CAJ | 학술논문

为研究宏观温度梯度对Marangoni凝结的影响,设计了一个截面为梯形的试验块。在大范围的酒精气相浓度条件下（0%～50%）,用实验的方法研究了宏观温度梯度对Marangoni凝结的影响。对于每个浓度都在不同蒸汽流速和压力下进行了实验并拍摄凝结图片。以凝结实验中所拍摄的实验图片为分析对象,分析不同质量分数、过冷度和流速下的凝结液珠脱离半径。凝结液珠的脱离半径与表面过冷度、凝结表面的横向温差、酒精质量分数、蒸汽流速等因素有关。以纯水的脱离半径公式为基础,考虑温差带来的Marangoni效应和蒸气流速后,拟合出Marangoni凝结凝结液珠的最大脱离半径公式,在大部分过冷度的情况下,计算值与实验数据一致性较好,最大误差为23%。
위연구굉관온도제도대Marangoni응결적영향,설계료일개절면위제형적시험괴。재대범위적주정기상농도조건하（0%～50%）,용실험적방법연구료굉관온도제도대Marangoni응결적영향。대우매개농도도재불동증기류속화압력하진행료실험병박섭응결도편。이응결실험중소박섭적실험도편위분석대상,분석불동질량분수、과랭도화류속하적응결액주탈리반경。응결액주적탈리반경여표면과랭도、응결표면적횡향온차、주정질량분수、증기류속등인소유관。이순수적탈리반경공식위기출,고필온차대래적Marangoni효응화증기류속후,의합출Marangoni응결응결액주적최대탈리반경공식,재대부분과랭도적정황하,계산치여실험수거일치성교호,최대오차위23%。
An oblique copper block,which created surface temperature gradient,was designed to experimentally study the effect of macroscopic temperature gradient on Marangoni condensation of ethanol–water vapor mixtures.The experiment was carried out under a wide range of concentrations（0%-50%）.For each concentration,the experiment was performed at different velocities and pressures.During the experiment condensation photographs were shot.Dropwise condensation departure radii was studied based on these photographs under the condition of different concentration,vapor-to-surface temperature difference and vapor velocity.The departure radii of dropwise condensation closely depended on the above factors.The correlation for the maximum departure radii of condensate drops was obtained on the basis of the formula for pure water vapor with velocity and Marangoni effect caused by condensation surface temperature difference.The calculation results are in good agreement with the experimental measurement over large vapor-to-surface temperature difference,and its maximum error is 23%.