Experimental Two-Phase Flow Characterization of Subcooled Boiling in a Rectangular Channel

摘要

On the efforts to provide a reliable source of experimental information on turbulentsubcooled boiling ow, time resolved Particle Tracking Velocimetry (PTV) experimentswere carried out using HFE-301 refrigerant ow through a vertical rectangularchannel with one heated wall. Measurements were performed at liquid Reynolds numbersof 3309, 9929 and 16549 over a wall heat flux range of 0.0 to 64.0 kW=m2. Fromthe PTV measurements, liquid two dimensional turbulence statistics are available,such as: instantaneous 2-D velocity fields, time-averaged axial and normal velocities,axial and normal turbulence intensities, and Reynolds stresses. The present resultsagree with previous works and provide new information due to the 2-D nature ofthe technique, for instance, this work shows that by increasing heat ux, the boilingbubbles influence on the liquid phase is portrayed as a persistent increase of axialvelocity on regions close to the heater wall. This persistent increase on the axialvelocity reaches a maximum value attributed to the terminal bubble velocity. Thesenew observed phenomena must be considered for the development and improvementof two-phase ow turbulence models. To this end, an extensive error analysis was alsoperformed with emphasis on the applicability of the PTV measurement technique onoptically inhomogeneous flows. The error quantification exhibited negligible opticallyinduced errors for the current conditions, making the data acquired in this work avast and reliable source.