Bubble departure size in forced convective subcooled boiling flow under static and heaving conditions

Abstract A visual study of bubble departure size in forced convective subcooled boiling flow under static and heaving conditions was presented. High-speed digital images of flow boiling phenomena were obtained, which were used to measure bubble departure diameter. Experiments were conducted at atmosphere pressure in a narrow rectangular channel, with mass flux ranging from 300 to 710 kg/m 2  s, heat flux ranging from 65 to 298 kW/m 2 and inlet subcooling ranging from 20 to 40 K. The heaving frequency, which is generated by a six degrees-of-freedom platform, ranged from 0.2 to 0.61 Hz. The results indicated that decreasing mass flux and increasing heat flux had a tendency to increase bubble departure diameter under static condition. In heaving motion, bubble departure size was affected by additional heaving acceleration and flow rate fluctuation. A bubble departure model was proposed to predict the bubble departure diameter under static and heaving conditions by considering the additional acceleration and flow rate fluctuation. The proposed model agreed well with the experimental data within the averaged relative deviation of ±17.5%.

[1]  M. Shoukri,et al.  Bubble Behavior and Mean Diameter in Subcooled Flow Boiling , 1996 .

[2]  Toshihisa Ishida,et al.  Effects of ship motions on natural circulation of deep sea research reactor DRX , 2002 .

[3]  V. Ilchenko,et al.  Automated high-speed video analysis of the bubble dynamics in subcooled flow boiling , 2004 .

[4]  J. C. Chen.  Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow , 1966 .

[5]  V. Ilchenko,et al.  Study of the bubble characteristics and the local void fraction in subcooled flow boiling using digital imaging and analysing techniques , 2002 .

[6]  A. Kurosawa,et al.  Critical heat flux of forced convection boiling in an oscillating acceleration field. II: Contribution of flow oscillation , 1983 .

[7]  Yanhua Yang,et al.  Experimental study on onset of nucleate boiling in narrow rectangular channel under static and heaving conditions , 2012 .

[8]  Jiyuan Tu,et al.  A unified model considering force balances for departing vapour bubbles and population balance in subcooled boiling flow , 2005 .

[9]  R. Winterton,et al.  Bubble diameter on detachment in flowing liquids , 1981 .

[10]  S. Levy.  Forced convection subcooled boiling—prediction of vapor volumetric fraction , 1967 .

[11]  A. Kurosawa,et al.  Critical heat flux of forced convection boiling in an oscillating acceleration field — III. Reduction mechanism of CHF in subcooled flow boiling , 1984 .

[12]  A. R. Balakrishnan,et al.  Convective heat transfer in single-phase flow in a vertical tube subjected to axial low frequency oscillations , 2008 .

[13]  Michitsugu Mori,et al.  Bubble Lift-off Size in Forced Convective Subcooled Boiling Flow , 2005 .

[14]  A. R. Balakrishnan,et al.  Flow and pressure drop fluctuations in a vertical tube subject to low frequency oscillations , 2008 .

[15]  R. Mei,et al.  A unified model for the prediction of bubble detachment diameters in boiling systems—II. Flow boiling , 1993 .

[16]  Yanhua Yang,et al.  Effects of ship motions on laminar flow in tubes , 2010 .

[17]  S. J. Kline,et al.  Describing Uncertainties in Single-Sample Experiments , 1953 .

[18]  G. Su,et al.  Study on onset of nucleate boiling in bilaterally heated narrow annuli , 2010 .

[19]  Walter Frost,et al.  BUBBLE GROWTH AND HEAT-TRANSFER MECHANISMS IN THE FORCED CONVECTION BOILING OF WATER CONTAINING A SURFACE ACTIVE AGENT , 1967 .

[20]  Akira Kurosawa,et al.  Critical heat flux of forced convection boiling in an oscillating acceleration field — I. General trends , 1982 .

[21]  F. Staub.  The Void Fraction in Subcooled Boiling—Prediction of the Initial Point of Net Vapor Generation , 1968 .

[22]  F. White.  Viscous Fluid Flow , 1974 .

[23]  Renwei Mei,et al.  Vapor bubble departure in forced convection boiling , 1993 .

[24]  Jian-jun Xu,et al.  Prediction of Sliding Bubble Velocity and Mechanism of Sliding Bubble Motion along the Surface , 2010 .

[25]  Yanhua Yang,et al.  Experimental research of bubble characteristics in narrow rectangular channel under heaving motion , 2012 .

[26]  van Wgj Wim Helden,et al.  Forces on bubbles growing and detaching in flow along a vertical wall , 1995 .

[27]  N. Zuber,et al.  The dynamics of vapor bubbles in nonuniform temperature fields , 1961 .