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At least 451 records · Page 25

The future of very large subsonic transports

The Very Large Subsonic Transport (VLST) is a multi-use commercial passenger, commercial cargo, and military airlifter roughly 50% larger than the current Lockheed C-5 and Boeing 747. Due to the large size and cost of the VLST, it is unlikely that the commercial market can support more than one aircraft production line, while declining defense budgets will not support a dedicated military VLST. A successful VLST must therefore meet airline requirements for more passenger and cargo capacity on congested routes into slot-limited airports and also provide a cost effective heavy airlift capacity to support the overseas deployment of US military forces. A successful VLST must satisfy three key missions: commercial passenger service with nominal seating capacity at a minimum of 650 passengers with a range capability of 7,000 to 10,000 miles; commercial air cargo service for containerized cargo to support global manufacturing of high value added products, 'just-in-time' parts delivery, and the general globalization of trade; and military airlift with adequate capacity to load current weapon systems, with minimal break-down, over global ranges (7,000 to 10,000 miles) required to reach the operational theater without need of overseas bases and midair refueling. The development of the VLST poses some technical issues specific to large aircraft, but also key technologies applicable to a wide range of subsonic transport aircraft. Key issues and technologies unique to the VLST include: large composite structures; dynamic control of a large, flexible structure; aircraft noise requirements for aircraft over 850,000 pounds; and increased aircraft separation due to increased wake vortex generation. Other issues, while not unique to the VLST, will critically impact the ability to build an efficient and affordable aircraft include: active control systems: Fly-By-Light/Power-By-Wire (FBL/PBW); high lift systems; flight deck associate systems; laminar flow; emergency egress; and modular design. The VLST will encounter severe restrictions on weight, ground flotation, span, length, and door height to operate at current airports/bases, gates, and cargo loading systems. One option under consideration is for a sea-based VLST, either a conventional seaplane or Wing-In-Ground effect (WIG) vehicle, which would allow greater operational flexibility, while introducing other design challenges such as water impact loads and salt-water corrosion. Lockheed Martin is currently developing a floatplane version of the C-130 Hercules which will provide experience with a modern sea-based aircraft. In addition to its own ongoing research activities, Lockheed Martin is also participating in the NASA Advanced Subsonic Technology, High Speed Research (HSR), and other programs which address some of the technologies needed for the VLST. The VLST will require NASA and US aerospace companies to work together to develop new capabilities and technologies for make the VLST a viable part of transportation beyond 2000.

Justice, R. Steven↗

Capability 9.1 Exploration

The exploration challenge are: To build an efficient, cost effective exploration infrastructure, To coordinate exploration robots & crews from multiple. earth sites to accomplish science and exploration objectives. and To maximize self-sufficiency of the lunar/planetary exploration team.

Eckelkamp, Rick↗

Downscaling NASA Climatological Data to Produce Detailed Climate Zone Maps

The design of energy efficient sustainable buildings is heavily dependent on accurate long-term and near real-time local weather data. To varying degrees the current meteorological networks over the globe have been used to provide these data albeit often from sites far removed from the desired location. The national need is for access to weather and solar resource data accurate enough to use to develop preliminary building designs within a short proposal time limit, usually within 60 days. The NASA Prediction Of Worldwide Energy Resource (POWER) project was established by NASA to provide industry friendly access to globally distributed solar and meteorological data. As a result, the POWER web site (power.larc.nasa.gov) now provides global information on many renewable energy parameters and several buildings-related items but at a relatively coarse resolution. This paper describes a method of downscaling NASA atmospheric assimilation model results to higher resolution and maps those parameters to produce building climate zone maps using estimates of temperature and precipitation. The distribution of climate zones for North America with an emphasis on the Pacific Northwest for just one year shows very good correspondence to the currently defined distribution. The method has the potential to provide a consistent procedure for deriving climate zone information on a global basis that can be assessed for variability and updated more regularly.

