Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Energy Modeling”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,405 records · Page 78
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

pnnl/openstudio-building-energy-standard-measures-gem

The OpenStudio Building Energy Standards Measure Repository is a comprehensive collection of innovative OpenStudio measures designed to facilitate energy code analysis. OpenStudio is a cutting-edge platform brings together physics-based building energy modeling (BEM), BEM process automation, and large-scale computing capabilities. Contains OpenStudio Standards Performance Rating Method Measure (IPID 32936) and OpenStudio Measure to Generate IPLV-specific Chiller Performance Curves for Chillers (IPID 32940)

Xu, Weili [PNNL]↗
DOE OSTI2022

NucMesh: nuclear reactor geometry creation and mesh generation module in NEMoSys

NucMesh is a parameterized geometry and mesh generator for nuclear reactors developed within the Nuclear Energy Modeling System NEMoSys at Illinois Rocstar. NEMoSys is a platform developed for mesh generation, adaptive refinement, and solution verification. NucMesh is implemented to be generalized and extensible with a robust computer aided design engine and multiple mesh generation algorithms for unstructured triangular, quad-dominant, and structured quadrilateral meshing. In this paper, we present the geometric and meshing features of NucMesh. Geometrically objects are constructed bottom-to-top and overlaps are addressed automatically. A sophisticated object tracking algorithm prevents data from being lost for segmented objects. We discuss the primitive objects of circle and polygons that constitute the module and show how they are used with example inputs. Arrays of primitives and arrays of arrays are utilized to build large assemblies of objects. The concept of saved objects is discussed to demonstrate how repetitive objects can be reused easily and augmented in place. Three dimensional meshes can be obtained through mesh extrusion where all materials and side sets are extended to three dimensions. We show that side sets can be defined nearly anywhere within the geometry and can then be applied to the mesh. Finally, example reactor meshes are demonstrated for the Idaho National Laboratory Advanced Test Reactor and Los Alamos National Lab Empire reactor, both of which use control drums that NucMesh handles easily. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2014

Comparative Analysis for the Chicago Energy Retrofit Project: Project Report

For the Chicago Loop Energy Efficiency Retrofit project, Argonne is developing and piloting analytic methods that capture the energy performance of individual commercial buildings; can be scaled to communities; and appropriately evaluate retrofit options in real contexts. The decision tools under development span and integrate building energy performance calculations, uncertainty analysis, and financial risk assessment. A key outcome from this project is an energy calculator, EECalc, developed in collaboration with the Georgia Institute of Technology. The energy modeling methodology used in EECalc was chosen specifically because it (1) is computationally efficient, (2) uses only observable building data that take a relatively low level of effort to compile, and (3) requires minimal modeling expertise and judgment from the user. These features expand the possibilities for EECalc’s widespread, large-scale use in retrofit and uncertainty analysis.

Guzowski, Leah B.↗
DOE OSTI2013

Short-Term Monitoring Results for Advanced New Construction Test House—Roseville, California

A builder (K. Hovnanian® Homes®), design consultant, and trades collaborated to identify a systems integrated measures package for a 2,253-ft 2 slab-on-grade ranch house to achieve a modeled energy savings of 60% with respect to the Building America House Simulation Protocols, while minimizing construction costs and without requiring changes to the drawing that would impact local code or zoning approval. The key building improvements were applying R-10 insulation to the slab edge, increasing exterior wall cavity insulation from R-13 to R-15, and increasing attic insulation from R-30 to R-38. Also, the air handling unit was relocated from the attic to conditioned space, and ductwork was relocated along the attic floor with an insulated bulkhead built above it. Short-term testing results showed that duct air leakage was low due to short duct runs and the placement of ductwork in conditioned space. However, during commissioning, the lack of access for servicing the ductwork and dampers in the bulkhead area prevented retroactive balancing of individual branches, resulting in significant differences between specified and measured airflow values for some duct runs. Thermal imaging results performed on the house when operating in both heating and cooling modes validated historic stratification issues of ceiling supply registers with high supply air temperatures. Long-term monitoring results will be detailed in a future report.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

Short-Term Monitoring Results for Advanced New Construction Test House -- Roseville, California

A builder (K. Hovnanian Homes), design consultant, and trades collaborated to identify a systems integrated measures package for a 2,253-ft2 slab-on-grade ranch house to achieve a modeled energy savings of 60% with respect to the Building America House Simulation Protocols (Hendron, R. and Engebrecht, C. 'Building America House Simulation Protocols.' Golden, CO: National Renewable EnergyLaboratory, 2010) while minimizing construction costs and without requiring changes to the drawing that would impact local code or zoning approval. The key building improvements were applying R-10 insulation to the slab edge, increasing exterior wall cavity insulation from R-13 to R-15, and increasing attic insulation from R-30 to R-38. Also, the air handling unit was relocated from the attic toconditioned space, and ductwork was relocated along the attic floor with an insulated bulkhead built above it. Short-term testing results showed that duct air leakage was low due to short duct runs and the placement of ductwork in conditioned space. However, during commissioning, the lack of access for servicing the ductwork and dampers in the bulkhead area prevented retroactive balancing ofindividual branches, resulting in significant differences between specified and measured airflow values for some duct runs. Thermal imaging results performed on the house when operating in both heating and cooling modes validated historic stratification issues of ceiling supply registers with high supply air temperatures. Long-term monitoring results will be detailed in a future report.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

