An investigation into heat transfer for a pulsating laminar flow in a rectangular channel with a boundary condition of the first kind

A finite difference method is used for modeling heat transfer in a pulsating laminar flow in rectangular channels with different aspect ratios for the wall boundary condition $T_w = \text{const}$. With high amplitudes of oscillation of the cross-section averaged flow velocity, a considerable increase in the cross-section averaged and time-averaged Nusselt number as compared with its stationary value was revealed. The range of dimensionless oscillation frequencies where the Nusselt number increases in the vicinity of the inlet to the heated section and also along the entire length of this section as compared with a steady-state flow was found.