Chandler, William S.↗

NIRPS: A Year of Progress and Challenge

In the past 14 months NIRPS has gone from an idea on a sheet of paper to a working organization, performing tasks of national scale. NIRPS is beginning to establish itself among the Propulsion Community. Need is recognized for a coordination and integration function across the US Government s propulsion activities. NIRPS acts as a collaboration agent - serves as a catalyst and multi-agency facilitator NIRPS is leading a high-priority Government-wide task. 2012 Defense Authorization Act, Sec 1095; Develop National Rocket Propulsion Strategy. Beginning to perform in accordance with Grand Challenges. Performing to an Executable plan, adjusting to to Center and Agency priorities. Challenges remain to building a sustainable Institute. Effective integration and Coordination with other Government Agencies. Continued Active engagement with Industry and Academia. Building an Efficient and Responsive Governance System for a growing Institute.

Thomas, Dale↗

Buckling Response of a Large-Scale, Seamless, Orthogrid-Stiffened Metallic Cylinder

Results from the buckling test of a compression-loaded 8-ft-diameter seamless (i.e., without manufacturing joints), orthogrid-stiffened metallic cylinder are presented. This test was used to assess the buckling response and imperfection sensitivity characteristics of a seamless cylinder. In addition, the test article and test served as a technology demonstration to show the application of the flow forming manufacturing process to build more efficient buckling-critical structures by eliminating the welded joints that are traditionally used in the manufacturing of large metallic barrels. Pretest predictions of the cylinder buckling response were obtained using a finite-element model that included measured geometric imperfections. The buckling load predicted using this model was 697,000 lb, and the test article buckled at 743,000 lb (6% higher). After the test, the model was revised to account for measured variations in skin and stiffener geometry, nonuniform loading, and material properties. The revised model predicted a buckling load of 754,000 lb, which is within 1.5% of the tested buckling load. In addition, it was determined that the load carrying capability of the seamless cylinder is approximately 28% greater than a corresponding cylinder with welded joints.

Rudd, Michelle Tillotson↗

Swamp Works Technology Development 10th Anniversary: 2013-2023 - Innovative Research & Technology Development Summary

Kennedy Space Center’s (KSC) Swamp Works, provides government and commercial space ventures with the technologies required for working and living on the surfaces of the Moon or other planets and bodies in our solar system. The Swamp Works team establishes rapid, innovative and cost-effective exploration mission solutions through leveraging of partnerships across NASA, industry and academia. Concepts start small and build up efficiently, with lean development processes and a hands-on approach. Testing is performed in early stages to drive design improvements and progressively increase Technology Readiness Levels (TRL). Swamp Works provides concepts, architecture studies and trades, designs, data, technology development, technology demonstration hardware, flight hardware, testing, flight support and knowledge in support of the development of surface systems. It consists of several teams with associated laboratories and test capabilities. The Granular Mechanics and Regolith Operations (GMRO) Laboratory and the Electrostatics and Surface Physics Laboratory (ESPL) are co-located in the Engineering Development Lab (EDL) facility high bay. The Applied Chemistry Lab (ACL) is in an adjacent facility and other KSC labs are being influenced by the innovation methods pioneered at the Swamp Works. The Swamp Works was founded in January 2013 by a group of scientists and engineers at KSC with the over-arching vision of expanding humanity and civilization into the solar system by the use of space resources via advanced technology. Ultimately, this will create a solar system economy that will improve the human condition due to the abundance of energy and resources. This presentation will summarize the projects and technology development that have been performed by the Swamp Works to celebrate its 10th Anniversary of innovation success.

