An official website of the United States government
Abstract This report investigates a stabilization method for first order hyperbolic differential equations applied to DNA transcription modeling. It is known that the usual unstabilized finite element method contains spurious oscillations for nonsmooth solutions. To stabilize the finite element method the authors consider adding to the first order hyperbolic differential system a stabilization term in space and time filtering. Numerical analysis of the stabilized finite element algorithms and computations describing a few biological settings are studied herein.
more »
« less
An HPC-Based Hydrothermal Finite Element Simulator for Modeling Underground Geothermal Behavior with Example Simulations on The Treasure Island and UC Berkeley Campus
This submission contains the source code of the Hydrothermal Finite Element Simulator used for the Treasure Island and UC Berkeley campus geothermal simulation. It contains a report that summarizes the development and validation of this Hydrothermal Finite Element Simulator, with a case study on Treasure Island site. It also contains a report that investigates the feasibility of upgrading the existing campus energy delivery system at UC Berkeley to a fifth-generation district heating and cooling system that includes geothermal heat/cold storage.
more »
« less
- Award ID(s):
- 1903296
- PAR ID:
- 10469204
- Publisher / Repository:
- DOE Geothermal Data Repository; Lawrence Berkeley National Laboratory
- Date Published:
- Subject(s) / Keyword(s):
- 15 Geothermal Energy geothermal energy Finite Element Coupled Hydrothermal Modeling Community Scale ground source heat pump Parallel Computing Deal.II district heating and cooling system Subsurface Heat Response Treasure Island UC Berkeley Campus C simulation UC Berkeley district heating district cooling energy delivery geothermal storage goethermal energy storage energy storage
- Format(s):
- Medium: X Size: 5 files
- Size(s):
- 5 files
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
McCartney, J.S.; Tomac, I. (Ed.)Storing and extracting heat during different seasons of the year is possible through the utilization of a ground aquifer with an open loop Ground Source Heat Pump (GSHP) system. Being able to predict the hydrothermal performance of geothermal storage is required for an efficient operation of the system for cooling and heating of buildings. Complex 2D and 3D hydrothermal numerical models can simulate the thermal performance of geothermal storage accurately but often lack the desired computational speed for conducting large number of simulations for performance optimization. Instead, a 1D radial model can be used to conduct fast evaluation. However, it is important that the model computes the amount of heat loss from an aquifer into the overburden and underlying layers accurately to evaluate the amount of geothermal storage in the aquifer at different times. In this study, a source term is introduced into a 1D model to simulate the heat transfer between the aquifer and caprock/baserock in the vertical direction. The following two heat loss models are introduced in the heat advection-conduction equation: (i) Newton’s heating/cooling law, which leads to a closed form solution, and (ii) a conduction-based semi-analytical model, which requires a 1D finite element solution. When compared to a full 2D axisymmetric simulation result, it was found that the Newton’s heating/cooling law model with a constant heat transfer coefficient works well in cases of fast heat flow rate in thick aquifers of around 100 meters. But large errors in estimating heat dissipation are observed in cases with low heat flow rate in thin aquifers, especially for simulations exceeding two to five years. On the other hand, the model with the conduction-based semi-analytical solution gives a better match for these conditions.more » « less
-
A team of interdisciplinary investigators from the University of California, Berkeley, proposes to conduct exploratory research on informal STEM learning among older adults through an 18-month pilot study, Investigating the Measurement of STEM Engagement and Advocacy in Older Adults. The researchers include faculty and staff from three campus units: the Osher Lifelong Learning Institute @UC Berkeley (OLLI); the Fung Fellowship for Wellness and Technology (the Fellowship), part of the The Coleman Fung Institute for Engineering Leadership in the College of Engineering; and the Lawrence Hall of Science (LHS), the university’s public science center. This project focuses on understanding older adult participation and engagement in informal STEM learning environments and develops new methods for measuring participation, engagement, and advocacy in this population. This project aims to: (a) develop and apply methods for measuring engagement in informal STEM learning (ISL) and STEM advocacy in older adults (50+ years of age); and (b) explore factors that lead to the engagement of this population in ISL and that moderate the outcome of enhanced STEM advocacy.more » « less
-
Motivated by Cornell University's aspiration to use geothermal heat to replace fossil fuels to heat campus buildings, a 3-km deep geothermal exploratory well, the Cornell University Borehole Observatory (CUBO), was drilled on the Ithaca, NY campus in the summer of 2022. CUBO extends through largely low porosity and low permeability Paleozoic sedimentary rocks above low-grade metamorphic basement rocks. In order to assess the potential for and inform the design of an operational deep direct-use geothermal system within the US Northeast, the main objective of CUBO is to characterize the subsurface and potential fracture-dominated reservoir targets in both the sedimentary units and basement within a temperature range between 70 – 90 °C. Here we report results of our analysis which provide insight into the hydrologic, thermal, and mechanical conditions at depth and the associated physical rock fracture properties and characteristics. This integrative work incorporates regional well logs and geologic and geophysical data, as well as the CUBO-specific downhole logging and borehole image data collected during drilling operations, subsequent borehole temperature profiling and fluid sampling, downhole dual-packer mini-frac stress tests, and microstructural and physical property analysis of sidewall cores and cuttings. Altogether the knowledge from this information guides decisions regarding the design, depth, and orientation of subsequent injection and production wells at Cornell, as well as highlighting University, and highlights particular geologic targets and strategies for developing an effective and efficient enhanced geothermal reservoir. These comprehensive results, as well as lessons learned regarding the overall approach, can help de-risk decisions regarding the development of deep geothermal energy systems both at Cornell University and elsewhere.more » « less
-
Wang, Ping; Royer, Elizabeth; Rosati, Julie D. (Ed.)Three cycles of beach nourishment at two barrier islands: Sand Key and Treasure Island, were studied over 17 years. Seventy-four and 17 beach profiles spaced ∼300 m apart were surveyed bimonthly to quarterly on Sand Key and Treasure Island, respectively. Six beach sections were distinguished based on beach dynamics, including 2 erosional hotspots, 1 gap in the nourishment and 3 typical erosive beaches. At most locations, the shoreline (defined at +1 m contour) returned to a similar location at the end of each cycle, indicating the nourishment successfully maintained the target beach width. The Treasure Island erosion hotspot experienced increased beach loss over time, suggesting that the current nourishment design may not be adequate. The gap in the nourishment did not experience significant sand gain on the dry beach. A mechanism to impound sand on the dry beach is necessary. The current nourishment successfully compensated the sand deficit. The mechanism causing sand deficit was not eliminated at all the sites, suggesting that the current nourishment design serves as a long-term maintenance strategy.more » « less
