Skip to main content

PNNL

  • About
  • News & Media
  • Careers
  • Events
  • Research
    • Scientific Discovery
      • Biology
        • Chemical Biology
        • Computational Biology
        • Ecosystem Science
        • Human Health
          • Cancer Biology
          • Exposure Science & Pathogen Biology
        • Integrative Omics
          • Advanced Metabolomics
          • Chemical Biology
          • Mass Spectrometry-Based Measurement Technologies
          • Spatial and Single-Cell Proteomics
          • Structural Biology
        • Microbiome Science
          • Biofuels & Bioproducts
          • Human Microbiome
          • Soil Microbiome
          • Synthetic Biology
        • Predictive Phenomics
      • Chemistry
        • Computational Chemistry
        • Chemical Separations
        • Chemical Physics
        • Catalysis
      • Earth & Coastal Sciences
        • Global Change
        • Atmospheric Science
          • Atmospheric Aerosols
          • Human-Earth System Interactions
          • Modeling Earth Systems
        • Coastal Science
        • Ecosystem Science
        • Subsurface Science
        • Terrestrial Aquatics
      • Materials Sciences
        • Materials in Extreme Environments
        • Precision Materials by Design
        • Science of Interfaces
        • Solid Phase Processing
          • Cold Spray
          • Friction Stir Welding & Processing
          • ShAPE
      • Nuclear & Particle Physics
        • Dark Matter
        • Flavor Physics
        • Fusion Energy Science
        • Neutrino Physics
      • Quantum Information Sciences
    • Energy Resiliency
      • Electric Grid Modernization
        • Emergency Response
        • Grid Analytics
          • AGM Program
          • Tools and Capabilities
        • Grid Architecture
        • Grid Cybersecurity
        • Grid Energy Storage
        • Transmission
        • Distribution
      • Energy Efficiency
        • Appliance and Equipment Standards
        • Building Energy Codes
        • Building Technologies
          • Advanced Building Controls
          • Advanced Lighting
          • Building-Grid Integration
        • Building and Grid Modeling
        • Commercial Buildings
        • Federal Buildings
          • Federal Performance Optimization
          • Resilience and Security
        • Grid Resilience and Decarbonization
        • Residential Buildings
          • Building America Solution Center
          • Energy Efficient Technology Integration
          • Home Energy Score
        • Energy Efficient Technology Integration
      • Energy Storage
        • Electrochemical Energy Storage
        • Flexible Loads and Generation
        • Grid Integration, Controls, and Architecture
        • Regulation, Policy, and Valuation
        • Science Supporting Energy Storage
        • Chemical Energy Storage
      • Environmental Management
        • Waste Processing
        • Radiation Measurement
        • Environmental Remediation
      • Fossil Energy
        • Subsurface Energy Systems
        • Carbon Management
          • Carbon Capture
          • Carbon Storage
          • Carbon Utilization
        • Advanced Hydrocarbon Conversion
      • Nuclear Energy
        • Fuel Cycle Research
        • Advanced Reactors
        • Reactor Operations
        • Reactor Licensing
      • Renewable Energy
        • Solar Energy
        • Wind Energy
          • Wind Resource Characterization
          • Wildlife and Wind
          • Community Values and Ocean Co-Use
          • Wind Systems Integration
          • Wind Data Management
          • Distributed Wind
        • Marine Energy
          • Environmental Monitoring for Marine Energy
          • Marine Biofouling and Corrosion
