CALCULATION OF NON-STEADY-STATE THERMAL CONDUCTION FOR LOW FOURIER NUMBERS (FO-LESS-THAN-0.001)

Assuming that for small Fourier numbers heat transfer is determined by the specific heat of a heated layer of thickness delta = root a . tau , an equation is derived for the temperature field, whose solution is satisfied in finite quadratures and has a fairly simple form. The resu lts of calculations made using the proposed dependence are compared wi th the accurate solutions obtained by A. V. Lykov. This suggests that acceptable calculation accuracy may be achieved for Fo<0.001 and Bi<20 . In this case the values of the dimensionless temperature do not depe nd on the shape of the body, and the proposed dependence can be used f or calculations of plates, cylinders, or spheres. (C) 1997 American In stitute of Physics. [S1063-7850(97)00501-6].