Instantaneous bubble velocity measurements using digital image analysis

Dinh, Tri Bui; Choi, Tae‐Sun

doi:10.1117/1.1337038

Cited by 2 publications

(1 citation statement)

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“…Finally, the velocity can be calculated by combining the distance and time difference of the falling weight between the two images [ 7 ]. T. B. Dinh [ 8 ] used the PIV method to measure the velocity of bubbles in the fluid. W. C. Liu [ 9 ] measured the flow velocity of the river using the PIV method.…”

Section: Introductionmentioning

confidence: 99%

Impact Velocity Measurement Method Based on Trajectory and Impact Position

Liu

Wang

2022

Sensors

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The impact velocity of falling weight is an instantaneous quantity. Currently, measurement of impact velocity relies on high-speed sensors to capture the moment of impact. The trajectory-position measurement method (TPMM) is proposed in this study. The main steps are: (1) The impact position is used to capture the impact time. It can be measured when the falling weight is stationary. (2) The discrete falling trajectory is measured and a new empirical regression algorithm is proposed to fit the expression of falling trajectory. (3) The impact velocity is obtained by taking the impact time into the first derivative of the trajectory expression. For 1–5 m falling height, the simulation shows that the relative maximum error and relative expanded uncertainty of the proposed method are less than 0.481% and 0.442%, respectively. Then, the actual experiment is carried out to verify the simulation. The proposed method has high accuracy and low uncertainty. The reasons are: (1) Only a low-speed displacement sensor is need for impact velocity measurement. It is easier to improve accuracy and stability of a low-speed sensor. (2) The empirical regression algorithm can improve the stability of falling trajectory fitting.

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Section: Introductionmentioning

confidence: 99%