Ultrasonic Spike Signal Analysis for Subcooled Boiling Condensation Measurement

Condensation is a key factor in subcooled boiling, significantly affecting heat and mass transfer, which are critical in many industrial processes.In a previous study, we successfully obtained the condensation rate -the collapsing speed of vapor bubbles during subcooled boiling using the ultrasonic velocity profile method -UVP method, employing two primary ultrasonic frequencies.The ultrasonic sensor was driven by sinusoidal electrical burst signals, also called tone-bursts, with a specified center frequency.This study examines the application of spike excitation signals within the same method.Spike signals, commonly produced by pulsers, i.e. pulse generators, in the ultrasonic testing field, offer the potential to enhance the accuracy of the UVP method while can reduce the cost of the measurement system.Our investigation involved measuring and analyzing ultrasonic echoes in water under two conditions: ambient temperature and boiling.Subsequently, these signals were applied to measure air-water adiabatic bubbly flow, and the measurement accuracy was validated.Finally, subcooled boiling flow measurements were performed, and the associated uncertainties were thoroughly analyzed.