New water tunnel provides nearly oceanic levels of turbulence

From bubbles in crashing waves to oil droplets in chemical reactors, turbulent water often contains foreign objects of different phases, and the interaction between these phases continue to have many features that remain poorly understood. In order to better understand turbulence, the aerospace and marine engineering industry and the research community rely on experimental results obtained using large-scale wind and water tunnels. One new facility looks to expand the capabilities of current water tunnels – by flipping it on its head.

Masuk et al. introduce a new vertical water tunnel facility for studying the dynamics of turbulent multiphase flow. Named Vertical Octagonal Noncorrosive Stirred Energetic Turbulence (V-ONSET), the new facility uses a custom-designed and 3D printed high-pressure jet array to fire 88 random high-speed momentum jets to attain dissipation rates similar to turbulence found in the ocean.

V-ONSET features an octagonal cross section and six high-speed cameras to simultaneously capture the deformation of small bubbles and droplets along with the flow condition near them. The algorithm for both particle tracking and reconstruction are run on parallelized, high-performance computing clusters to efficiently process the large amount of datasets generated from the system.

“V-ONSET is a new type of experimental setups that will create an environment to study bubble and droplet dynamics in strong turbulence to shed new light on bubble dynamics in the ocean or droplet behaviors in chemical reactors,” said author Rui Ni.

The experimental capabilities of V-ONSET can help better understand the behaviors of freely-deformed bubbles and droplets in extremely turbulent environments, which are important for power plant and chemical reactor designs, and even the understanding of the ocean acidification process.

Source: “V-ONSET (Vertical Octagonal Noncorrosive Stirred Energetic Turbulence): A vertical water tunnel with a large energy dissipation rate to study bubble/droplet deformation and breakup in strong turbulence,” by Ashik Ullah Mohammad Masuk, Ashwanth Salibindla, Shiyong Tan, and Rui Ni, Review of Scientific Instruments (2019). The article can be accessed at https://doi.org/10.1063/1.5093688 .