SubCooled Flow Boiling Heat Transfer Correlation

5 SubCooled Flow Boiling Heat Transfer Correlation 

Lee and Mudawar (2009) proposed the subcooled boiling CHF correlation based on the inlet condition as 

Smooth annular flow regime This regime is characterized by a very thin and fairly smooth liquid film flowing along the channel wall. There is a simultaneous vapor flow in the core clear of any liquid droplets. This regime occurs in the inlet region of the microchannel. 

Wavy-annular regime This regime features a liquid film, which is thicker than that of smooth annular regime with discernible inter facial waves. 

Transition regime This regime is characterized by bridging of liquid ligaments across the vapor core. 

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Typical flow pattern for flow boiling are shown in Fig. 5. For subcooled boiling and high liquid flow rate, the observed bubble detachment size is smaller than the gap size. The treatment of the data showed that correlation [26] obtained for a large tube flow boiling can be applied to predict subcooled flow boiling heat transfer in a confined space. For saturated flow, the vapor bubbles have a tendency to merge and produce the... 

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Liu Z, Winterton RHS (1991) A general correlation for saturated and subcooled flow boiling in tubes and annuli, based on a nucleate pool boiling equation. Int J Heat Mass Transfer 34 2759-2766... 

Celata, G. P, M. Cumo, and A. Mariani, 1994c, Assessment of Correlations and Models for the Prediction of CHF in Subcooled Flow Boiling, Int. J. Heat and Mass Transfer 37(2) 237—255. (5)... 

Liu, Z., and R. H. S. Winterton, 1991, A General Correlation for Saturated and Subcooled Flow Boiling in Tubes and Annuli Based on a Nucleate Pool Boiling Equation, Int. J. Heat Mass Transfer 34(11) 2759 2766. (4)... 

Transient Reactor Analysts Code (TRAC) equation of state O for water and steam (obtained by fits to the steam tables) and a stiff gas equation of state for the melt. The constitutive relations required for the interfield coupling terms (heat transfer, momentum exchange, and phase change) include a bulk boiling model, a subcooled surface boiling model, a three-field flow regime map, and adaptations of standard heat transfer and momentum transfer correlations. 

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