Gs. Prakash et al., Numerical modelling of microscale effects in conduction for different thermal boundary conditions, NUM HEAT A, 38(5), 2000, pp. 513-532
Non-Fourier microscale effects are significant during the rapid hearing of
metallic substrates. Recently, a two phase lag model for conduction has bee
n proposed,,which accounts for the finite propagation speed of a thermal wa
ve mid the equilibration time between the electrons and lattice. Available
closed-form solutions for the dual phase las model are found to be very dif
ferent for apparently similar boundary conditions. in this study, the origi
n of the discrepancy in the available analytical results has been identifie
d as the sensitivity of the predicted solution to the way of implementing t
he surface boundary condition. A numerical solution procedure based on the
finite element method and fourth-order Runge-Kutta time marching procedure
has been employed for the spatial and temporal discretisations, respectivel
y. The predicted results Soi different boundary conditions clearly capture
thermal wavelike and pure diffusion-type phenomena in the appropriate range
of time lag values. Application of the two phase lag model to laser pulse
heating illustrates that the effects of microscale phenomena on the spatial
and temporal variations of temperature could become important for high fre
quency pulsing.