AN EXPERIMENTAL INVESTIGATION OF RESONANT HEAT-TRANSFER ENHANCEMENT IN GROOVED CHANNELS

Experiments on hydrodynamic resonance and its effect on heat transfer in laminar flows through ducts with periodically spaced transverse grooves cut into one wall are presented. Oscillatory perturbation of the flow rate at the frequency of the most unstable linear modes results in a resonant response with associated mixing and significant heat transfer enhancement. Measurements confirm previous calculations demonstrating that a 20% flow rate oscillation at the optimal frequency more than doubles the convective heat transfer coefficient. The experimental frequency band for significant enhancement is, however, broader than the numerically predicted one.