Simultaneous measurements of all three components of velocity and vorticity vectors in a lobed jet flow by means of dual-plane stereoscopic particle image velocimetry

Abstract

Results from an advanced particle image velocimetry ͑PIV͒ technique, named as dual-plane stereoscopic PIV technique, for making simultaneous measurements of all three components of velocity and vorticity vectors are presented for a lobed jet flow. The dual-plane stereoscopic PIV technique uses polarization conservation characteristic of Mie scattering to achieve simultaneous stereoscopic PIV measurements at two spatially separated planes. Unlike ''classical'' PIV systems or conventional stereoscopic PIV systems, which can only get one component of vorticity vectors, the present dual-plane stereoscopic PIV system can provide all three components of velocity and vorticity distributions in fluid flows instantaneously and simultaneously. The evolution and interaction characteristics of the large-scale streamwise vortices and azimuthal Kelvin-Helmholtz vortices in the lobed jet flow are revealed very clearly and quantitatively from the simultaneous measurement results of the dual-plane stereoscopic PIV system. A discussion about the satisfaction of the measurement results of the present dual-plane stereoscopic PIV system to mass conservation equation is also conducted in the present paper to evaluate the error levels of the measurement results.

Experimental and numerical study of mixing characteristics of a rectangular lobed mixer in supersonic flow

“…McCormick and Bennett (17) further investigated experimentally the mixing mechanism downstream of the lobed mixer in detail and concluded that the intense small-scale turbulence mixing was mainly due to the formation of the pinchedoff structures which is unstable. Similar conclusions were obtained by the Belovich et al (24) , Hu et al (25)(26)(27)(28) and Yu et al (29) . More recently, the K-H vortex rolling-up mechanisms in the enhanced mixing processes has been partly revealed (30)(31)(32)(33)(34) .…”

Application of a Novel Laser-Doppler Velocimeter for Turbulence: Structural Measurements in Turbulent Boundary Layers

“…Stereo-, holographic-, and micro-Particle Imaging Velocimetry (PIV) offer the possibility for high-spatial-resolution velocity-gradient measurements (Zhang et al 1997, Santiago et al 1998, Tao et al 2000, Hu et al 2001, Hu et al 2002, van der Bos et al 2002, and Mullin and Dahm 2004. Of these techniques, micro-PIV offers the greatest spatial resolution, with O(1pn) interrogation volumes possible.…”

Melt Volume Flow Measurement in the Mineral-Wool Production Process

“…Application of PIV is broad, Cheng et al [8] algorithm was based on computing the cross correlation of bubble images with multiple spatial resolutions for bubbles flow in the tank, Zosel et al [9] used μPIV for measurement of flow in micro holes and Hann et al [10] used PIV for the measurement of flow velocity and acoustic particle velocity in a standing wave tube. Among measurements of jets, Patte-Rouland et al [11] used PIV method with orthogonal decomposition of a jet in the recirculation region, Hui Hu et al [12] studied the mixing process in a lobed jet flow, and Sakakibara et al [13] performed measurements of the particle/ fluid velocity correlation and the dissipation of turbulent kinetic energy by particles. Cross correlation techniques are also used for flow velocity and volume flow rates measurement with other measurement principles [14].…”