Self-sustained instabilities and pseudo-periodic motion may be observed in hydraulic structures and industrial flows. Documented examples include the hydraulic jump, sloshing motion in a reservoir and surging waves in pooled stepped spillways. The instabilities may generate some very large turbulence levels and integral turbulent scales, combining the contributions of both slow fluctuations and...

A new dynamical subgrid model for turbulent flow is used to derive the structure of the heat and momentum fluxes, mean wind and temperature profiles, and temperature and velocity variances, as a function of the Richardson number, in the surface layer of the planetary boundary layer. Analytical solutions are obtained for stationary, homogeneous surface layers and are compared with field observat...

In an open channel, a sudden drop in free-surface elevation is associated with the development of a negative wave. While some simple analytical solution is widely described in textbooks, little research was conducted to date on the unsteady turbulence properties beneath negative waves. A series of new physical experiments were conducted in a rectangular channel. The unsteady free-surface profil...

In the process of continuous casting, submerged nozzle will affect flow liquid steel and quality slab. this paper, three structures are investigated to compare influence structure on solidification steel. addition, field, velocity, recirculation zone, free-surface turbulent kinetic energy heat transfer fluid calculated. The results demonstrate that among nozzles, B is best. flows out from at a ...

A free-floating plate is introduced in a Benard convection cell with an open surface. It partially covers the cell and distorts the local heat flux, inducing a coherent flow that in turn moves the plate. Remarkably, the plate can be driven to a periodic motion even under the action of a turbulent fluid. The period of the oscillation depends on the coverage ratio, and on the Rayleigh number of t...

We complement the recently achieved status quo of a self-consistent asymptotic theory: incompressible-flow separation from the perfectly smooth surface of a bluff rigid obstacle that perturbs an otherwise uniform flow in an unbounded domain. Here the globally formed Reynolds number, Re, takes on arbitrarily large values, and we are concerned with a long-standing challenge in boundary layer theo...

The behavior of turbulent open channel flows over permeable surfaces is not well understood. In particular, it is not clear how the surface and the subsurface flow within the permeable bed interact and influence each other. In order to clarify this issue we carried out two sets of experiments, one involving velocity measurements in open channel flows over an impermeable bed composed of a single...

This thesis presents the formulation of a Smoothed Particle Hydrodynamics (SPH) model and its application to a range of engineering applications. The motivation for this research lies in the desire to accurately model viscous and turbulent free-surface flows, including those with complete break-up of the free-surface. At present, boundary element modelling is typically chosen to describe free-s...