Spatial superresolution based on simultaneous dual PIV measurement with different magnification

Ozawa, Yuta; Honda, Harutaka; Nonomura, Taku

doi:10.1007/s00348-024-03778-0

Cited by 4 publications

(1 citation statement)

References 42 publications

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“…Among these models, a resolvent analysis has recently been attracting attention for applications in stability analysis in the aeroacoustic field [7][8][9][10][11]. Moreover, super-resolution measurements based on reduced-order models have recently proposed, and they reveal the unsteady behaviors of jets [12][13][14][15][16]. Super-resolution measurements rely on modal decomposition [17] such as proper orthogonal decomposition (POD) [18] or dynamic mode decomposition (DMD) [19,20], and thus, it is possible to replace them with resolvent modes.…”

Section: Introductionmentioning

confidence: 99%

Data Assimilation of Ideally Expanded Supersonic Jet Using RANS Simulation for High-Resolution PIV Data

Ozawa,

Nonomura

2024

Aerospace

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Data assimilation using particle image velocimetry (PIV) and Reynolds-averaged Navier–Stokes (RANS) simulation was performed for an ideally expanded supersonic jet flying at a Mach number of 2.0. The present study aims to efficiently reconstruct all the physical quantities in the aeroacoustic fields that match well with a realistic, experimentally obtained flow field. The two-dimensional, two-component PIV measurement was applied to the jet axis plane, and the time-averaged velocity field was obtained using single-pixel ensemble correlation. Two-dimensional axisymmetric RANS simulation using the Menter shear stress transport (SST) model was also performed, and the parameters of the SST model were optimized via data assimilation using the ensemble Kalman filter. The standard deviation of the observation noise σ, which is a parameter of the ensemble Kalman filter, is estimated by the previously proposed method (Nakamura et al., Low-Grid-Resolution-RANS-Based Data Assimilation of Time-Averaged Separated Flow Obtained by LES. Int. J. Comp. Fluid. Dyn., 2022), and its effectiveness was investigated for the first time. This method effectively estimated the magnitude of σ at each generation without tuning the hyperparameters. The assimilated flow fields exhibited similar flow structures observed in PIV such as the potential core length or shear layer. Therefore, the present framework can be used to estimate time-averaged full flow fields that match well with experimentally observed flow fields, and has the potential to construct a database for the Navier-Stokes-based stability analysis that requires a full flow field.

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Section: Introductionmentioning

confidence: 99%

Data Assimilation of Ideally Expanded Supersonic Jet Using RANS Simulation for High-Resolution PIV Data

Ozawa,

Nonomura

2024

Aerospace

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DMD-based spatiotemporal superresolution measurement of a supersonic jet using dual planar PIV and acoustic data

Kaneko,

del Pozo,

Nishikori

et al. 2024

Exp Fluids

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The present study applies a framework of the spatiotemporal superresolution measurement based on the total-least-squares dynamic mode decomposition, the Kalman filter and the Rauch-Tung-Striebel smoother to an axisymmetric underexpanded supersonic jet of a jet Mach number of 1.35. Dual planar particle image velocimetry was utilized, and paired velocity fields of the flow with a short time interval were obtained at a temporal resolution of 5000 Hz. High-frequency acoustic data of 200,000 Hz were simultaneously obtained. Then, the time-resolved velocity fields of the supersonic jet were reconstructed at a temporal resolution of 200,000 Hz. Also, time coefficients of dynamic modes in high temporal resolution were calculated. The correlation between time coefficients implies that the mixing promotion by screech tone causes the lift-up of the high-velocity fluid from the jet center and accelerates at the downstream side.

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Modal analyses of double pulsed pressure-sensitive paint data of impinging supersonic jet

Li,

Oka,

Ozawa

et al. 2024

J Vis

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Spatial superresolution based on simultaneous dual PIV measurement with different magnification

Cited by 4 publications

References 42 publications

Data Assimilation of Ideally Expanded Supersonic Jet Using RANS Simulation for High-Resolution PIV Data

Data Assimilation of Ideally Expanded Supersonic Jet Using RANS Simulation for High-Resolution PIV Data

DMD-based spatiotemporal superresolution measurement of a supersonic jet using dual planar PIV and acoustic data

Modal analyses of double pulsed pressure-sensitive paint data of impinging supersonic jet

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