          • Marine Energy Resource Characterization
          • Testing for Marine Energy
          • The Blue Economy
        • Hydropower
          • Environmental Performance of Hydropower
          • Hydropower Cybersecurity and Digitalization
          • Hydropower and the Electric Grid
          • Materials Science for Hydropower
          • Pumped Storage Hydropower
          • Water + Hydropower Planning
        • Grid Integration of Renewable Energy
        • Geothermal Energy
      • Transportation
        • Bioenergy Technologies
          • Algal Biofuels
          • Aviation Biofuels
          • Waste-to-Energy and Products
        • Hydrogen & Fuel Cells
        • Vehicle Technologies
          • Emission Control
          • Energy-Efficient Mobility Systems
          • Lightweight Materials
          • Vehicle Electrification
          • Vehicle Grid Integration
    • National Security
      • Chemical & Biothreat Signatures
        • Contraband Detection
        • Pathogen Science & Detection
        • Explosives Detection
        • Threat-Agnostic Biodefense
      • Cybersecurity
        • Discovery and Insight
        • Proactive Defense
        • Trusted Systems
      • Nuclear Material Science
      • Nuclear Nonproliferation
        • Radiological & Nuclear Detection
        • Nuclear Forensics
        • Ultra-Sensitive Nuclear Measurements
        • Nuclear Explosion Monitoring
        • Global Nuclear & Radiological Security
      • Stakeholder Engagement
        • Disaster Recovery
        • Global Collaborations
        • Legislative and Regulatory Analysis
        • Technical Training
      • Systems Integration & Deployment
        • Additive Manufacturing
        • Deployed Technologies
        • Rapid Prototyping
        • Systems Engineering
      • Threat Analysis
        • Advanced Wireless Security
          • 5G Security
          • RF Signal Detection & Exploitation
        • Grid Resilience and Decarbonization
        • Internet of Things
        • Maritime Security
        • Millimeter Wave
        • Mission Risk and Resilience
    • Data Science & Computing
      • Artificial Intelligence
      • Graph and Data Analytics
      • Software Engineering
      • Computational Mathematics & Statistics
      • Future Computing Technologies
        • Adaptive Autonomous Systems
      • Visual Analytics
    • Publications & Reports
    • Featured Research
  • People
    • Inventors
    • Lab Leadership
    • Lab Fellows
    • Staff Accomplishments
  • Partner with PNNL
    • Education
      • Undergraduate Students
      • Graduate Students
      • Post-graduate Students
      • University Faculty
      • University Partnerships
      • K-12 Educators and Students
      • STEM Education
        • STEM Workforce Development
        • STEM Outreach
        • Meet the Team
      • Internships
    • Community
      • Regional Impact
      • Philanthropy
      • Volunteering
    • Industry
      • Available Technologies
      • Industry
      • Industry Partnerships
      • Licensing & Technology Transfer
      • Entrepreneurial Leave
      • Visual Intellectual Property Search (VIPS)
  • Facilities & Centers
    • All Facilities
      • Atmospheric Radiation Measurement User Facility
      • Electricity Infrastructure Operations Center
      • Energy Sciences Center
      • Environmental Molecular Sciences Laboratory
      • Grid Storage Launchpad
      • Institute for Integrated Catalysis
      • Interdiction Technology and Integration Laboratory
      • PNNL Portland Research Center
      • PNNL Seattle Research Center
      • PNNL-Sequim (Marine and Coastal Research)
      • Radiochemical Processing Laboratory
      • Shallow Underground Laboratory

