Rutger H A Ijzermans

Shell Global | Shell · Fluid Flow Research

This paper investigates the interaction between large waves and floating offshore structures. Here, the fluid–structure interaction is considered using the weakly compressible smoothed particle hydrodynamics (SPH) method. To ensure the applicability of this method, we validate its prediction for fluid forces and rigid-body motion against two sets o...

An accurate estimate of forces exerted by extreme sea waves on offshore structures is vital to assess potential risks to structural integrity. The present work describes a methodology to simulate multi-modal and multi-directional sea waves impacting on offshore structures. The waves are generated by moving the side boundaries of the fluid domain ac...

In this article we present a discretisation of a one-dimensional, hyperbolic model for two-phase pipe flow based on a Discontinuous Galerkin Finite Element Method with a viscous regularisation to suppress the Gibbs phenomenon.

In this survey we consider the impact of turbulence on cloud formation from the cloud scale to the droplet scale. We assess progress in understanding the effect of turbulence on the condensational and collisional growth of droplets and the effect of entrainment and mixing on the droplet spectrum. The increasing power of computers and better experim...

The results presented here are part of a long-term study in which we analyse the segregation of inertial particles in turbulent flows using the so called full Lagrangian method (FLM) to evaluate the ‘compressibility’ of the particle phase along a particle trajectory. In the present work, particles are advected by Stokes drag in a random flow field...

The condensation of microdroplets in model systems, reminiscent of atmospheric clouds, is investigated numerically and analytically. Droplets have been followed through a synthetic turbulent flow field composed of 200 random Fourier modes, with wave numbers ranging from the integral scales O10 2 m to the Kolmogorov scales O10 −3 m. As the influence...

Preferential concentration of inertial particles in turbulence is studied numerically by evaluating the Lagrangian compressibility of the particle velocity field using the "full Lagrangian method." This is compared with the "mesoscopic Eulerian particle velocity field" both in a direct numerical simulation of turbulence and in a synthetic flow fiel...

Suspensions of small heavy particles in turbulent ows are found in a variety of natural and industrial applications such as droplets in clouds (1), soot particles in post combustion devices and reacting particles in chemical processs facilities (2). It is well known from experimental results (3), numerical simulations (4) and theoretical studies (5...

The motion of small heavy particles near a helical vortex filament in incompressible flow is investigated. Both the configurations of a helical vortex filament in free space and a helical vortex filament in a concentric pipe are considered, and the corresponding helically symmetric velocity fields are expressed in terms of a stream function. Partic...

The motion of heavy particles in potential vortex flows on the unit disk is investigated theoretically and numerically. Configurations with one vortex and with two vortices are considered. In both cases, each vortex follows a regular path on the disk. In the one-vortex case, it is shown that small, heavy particles may accumulate in elliptic regions...

Much research has been done on the motion of heavy particles in simple vortex flows. In most of this work, particle motion is investigated under the influence of fixed vortices. In the context of astrophysics, the motion of heavy particles in rotating two-dimensional flows has been investigated; the rotation follows from the laws of Kepler. In the...

Condensing flows can be found in a large variety of industrial machinery such as steam turbines and supersonic gas conditioners. In many of these applications, it is very important to predict the droplet size distributions accurately. In the present research, the droplet size distribution in condensing flows is investigated numerically. We consider...

We consider condensing flow with droplets that nucleate and grow, but do not slip with respect to the surrounding gas phase. To compute the local droplet size distribution, one could solve the general dynamic equation and the fluid dynamics equations simultaneously. To reduce the overall computational effort of this procedure by roughly an order of...