Periodic Reporting for period 1 - Partres (Particle Resolving Fluid-Sediment Interaction)
Reporting period: 2023-01-01 to 2025-06-30
With continuing climate change, flood events in rivers and storm surges in coastal areas often lead to significantly increased sediment transport and erosion rates. This poses significant challenges to society, as resulting erosion and soil mechanical failures can result in severe damage to civil infrastructure and buildings. With the increased likelihood of extreme weather events, there is an urgent need to study coastal morphology and mitigation approaches from a multi-disciplinary physics-based perspective.
The current project PARTRES aims at understanding the connected physical processes of the environmental loading due to current and wave action as well as its effect on the sediment and soil response respectively. Particle based sediment transport models are used to realistically represent those processes. Advancing the current state of the art, the behavior of sediment and soil particles are described in a unified multi-physics framework, bridging the confinements of the disciplines of hydraulic, coastal and geotechnical engineering.
The relevant extreme environmental scenarios occur on relatively large length scales, whereas the the sediment transport and soil particle physics are of much smaller scale. In response to this, the different aspects of the hydrodynamic events and resulting erosion are integrated in a holistic multi-scale numerical framework. Throughout the project, this is being achieved by creating new numerical approaches to the sediment transport problem and implementing them into an open-source hydrodynamics framework, making it accessible to the wider research community as well as end users from various fields.
The current project PARTRES aims at understanding the connected physical processes of the environmental loading due to current and wave action as well as its effect on the sediment and soil response respectively. Particle based sediment transport models are used to realistically represent those processes. Advancing the current state of the art, the behavior of sediment and soil particles are described in a unified multi-physics framework, bridging the confinements of the disciplines of hydraulic, coastal and geotechnical engineering.
The relevant extreme environmental scenarios occur on relatively large length scales, whereas the the sediment transport and soil particle physics are of much smaller scale. In response to this, the different aspects of the hydrodynamic events and resulting erosion are integrated in a holistic multi-scale numerical framework. Throughout the project, this is being achieved by creating new numerical approaches to the sediment transport problem and implementing them into an open-source hydrodynamics framework, making it accessible to the wider research community as well as end users from various fields.
1. New PIC sediment particle concept
We have created an efficient and parallelized particle-based sediment transport model. For the hydrodynamic interaction, a particle-centric perspective is taken. For sediment particle resolving models, the most time consuming aspect is the particle-particle interaction, or the inter-particle stress. To circumvent this, we are offloading the inter-particle stress calculation to the Eulerian background mesh of the high-resolution model, that solves the fluid flow. There are several advantages of this approach: It is computationally efficient and it represents the actual physics realistically. Most importantly, it unifies the two concepts of sediment and soil modeling into one consistent particle-based approach.
2. Large Element representation
An important aspect of the particle-based sediment transport modeling, is the ability to represent larger rocks of more arbitrary shape. Those exist as part of coastal or riverine protection structures or as part of scour protections around the foundations of structures. These elements need to be treated discretely to resolve the collision physics and rotation in addition to the translatory motion.In the current project, the solid elements are represented through the direct forcing immersed boundary method, which is also used for 6DOF rigid body dynamics. The advantage of the method is that the Eulerian background mesh stays fixed and only the rigid body is moving. In extending this approach, multiple bodies can be represented. The large elements also interact with the smaller sediment particles in the sediment transport algorithm.
3. Large-Scale Hydrodynamics:
A new non-hydrostatic model has the capability to model phase-resolved waves, current and sediment transport. It combines shock absorbing properties and high-order discretization with excellent dispersion characteristics in a unique way. High-performance computing was a focus for the model development and testing. The model is connected to a continuum-based sediment transport algorithm for bedload and suspended sediment transport and will be applied to real world sediment transport simulations.
4. Multi-Scale Hydrodynamics:
In a simulation-based and data-driven engineering approach, open-access met-ocean data sets and open-source simulation tools are combined into a downscale numerical approach. It is used to propagate offshore met-ocean data to near-field wave physics from offshore to coastal waters, This approach enables workflow automation for large simulation sets that produce synthetic data used to the train machine learning algorithms for near-instantaneous coastal hydrodynamic event predictions at the identified hotspots.
5. Consistent Sediment Transport Algorithm across the hydrodynamic framework
On the larger scales, the continuum sediment transport algorithm will be used. The re-implemented version (available to all models of the hydrodynamic framework) has been thoroughly validated.