National Cost-Effectiveness of ASHRAE Standard 90.1-2010 Compared to ASHRAE Standard 90.1-2007

The purpose of this analysis is to examine the cost-effectiveness of the 2010 edition of ANSI/ASHRAE/IES1 Standard 90.1. Standard 90.1 is the model energy standard for commercial and multifamily residential buildings over three floors (ECPA, Public Law 94-385). PNNL analyzed the cost-effectiveness of changes in Standard 90.1 from 90.1-2007 to 90.1-2010, as applied in the United States. During the development of new editions of Standard 90.1, the cost-effectiveness of individual changes (addenda) is often calculated to support the deliberations of Standard Standing Project Committee (SSPC) 90.1. The process does not include analysis of the cost-effectiveness of the entire package of addenda from one version of the standard to the next. Providing states with an analysis of cost-effectiveness may encourage more rapid adoption of newer editions of energy codes based on Standard 90.1. This information may also inform the development of future editions of Standard 90.1.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

National Cost-Effectiveness of ANSI/ASHRAE/IES Standard 90.1-2016

The purpose of this analysis is to examine the cost-effectiveness of the 2016 edition of ANSI/ASHRAE/IES Standard 90.1, which is developed by the ASHRAE Standard Standing Project Committee (SSPC) 90.1, and is the model energy standard for all commercial buildings and multifamily residential buildings over three floors. PNNL analyzed the cost-effectiveness of changes in Standard 90.1-2016, compared to the previous 90.1-2013 edition, as applied in commercial buildings across the United States.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Industrial Conveyor Motor Performance Evaluation

The purpose of this project is to estimate the energy savings potential from a switched-reluctance motor (SRM) compared to an induction motor equipped with variable frequency drive (VFD) in a straight belt conveyor application. To experimentally evaluate savings in a realistic scenario, a baseline motor and VFD were selected from one of ComEd’s manufacturing customers’ conveyor systems. It was desired to not only estimate savings in the selected conveyor system, but to evaluate potential savings from using the SRM in any straight belt conveyor. Therefore, NREL developed a conveyor system energy calculation tool to supplement the experimental results of this assessment.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Conceptual Design of Pulverized Coal Electricity Generating Units for Flexible Operation

This National Energy Technology Laboratory (NETL) study addresses the conceptual design of greenfield pulverized coal (PC) plants intended for flexible rather than high capacity factor baseload operation. The United States has plentiful, low-cost natural gas resources - studies of aggressive decarbonization scenarios of the US energy sector suggest that the variability of carbon-free power can be economically addressed using dispatchable natural gas-fueled generation. Globally, natural gas resources are not as plentiful or low cost; consequently, some regions of the world are anticipated to continue to rely upon coal generation, even as they pursue decarbonization efforts. To support the increased utilization of variable renewable generation in these coal-dependent regions, plant designs must target low-capacity factor coal plants with increased emphasis on flexibility attributes such as start-up times, ramp rates, minimum load, and part-load heat rates. While much work has been performed on the improvement of the flexibility for existing coal plants originally designed for baseload service, little public literature exists on clean sheet design for flexible operation. This conceptual design study aims to define the features, performance characteristics, and costs for greenfield coal plants intended for flexible operation. Quantifying these characteristics provides critical information required by utility owners, grid planners, energy market modelers, and energy policy decision makers in coal-dependent regions of the world to better understand how coal-fired power plants can support a transition to low carbon generation.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2022

Post-Marcus Theory and Simulation of Interfacial Charge Transfer Dynamics in Organic Semiconducting Materials (Final Report)

The research program developed, validated and applies predictive computational protocols for calculating charge transfer (CT) rates in complex molecular systems, including molecular dyads and triads in liquid solution and solid-state organic semiconducting (OSC) materials. We have established a transformative computational scheme that goes beyond widely used simplifications, to achieve realistic descriptions of CT processes. The approach properly addresses the contribution of molecular environment at ambient conditions to CT processes. Our approach achieves unique insight on investigated CT processes in relevant experimental efforts. The collaborative team included three principal investigators (PIs), with complimentary expertise in classical molecular dynamics simulations and data science (Cheung), state-of-the-art electronic structure calculations (Dunietz), and cutting-edge theory and simulation techniques for modeling energy, charge and coherence transfer dynamics in molecular systems (Geva).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Uncertainties in Actinide Optical Potentials

The inelastic (n,n’) reactions on actinide nuclei cannot easily be measured, especially those which populate states of low excitation energies. Model calculations are therefore need to interpolate between (and extrapolate from) the data for those discrete and continuum states that can be measured. Such models are critically dependent on several ingredients: the choice of neutron optical potentials, the collective deformations of these deformed actinides, and the level densities. I here focus on uncertainties arising from the optical potentials, especially when different optical potentials may be fitted almost as well to the same data, yet produce different predictions for what must be inferred indirectly.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Method of Test for Evaluating Building Performance Simulation Software

ANSI/ASHRAE Standard 140 Method of Test for Evaluating Building Performance Simulation Software specifies the method to test the core competency of building performance simulation (BPS) software, a broad class of software which includes building energy modeling (BEM) software. Standard 140 has been widely used by BEM software vendors to help diagnose and compare the results from the program with other modeling programs. The Standard is also referenced by codes, standards, government programs, and other incentive programs as a part of minimum requirements for qualifying BEM software. The explanatory information, summary tables and figures in this 140 User’s Manual (referred to as “this Manual”) are provided to help users in implementing various suites of tests specified in Standard 140-2023 (referred to in this manual as “Standard 140” or “the Standard”).

