Kate Evans brings a rare combination of scientific rigor and seasoned leadership to her new role at BESSD. Her career trajectory illustrates a dedicated focus on harnessing computational sciences and engineering to solve complex biological and environmental problems. Under her direction, the BESSD is set to integrate expansive scientific datasets with advanced computational models to create robust frameworks aimed at improving energy resilience and infrastructure protection. This direction is particularly important as the nation confronts an evolving landscape of climate risks, resource scarcity, and technological disruption.

ORNL Director Stephen Streiffer highlighted Evans’s diverse experience and visionary approach. Streiffer emphasized her ability to bridge laboratory-wide strategic initiatives with hands-on scientific innovation. As a leader, Evans has not only advanced ORNL’s quantum computing roadmap but has also prioritized scalable, autonomous research methodologies that capitalize on exascale computing and artificial intelligence. These cutting-edge technologies will be pivotal in BESSD’s mission to accelerate biomanufacturing capabilities and foster resilient energy systems aligned with the Department of Energy’s strategic objectives.

Evans’s previous role as director of the Office of Institutional Strategic Planning (OISP) positioned her at the nexus of ORNL’s long-term scientific planning and technology integration. She managed the development of critical documents such as the Annual Lab Plan and Laboratory Agenda, ensuring coherence across multidisciplinary research endeavors. This elevated her influence in shaping laboratory directed research and development (LDRD) investments aimed at pioneering scientific breakthroughs. Her leadership of the “Accelerating Southeast Resilience at ORNL” initiative exemplifies her commitment to regional and national strategies that leverage scientific innovation for societal benefit.

With a firm belief in multidisciplinary approaches, Evans underlines the importance of integrating exascale computing power, machine learning, and autonomous research pipelines into biological and environmental sciences. The BESSD under her stewardship will pursue research avenues ranging from critical mineral sustainability to next-generation biomanufacturing. By exploiting ORNL’s computational infrastructure, the directorate aims to translate scientific discoveries into scalable solutions that support energy abundance and infrastructure resilience, key components in addressing the pressing challenges of climate adaptation and industrial innovation.

Evans’s tenure leading the Computational Sciences and Engineering Division reinforced her expertise in scalable computing solutions across diverse science domains. Her efforts contributed to address computational challenges spanning physics, engineering, health sciences, and quantum information, underscoring her capability to lead interdisciplinary teams addressing complex scientific questions. This foundation equips her well to helm BESSD’s multifaceted research portfolio, which integrates biological systems science with environmental analytics and energy technologies.

Since joining ORNL in 2007, Evans has ascended through roles demonstrating her aptitude for scientific problem-solving and team leadership. She transitioned from an R&D staff member to a group leader in Computational Earth Sciences before taking on divisional directorships. Her technical acumen is matched by her commitment to scientific communication and community engagement, exemplified by her leadership roles in the ORNL Gives campaign. This blend of technical and community-oriented leadership underscores her holistic approach to advancing science with societal relevance.

Beyond her responsibilities at ORNL, Kate Evans holds a faculty position at the University of Tennessee’s Bredesen Center, an interdisciplinary hub combining engineering, science, and policy. Her engagement in academia fosters a fertile environment for collaborative innovation, spanning university and national laboratory partnerships. Such integration between academic research and national labs accelerates the translation of disruptive technologies from conceptual science to practical application, reinforcing ORNL’s role in the national innovation ecosystem.

Evans is a recognized authority within the scientific community, actively involved in organizations such as the American Meteorological Society, the American Geophysical Union, and the Society for Industrial and Applied Mathematicians. Her interdisciplinary expertise was recently honored with the prestigious SIAM Activity Group on Mathematics of Planet Earth Prize in 2024, acknowledging her contributions to multidisciplinary algorithm development, scientific computing, and leadership in integrating diverse scientific disciplines. This acclaim further validates her capacity to drive pioneering research at the interface of computation, biology, and environmental sciences.

Her academic credentials are rooted in earth and atmospheric sciences, with a doctorate and master’s degree from the Georgia Institute of Technology, complemented by a bachelor’s degree in physics from Haverford College. This strong foundation underscores an enduring commitment to quantitative sciences as tools to understand and solve environmental and technological challenges. Evans’s career exemplifies the trajectory from foundational sciences through computational innovation to strategic laboratory leadership, embodying the evolving nature of 21st-century scientific enterprise.

As the associate laboratory director of BESSD, Evans is poised to lead initiatives that capitalize on ORNL’s exceptional scientific resources, including exascale computing and a suite of analytical and autonomous research capabilities. These resources enable the laboratory to advance fundamental understanding and applied innovation in domains critical to the Department of Energy’s mission: from securing resilient energy infrastructures and optimizing biomanufacturing to safeguarding ecosystems. Under her guidance, BESSD is expected to emerge as a nexus for transforming biological and environmental data into actionable technologies that address both national needs and global challenges.

UT-Battelle’s stewardship of ORNL ensures that the laboratory continues to serve as a fundamental engine of basic and applied scientific research, supported robustly by the Department of Energy’s Office of Science. This partnership facilitates resource-intensive investigations aimed at solving some of the most profound scientific and technological questions of our time. With leaders like Kate Evans, ORNL is well-positioned to sustain its trajectory as a world-class research institution that blends scientific discovery with innovative solutions to enhance national security and promote sustainable development.

Subject of Research: Biological and environmental systems science directed at energy security, infrastructure resilience, and biotechnology innovation.

Article Title: Katherine Evans Appointed to Lead Biological and Environmental Systems Science Directorate at ORNL

News Publication Date: 2024

Web References: https://energy.gov/science

Image Credits: Credit: Carlos Jones/ORNL, U.S. Dept. of Energy

Keywords

Life sciences, Energy, National laboratories, Biological systems, Environmental systems, Exascale computing, Biotechnology, Energy resilience, Quantum computing, Scientific leadership, Computational sciences, Multidisciplinary research

Geothermal energy, known for its sustainability and low carbon footprint, traditionally relies on the circulation of water or steam through porous rock formations heated by subsurface magma. However, the presence of fractures in rock matrices presents both a challenge and an opportunity. These fractures can serve as pivotal conduits for heat transfer and fluid movement. By numerically studying these complex fractured networks, the researchers offer a new perspective on optimizing geothermal power plants that target these types of reservoirs, which are abundant yet underexploited.

Central to the study is the application of CO₂ as a working fluid, replacing conventional water-based systems. This choice stems from CO₂’s distinctive thermophysical properties, including lower viscosity and higher expansivity when compared to water. These characteristics enhance the fluid’s ability to extract heat more efficiently from geothermal formations. Using CO₂ not only implies potentially higher energy yields but also opens up avenues for simultaneous carbon sequestration, addressing two critical environmental issues in one innovative approach.

The researchers employed sophisticated numerical simulations to analyze the behavior of CO₂ within fractured hydrothermal reservoirs. Their models incorporate the geological heterogeneity of fractured rock, thermal dynamics, fluid flow mechanisms, and chemical interactions within the reservoir. This comprehensive approach allows for highly realistic predictions of energy production over time, accounting for complex physical processes, including heat transfer from hot rock to the circulating CO₂ and the impact of fracture geometry on fluid flow.

One of the most striking revelations from the study is the enhancement of heat extraction efficiency when using CO₂. Simulations demonstrated that CO₂ could sustain higher enthalpy extraction rates, translating into more stable and robust power generation over extended operational periods. This finding counters previous assumptions that water-based geothermal systems outperform alternatives, positioning CO₂ as a superior medium in fractured reservoirs due to its ability to penetrate deeper and transfer heat more effectively through intricate fracture networks.

The study also dives deep into the reservoir’s anisotropic permeability—a measure of how directional properties of the fractures affect fluid movement. Since fractures have varied orientations and apertures, fluid flow is non-uniform. The team’s numerical framework accounts for these complexities, showing that CO₂’s distinct flow behavior enables it to traverse these anisotropies more efficiently than water, mitigating energy losses and optimizing overall system performance.

Additionally, the researchers investigated the thermal-hydraulic-chemical (THC) interactions resulting from CO₂ injection and circulation. These interactions can induce mineral dissolution and precipitation within fractures, potentially altering permeability over time. The simulations accounted for these dynamic geological changes, providing valuable insights into the long-term sustainability and operational stability of CO₂-based geothermal systems. Such understanding is crucial for designing extraction strategies that minimize reservoir damage and maximize longevity.

Another highlight of the work is the integration of fracture-matrix heat transfer modeling. Heat conduction from the rock matrix into fluid-filled fractures controls the energy available for extraction. The study’s models finely resolved the thermal gradients and fluxes at these interfaces, revealing that CO₂’s thermophysical properties enable more efficient heat uptake despite lower fracture volumes available for flow, a common limitation in fractured geothermal reservoirs.

The implications of this study extend far beyond academic curiosity. With the global push towards decarbonization, leveraging geothermal reservoirs using CO₂ could revolutionize renewable energy portfolios. It offers a dual advantage: extracting clean, renewable power and providing a mechanism for geologic carbon storage. This synergy aligns perfectly with international climate goals, presenting an economically viable strategy with significant environmental benefits.

Industrial applications of these findings could transform the geothermal energy sector. Enhanced geothermal systems (EGS) often involve engineering fractures to optimize heat extraction. By validating CO₂ as an effective working fluid, the research paves the way for designing next-generation EGS that maximize energy output while reducing environmental risks associated with water use, such as scaling and chemical corrosion.

Moreover, the use of CO₂ could reduce dependency on freshwater resources. Many geothermal operations face challenges due to water scarcity, especially in arid regions. CO₂, often available as an industrial byproduct, offers an alternative that can adapt to such constraints. The modeling framework presented by Adhikary and colleagues not only clarifies performance metrics but also provides a decision-making tool for project developers seeking to evaluate feasibility under various geological and operational scenarios.

The study, rooted in numerical experimentation, also underscores the importance of interdisciplinary collaboration. By bridging geology, reservoir engineering, thermodynamics, and environmental science, the work exemplifies how complex earth systems can be effectively studied to yield actionable insights. The predictive models serve as a platform for further refinement through field trials, encouraging academia and industry to push forward the development of CO₂-based geothermal technologies.

Furthermore, the research highlights the variability of fractured reservoirs globally. Fracture density, orientation, and connectivity drastically impact how fluids behave underground. By customizing numerical models to specific site conditions, the methodology can be adapted to local geological setups, enhancing the relevance and applicability of findings to real-world geothermal projects. Such adaptability is critical for scaling geothermal energy solutions worldwide.

The environmental ramifications of substituting water with CO₂ are also profound. Beyond improved energy efficiency, CO₂ circulation reduces the risk of induced seismicity, a concern in hydraulic fracturing-based geothermal projects. The lower viscosity fluid leads to less pressure buildup and more controlled reservoir stimulation. This facet of CO₂ injection could mitigate public and regulatory concerns surrounding geothermal energy expansion, fostering greater acceptance and streamlined project approvals.

Detailed insights from this study can inform policy frameworks aimed at integrating geothermal energy with carbon capture and storage (CCS) initiatives. The dual benefit of energy production and CO₂ sequestration provides a compelling narrative for investment and regulatory support. Governments and stakeholders may leverage these findings to create incentives and guidelines that promote sustainable geothermal practices tied to emissions reduction targets.

Looking ahead, the research team emphasizes the need for experimental validation to complement their numerical results. Field-scale pilot projects deploying CO₂ as a working fluid in fractured reservoirs will be essential to confirm model predictions, optimize operational parameters, and identify potential unforeseen challenges. Such demonstrators will advance the technology readiness level and accelerate commercial deployment.

In summary, this pioneering numerical study not only advances the scientific understanding of geothermal energy extraction in fractured rocks but also unveils CO₂ as a transformative working fluid. By carefully simulating the complex interplay of thermal, hydraulic, and chemical processes, the research crafts a vision of more efficient, sustainable, and integrated geothermal systems. It promises to reshape energy strategies and catalyze innovation in a sector poised to contribute significantly to the world’s clean energy future.

