Abstract:

This dataset was obtained from a series of laboratory experiments carried out in the Fluid Dynamics Laboratory in the Ocean Engineering Program at Texas A&M University from January to March 2015. A planar particle image velocimetry (PIV) system was used to measure the residual flow following the abrupt shut-off of a bubble plume. The measurements were taken in the plume centerline plane, giving the two-dimensional flow field on a regular Cartesian grid in this plane. The plume flow was generated by injecting compressed air into a 1m3 water tank via an aquarium airstone located at the center of the tank bottom face. The air bubbles were 2-3mm in diameter with a median value of 2.4mm. The uploaded dataset contains the images of the residual flow at three different air inflow rates. Calibration images of a ruler are also included for length conversion.

Suggested Citation:

Chungkei Chris, Lai. 2016. Planar particle image velocimetry (PIV) measurements of the residual flow following the abrupt shut-off of a stead bubble plume. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7JH3J7F

Purpose:

Fluid turbulence generated inside an air-water bubble plume differs from that described by classical theories of Kolomogorov, owing to the injection of energy at the bubble scale. Because most current turbulent transport and closures models are based on the existence of a classical energy cascade, new phenomenological models have to be developed to account for non-classic behavior observed in multiphase plume. To investigate into multiphase turbulence, a series of laboratory experiments have been conducted to measure the residual velocity (flow) field following the abrupt shutoff of a bubble plume in a square, 1m3 water tank.

Data Parameters and Units:

Three gas inflow rates were tested; 0.5, 1.0 and 1.5 liter/min at atmospheric pressure. The plume was allowed to run to a time-steady state for 30mins. Image acquisition then started with the plume flow turned on and continued following the abrupt shutoff of the plume. Images were sampled at temporal frequencies of 100Hz or 200Hz and the whole sequence measured about 20s long. For PIV computations, only the portion of images that does not contain any air bubbles should be used since bubble signatures have not been filtered out during the experiments; this reduces the length of dataset to about 10s. However, the reminiscence of, and its subsequent decay, bubble-induced turbulence are captured in the images, from which a detail study of its characteristics can be made. The measurements were taken at three different regions, A, B and C. Region A was located at the plume center whereas region C was outside the plume. Region B was midway between A and C. The field-of-view (FOV) of the PIV images is about 4.7cm by 4.7cm.

Methods:

planar particle image velocimeter image capture system

Individual Files: