Particles concentration and distribution over fixed rippled beds under waves by digital in-line holography
نویسندگان
چکیده
Digital in-line holography (DIH) measurements are performed in a wave flume tank to study the three dimensional distribution of spherical Polyvincyl Chloride (PVC) particles over fixed rippled beds under regular water waves. Homogeneous and heterogeneous sizes considered. The positions PVC reconstructed from holograms assess their volume concentration during decay surface Particles estimated close bottom zones: above ripple crest, trough between them. 3D Particle trajectories vicinity crest studied sedimentation. It is observed that distributions fine larger troughs amplitudes motion than coarse particles, when they reach bed faster.
منابع مشابه
A general wave equation for waves over rippled beds
A time-dependent extension of the reduced wave equation of Berkhoff is developed for the case of waves propagating over a bed consisting of ripples superimposed on an otherwise slowly varying mean depth which satisfies the mild-slope assumption. The ripples are assumed to have wavelengths on the order of the surface wavelength but amplitudes which scale as a small parameter along with the botto...
متن کاملAccurate Axial Location for Particles in Digital In-Line Holography
The potential of in-line holography to analyze flow by means of particles has been noted since its very beginnings. The development of optical holography applications in fluid mechanics established the capability of holography to provide both particle size and tridimensional position (Adams et al., 2000). In classical holography, the diffraction pattern produced by a particle field is recorded ...
متن کاملParticles Depth Detection using In-Line Digital Holography Configuration
Digital holography (DH) is the direct recording of the Fresnel or Fourier holograms using a CCD or CMOS camera and is considered as an alternative to the optical holography which uses a film or a plate involving wet-chemical or other processes. However, the poor pixel resolution of CCD or CMOS cameras as compared to that of holographic films gives poor depth resolution for images which in turn ...
متن کاملDigital in-line holography
H.]. Kreuzer and R.A. Pawlitzek" 'Department ofPhysics, Dalhousie University, Halifax, Canada "IBM Zurich Research Laboratory, Switzerland out by larger objects, classical diffraction becomes more important. When it eventually dominates the image,we are in the regime of classical wave optics. A hologram is just a complicated interference pattern from which little information about the shape and...
متن کاملLarge eddy simulation of sediment transport over rippled beds
Wave-induced boundary layer (BL) flows over sandy rippled bottoms are studied using a numerical model that applies a one-way coupling of a “far-field” inviscid flow model to a “near-field” large eddy simulation (LES) Navier– Stokes (NS) model. The incident inviscid velocity and pressure fields force the LES, in which near-field, wave-induced, turbulent bottom BL flows are simulated. A sediment ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Comptes rendus
سال: 2022
ISSN: ['1873-7234']
DOI: https://doi.org/10.5802/crmeca.121