Heat transfer mechanism driven by acoustic body force under acoustic fields

We demonstrate a heat transfer (HT) mechanism based on the relocation of an inhomogeneous fluid under acoustic fields. The proposed HT mechanism is studied under gravity and microgravity conditions. When differentially heated fluid is subjected to ultrasonic waves perpendicular to the HT direction, HT is found to be enhanced up to one order. Depending on acoustic properties, different flow patterns are observed for different fluids. A modified Rayleigh number is proposed for HT characterization that accounts for both gravity and acoustic effects. Furthermore, suppression of natural convection HT is observed when acoustic waves are applied parallel to the HT direction.