian unsteady equation of motion for spherical particles contains a history (Basset) term, which appears as a time integral. This term arises from the diffusion of vorticity around the spheres. Its effect is to render the equation of motion of a sphere an integrodifferential equation (and hence, more complex to solve analytically or numerically). Michaelides and Feng [1] solved the transient heat/mass transfer equations around a sphere at the limit of creeping flow conditions (very low Pe and Re) and proved that there is a history term associated with the process of heat or mass transfer. The form and behavior of the history term is similar to that of the history term in the equation of motion. This paper examines the analytical form of the history terms at zero and finite Re and Pe for spheres and ellipsoids as well as the effect of the shape of the particle on the functional form of the history terms. Numerical results are shown for the effect of this term on the temperature of a heated particle. It also addresses the question as to when the contribution of these history terms is significant in the heat and mass transfer processes from particles, bubbles and droplets.