Visualization of vapor bubbles using high speed VTR on subcooled nucleate boiling from a horizontal wire.

The effect of subcooling on nucleate pool boiling heat transfer was studied on a horizontal platinum wire, 0.1mm in diameter and 50mm in length, using Freon R113 at atmospheric pressure. Rate of subcooling was changed from 1.7 to 37K. A high speed VTR (400 frames/s) was used to visualize boiling characteristics. On higher degrees of subcooling a higher heating surface temperature was measured in a developed nucleate boiling region where data were correlated by q=C.ΔTs7. The images of the VTR were processed to examine frequency of bubble departure and bubble size.