Center for the Remediation of Complex Sites

  • About RemPlex
    • History
    • Leadership
    • Working with PNNL
  • Seminars
  • Engage
    • Learn and Study
  • Workshops
  • Past Summits
    • 2023 Summit
    • 2021 Summit
  • 2025 Summit
    • Case Studies
    • Technical Sessions
    • Sponsors

Breadcrumb

  1. Home
  2. Projects
  3. Center for the Remediation of Complex Sites
  4. RemPlex 2023 Summit

Technical Session 8

Multiscale Modeling in Porous Media: Theory to Applications
Thursday, November 16 | 1:00 - 5:00 p.m. Pacific Time

► WATCH THE RECORDING:
Technical Session 8: Multiscale Modeling in Porous Media: Theory to Applications, November 16, 2023
RemPlex Technical Session Eight

One of the biggest challenges of predictive modeling in porous media is that different aspects of physical, chemical, and biological systems (flow, transport, reactions, etc.) are interconnected across a variety of spatial and temporal scales. Modeling and prediction of coupled physicochemical and/or biogeochemical processes at multiple space and time scales is critical for achieving a mechanistic understanding of processes occurring in both engineered and natural systems. For engineered systems, multiscale modeling is used in a myriad of applications, including the design and optimization of porous media, combustion systems, fuel cells, and chemical reactors. In contrast to engineered systems, which are often well-characterized, natural subsurface systems generally have uncharacterized heterogeneity with coupled process interactions across a wide spectrum of scales. This gives rise to both emergent properties and scale-dependent behavior that is not always readily predictable. Although significant advancements have been made in the theory of complex, multiscale phenomena, there remain numerous open questions regarding both the appropriate theoretical frameworks needed, and the level of detail required to accurately represent such processes once a framework is identified. This session will explore recent developments in multiscale modeling of both engineered and natural systems and may include presentations on new theoretical approaches as well as case studies involving field applications. This topic is posed broadly and may include upscaling methods and upscaled model formulations, multiscale model coupling, multiresolution or multi-fidelity modeling, linkage of physics-based models with ML, and model abstraction approaches. Of particular interest are the representations of coarse-grained nonlinear phenomena (reactions, nonlinear diffusion, etc.).

Session Organizers: Xiaoliang (Bryan) He and Mark Rockhold, Pacific Northwest National Laboratory; Brian Wood, Oregon State University

 


1:00 - 1:05 p.m.

Opening Remarks 

__________________________________________________

1:05 - 1:25 p.m.

Turbulent Transport Across Sediment-Water Interface: Pore-resolved Simulations and Upscaled Modeling

Sourabh V. Apte, Oregon State University

► PRESENTATION PDF
Vortical structures over permeable beds colored by vorticity in z direction (Sourabh V. Apte, Oregon State University)
Vortical structures over permeable beds colored by vorticity in z direction (Sourabh V. Apte, Oregon State University)

Simulations of turbulent open channel flow over a porous sediment bed are performed over a range of permeability Reynolds number of (2-10) representative of aquatic systems. A diffuse interface continuum approach based on the volume-averaged Navier-Stokes (VANS) equations is used by defining smoothly varying porosity across the bed interface and modeling the drag force in the porous bed using a modified Ergun equation with Forchheimer corrections for inertial terms (Wood et al., Annual Review of Fluid Mechanics, 2020). The results from the continuum approach are compared with a pore-resolved DNS in which turbulent flow over a randomly packed sediment bed is performed using a fictitious domain method to enforce the rigidity and no-slip condition on the monodispersed spherical particles representing the sediment bed. A spatially varying porosity profile generated from the pore-resolved DNS is used in the continuum approach. Mean flow and Reynolds stress, pressure fluctuation statistics ,and net momentum exchange between the free-stream and the porous bed are compared between the two DNS studies, showing good agreement. Effect of protrusions from the top layer of the sediment bed, present in the pore-resolved study, is not captured by the diffuse interface model, and further improvements to the VaNS approach will be investigated in the future.

Coauthors: Shashank Karra (Oregon State University)
__________________________________________________

1:25 - 1:45 p.m.

Digital Twins from Microscope Image Data

James E. McClure, Virginia Tech

► PRESENTATION PDF
The LBPM software package has been developed to perform simulations based on microscope image data. Existing capabilities have been used to study flow processes such as (a) geological porous media; (b) PEM fuel cells; and (c)-(d) cell membrane biophysics. (James E. McClure)
The LBPM software package has been developed to perform simulations based on microscope image data. Existing capabilities have been used to study flow processes such as (a) geological porous media; (b) PEM fuel cells; and (c)-(d) cell membrane biophysics. (James E. McClure, Virginia Tech)

LBPM is an open source software package designed to model complex fluid flows using lattice Boltzmann methods (LBMs) based on microscope image data. LBPM includes a variety of simulators to model fluid flow through complex microstructures, with applications to geological fluid flows, hydrogen fuel cells and cell biology. Lattice Boltzmann methods can be constructed to model a wide range of physics, and LBPM solvers are capable of recovering the Navier-Stokes equations, modeling the behavior of immiscible fluids, and solving the Nernst-Planck equations with Gauss's law to predict transport in ionic systems. Cell membrane biophysics capabilities support whole cell modeling for electrochemical transport processes that control many biological phenomena. Lattice Boltzmann methods are well-suited toward parallel implementation, and LBPM is capable of scaling to thousands of GPU.

