General second-order, variable-density, three-step and four-step projection methods are developed to simulate unsteady incompressible interfacial flows. A high-accuracy, variabledensity RKCN projection method is presented, in which the three-stage, low-storage RungeKutta technique and second-order semi-implicit Crank-Nicholson technique are employed to temporally update the convective and diffu...

Wire-mesh sensors are flow imaging devices which produce three-dimensional data of void fraction distribution at high resolution thus being an appropriate tool to investigate two-phase gas-liquid flows. Slug flow is typically found in petroleum production lines. This type of flow is characterized by the intermittent occurrence of gas bubbles and liquid slugs along the pipe. An important issue o...

For the last three decades, the research into skimming flows down stepped chutes was driven by needs for better design guidelines. The skimming flow is characterised by some momentum transfer from the main stream to the recirculation zones in the shear layer developing downstream of each step edge. In the present study some physical modelling was conducted in a relatively large facility and det...

We use a three dimensional hydrodynamical code to simulate the effect of energy injection on cooling flows in the intracluster medium. Specifically, we compare a simulation of a 10 M cluster with radiative cooling only, with a second simulation in which thermal energy is injected 31 kpc off-centre, over 64 kpc at a rate of 4.9×1044ergs s−1 for 50 Myr. The heat injection forms a hot, low density...

The aim of this presentation is to highlight the role that Particle-based simulations and Radial Basis Functions (RBFs) have played in the development of a computationally efficient, level-set, Finite Element method for the simulation of Newtonian and non-Newtonian interface flows [1]. First, we introduce the mathematical formulation and the interface-capturing technique used in the simulation ...

By performing near-critical fluid experiments in the weightlessness of an orbiting space vehicle, we have suppressed buoyancy-driven flows and gravitational constraints on the liquid-gas interface of a large gas bubble. At equilibrium, the liquid completely wets the walls of a cylindrical cell, and the bubble is pushed to the sidewall. In these experiments the system's temperature T is increase...

In this paper, a Lagrangian particle method is proposed for the simulation of multiphase flows with surfactant. The model is based on the multi-phase smoothed particle hydrodynamics (SPH) framework of Hu and Adams [1]. Surfaceactive agents (surfactants) are incorporated into our method by a scalar quantity describing the local concentration of molecules in the bulk phase and on the interface. T...

A new, simple, and computationally efficient interface capturing scheme based on a diffuse interface approach is presented for simulation of compressible multiphase flows. Multi-fluid interfaces are represented using field variables (interface functions) with associated transport equations that are augmented, with respect to an established formulation, to enforce a selected interface thickness....

The growth and breakdown of localised disturbances into a turbulent spot in a Mach 2 boundary-layer flow have been investigated by direct numerical simulation. In particular, the interaction of a turbulent spot with a shock-induced separation bubble is studied. The primary vortex structures triggered by the injected low momentum fluid and the metamorphosis of the hairpin structures into a turbu...

Abstract—The presence of bubbles in the boundary layer introduces corrections into the log law, which must be taken into account. In this work, a logarithmic wall law was presented for bubbly two phase flows. The wall law presented in this work was based on the postulation of additional turbulent viscosity associated with bubble wakes in the boundary layer. The presented wall law contained empi...