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2026

Energy-Transit Nexus Tools for Bus Fleet Electrification (NEXTBUS)

NEXTBUS is an open-source software project that integrates NLR's bus energy modeling and simulation tools with multi-objective optimization for fleet operations. NLR is collaborating with a transit technology startup, ReVolt, to commercialize these capabilities by deploying NEXTBUS in ReVolt's software platform. The goal is to manage the added complexities of running a heterogeneous fleet, encompassing battery electric and diesel buses, across a large, multi-depot transit network.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2026

Energy Cost Estimate Tool v2.0: Methodology and Usage

Information about home energy costs is essential for appraisers, lenders, and buyers, but reliable data are often unavailable in real estate transactions. To fill this gap, the National Laboratory of the Rockies developed the Energy Cost Estimate (ECE) tool. The tool provides flexible, data-driven estimates of annual household energy use and costs across the contiguous United States, using only a small number of inputs typically found in mortgage appraisals. This report presents the methodology behind version 2.0 of the ECE tool, demonstrates how users can generate estimates through its interface, and discusses its applications and limitations.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2026

Functional characterization of glycosyltransferases in duckweed to enable predictive biology

Glycosyltransferases (GTs) catalyze the formation of glycosidic linkages to produce almost all complex carbohydrates. This project used a multi-disciplinary, high-throughput (HTP) biochemical and computational biology approach focused on duckweed as a model energy crop, to study carbohydrate metabolic processes. To achieve this, developed and carried out out high-throughput (HTP) functional characterization of plant glycosyltransferases (GTs) role of enzymatic microenvironments be assessed through a combined proteomic and computational biology approach, and the combined data was used to populate deep-learning frameworks to predict plant GT function. Functional validation achieved through this research is being used to assign gene function and study plant processes at the systems level to efficiently link the genome sequence with gene function. Together, the combined approaches used within this study provide a foundation for how computational prediction, in combination with high-throughput functional validation, can be used to study plant processes at the systems level and translate knowledge gained to efficiently link genome sequence with gene function in a species agnostic manner.

09 BIOMASS FUELS↗
DOE OSTI2016

Technical Note: A generic law-of-the-minimum flux limiter for simulating substrate limitation in biogeochemical models

We present a generic flux limiter to account for mass limitations from an arbitrary number of substrates in a biogeochemical reaction network. The flux limiter is based on the observation that substrate (e.g., nitrogen, phosphorus) limitation in biogeochemical models can be represented as to ensure mass conservative and non-negative numerical solutions to the governing ordinary differential equations. Application of the flux limiter includes two steps: (1) formulation of the biogeochemical processes with a matrix of stoichiometric coefficients and (2) application of Liebig's law of the minimum using the dynamic stoichiometric relationship of the reactants. This approach contrasts with the ad hoc down-regulation approaches that are implemented in many existing models (such as CLM4.5 and the ACME (Accelerated Climate Modeling for Energy) Land Model (ALM)) of carbon and nutrient interactions, which are error prone when adding new processes, even for experienced modelers. Through an example implementation with a CENTURY-like decomposition model that includes carbon, nitrogen, and phosphorus, we show that our approach (1) produced almost identical results to that from the ad hoc down-regulation approaches under non-limiting nutrient conditions, (2) properly resolved the negative solutions under substrate-limited conditions where the simple clipping approach failed, (3) successfully avoided the potential conceptual ambiguities that are implied by those ad hoc down-regulation approaches. We expect our approach will make future biogeochemical models easier to improve and more robust.

58 GEOSCIENCES↗
NASA NTRS1971

Nutational stability of a dual-spin satellite under the influence of applied reaction torques

It is assumed that since the solar paddle attachments to the hub of the spacecraft are not rigidly locked, the effect of the solar panels can be replaced by a constant reaction torque acting on the hub of the spacecraft. This could result in the satellite having an equilibrium motion about an axis displaced from the nominal axis of symmetry. The variational equations of motion are developed about such an equilibrium position using the SAS-A spacecraft as a model. Energy dissipation on the rotor as well as the main body is included. This nonautonomous set of differential equations are linearized and transformed to an autonomous set using the Liapunov reducibility theorem. The stability of the kinematically similar system is examined numerically using representative SAS-A parameters for the case when either pair of solar panels is assumed to be loosely attached. Stability is verified for small system nutation angles (0.1 degree).

Bainum, P. M.↗