In this talk I will summarize recent performance optimization of LBPM for leadership-class computing systems at the Oak Ridge Leadership Computing Facility (OLCF) based on the Frontier Center for Accelerated Application Readiness (CAAR). I will discuss the implementation strategy used by LBPM to target different computing architectures, with support for conventional CPU as well as both NVIDIA and AMD GPU. We further consider the growing near-term opportunities to link simulations with microscope image data and AI/ML techniques to construct digital twins for small systems. Within this context, physics-based modeling can play a major role in informing the complex engineering solutions needed to navigate the energy transition.​ 
__________________________________________________

1:45 - 2:05 p.m.

Numerical Modeling of Heterogeneous Porous Media Burners Using Volume-Averaged Method

Aniruddha Saha, Cornell University

► PRESENTATION PDF

The presence of a variety of length scales in the phenomenon of combustion in a porous media demands for an effective upscaling process to tackle the computational complexity in a numerical study. The volume-averaged method allows us to capture the essential features of the microstructure by averaging the microscopic equations over a suitable representative elemental volume. Predicting system behavior such as combustion rate, emissions, and temperature distribution at a larger scale closely matches detailed simulation results at a fraction of the computational cost. Achieving efficient combustion in porous media relies on the burner’s geometric characteristics, flame stabilization, reduced NOx emissions, and enhanced material properties. Stabilizing the flame in the matrix provides higher flame speeds and can burn in fuel-lean conditions. The recirculation of heat generated from combustion by conduction through the solid matrix enables reducing unburnt hydrocarbons.

A new solver based on OpenFOAM is presented to model the interactions between a pre-mixed flame and a heterogeneous porous media. The non-catalytic combustion dynamics of methane are being simulated computationally in an inert porous media. A volume-averaged approach is adopted to study the combustion of the gaseous mixture and the thermodynamic coupling of the gas-solid system. Our model helps us validate the experimental results and incorporates underlying topological details of the porous matrix to explore flame stabilization conditions, temperature, and emissions. The modelling of heterogeneous porosity and thermophysical properties, such as effective conductivity and heat transfer coefficient, is performed. The combustion is described through detailed GRI3.0 mechanism (53 species and 325 reactions). By leveraging volume-averaged methods, this novel approach accurately captures microstructural effects on the modulation of a flame in a porous media. Therefore, it allows for predicting the behaviour of tailored porous structures, informed by experimental data, and can be used for much broader flame conditions.

Coauthors: Sadaf Sobhani (Cornell University)
__________________________________________________

2:05 - 2:25 p.m.

Upscaling Reactions in Tissues with Deep Neural Networks for Closure

Brian D. Wood, Oregon State University

► PRESENTATION PDF

In this work, we use a combination of formal upscaling and data-driven machine learning for explicitly closing a nonlinear transport and reaction process in a multiscale tissue. The classical effectiveness factor model is used to formulate the macroscale reaction kinetics. We train a multilayer perceptron network using training data generated by direct numerical simulations over thousands of microscale examples. Once trained, the network is applied in an algorithm for numerically solving the upscaled (coarse-grained) differential equation describing mass transport and reaction in two example tissues. The network is described as being explicit in the sense that the network is trained using macroscale concentrations and gradients of concentration as components of the feature space.

Network training and solutions to the macroscale transport equations were computed for two different tissues. The two tissue types (brain and liver) exhibit markedly different geometry and spatial scale (cell size and sample size). The upscaled solutions for the average concentration are compared with numerical solutions derived from the microscale concentration fields by a posteriori averaging.

There are two outcomes of this work of particular note: 1) we find that that the trained network exhibits good generalizability, and it is able to predict the effectiveness factor with high fidelity for realistically-structured tissues despite the significantly different scale and geometry of the two example tissue types; and 2) the approach results in an upscaled PDE with an effectiveness factor that is predicted (implicitly) via the trained neural network. This latter result emphasizes our purposeful connection between conventional averaging methods with the use of machine learning for closure; this contrasts with some machine learning methods for upscaling where the exact form of the macroscale equation remains unknown.
__________________________________________________

2:25 - 2:45 p.m.

Open Discussion

__________________________________________________

2:45 - 3:15 p.m.

Posters and Vendor Exhibit

__________________________________________________

3:15 - 3:35 p.m.

