The mechanism of intensive sound during heating of water in an ordinary pan is under investigation in the ATS Lab at Western Michigan University.
(please click images for larger view)
|Two thermocouple probes and a noise level meter were employed to measure the bulk temperature and noise level while the water in the pan is heated by an electric range. Also a thermocouple was embedded to the bottom plate of the pan to measure the surface temperature. A high speed digital camera (2000 fps) with an endoscope and a light source was used to observe the boiling cavitation during subcooled boiling. As shown in the figure, both a noise level meter and a hydrophone were deployed to measure acoustic signals not only from the pan but also from the bubbles.|
|A National Instrument with LabView graphical programmable language was used for data acquisition.|
|Bulk temperatures, surface temperature and noise level measurements during pan boiling. It is found that the abrupt increase of sound level is associated with the so-called boiling cavitation.|
|Pool Boiling Experiments on a copper heater with a hydrophone enables to further study the characteristics of boiling in terms of frequency and intensity. The lower part of the left picture indicates time domain signals measured during the pan boiling. Click on the pool boiling to see the motion picture (7.8MB).|
|A hydrophone (Bruel & Khar Model 8103) deployed to measure the acoustic signals during boiling.|
A water vapor bubble reveals a water jet toward the surface during the collapse, which produces an intensive acoustic signal.