Heat Transfer Effectiveness of Saturated Drops in the Nonwetting Regime Impinging on a Heated Surface.

Micro‐bubble emission boiling from horizontal and vertical surfaces to subcooled parallel flow water

“…Under the condition of ∆T sub = 90 K and v = 2.0 m/s, on the contrary, S-MEB I occurred stably without swinging to film boiling. This was also reported by Inada and colleagues [1]. In their pool boiling experiment, MEB occurred under ∆T sub = 35 to 50 K, while it did not under 85 K. In that respect, there is a report [15] of a vapor explosion experiment of a molten metal in water, which is accompanied by a radical phase change like MEB.…”

“…Inada and colleagues [3] also pointed out that two types of MEB are found in their pool boiling experiment. One occurs at ∆T sub = 30 K showing a steep increase of heat flux in a boiling curve, and the other at ∆T sub = 50 K showing a moderately inclining boiling curve.…”

“…The crosses denote the absence of MEB. Figure 7(a) is for the horizontal surface, and plots data on pool boiling condition reported by Inada and colleagues [1], Saito and colleagues [14], and Hirono and colleagues [6]. Under high subcooling conditions S-MEB I is dominant, while S-MEB II or C-MEB become superior under low subcooling conditions.…”

“…Heat Transfer-Asian Research, 32 (2), 2003 and lower velocity, and occurs at around 100 K in the surface superheat, showing an aspect of squashed bubble mass over the surface. The emitted bubbles do not have enough power to intermix with surrounding water in a wide area, and travel on the bulk flow with a gentle boiling sound.…”

“…Under some conditions of subcooling and liquid velocity, there appears a peculiar phenomenon in the transition from CHF to film boiling. Under these conditions the heat flux increases steeply to significantly exceed CHF without a considerable increase in the surface superheat [1][2][3][4][5][6][7]. In this boiling environment, many minute bubbles are emitted from the surface accompanied by a loud boiling noise.…”