Holographic Interferometry Studies of the Temperature Field near a Condensing Bubble
For a better understanding of the mechanism of bubble collapse, holographic interferometry combined with high-speed cinematography was used as measuring technique to study the temperature field near a condensing bubble.
To ensure well-defined reproducible conditions, experiments have been carried out by injecting single vapour bubbles into subcooled liquid through a nozzle. The experiments were performed for a range of pressure from 0.25 to 4 bar, for subcoolings from 5 to 50 K and for initial bubble diameters of about 2 mm. Freon 113 and Ethanol were used as test fluids.
To evaluate the axisymmetric temperature field around the bubble from the interference fringe field, the methods of Abel-integral are not sufficient. A correction procedure considering the light deflection caused by the local temperature gradient has been developed and applied to calculate the heat transfer coefficient. Calibration tests with a heated solid sphere showed that the experimental results agree with additional thermocouple measurements to ± 10%.
Some interferograms and the experimental results are presented.
KeywordsHeat Transfer Coefficient Vapour Bubble Holographic Interferometry Bubble Collapse Subcooled Liquid
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- /1/.Nordmann, D.: Temperature, Pressure and Heat Transfer near Condensing Bubbles. Dissertation, University of Hannover (1980).Google Scholar
- /3/.Voloshko, A.A.; Vurgaft, A.V.: Study of condensation of single vapor bubbles in a layer of subcooled liquid. Heat Transfer - Soviet Research, Vol. 3, No. 2 (1971).Google Scholar
- /4/.Florschuetz, L.W.; Chao, B.T.: On the mechanics of vapour bubble collapse. J. Heat Transfer 87, 209–220 (1965).Google Scholar
- /5/.Moalem, D.; Vurgaft, A.V.; Akselrod, L.S.: Condensation of vapour bubble in a liquid. Theoreticheskie Osnovy Khimicheskoi, Tekhnologii, Vol. 7, No. 2, 269–272 (1973).Google Scholar
- /8/.Mayinger, F.; Panknin, W.: Holography in Heat and Mass Transfer. 5th Int. Heat Transfer Conference VI, 28, Tokyo (1974).Google Scholar
- /9/.Chen, Y.M.: Report for DFG, Ma 501/23–01 (1982).Google Scholar