文丘里气泡发生器内气泡受力量级分析

文丘里气泡发生器内气泡的输运过程一直是国内外的研究重点。本文设计了矩形截面的文丘里气泡发生器及相关的实验回路,通过高速摄像仪,利用可视化的研究方法研究文丘里通道内的气泡运动的过程。实验结果表明,气泡在进入文丘里通道扩张段后会经历约为4ms的剧烈减速,此后缓慢减速。针对文丘里管内的流场速度改变,引入加速数估算气泡受力,发现压力梯度力和附加质量力是气泡减速的主要作用力,均达到10-4N量级;曳力达到10-4N,是气泡运动的主要推动力;历史力量级仅为10-7N,但是由于与曳力量级相同,因此对于气泡减速影响不可忽略。

The investigation of the bubbles’ transportation in a Venturi is developing rapidly. For a better understanding of the bubble transportation process in the diverging section of a Venturi channel, a visualization experiment was conducted by observed the bubbles moving through a Venturi tube with the help of a high speed camera. The result shows that the bubble would decelerate rapidly in four milliseconds. In consideration of changing of the velocity distribution in the diverging section, accelerated number was introduced to estimate the forces. The conclusion is that the pressure force and the add-mass force caused the deceleration, while the drag force pushes the bubble forward. The magnitude of those forces was 10-4 N. Otherwise, the influence of the history force on the bubble’s deceleration should not be neglected.