異なる物性値をもつ液体への核沸騰熱伝達 : その1.気ほうの有効かきまぜ長

抄録

In nucleate boiling the physical meaning of liquid level above the heating surface had never been clarified. Therefore, we carried out the experiments for this purpose, and found that there was an effective stirring length of bubbles which was proper to liquid. This is the effective height from heating surface to a liquid level, through which the bubbles have the stirring effect. The effective stirring length of bubbles relates to the drag of rising bubbles. The following relation was obtained from the experiments. [numerical formula] where H_e=the effective stirring length of bubbles, R=the representative length of the heating surface, R^^-_e·b=the bubble Reynolds number, d₀=the diameter of vapour bubble just leaving the heating surface, U_m=mean rising velocity of bubble and υ=the kinematic viscosity of liquid.