Optimising flow and mixing in a full-scale gas-mixed anaerobic digester by integrating sludge rheological data using computational fluid dynamics

Gas-mixing is commonly applied in anaerobic digesters, yet the resulting flow and hydraulic mixing are difficult to evaluate because of limited full-scale experimental data and uncertainties in integrating sludge rheological data. This study used computational fluid dynamics (CFD) to assess the impact of treated sludge rheology on flow and...

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...

Three-Dimensional Sediment Dynamics in Well-Mixed Estuaries: Importance of the Internally Generated Overtide, Spatial Settling Lag, and Gravitational Circulation

To investigate the dominant sediment transport and trapping mechanisms, a semi-analytical three-dimensional model is developed resolving the dynamic effects of salt intrusion on sediment in well-mixed estuaries in morphodynamic equilibrium. As a study case, a schematized estuary with a converging width and a channel-shoal structure...

Salt Dynamics in Well-Mixed Estuaries: Importance of Advection by Tides

Understanding salt dynamics is important to adequately model salt intrusion, baroclinic forcing, and sediment transport. In this paper, the importance of the residual salt transport due to tidal advection in well-mixed tidal estuaries is studied. The water motion is resolved in a consistent way with a width-averaged analytical model, coupled to...

Review of models and actors in energy mix optimization – can leader visions and decisions align with optimum model strategies for our future energy systems?

Organizational behavior and stakeholder processes continually influence energy strategy choices and decisions. Although theoretical optimizations can provide guidance for energy mix decisions from a pure physical systems engineering point of view, these solutions might not be optimal from a political or social perspective. Improving the...