基于振荡气泡法测定声悬浮液滴的表面张力

Measuring surface tension of acoustical suspension droplet based on oscillating bubble method

通过调节阵列式声悬浮装置的悬浮声压,使悬浮液滴转变为气泡.利用振荡气泡法的原理,结合声悬浮气泡在声场中处于缓慢变形的非平衡状态特点,对原始气泡表面膨胀系数的公式进行了修正.实验过程中采用高速摄像机记录气泡形成及振荡过程的图像,并对图像进行处理,测定悬浮气泡的表面膨胀模量,得到液体的动态表面张力.以锅炉用油为样品,利用声悬浮气泡的膨胀模量,对液滴动态表面张力进行非接触式测量.

The suspension droplets were transformed into bubbles by adjusting the suspension sound pressure of the self-developed acoustical suspension device.Based on the theory of the oscillating bubble method,the primitive formula of the surface expansion coefficient of the original bubble was modified,which combined the non-equilibrium characteristic of slow deformation of the acoustical suspension bubble in sound field.The formation and oscillation process images of the bubbles were recorded by high-speed camera,and the surface expansion coefficient of suspension bubbles was measured after digital image processing,as well as the dynamical surface tension of the liquid.By using the above obtained expansion coefficient of acoustical suspension bubbles,the dynamical surface tension of the boiler oil droplet was measured based on the non-contact method.