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DOE OSTI · 3002437

Multimode turbulent flow measurements using magnetic resonance imaging- and laser-based techniques and computational fluid dynamics simulations

Nguyen, Thien D. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000159722006)·Benson, Michael [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:000000023210116X)·Borup, Daniel [Borup Solutions, Rochester, MN (United States)] (ORCID:0000000317432216)·Banko, Andrew [United States Military Academy, West Point, NY (United States)] (ORCID:000000017150137X)
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Abstract

We studied the flow field characteristics of a turbulent flow over a regularized cube array with a perpendicular injection flow through the floor between the second and third cubical elements, representing the complex flow interactions of a 3D jet and the wake flows behind cubical obstacles. Four different experimental measurements were performed: two magnetic resonance imaging-based measurements for three-dimensional three-component velocity (MRV) and concentration (MRC) and two laser-based techniques, particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF), for two-dimensional two-component velocity and concentration measurement, respectively. The mainstream Reynolds number is Re = 15 000⁠, based on the primary inlet velocity U m and channel height D H ⁠, whereas the injector Reynolds number is Re j = 3400⁠, based on the injector velocity U j and the injector's exit width D j ⁠. Numerical simulations were performed for the studied flow configuration of turbulent flow over a regularized cube array using Reynolds-averaged Navier–Stokes (RANS) and large-eddy simulation (LES) approaches. Results obtained from experimental measurements—including MRV, MRC, PIV, and PLIF—as well as RANS and LES simulations are discussed and compared along several horizontal and vertical planes of the studied configuration. In addition, 3D turbulent flow structures, such as leading-edge vortex, horseshoe vortex, and jet shear-layer vortex, and the isosurfaces of scalar concentration successfully revealed by MRV and MRC techniques were found to be in very good agreement with those 3D features extracted from RANS and LES simulations. In conclusion, the high-resolution experimental and numerical database obtained from this study could be useful for validation and verification of numerical codes.

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Computational fluid dynamicsFlow visualizationFluid flowsFluid wakesLasersMagnetic resonance imagingNavier Stokes equationsPlume flowTurbulence simulationsTurbulent flows

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Nguyen, Thien D. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000159722006), Benson, Michael [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:000000023210116X), Borup, Daniel [Borup Solutions, Rochester, MN (United States)] (ORCID:0000000317432216), Banko, Andrew [United States Military Academy, West Point, NY (United States)] (ORCID:000000017150137X). 2025-09-17. Multimode turbulent flow measurements using magnetic resonance imaging- and laser-based techniques and computational fluid dynamics simulations. https://doi.org/10.1063/5.0283540

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