From August 20th to 23rd, the 14th National Conference on Experimental Fluid Mechanics, themed "Exploring Mathematics, Driving the Future with Intelligence," was grandly held in Hohhot. The conference focused on cutting-edge advances in areas such as "turbulence and flow stability," "hypersonic aerodynamics," and "hydrodynamics and micro- and nanoscale flows."
Revealer Scientific Instruments participated in the conference with its independently developed High Speed Cameras and Particle Image Velocimetry (PIV) systems, demonstrating classic applications in experimental fluid mechanics research to participating experts and scholars.
Jets are a core flow form in aerospace propulsion and combustion systems. The vortex structures generated within the jet shear layer are the primary source of turbulent energy cascades. A deeper understanding of the mechanisms of vortex generation, evolution, pairing, and breakup will help improve aircraft engine efficiency.
The Revealer high-frequency PIV system enables non-contact capture of the transient structure of the initial vortex ring generated by the Kelvin-Helmholtz instability in the jet shear layer, as well as the subsequent highly unsteady three-dimensional vortex pairing, stretching, and breakup processes. Furthermore, based on the full-field velocity information acquired by PIV, Rflow flow field measurement software accurately calculates vortex identification metrics such as the Q criterion, distinguishing the vortex core structure from the background shear flow and enabling quantitative characterization of the vortex structure.
Aircraft engine inlet design must provide stable and uniform airflow for the compressor under various flight conditions. Incoming detached vortices
And complex vortex structures can cause compressor surge or stall, compromising flight safety. Therefore, accurate measurement of the inlet flow field, especially large-scale detached vortex structures, is a key component of aircraft engine inlet design.
A Revealer High Speed Camera was used to visualize the location, strength, scale, and temporal evolution of boundary layer separation, corner vortices, and horseshoe vortices at the inlet lip. A PIV measurement system was used to obtain the velocity vector field and velocity isosurfaces under the Q criterion from the inlet to the outlet, clearly outlining the location and morphology of the vortex cores.
Hydraulic flow is a crucial phenomenon in environmental, geological, and marine engineering. Liquid-liquid and liquid-solid collisions in hydraulic flow are accompanied by complex vortex formation, interfacial mixing, and vorticity transport.
Utilizing the Revealer Tomographic PIV-3D3C system, four High Speed Cameras observed vortex formation, development, and breakdown, reconstructing the three-dimensional flow structure of the hydraulic flow and measuring its internal velocity and vorticity fields.
Microfluidics technology has been widely used in fields such as chip development and biomedical engineering. Flow characteristics at the microscale and nanoscale are dominated by viscous forces and surface tension, making slip boundaries and discontinuity effects more likely to occur.
The Revealer micro-PIV system, combined with a High resolution, High Speed Camera and a microscopic optical system, captures transient flow phenomena within microchannels at micron-level resolution. Velocity profiles are precisely measured at key sections within the microchannel, such as entrances and bends, to verify the presence of slip velocity and discontinuity effects.
From macro-aviation propulsion to micro-chip flow, from single-phase turbulence to complex multiphase systems, the combination of Revealer High Speed Camera technology and particle image PIV velocimetry technology enables the observability and measurability of complex flow phenomena. With the development of multi-scale PIV technology and ultra-high-speed imaging technology, experimental fluid mechanics will usher in a new round of breakthroughs in spatiotemporal resolution and multi-dimensional in-depth analysis of data.
