Application of Unmanned Aerial Vehicle with Large-Scale Particle Image Velocimetry for Measuring Water Surface Velocities

• Main Authors: Tzu-Chia Wu, 吳子佳
• Other Authors: 詹勳全
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/67517994313211888131

碩士 === 國立中興大學 === 水土保持學系所 === 103 === River flow measurement technologies are divided into intrusive and nonintrusive methods. Intrusive method requires infield operations. Its protocols are time consuming, and likely to cause damages of operator and instrument. Nonintrusive methods require fewer operators and instrument damages can be avoided from directly attaching to the flow. Nonintrusive measurements use radar or image velocimetry to measure the velocities at the free surface.The image velocimetry, such as large scale particle image velocimetry (LSPIV), access not only the point velocity but the flow velocities in an area. Flow properties of an area hold the promise of providing spatially information of flow fields. This study attempts to construct a mobile system UAV-LSPIV by using an unmanned aerial vehicle (UAV) with LSPIV to measure flows in a field. The mobile system is based on a six-rotor UAV helicopter, with a Sony nex5T camera, a gimbal, and an image transfer device. UAV attaches an activate gimbal, which help maintain the camera lens orthogonal to the water surface and prevent images from being distorted. The image transfer device can monitor the captured image simultaneously. Verification of LSPIV was first set up in laboratory, the deviation from velocity measured by current meter and LSPIV is below 9%. After that, the mobile system was applied to field experiments under different flow conditions. In the low flow experiments, the deviation of velocities measured by UAV-LSPIV and handhold Acoustic Doppler Velocimeter (ADV) is under 8%. In the high flow experiment, the deviation of velocities measured by UAV-LSPIV and Particle Tracking Velocimetry (PTV) is about 4%. The results of the field experiments suggest that the UAV-LSPIV is applicable to measure the surface flows in the fields.