AI-Augmented Drone Observation and Multiscale Modeling of Streambed Hydro-Biogeochemistry

Yunxiang Chen, Pacific Northwest National Laboratory  

► PRESENTATION PDF

Stream hydro-biogeochemistry (HBGC) is controlled by the complex interactions among microtopography, turbulence, and microbial reactions. Despite their importance in regulating river ecosystem functions, our knowledge of the complex interactions is limited largely due to the lack of high-resolution data of microtopography and therefore limited capability to study the interactions of HBGC under realistic microtopography conditions. In this presentation, we will first demonstrate an AI-augmented drone observation technology that enables acquiring the data of high-resolution microtopography, grain size distributions, and water availability from drone photos, and then show how these data could be integrated with fully coupled surface-subsurface computational fluid dynamics modeling to extract key HBGC parameters at realistic streambeds in the Yakima River Basin.

Coauthor: Jie Bao (Pacific Northwest National Laboratory)
__________________________________________________

3:35 - 3:55 p.m.

Evaluation of Remedy Performance of the Uranium Plume in the 300 Area of Hanford Site

Sunil Mehta, INTERA Inc.   

► PRESENTATION PDF

Uranium contamination exists in the 300 Area of the Hanford Site. The selected remedy is a combination of enhanced attenuation (via in-situ phosphate treatment) over a 12,140 m2 (3 acre) area along with monitored natural attenuation for the remaining portion of the groundwater plume. To assess the long-term performance of the selected remedies, scale-dependent numerical models are developed to evaluate the fate and transport of uranium in variably saturated media.   
The models incorporate (a) an estimation of spatially distributed labile residual uranium mass in the vadose zone, (b) a best available geoframework model with hydrostratigraphic units represented as equivalent homogeneous media, (c) relevant boundary conditions including daily averaged Columbia River stage fluctuations, and (d) the impact of in-situ phosphate treatment (conducted in 2015 and 2018). Transport modeling is conducted using a single-site kinetic sorption-desorption parameter model based on pre- and post-injection leaching characteristics. The models are calibrated based on water-level measurements, river-groundwater mixing ratios, and uranium concentrations at monitoring wells.  
The simulated average uranium concentrations in selected monitoring wells compare well with the observed trends and magnitude indicating reasonableness of the modeling parameters. The spatio-temporal distribution of the plume in the shallow aquifer indicates the existence of local residual contamination sources where uranium leaches out from periodic rewetting. Long-term simulations are conducted to predict future concentrations over the next two decades. The spatial plume distribution near the end of the simulation indicates overall reduction in uranium concentrations in the aquifer below the cleanup levels with localized areas of higher concentrations

Coauthors: Mart Oostrom (INTERA Inc.), Rainer Senger (INTERA Inc.), Praveena Allena (INTERA Inc.), Fred Zhang (INTERA Inc.), Ryan Nell (INTERA Inc.)
__________________________________________________

3:55 - 4:15 p.m.

Evaluation of the Need for Three-Dimensional Contaminant Transport Modeling of the Hanford Central Plateau Vadose Zone

Mart Oostrom, INTERA, Inc.

► PRESENTATION PDF

The Hanford Site Composite Analysis for low-level waste disposal on the Hanford Site’s Central Plateau includes simulation of flow and transport in the vadose zone (VZ). The VZ modeling for the Central Plateau faces some unique challenges due to the number of sources (several hundred disposal sites, many with large disposal volumes with potential for comingling of water and contaminant from multiple sites in the VZ) and highly variable contaminant inventory in a setting with considerable thickness of the VZ, significant sediment heterogeneity, variable anisotropic hydraulic and transport properties, and spatial and temporal variation in recharge.  To address the resulting complexity, the area was divided into 26 three dimensional (3D) multi million node models that contain contaminant sources and liquid discharges likely to commingle during migration through the VZ to the water table.

VZ plume commingling may affect the spatial and temporal distribution of contaminant flux to groundwater. Commingling occurs when liquid discharge sources are near other liquid sources and is impacted by disposal characteristics, hydrological properties, and the distance between waste sites and other release areas. When a contaminant emanating from multiple waste sites commingles, complex transport behavior might develop with multiple peak arrival times at the water table. This behavior may only be captured when waste sites creating commingled contaminant plumes are evaluated in the same 3D VZ model. The compounding effect of adjacent waste sites on subsurface transport cannot be captured using models representing a single waste site, or by models simulating flow and transport using a one-dimensional (1D) approach.