We have created an efficient and parallelized particle-based sediment transport model. For the hydrodynamic interaction, a particle-centric perspective is taken. For sediment particle resolving models, the most time consuming aspect is the particle-particle interaction, or the inter-particle stress. To circumvent this, we are offloading the inter-particle stress calculation to the Eulerian background mesh of the high-resolution model, that solves the fluid flow. There are several advantages of this approach: It is computationally efficient and it represents the actual physics realistically. Most importantly, it unifies the two concepts of sediment and soil modeling into one consistent particle-based approach.
2. Large Element representation
An important aspect of the particle-based sediment transport modeling, is the ability to represent larger rocks of more arbitrary shape. Those exist as part of coastal or riverine protection structures or as part of scour protections around the foundations of structures. These elements need to be treated discretely to resolve the collision physics and rotation in addition to the translatory motion.In the current project, the solid elements are represented through the direct forcing immersed boundary method, which is also used for 6DOF rigid body dynamics. The advantage of the method is that the Eulerian background mesh stays fixed and only the rigid body is moving. In extending this approach, multiple bodies can be represented. The large elements also interact with the smaller sediment particles in the sediment transport algorithm.
3. Large-Scale Hydrodynamics:
A new non-hydrostatic model has the capability to model phase-resolved waves, current and sediment transport. It combines shock absorbing properties and high-order discretization with excellent dispersion characteristics in a unique way. High-performance computing was a focus for the model development and testing. The model is connected to a continuum-based sediment transport algorithm for bedload and suspended sediment transport and will be applied to real world sediment transport simulations.
4. Multi-Scale Hydrodynamics:
In a simulation-based and data-driven engineering approach, open-access met-ocean data sets and open-source simulation tools are combined into a downscale numerical approach. It is used to propagate offshore met-ocean data to near-field wave physics from offshore to coastal waters, This approach enables workflow automation for large simulation sets that produce synthetic data used to the train machine learning algorithms for near-instantaneous coastal hydrodynamic event predictions at the identified hotspots.
5. Consistent Sediment Transport Algorithm across the hydrodynamic framework
On the larger scales, the continuum sediment transport algorithm will be used. The re-implemented version (available to all models of the hydrodynamic framework) has been thoroughly validated.
1. New sediment particle concept
The new PIC methodology for the particles sediment transport is a breakthrough: We now have a method that can represent the inter-particle stress realistically, yet is much more efficient than calculating particle-particle interactions explicitly. The new solution integrates both processes into a single approach. In addition to the sediment transport (which is the focus at the moment), this approach promises to also have significant impact on the modeling of soil dynamics. We expect the new approach to be more efficient than existing particle-centric soil models.
2. Large-Scale Hydrodynamics
The new non-hydrostatic model combines very good wave dispersion characteristics and shock-absorbing properties in a unique fashion together with a focus on high-performance computing. This means that it is possible to predict the wave propagation from deep water towards the coast for extreme sea states for relatively large spatial domains. At the same time the model resolves the nearshore processes including wetting and drying in a stable and accurate fashion. Further, it is integrated within an open-source hydrodynamic framework, and benefits from the hydrodynamic coupling and continuum-based sediment transport algorithms. We expect the model to have a significant impact on the coastal and offshore community.
3. Multi-scale wave procedure
A new multi-scale wave procedure provides an open and efficient way to downscale waves to the area of interest and can be implemented in an automated work flow. The method is a breakthrough because it combines open-access data and open-source models to enable realistic, time-efficient, and adaptable hydrodynamic analysis for coastal and marine applications.
The new PIC methodology for the particles sediment transport is a breakthrough: We now have a method that can represent the inter-particle stress realistically, yet is much more efficient than calculating particle-particle interactions explicitly. The new solution integrates both processes into a single approach. In addition to the sediment transport (which is the focus at the moment), this approach promises to also have significant impact on the modeling of soil dynamics. We expect the new approach to be more efficient than existing particle-centric soil models.
2. Large-Scale Hydrodynamics
The new non-hydrostatic model combines very good wave dispersion characteristics and shock-absorbing properties in a unique fashion together with a focus on high-performance computing. This means that it is possible to predict the wave propagation from deep water towards the coast for extreme sea states for relatively large spatial domains. At the same time the model resolves the nearshore processes including wetting and drying in a stable and accurate fashion. Further, it is integrated within an open-source hydrodynamic framework, and benefits from the hydrodynamic coupling and continuum-based sediment transport algorithms. We expect the model to have a significant impact on the coastal and offshore community.
3. Multi-scale wave procedure
A new multi-scale wave procedure provides an open and efficient way to downscale waves to the area of interest and can be implemented in an automated work flow. The method is a breakthrough because it combines open-access data and open-source models to enable realistic, time-efficient, and adaptable hydrodynamic analysis for coastal and marine applications.