起旋粗螺纹间隙中流体流动特性的PIV实验研究

PIV-based Experimental Study on Fluid Flow Characteristics in Coarse Thread Clearance of Spiral Flow Generators

利用粒子图像测速(PIV)技术对不同介质流体在垂直粗螺纹间隙中的螺旋流动进行全流场测量。用Tecplot软件进行粗螺纹间隙中螺旋流场显示并对沿流动方向上的流体速度进行提取。分析了不同流量条件下,粗螺纹间隙中不同介质流动流场瞬时特性、沿流动方向上流体速度分布特征和涡量场分布特征。结果显示:流体在粗螺纹间隙中存在高速区和低速区,随着流量的增加,高速区速度逐渐增大,面积逐渐减小,涡旋强度增加,正涡逐渐下移,负涡位置基本保持不变。在粗螺纹间隙中流体介质的粘度对螺旋流场的影响较小。

The particle image velocimetry( PIV) was adopted to measure different fluid's flow field in vertical coarse thread clearance. Through making use of Tecplot software,the spiral flow in coarse thread clearance was displayed and the velocity along flow direction was extracted. Having characteristics of instantaneous flow fields,distribution of velocity along flow direction and vorticity field of different fluids at different flow rates in coarse thread clearance analyzed to show that,both high velocity zone and low velocity zone can be seen in the coarse thread clearance; and with the increase of flow rates,the velocity in the high velocity zone including the vortex intensity becomes increased in the coarse thread clearance,but the acreage of high-speed area gets decreased and the positive vortex moves down and the position of negative vortex stays unchanged. The viscosity of fluids has little influence on spiral flow field in the coarse thread clearance.