Subject of Research:
Numerical modeling of geothermal energy production from fractured rock hydrothermal reservoirs using carbon dioxide as a working fluid.

Article Title:
Numerical study of energy production from fractured rock hydrothermal reservoirs using CO₂ as the working fluid.

Article References:
Adhikary, S.S., Chaudhuri, A., & Annavarapu, C. Numerical study of energy production from fractured rock hydrothermal reservoirs using CO₂ as the working fluid. Environmental Earth Sciences, 85, 47 (2026). https://doi.org/10.1007/s12665-025-12767-3

Image Credits:
AI Generated

DOI:
https://doi.org/10.1007/s12665-025-12767-3

Published on August 19, 2025, in the prestigious journal Physics of Fluids, this study dives deep into the mathematical and numerical representation of shock waves within computers. Unlike strong shock waves, which are easily identifiable both theoretically and experimentally, very weak shock waves hover near the speed of sound and manifest subtle pressure and velocity variations. These subtle features have long been difficult to simulate accurately, sometimes causing computational models to misrepresent key physical properties, resulting in less reliable predictions when applied to real-world engineering problems.

“Shock waves cause instantaneous compression, leading to increased entropy in a flow,” explains Professor Keiichi Kitamura of YOKOHAMA National University’s Faculty of Engineering, who co-authored the study. Entropy, a cornerstone concept in thermodynamics, broadly measures disorder in a system. While classical physics dictates certain expectations for entropy change across a shock, computations often reveal contradictory behavior, especially for weak shocks. This discrepancy arises from how numerical methods, especially finite volume approaches commonly used in CFD simulations, approximate shock discontinuities.

Finite volume methods work by dividing the flow domain into discrete cells and applying conservation laws to each. While effective in many scenarios, these methods introduce numerical diffusion — a sort of artificial smoothing — that diffuses the shock wave over several cells, contradicting the sharp physical discontinuity. When dealing with very weak shock waves, this diffusion becomes more pronounced, causing the computed shock wave to lose its distinctive character and leading to incorrect increases in entropy generation. The study meticulously analyzed how these numerical effects distort the representation of weak shocks, revealing that what was often labeled as “diffused” shocks might actually be a computational artifact.

The researchers categorized numerically simulated weak shocks into three distinct regimes based on their final state: dissipated, transitional, and thinly captured. Each regime reflects how the computational scheme’s assumptions internally adjust parameters to reconcile physical constraints such as entropy changes. In the dissipated regime, the weak shock essentially fades away in the simulation, losing its strength; in the transitional regime, the shock exhibits intermediate characteristics; and in the thinly captured regime, the shock is sharply resolved, more closely matching physical reality. Understanding these regimes clarifies why prior simulations have struggled to consistently capture weak shock behavior.

What makes this investigation particularly revolutionary is its focus on the entropy generation mechanism intrinsic to the numerical expression of shock waves. The team demonstrated that conventional methods inadvertently generate entropy within computed shocks beyond what physical theory predicts. This artificially generated entropy bridges the gap between the modeled flow and theoretical expectations but simultaneously distorts the true nature of weak shock waves. By recognizing this nuance, the researchers outlined pathways to refine shock modeling techniques, minimizing computational artifacts that have clouded prior results.

These insights bear profound implications for industries relying on accurate shock wave predictions. Rocket launches, supersonic flight, and high-speed transportation engineering depend on simulations that faithfully represent instantaneous pressure jumps, their propagation, and dissipation. Inaccuracies in modeling weak shock waves can lead to erroneous stress estimations, potentially jeopardizing structural integrity or inflating the cost and complexity of designs. By improving the theoretical underpinnings and numerical schemes for these subtle phenomena, this research paves the way for safer, more economical aerospace innovations.

The study’s methods leaned heavily on advanced mathematical analysis, leveraging entropy-based frameworks to dissect the stability and completeness of numerical shock wave representations. Such frameworks help demystify why certain computational shock profiles deviate from physically measured patterns and offer a lens through which computational scientists can calibrate and optimize CFD algorithms. In doing so, the work transcends a mere critique of numerical errors and becomes an enabling tool for computational mechanics advancement.

