PIV技术在冰盖下复式断面渠道流速测量中的运用

Application of PIV Technique in the Measurement of Flow Velocity Distribution in Compound Section under Ice Sheet

在测定冰盖下复式断面流场、流速的模型试验中,水体中的运动粒子是重点研究对象。粒子图像测速(Particle Image Velocimetry,PIV)技术已在水力学研究领域得到普遍应用,但该技术在冰盖下复式断面渠道模型试验的应用为国内首次。基于试验特点,设计砖砌混凝土的循环水箱,采用变频器配合水泵、流量计实现对流量的定量控制,对不同流量下不同断面的流场、流速进行测定,采用PIV技术对水体中运动的粒子的位移场进行具体分析。试验结果表明,PIV分析结果能够直观反映流场中的状态,且可以避免测量盲区,其所测的流速与多普勒超声测速仪测得值吻合较好,并给出了横向流速分布图,弥补了传统方法无法获得冰盖下的流场分布的难题。

In the model test for measuring the flow field and flow velocity of the complex section under ice sheet,the moving particles in water body are the key research objects.The Particle Image Velocimetry(PIV)technique has been widely used in the field of hydraulics research,but the application of PIV technique for the dual-section channel model test under ice sheet is first in China.Based on the characteristics of test,the circulating water tank of brick concrete is designed.The frequency converter is used to control the flow rate by using pump and flow meter.The flow field and flow velocity of different sections under different flow rates are measured,and the displacement field of particles is analyzed by PIV technique.The test results show that the PIV analysis results can directly reflect the state of flow field,and can avoid measurement blind zone.The measured flow velocity is in good agreement with the measured value of the Doppler ultrasonic velocimeter,and the lateral velocity distribution map is also given to make up,which solve the problem of traditional method cannot obtain the flow field distribution under ice sheet.