The computational demands of the Central Plateau 3D VZ simulation suite are considerable, with a typical run time of several days per VZ model using a high-performance computer and parallelization. The intensive nature of the simulations complicates execution of extensive sensitivity and uncertainty analyses. To validate the need for complex 3D simulations, an alternative approach using 1D simulations of VZ transport below individual waste sites is applied and evaluated. 1D simulations have much smaller run times and are therefore more suitable for sensitivity and uncertainty analyses. The purpose of this presentation is to compare 1D and 3D technetium 99 VZ transport and transfer rates to groundwater for five selected waste sites (two tanks, two cribs, and one trench) to demonstrate the need to consider 3D flow and transport mechanisms.  

Coauthors: Dennis Fryar (INTERA, Inc.), Will Nichols (INTERA, Inc.)
__________________________________________________

4:15 - 4:35 p.m.

Modeling Evapotranspiration and Soil-Moisture Flow of a Modified RCRA Subtitle C Surface Barrier

Fred Zhang, INTERA, Inc.

► PRESENTATION PDF
Contour of the simulated vertical flux rate in the time-depth plane at the top portion of the vadose zone including the modified RCRA C barrier. (Fred Zhang, INTERA, Inc.)
Contour of the simulated vertical flux rate in the time-depth plane at the top portion of the vadose zone including the modified RCRA C barrier. (Fred Zhang, INTERA, Inc.)

The modified Resource Conservation and Recovery Act Subtitle C (RCRA C) surface barrier is an engineered design to immobilize the buried nuclear waste by limiting infiltration through the use of evapotranspiration (ET) layers and by preventing bio-intrusion into waste with the use of an asphalt layer. Such type of surface barrier with protective side slopes has been designed for the C Tank Farm at the Hanford site. In this investigation, the 500-year performance of the ET surface barrier was evaluated by numerical simulation using the eSTOMP-W simulator with newly added ET simulation capability. Sensitivity analysis was conducted for selected model inputs. The two-dimensional simulation domain consisted of a 230-m wide ET barrier and a 10-m buffer zone on each side with a deep vadose zone extending to the groundwater table. ET was simulated as sinks (negative sources) in the surface barrier with the consideration of root distribution and soil water stress. Multi-year daily potential or reference ET, which was an input and determined externally, and hourly precipitation cycles were repeated for the 500-year evaluation.

The results indicate that the ET surface barrier experienced an annual cycle of recharge-release process. For a surface barrier without degradation, there was no percolation from the surface barrier and hence a zero-flux plane (ZFP), which is a nearly lateral plane that no soil-moisture flow passes through, formed beneath the surface barrier. This ZFP, also termed as the ET-drainage divide, separated the vadose zone into the ET zone above the ZFP and the drainage zone below it. The ET-drainage divide disappeared over the time period when there was percolation from the surface barrier, for example, for the combination case of degraded asphalt layer with very wet years. The ET-drainage divide did not exist below the surface barrier when there was a continuous percolation from the surface barrier, for example, for the case with degraded vegetation.

These results provide insight towards finding ways to reduce recharge using engineering measures in the arid and semi-arid regions.

Coauthors: Sunil Mehta (INTERA, Inc.), Marcel Bergeron (Washington River Protection Solutions, LLC)
__________________________________________________

4:35 - 5:00 p.m.

Open Discussion and Closing Remarks

__________________________________________________

 

Return to technical sessions overview

PNNL

  • Get in Touch
    • Contact
    • Careers
    • Doing Business
    • Environmental Reports
    • Security & Privacy
    • Vulnerability Disclosure Policy
  • Research
    • Scientific Discovery
    • Energy Resiliency
    • National Security
Subscribe to PNNL News
Department of Energy Logo Battelle Logo
Pacific Northwest National Laboratory (PNNL) is managed and operated by Battelle for the Department of Energy
  • YouTube
  • Facebook
  • X (formerly Twitter)
  • Instagram
  • LinkedIn