Effect of density ratio on critical heat flux in closed end vertical tubes

Critical heat flux in a closed two-phase thermosyphon

“…The results of the critical heat flux calculation for the experimental setup developed are shown in [7]; Z. Nejat [8] 1013.0 R. K. Sakhuja [9]; G. B. Wallis [10] 1390.3 O. L. Pushkina, Yu. L. Sorokin [11] 12605.7 C. L. Tien, K. S. Chung [12] 5403.4 S.S. Kutateladze hydrodynamic theory of the heat transfer crisis during boiling H. Imura, K. Sasaguchi, H. Kozai, S. Numata [2] 1345.2 Y. Haramura; Y. Katto [3] 1105.3 J. H. Lenhard; V. K. Dhir [4] 1263.8 V. M. Borishanskiy [5] 1207.8 E. E. Kazakova [6] 1016.8 S.S. Kutateladze [13] 1355.8 B. P. Avksentyuk; S. S. Kutateladze [14] 1186.3 N. Zuber [15] 1157.1 W. M. Rohsenow, P. Grifts [16] 1356.3 I. Mudawar, A. H. Howard, C. O. Gersey [17] 1279.5 C. K.Guan, J. F. Klausner, R. Mei [18] 990.6…”

“…It should be noted that this is the only correlation from the formulas presented which takes into account the liquid viscosity influence on the critical heat flux. It is possible to determine CHF based on the theoretical contributions of the occurrence of a "flooding" regime in a thermosyphon by using correlations based on the Wallis numbers [7][8][9][10] (the dependences are based on the balance of inertial and hydrostatic forces). Correlations based on Kutateladze numbers [11][12] (based on the balance of dynamic forces, surface tension and gravity forces) can not be used for the experimental setup developed.…”

“…Based on the analysis of known dependences [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] for the critical heat flux calculation they may be conditionally divided into two groups based on different concepts. The first concept correlations [7][8][9][10][11][12] are based on the achievement of the vapor velocity limit, at which the hydrodynamic instability of the liquid-vapor interface and the entrainment of the descending liquid part by an ascending vapor stream occur. The correlations are based on the numbers: Wallis [7][8][9][10] and Kutateladze [11,12].…”

“…The first concept correlations [7][8][9][10][11][12] are based on the achievement of the vapor velocity limit, at which the hydrodynamic instability of the liquid-vapor interface and the entrainment of the descending liquid part by an ascending vapor stream occur. The correlations are based on the numbers: Wallis [7][8][9][10] and Kutateladze [11,12]. The second concept correlations [13][14][15][16][17][18] are based on the heat transfer crisis from the heating surface to the liquid (the vapor film occurrence between the wall and the coolant).…”

Length effect on entrainment limitation of vertical wickless heat pipe

“…In 1978, Tien and Chung suggested an entrainment correlation using the Kutateladze flooding criterion [8], whereas in the same year, Katto performed countercurrent flow experiments for largefilling-ratio thermosyphons to investigate this correlation [9]. In 1981, Nejat developed a model to obtain a correlation for the flooding limit in a confirmed channel [10]. In 1983, Imura et al developed another correlation using an approach similar to that of Katto and Nejat [11].…”