摘要
推广了原有气液两用流局部界面密度双探针方法测量模型，使这一模型不仅可用于球形界面，而且可用于各种长、短轴半径之比的椭圆形扁球体界面型式的气液分散流动。基于改进的测量模型，应用光导纤维双探针技术测量了垂直圆管内气液两相泡状流的界面密度。测量结果与照相方法所测结果符合良好。
An improved model for measurement of the local interfacial area concentration by one-dimensional dual-sensored probe method was developed without the assumption of spherical interfacial shape. Bubbles or droplets in gas-liquid two-phase flows might have an elliptiacl shape with various ellipticities. As a result, interfaces of various bubbles in gas-liquid dispersed flows can be described by the elliptical shape. Then the probability density function of angles between the flow direction and the elliptical interface P (μ) was deduced. And the ellipticity of interfaces can also be estimated by analyzing the distribution of bubble size measured by the probe. Finally,the local inter facial area concentration can be obtained according to the bubble frequency, the velocity distrbution of interfaces and the interfacial shape.Based on the model, the local interfacial area concentration in air-water bubbly flow was measured by dual-sensored optical fiber probe. The result measured by the probe method is in agreement with that measured by the photographic method. However, there is observable deviation between two results if the inter facial area is large. A probable reason is that the photographicmethod may underestimate the interfacial area of flows because some bubbles were hidden by other bubbles when they are taken a picture. In addition, we found that most bubbles in the air-water flow were not of spherical shape but of elliptical shape with a considerable ellipticity. So the spherical interface model is not applicable to the gas-liquid flow with large bubbles.
出处
《核科学与工程》
CSCD
北大核心
1996年第2期120-126,共7页
Nuclear Science and Engineering
基金
国家自然科学基金
