3D mantle flow induced by retreating and advancing slabs: insights from analogue subduction models analysed with a tomographic Particle Image Velocimetry technique

Subduction Zones ◽

Particle Image ◽

Mantle Flow ◽

Tomographic Particle Image Velocimetry ◽

Intraplate Volcanism ◽

Slab Rollback ◽

Image Velocimetry ◽

Subducting Plate

<p>Slab rollback-induced mantle flow in retreating subduction zones is known to have a significant geodynamic impact on Earth. The resulting quasi-toroidal circulation can deflect mantle plumes, transport geochemical signatures and have an upwelling component that thereby generates atypical intraplate volcanism near lateral slab edges. Nevertheless, the mantle flow generated by advancing slabs remains unstudied and its geodynamic significance unclear. We therefore conducted analogue buoyancy-driven subduction models to investigate the mantle flow generated in both retreating and advancing subduction modes. We analysed our models using a novel tomographic Particle Image Velocimetry technique, allowing us to compute the 3D velocity field in a volume of the mantle. Our model results show that the advancing subduction mode develops a slab rollover geometry that produces a quasi-toroidal mantle flow with mantle material displaced from the mantle wedge domain to below the subducting plate, opposite to mantle flow during the retreating mode. This slab rollover-induced mantle flow generates an upwelling component that is laterally offset from the subducting plate and is located some ~1000 km from the trench on the subducting plate side. Such newly imaged mantle flow may have implications for intraplate volcanism and the distribution of mantellic geochemical signatures associated with advancing subduction zones, such as the Makran, and continental subduction zones, such as the Himalaya.</p>

Evolution of 3-D subduction-induced mantle flow around lateral slab edges in analogue models of free subduction analysed by stereoscopic particle image velocimetry technique

Earth and Planetary Science Letters ◽

10.1016/j.epsl.2014.07.007 ◽

2014 ◽

Vol 403 ◽

pp. 368-379 ◽

Cited By ~ 38

Author(s):

Vincent Strak ◽

Wouter P. Schellart

Keyword(s):

Particle Image ◽

Stereoscopic Particle Image Velocimetry ◽

Mantle Flow ◽

Image Velocimetry ◽

Analogue Models

Analysis of local velocity gradients in rapid mixer using particle image velocimetry technique

Water Science & Technology Water Supply ◽

10.2166/ws.2002.0149 ◽

2002 ◽

Vol 2 (5-6) ◽

pp. 47-55

Author(s):

N.-S. Park ◽

H. Park

Keyword(s):

Particle Image ◽

Velocity Fields ◽

Local Velocity ◽

Mixing Condition ◽

Velocity Gradients ◽

Image Velocimetry ◽

Current Design ◽

G Value

Recognizing the significance of factual velocity fields in a rapid mixer, this study focuses on analyzing local velocity gradients in various mixer geometries with particle image velocimetry (PIV) and comparing the results of the analysis with the conventional G-value, for reviewing the roles of G-value in the current design and operation practices. The results of this study clearly show that many arguments and doubts are possible about the scientific correctness of G-value, and its current use. This is because the G-value attempts to represent the turbulent and complicated factual velocity field in a jar. Also, the results suggest that it is still a good index for representing some aspects of mixing condition, at least, mixing intensity. However, it cannot represent the distribution of velocity gradients in a jar, which is an important factor for mixing. This study as a result suggests developing another index for representing the distribution to be used with the G-value.

Tomographic Particle Image Velocimetry for Flow Analysis in a Single Cylinder Optical Engine

SAE International Journal of Materials and Manufacturing ◽

10.4271/2015-01-0599 ◽

2015 ◽

Vol 8 (2) ◽

pp. 472-481 ◽

Cited By ~ 7

Author(s):

Akhilendra Pratap Singh ◽

Aditya Gupta ◽

Avinash Kumar Agarwal

Keyword(s):

Particle Image ◽

Flow Analysis ◽

Tomographic Particle Image Velocimetry ◽

Single Cylinder ◽

Optical Engine ◽

Image Velocimetry

A New Particle Image Velocimetry Technique for Turbomachinery Applications

Journal of Turbomachinery ◽

10.1115/1.4033672 ◽

2016 ◽

Vol 138 (12) ◽

Cited By ~ 4

Author(s):

Sayantan Bhattacharya ◽

Reid A. Berdanier ◽

Pavlos P. Vlachos ◽

Nicole L. Key

Keyword(s):

Particle Image ◽

Laser Sheet ◽

Measurement Techniques ◽

Leakage Flow ◽

Tip Leakage Flow ◽

Optical Access ◽

Tip Leakage ◽

Image Velocimetry

Nonintrusive measurement techniques such as particle image velocimetry (PIV) are growing in both capability and utility for turbomachinery applications. However, the restrictive optical access afforded by multistage research compressors typically requires the use of a periscope probe to introduce the laser sheet for measurements in a rotor passage. This paper demonstrates the capability to perform three-dimensional PIV in a multistage compressor without the need for intrusive optical probes and requiring only line-of-sight optical access. The results collected from the embedded second stage of a three-stage axial compressor highlight the rotor tip leakage flow, and PIV measurements are qualitatively compared with high-frequency response piezoresistive pressure measurements to assess the tip leakage flow identification.

Abstract 14952: Volumetric Echocardiographic Particle Image Velocimetry (V-Echo-PIV)

Circulation ◽

10.1161/circ.130.suppl_2.14952 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Ahmad Falahatpisheh ◽

Arash Kheradvar

Keyword(s):

Particle Image ◽

Contrast Echocardiography ◽

Ultrasound Contrast Agent ◽

Three Dimensions ◽

Small Scale ◽

High Temporal Resolution ◽

Two Dimensional ◽

Image Velocimetry

Introduction: The two-dimensional (2D) echocardiographic particle image velocimetry technique that was introduced in 2010 received much attention in clinical cardiology. Cardiac flow visualization based on contrast echocardiography results in images with high temporal resolution that are obtainable at relatively low cost. This makes it an ideal diagnostic and follow-up tool for routine clinical use. However, cardiac flow in a cardiac cycle is multidirectional with a tendency to spin in three dimensions rather than two-dimensional curl. Here, for the first time, we introduce a volumetric echocardiographic particle image velocimetry technique that robustly acquires the flow in three spatial dimensions and in time: Volumetric Echocardiographic Particle Image Velocimetry (V-Echo-PIV). Methods: V-Echo-PIV technique utilizes matrix array 3D ultrasound probes to capture the flow seeded with an ultrasound contrast agent (Definity). For this feasibility study, we used a pulse duplicator with a silicone ventricular sac along with bioprosthetic heart valves at the inlet and outlet. GE Vivid E9 system with an Active Matrix 4D Volume Phased Array probe at 30 Hz was used to capture the flow data (Figure 1). Results: The 3D particle field was obtained with excellent spatial resolution without significant noise (Figure 1). 3D velocity field was successfully captured for multiple cardiac cycles. Flow features are shown in Figure 2 where the velocity vectors in two selected slices and some streamlines in 3D space are depicted. Conclusions: We report successful completion of the feasibility studies for volumetric echocardiographic PIV in an LV phantom. The small-scale features of flow in the LV phantom were revealed by this technique. Validation and human studies are currently in progress.