Application of Particle Tracking Velocimetry to the Measurement of the Velocity of Underwater Particles

• Main Authors: Kai-Che Hsu, 許哲愷
• Other Authors: Jeng-Horng Chen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/17247909517036240474

碩士 === 國立成功大學 === 系統及船舶機電工程學系碩博士班 === 96 === There are many underwater crude oil and nature gas pipelines on the ocean bottom around Taiwan. They are subjected to abrasive shear loading stemming from external force by nature phenomenon and human activities. In order to protect these pipelines, more research to advance underwater technology is needed. A prototype of particle tracking velocimetry system integrated with particle recognition has been developed for installation on an ROV (Remote-control Operated Vehicle). The system can measure the velocity of underwater current and drifting sand from ROV’s, and then transmit the information of velocity through the cable. Therefore, it can help the planning for underwater engineering. The measuring technique (PTV, Particle Tracking Velocimetry) uses a High Intensity Discharge (HID) light source, and CCD camera to capture successive images for particle displacement measurement. The present study uses material of tracing particle and experimental environment similar to underwater condition, including the development of image velocimetry system and particle subsided experiment. As can be discerned from the results, the range of experimental uncertainty varies due to the brightness, velocity of the flow fields, and the shutter of the camera. Extortionate magnitudes of the brightness of flow fields and high sensitivity of the CCD camera will overly illuminate particle resulting in positive error of velocity, and vice versa.