Underlying this work is the broader vision of blending theoretical physics, computational science, and mechanical engineering into a cohesive approach to fluid dynamics challenges. The researchers acknowledge that shock waves reside at the intersection of multiple domains — classical mechanics, thermodynamics, and wave mechanics — thereby calling for interdisciplinary collaboration. YOKOHAMA National University’s commitment to pioneering integrated research platforms played a crucial enabling role in facilitating this innovative study.

Co-author Gaku Fukushima, then a Japan Society for the Promotion of Science postdoctoral fellow at YOKOHAMA National University and now a researcher at Université de Sherbrooke, Canada, spearheaded many of the computational experiments and analytical modeling. His work underscores how international scientific partnerships drive progress in unraveling complex physics problems. The research team also credits continuous support from the Japan Society for the Promotion of Science, reflecting the importance of sustained funding for fundamental fluid mechanics research.

These advancements in shock wave computation do not merely address academic curiosity but have direct real-world impact. Improved models translate into better predictive maintenance for aerospace vehicles, enhanced simulation software for engineers, and ultimately contribute to the safe deployment of technologies that shape human mobility beyond current limits. The balance between accuracy and computational feasibility remains delicate, yet this research marks an important milestone toward achieving that balance for weak shock waves.

While the technical challenges are far from fully resolved, this study lays essential groundwork that could lead to the next generation of numerical solvers specifically optimized for weak shocks. Future studies may integrate machine learning techniques to dynamically adjust parameters or explore mesh refinement strategies that ensure thin capturing of shock zones without excessive computational cost. The possibility of extending these principles to other discontinuities in fluid flows — such as contact surfaces and expansion fans — also opens exciting avenues for ongoing fluid mechanics research.

In summary, the YOKOHAMA National University team’s findings illuminate the nuanced interplay between physics and computation in the realm of shock waves, particularly those on the faint edge near sonic speeds. By unraveling how entropy generation within numerical shock representations leads to peculiar behaviors, their work resolves long-standing misconceptions and equips engineers and scientists with refined tools for modeling and simulation. As aerospace and mechanical engineering continue to confront ever more extreme flow conditions, such foundational research will remain indispensable for safe, efficient, and innovative technological progress.

Subject of Research: Computational modeling and numerical analysis of very weak shock wave behavior, focusing on entropy generation mechanisms within numerical simulations.

Article Title: Peculiarity of moving weak shock computations: Entropy generation analysis of numerically expressed shock waves

News Publication Date: 19-Aug-2025

Web References:

• Physics of Fluids DOI: 10.1063/5.0282374

Image Credits: YOKOHAMA National University

Keywords

• Fluid dynamics
• Mechanical engineering
• Aerospace engineering
• Shock waves
• Computational science
• Information science
• Computational mechanics

The Antarctic Ice Sheet, a colossal expanse approximately 14 million square kilometers in size, functions as a crucial regulator of global sea levels. Understanding the behaviors of subglacial water is paramount to accurately predicting future changes in ice dynamics and mass loss. The research team employed advanced computational modeling techniques, enabling them to simulate various scenarios of subglacial hydrology that provide a clearer picture of how water is distributed and flows beneath the ice sheet. The results indicate a network of active subglacial lakes and water channels, confirming that this hydrological system plays a significant role in the stability of the ice above.

In their findings, the researchers highlighted the presence of numerous subglacial lakes, which previously remained hidden beneath massive glaciers. These lakes, situated beneath ice streams in both East and West Antarctica, serve as critical reservoirs of water that influence the motion of the ice sheet. Interestingly, the study revealed that large fluxes of water are being discharged through these channels, an important factor that modeling efforts had often overlooked. This newly generated data indicates that water accumulation and flow beneath the Antarctic Ice Sheet are far more complex than traditional models suggested.

