A single-camera synthetic Schlieren method for the measurement of free liquid surfaces

Li, Huixin; Avila, Marc; Xu, Duo

doi:10.1007/s00348-021-03326-0

Cited by 9 publications

(6 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the purpose of surface reconstruction applied in this paper, a regular pattern (in the present case dots) makes the point identification and image reconstruction simple and easy to implement numerically. More advanced FSSS techniques [37,38] could evidently also be implemented for the present experimental system, however, we consider the relative simplicity of the concept of direct ray propagation and the simple linear transformations (equations ( 17)-( 19)) as appealing in a teaching situation, and the obtained results (figures 11 and 13) are quite satisfactory.…”

Section: Surface Reconstructionmentioning

confidence: 85%

“…To observe and analyze the structure of the Faraday waves on the liquid surface using CAM1, we use the idea of a free surface synthetic Schlieren (FSSS) technique introduced by Moisy et al [36] and further developed for example by Wildeman [37] and Li et al [38]. We explicitly apply a simple FSSS surface reconstruction technique based on direct simulations of light rays through the used imaging system to reveal the parameters needed for surface reconstruction.…”

Section: Reconstructing Surface Waves From Camera Imagesmentioning

confidence: 99%

“…In other implementations of the FSSS method, randomly distributed points or regular patterns have been applied (see e.g. Wildeman [37] and Li et al [38] for overviews of techniques applied). For the purpose of surface reconstruction applied in this paper, a regular pattern (in the present case dots) makes the point identification and image reconstruction simple and easy to implement numerically.…”

Section: Surface Reconstructionmentioning

confidence: 99%

See 2 more Smart Citations

A modular experimental system for teaching fluid dynamics with Faraday waves

Pedersen,

Abildgaard,

Søtang Jacobsen

et al. 2023

Eur. J. Phys.

View full text Add to dashboard Cite

We describe a modular setup for the observation of Faraday waves on a vibrating bath. The setup will be used as a project exercise on fluid dynamics in a first year course on experimental physics at Aarhus University as well as for future research on fluids. As a demonstration of the setup, the acceleration threshold for the onset of Faraday waves on a silicone oil bath as a function of the driving frequency is measured and compared to thresholds calculated using different existing models. The possibility to characterize surface waves with the system is demonstrated by recording and analyzing images of Faraday waves, e.g. showing explicitly that the Faraday waves in the present case are subharmonic, and establishing the dispersion relation for the waves.

show abstract

Section: Surface Reconstructionmentioning

confidence: 85%

Section: Reconstructing Surface Waves From Camera Imagesmentioning

confidence: 99%

Section: Surface Reconstructionmentioning

confidence: 99%

See 1 more Smart Citation

A modular experimental system for teaching fluid dynamics with Faraday waves

Pedersen,

Abildgaard,

Søtang Jacobsen

et al. 2023

Eur. J. Phys.

View full text Add to dashboard Cite

show abstract

“…Furthermore, FS-SS requires the most overhead clearance, in order to achieve the low paraxial angle approximation, as shown in (4). This often requires a more elaborate setup, which makes the camera prone to vibrations (Li et al, 2021;Moisy et al, 2009).…”

Section: Comparison Of Free Surface Optical Techniquesmentioning

confidence: 99%

“…Moisy et al (2009) furthered the work of Kurata et al (1990) for the reconstruction of a deformed water surface by plane and circular waves. This method was labelled 'free-surface synthetic Schlieren' (FS-SS) and has since been used for various applications (Li et al, 2021;Mandel et al, 2017Mandel et al, , 2019Paquier et al, 2015;Pathommapas et al, 2019;Wildeman, 2018). Shape from shading (SFS) has also been used for the reconstruction of water surfaces, wherein the gradual variation in shading is used to recover the shape of the features of interest (Chaudhari et al, 2014;Nie et al, 2021;Pickup et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Comparison of Schlieren-based techniques for measurements of a turbulent and wavy free surface

Bheeroo

Mandel

2023

Preprint

View full text Add to dashboard Cite

The free surface at an air-water interface can provide information regarding bathymetric complexities, as well as the subsurface flow. We present a comparison of the performance of two recent advances in light-based optical techniques for free surface measurements, Total Internal Reflection-Deflectometry and Moon-Glade Background Oriented Schlieren, with the more established method of Free-Surface Synthetic Schlieren. We make use of an optical flow algorithm over the more traditional Digital Image Correlation, in order to obtain higher spatial resolution data across the imaged free surface domain. The Optical flow algorithm presents additional benefits, such as computational efficiency and robustness in capturing large displacements and straining of tracked features. The three optical techniques are assembled in synchronization to image two free surface conditions: (1) a free surface being impinged upon by an underlying turbulent, free-shear flow and (2) a random and irregular wave field induced by a free jet. Using the high-resolution measurements, we provide insight on the emergence of multiple free surface dynamics for a turbulent free surface and dissect the local hydrodynamics of the free surface for several wave forcings. We present a comprehensive discussion on the benefits and drawbacks of each technique, including suggestions on the suitability of each technique for several experimental constraints.

show abstract