-- Researchers at the 32nd Fluid Mechanics Forum in Mexico reported new advances in experimental methods for studying multiphase and turbulent flows, with high-speed imaging and Particle Image Velocimetry (PIV) systems playing a central role in resolving complex, time-dependent fluid behavior across energy and industrial applications.
Across sessions focused on electrochemical systems, stirred tank reactors, gas–liquid–solid flows, and wind turbine wakes, presenters emphasized the limitations of traditional point-based or low-frame-rate measurement techniques when applied to strongly unsteady and multiscale flow environments. Instead, time-resolved full-field diagnostics using high-speed camera systems and laser-based PIV/PTV methods were widely adopted.
A recurring tool referenced in multiple studies was the Revealer high-speed camera system, integrated with PIV measurement setups to capture rapid transient flow structures that are otherwise inaccessible through conventional imaging methods.
Electrochemical Hydrogen Production: Resolving Gas–Liquid Transport in Electrolyzers
In electrolysis research, investigators applied a PIV system combined with a high-speed imaging setup using a Revealer high-speed camera (X150M, 2560×1920 at 2000 fps) and pulsed laser illumination to examine two-phase flow behavior inside electrolyzer channels.
Fluorescent tracer particles and optical filtering were used to suppress reflection from metallic electrode surfaces, enabling near-wall velocity field reconstruction. The measurements captured bubble formation, detachment, and transport dynamics in relation to channel geometry and local flow structures.
Results presented at the forum indicated that small variations in flow channel design significantly influence bubble accumulation zones and local mass transport efficiency, directly impacting electrochemical performance and gas removal pathways.
Stirred Tank Reactors: Phase-Resolved Turbulence Structures
In stirred tank systems, researchers used Revealer high-resolution PIV imaging with a high-speed camera operating at 5120×4096 resolution and 2000 fps to analyze turbulent flow structures generated by impeller rotation.
The data showed that flow fields in the impeller region, baffle zones, and upper circulation loops exhibit strong periodicity linked to blade passing frequency. Rather than steady turbulence, the system demonstrated repeatable phase-dependent vortex formation and dissipation cycles.
Velocity field comparisons across different impeller phases revealed significant spatial variability at identical measurement points, indicating that time-averaged flow representations may obscure key coherent structures governing mixing efficiency and energy dissipation.
Figure-Velocity vector diagrams, velocity contour plots, streamline plots and vorticity contour plots of the flow field near the baffle in the stirred tank at a rotational speed of 94 r/min measured by Revealer high-frequency 2D2C-PIV
Gas–Liquid–Solid Systems: Bubble–Particle Interaction Dynamics
For multiphase fluidized beds and flotation columns, combined Revealer 2D2C-PIV and 2D-PTV methods were used to simultaneously resolve liquid-phase velocity fields and discrete bubble trajectories.
High-speed imaging enabled by Revealer high-speed camera allowed researchers to track bubble size distribution, rise velocity, and trajectory deformation in real time, while PIV measurements captured turbulence modulation induced by solid particle concentration.
Experimental results showed that increasing particle loading significantly alters local flow structures, leading to enhanced turbulence intermittency and reduced stability of bubble rise paths. These effects are particularly relevant for mineral flotation efficiency and industrial separation processes.
Wind Turbine Wake Flows: Unsteady Vortex Evolution
In wind energy applications, Revealer high-speed PIV measurements using a high-speed camera at 5120×4096 resolution and 1000 fps were used to investigate wake behavior behind vertical-axis wind turbines under disturbed flow conditions.
The experiments captured unsteady vortex shedding and asymmetric wake deformation under wave-influenced inflow conditions. Results indicated that wake expansion rates and velocity deficit distributions vary significantly under transient environmental forcing.
These measurements provide experimental reference data for improving wind farm layout design and reducing turbine–turbine wake interference in complex operating environments.
Experimental Methods: Increasing Reliance on Time-Resolved Flow Diagnostics
Across all presented studies, a consistent methodological trend was reported: increasing reliance on time-resolved, full-field flow diagnostics enabled by high-speed imaging and PIV/PTV systems.
The integration of Revealer high-speed camera platforms with synchronized laser illumination systems allows researchers to capture transient flow structures at temporal scales previously unresolved in conventional experiments. This capability is particularly important for multiphase flows, where phase interfaces, turbulence structures, and particle interactions evolve rapidly and nonlinearly.
Rather than relying solely on steady-state or averaged measurements, researchers are increasingly using instantaneous velocity fields to directly validate CFD simulations and improve model fidelity in complex engineering systems.
Outlook
Presentations at the Mexico Fluid Mechanics Forum suggest that experimental fluid mechanics is increasingly defined by its ability to resolve fast-evolving, multiphase, and multiscale flow phenomena.
High-speed imaging systems such as the Revealer high-speed camera series, combined with Revealer PIV and PTV methodologies, are becoming standard tools in studies ranging from electrochemical energy systems to renewable energy aerodynamics and chemical reactor engineering.
As flow systems in energy and industrial applications continue to increase in complexity, demand for high-temporal-resolution, full-field experimental diagnostics is expected to grow, further strengthening the role of high-speed optical measurement technologies in both fundamental research and applied engineering.
Contact Info:
Name: Harrison Shawn
Email: Send Email
Organization: HF Agile Device Co., Ltd.
Website: https://www.revealerhighspeed.com
Release ID: 89196686
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