Dr. Shivani Ehrenfeucht, a post-doctoral fellow involved in the study, emphasized the importance of this research in formulating more precise projections of sea level rise. Higher accuracy in these models is essential for policymakers and coastal stakeholders who need to prepare for the profound impacts of anticipated sea level changes. As societies strive to transition towards net-zero emissions, the scientific community must provide realistic projections of their potential outcomes, so they can effectively develop adaptive strategies.

The previous approaches to modeling the Antarctic’s subglacial water systems have often led to estimations that failed to adequately account for the dynamic relationships between ice and water. The research team, led by Dr. Christine Dow, demonstrated that this layer of subglacial water is essential to understanding ice sheet behavior and its implications for sea level rise. "We’ve now provided a comprehensive dataset that makes it clear that subglacial water dynamics cannot be ignored in future predictions," stated Dow, underlining the potential consequences of neglecting this critical factor.

With the release of this dataset, the barriers that previously hindered the integration of subglacial water modeling into sea level rise projections have been removed. Researchers can now rely on empirical evidence rather than inference or approximation to inform their work. This newfound confidence enables improved accuracy in predicting how glacier melt and mass loss may escalate through the coming century.

The implications of this research extend beyond scientific inquiry. Rising sea levels possess the potential to drastically alter global coastlines, jeopardizing homes, ecosystems, and economies. The Antarctic Ice Sheet is a vital component in the intricate balance of Earth’s systems. Therefore, understanding how it behaves and reacts to stimuli, such as climate change, is paramount for anticipating and mitigating adverse outcomes on a global scale.

Through advanced simulations, the model not only calculates speed but also clarifies how and where water accumulates within the subglacial environment. As scientists continue to scrutinize these patterns, they will be able to correlate changes in subglacial water dynamics with broader climate shifts. Better understanding of these interconnected systems will form the backbone of future climate research and potentially inform international climate policy debates.

This study stands as a wake-up call, underscoring the urgency of comprehensive climate research funded by robust investment. As more teams adopt this groundbreaking methodology, a wave of new understandings regarding ice dynamics and sea level will undoubtedly emerge, compelling a reevaluation of existing climate models. The hope remains that by shedding light on these obscured systems, researchers can improve our collective readiness for a rapidly changing planet.

With this knowledge firmly established in the scientific community, future research will undoubtedly build on the foundations laid by this pioneering dataset. Researchers are poised to unlock even greater intricacies of the subglacial landscape beneath the Antarctic Ice Sheet, potentially revealing other unknown factors that contribute to global sea level rise. By continuing this line of inquiry, scholars will better equip society with the knowledge needed to navigate the challenges that arise in an evolving climate landscape.

As discussions about climate change continue to escalate, embracing the insights stemming from this research will be essential in conserving future generations. Society must grasp the intricate relationship between ice dynamics, water movement, and climate change to chart a course forward. By focusing efforts on understanding and mitigating the implications of rising seas, we can work together towards sustainable solutions that ensure a viable future on our planet.

Through collaborative efforts and groundbreaking studies such as this, the collective understanding of climate change progresses. The revelations gained from modeling Antarctica’s subglacial hydrology are critical stepping stones in comprehending how global systems interplay. As we march towards a future characterized by uncertainty and change, staying informed and taking proactive measures based on rigorous scientific evidence can empower individuals and societies as we face the consequences of climatic shifts.

In summary, the research on the Antarctic Ice Sheet’s subglacial water flow marks a pivotal chapter in climate science, promising enhanced accuracy in sea level rise projections. With the availability of this cutting-edge dataset, researchers are better prepared to confront the challenges posed by climate change, fostering a future whereby societies may adapt effectively to rising tides and ensure the preservation of coastal habitats.

Subject of Research: Subglacial hydrology of the Antarctic Ice Sheet
Article Title: Antarctic wide subglacial hydrology modeling
News Publication Date: 29-Dec-2024
Web References: Geophysical Research Letters
References: 10.1029/2024GL111386
Image Credits: Not applicable

Keywords: Antarctic ice, Climate modeling, Antarctica, Sea level rise, Data sets, Glaciers, Ice sheets, Climate change adaptation, Earth sciences, Environmental sciences, Hydrology, Modeling, Climatology.