A numerical model for local scour with free surface and automatic mesh deformation is constructed and numerical simulation is carried out to compare with experimental results. The k2 model is used to simulate the turbulent flow field. Two interfaces (water and air, water and sediment) in the domain are captured with different approaches. The free surface of the flow is captured by Volume of Flu...

Faraday surface instability measurements of the critical acceleration, a(c), and wave number, k(c), for standing surface waves on a tetracosanol (C24H50) melt exhibit abrupt changes at T(s)=54 degrees C, approximately 4 degrees C above the bulk freezing temperature. The measured variations of a(c) and k(c) vs temperature and driving frequency are accounted for quantitatively by a hydrodynamic m...

Labyrinth weirs have not a straight crest in the perpendicular direction to the flow. The plan view of the weir consists of multiple and broken linear crests that cause the increase of its effective length. The advantages of this type of weirs are higher discharge capacity, easy aeration as well as low fluctuations of water surface at the weir upstream. This paper deals with the simulation of t...

Flow around a rowing blade is a very complex phenomenon, involving unsteady three-dimensional flow with violent motion of the free surface. However, in the literature, forces acting on blades are modelled using extreme and dubious simplifications. The aim of the present study was to evaluate the influence of free surface and unsteadiness (two physical characteristics that are commonly neglected...

The development of predictive capability for free surface flow with phase change is essential to evaluate liquid wall protection schemes for various fusion chambers in IFE and MFE. This paper presents a numerical methodology for free surface flow with heat and mass transfer to help resolve feasibility issues encountered in the aforementioned fusion engineering fields. The numerical methodology ...

The steady, axisymmetric flow induced by a point sink (or source) submerged in an inviscid fluid of infinite depth is computed and the resulting deformation of the free surface is obtained. The effect of surface tension on the free surface is determined and is the new component of this work. The maximum Froude numbers at which steady solutions exist are computed. It is found that the determinin...

In an open channel, the transformation from a supercritical flow into a subcritical flow is a rapidly varied flow with large turbulent fluctuations, intense air entrainment, and substantial energy dissipation called a hydraulic jump. New experiments were conducted to quantify its fluctuating characteristics in terms of free-surface and two-phase flow properties for a wide range of Froude number...

Snow avalanches and other hazardous geophysical granular flows, such as debris flows, lahars and pyroclastic flows, often impact on obstacles as they flow down a slope, generating rapid changes in the flow height and velocity in their vicinity. It is important to understand how a granular material flows around such obstacles to improve the design of deflecting and catching dams, and to correctl...

We explain the rotating polygon instability on a swirling fluid surface [G. H. Vatistas, J. Fluid Mech. 217, 241 (1990) and Jansson et al., Phys. Rev. Lett. 96, 174502 (2006)] in terms of resonant interactions between gravity waves on the outer part of the surface and centrifugal waves on the inner part. Our model is based on potential flow theory, linearized around a potential vortex flow with...