Comparison Between Mike 21 Fm, Delft3d and Delft3d Fm Flow Models of Western Port Bay, Australia

Abstract

The performance of three different hydrodynamic modelling packages is compared in this study, namely Delft3D, Delft3D FM (both developed by Deltares) and MIKE 21 FM (developed by DHI). Delft3D and MIKE 21 FM are internationally known software packages while Delft3D FM (formerly known as D-Flow FM) is a relatively new package. The models use structured approaches (Delft3D), unstructured approaches utilising triangular and quadrilateral elements (MIKE 21 FM) and unstructured approaches utilising elements ranging from linear to six sided (Delft3D FM). Models of Western Port, Australia, were developed using the three different packages to allow a comparison of performance and to determine if there are any differences in using structured versus unstructured approaches. Model performance has been assessed based on model calibration, representation of channel flows and computational efficiency. Despite the inherent differences in the grid configuration and the implementation of the numerical schemes between structured and unstructured approaches, both approaches have been shown to be able to accurately predict hydrodynamic conditions in a complex estuarine environment. The unstructured approach was found to be the most computationally efficient both when run on multiple cores (MIKE 21 FM was the most efficient) and when run on a single core (Delft3D FM was the most efficient).

Numerical Modeling Tools Applied to Estuarine and Coastal Hydrodynamics: A User Perspective

“…For historical floods, the two models obtained very similar results, despite using different numerical approximations. The different numerical approximations of Mike 21 FM, Delft3D, and Delft3D FM were tested by Symonds et al [24], confirming that despite the differences in the grids configuration, all the approaches accurately predict hydrodynamic conditions in complex estuarine regions. They also demonstrate that the unstructured models present a higher computational efficiency.…”

“…It has been demonstrated that this kind of models can accurately reproduce current velocity, flood extent, and water levels, being useful to complement risk assessment tools and early warning systems, because less computational resources are required and the numerical solutions are much faster obtained. Several authors used 2DH models with satisfactory results [14,[17][18][19][20][21][22][23][24], though 3D models are required to properly represent several processes, like vertical stratification, vertical current profiles, turbulent mixing processes, sediment transport, turbidity, water quality, effects of salinity, and temperature gradients on river plumes or salt-wedge estuarine configurations [25][26][27][28].…”

Modelling the Main Hydrodynamic Patterns in Shallow Water Estuaries: The Minho Case Study

“…Despite the complexity of the parameters involved in estuarine systems, 2DH models are able to produce accurate solutions with good agreement between measured and simulated hydrodynamic data. The works of Horrit and Bates [36], Hu et al [37], Néelz and Pender [38,39], Robins and Davies [34], Monteiro et al [35], Wan et al [40], Symonds et al [41] and Iglesias et al [6] demonstrate that 2DH models are capable of adequately predicting velocity, flood extent and water level, proving that 2DH models results are suited for risk assessment. 2DH models are widely used by the scientific community to represent the hydrodynamics of shallow estuarine systems, reinforcing their applicability for the Minho estuary region [14,42,43].…”

Assessment of water quality in an artificial urban canal: A case study of Songdo City in South Korea

“…These models can either be setup with structured (rectangular) or unstructured (triangular and rectangular) mesh grid types, with both approaches being widely adopted widely for a range of hydraulic applications. The structured grids can be rectilinear or curvilinear and typically adopt a Finite Difference Method (FDM) scheme, while the unstructured grids have a flexible mesh (mesh elements can have a variable shape and size over the model domain) and typically adopt a finite volume solution scheme [6]. Toombes and Chanson [7] applied the four different numerical models on the experimental results of the weir test and compared each other.…”

“…Improving calculation efficiency of the simulation, the canal boundary was built with 949 nodes and 634 elements. Effective triangular (unstructured) grids were created to precisely implement the complex topography [6]. In Fig.…”