Characterising the two-phase flow and mixing performance in a gas-mixed anaerobic digester: Importance for scaled-up applications

This study aimed to characterise the gas-liquid flow and mixing behaviour in a gas-mixed anaerobic digester by improving phase interaction modelling using Computational Fluid Dynamics (CFD). A 2D axisymmetric model validated with experimental data was set up using an Eulerian-Eulerian method. Uncertainty factors, including bubble size, phase...

An effective fluid model for the bending failure of level ice

In this paper, the efficacy of an effective fluid model (EFM) is studied for replicating the effects that hydrodynamics has on the interaction between level ice, modeled as a semi-infinite Kirchhoff-Love plate, and a downward sloping structure, modeled as a rigid and immobile body. The proposed EFM is based on a distributed frequency-independent...

Fixed bed reactors of non-spherical pellets: Importance of heterogeneities and inadequacy of azimuthal averaging

Despite the substantial simplicities inherent in pseudo-continuum models of fixed bed reactors, there is a continued interest in the use of such models for predicting fluid flow and transport scalars. In this paper, we aim to quantitatively address the inadequacy of 2D pseudo-continuum models for narrow-tube fixed beds. We show this by...

The effect of hydrodynamics on the bending failure of level ice

In this paper, the bending failure of level ice caused by the interaction with a downward sloping structure is studied in 2D. The focus is on the effect of hydrodynamics on the interaction. This study is done by comparing the predictions of a model that includes both hydrostatics and hydrodynamics with one that only includes hydrostatics.<br/...

The influence of level ice on the frequency domain response of floaters

In this paper the effect of a nearby, semi-infinite, level ice sheet on the frequency domain response of a thin, floating, rigid body is studied using a 2D model. The ice is modeled using a dynamic Euler-Bernoulli beam and the finite depth water layer is described with the Laplace equation and the linearized Bernoulli equation. Eigenfunction...

Lagrangian modeling of hydrodynamic–kinetic interactions in (bio)chemical reactors: Practical implementation and setup guidelines

Large substrate concentration gradients can exist in chemical or biochemical reactions, resulting from a large circulation time compared to the turnover time of substrates. The influence of such gradients on the microbial metabolism can significantly compromise optimal bioreactor performance. Lapin et al. (2004) proposed an Euler–Lagrange CFD...

impact of beach states on alongshore transport

Impact of spatial variability in the nearshore bathymetry on net sediment transport rates has been investigated for a selection of observed beach states at the Dutch coast. The beach states comprise a longshore bar trough and two transverse bar rip situations, which were present at the large scale Sand Motor nourishment at the Holland coast....

An assessment of transport timescales and return coefficient in adjacent tropical estuaries

Transport timescales (TTS), namely residence time and exposure time, were computed for adjacent shallow meso-tidal tropical estuarines system using the Lagrangian model D-Waq Part coupled with the hydrodynamic model Delft3D-Flow, and the Constituent-oriented Age and Residence time Theory, CART. The main results are threefold: (a) The TTS...

Proceedings of the 19th WEGEMT School Numerical Simulation of Hydrodynamics: Ships and Offshore Structures, Part 2: Offshore Structures, Hydrodynamic problems of offshore structures, Ecole Centrale Nantes, France

Quasi-3D Nearshore Current Modelling: Wave-Induced Secondary Current

Symposium of the Fluid Dynamics Panel in Monterey. Agard Conference Proceedings Aerodynamic and Related Hydrdodynamic Studies Using Water Facilities

Contents of Symposium of the Fluid Dynamics Panel in Monterey. Agard Conference Proceedings Aerodynamic and Related Hydrdodynamic Studies Using Water Facilities