Thermal characterization of a heating cylinder under ultrasonic effects

•Information of heat transfer enhancement of a heating cylindrical heater in water by 40, 80, and 120 kHz ultrasound was provided.•The key mechanisms leading to the enhancement of heat transfer were obtained and visualized using thermocouples, IR-camera, and video camera.•An accurate prediction formula for the overall heat transfer enhancement ratio, depending on the ultrasonic frequency and the distance was proposed.