Swamp Works↗

Is the Adoption of Electric Vehicles (EVs) and Solar Photovoltaics (PVs) Interdependent or Independent? An Integrated EVs-PVs Modeling Framework

Transportation and residential energy consumption account for more than one-half of the overall energy consumption in the United States. Adoption of electric vehicles (EVs) can play a key role in decarbonizing the transportation sector, while the adoption of renewable energy sources (e.g., solar photovoltaics or PVs) could bring similar benefits to the residential energy sector and in turn support transport electrification. Although the market share for both EVs and PVs continue to grow, both these emerging technologies are deployed rather disjoint without considering the existence of potential similarities among users who own (or aspire to own) EVs and PVs. This might be due to lack of understanding of the behavioral interdependence in consumer preferences towards these technologies. To fill this gap in knowledge, this study utilizes data from the 2018 WholeTraveler Transportation Behavior Study to develop an integrated model system that explores EV and PV adoption behaviors. A structural equations model (SEM) is employed that incorporates direct effects as well as error correlations among the adoption behaviors for EVs and PVs. Model results indicate that the adoption behavior for both these technologies is indeed interconnected and significantly influenced by attitudes, values and personality traits. Findings from this research suggest that incentives (e.g., subsidies) that drive 'bundled' adoption of EVs and PVs could accelerate the adoption of both these sustainable technologies. The results highlights the need to consider transport and building energy efficient technology adoption behavior in a single integrated structure.

ADVANCED PROPULSION SYSTEMS,ENERGY PLANNING, POLIC↗

From Chills to Thrills: Revolutionizing Energy Efficiency and Load Flexibility in Supermarket Refrigeration

Open-vertical medium-temperature refrigerated display cases comprise nearly 50% of total case lineups in a typical supermarket, with more than 80% of their cooling load attributed to infiltration of warm and moist air from the surrounding space. The infiltration takes place across the air curtain system of the display case. While the air curtain acts as a thermal shield and as a cooling mechanism to maintain product temperature, it also entrains large amounts of heat and moisture from the adjacent space. Additionally, from food safety and quality standpoints, these fixtures are vulnerable to electric outages and traditionally cannot participate in load flexibility events. This paper describes key features of an innovative design of a self-contained, water-cooled, medium-temperature, open-vertical display case. The novel concept will eliminate the inefficient air curtain system and incorporate a hybrid radiant and low-airflow convective cooling design with a thermal-energy-storage-coupled heat exchanger integrated into the refrigeration circuit. The focus of this paper is on evaluating the thermal performance of the novel hybrid design in maintaining target product temperature. It presents thermal performance findings from thermo-fluid system modeling and robust state-of-the-art laboratory experiments used to validate those models. Load flexibility attributes from thermal energy storage are not discussed. A controlled-environment chamber at the National Renewable Energy Laboratory was leveraged to validate the thermal performance of the novel technology. Final results from bench-scale experiments indicate the proposed design maintained mean product temperatures within food safety guidelines.

commercial refrigeration↗

From Chills to Thrills: Revolutionizing Energy Efficiency and Load Flexibility in Supermarket Refrigeration: Preprint

Open-vertical medium-temperature refrigerated display cases comprise nearly 50% of total case lineups in a typical supermarket, with more than 80% of their cooling load attributed to infiltration of warm and moist air from the surrounding space. The infiltration takes place across the air curtain system of the display case. While the air curtain acts as a thermal shield and as a cooling mechanism to maintain product temperature, it also entrains large amounts of heat and moisture from the adjacent space. Additionally, from food safety and quality standpoints, these fixtures are vulnerable to electric outages and traditionally cannot participate in load flexibility events. This paper describes key features of an innovative design of a self-contained, water-cooled, medium-temperature, open-vertical display case. The novel concept will eliminate the inefficient air curtain system and incorporate a hybrid radiant and low-airflow convective cooling design with a thermal-energy-storage-coupled heat exchanger integrated into the refrigeration circuit. The focus of this paper is on evaluating the thermal performance of the novel hybrid design in maintaining target product temperature. It presents thermal performance findings from thermo-fluid system modeling and robust state-of-the-art laboratory experiments used to validate those models. Load flexibility attributes from thermal energy storage are not discussed. A controlled-environment chamber at the National Renewable Energy Laboratory was leveraged to validate the thermal performance of the novel technology. Final results from bench-scale experiments indicate the proposed design maintained mean product temperatures within food safety guidelines.

commercial refrigeration↗

Grid Interactive Micro-Distributed Refrigerated Display Case

Open-vertical medium-temperature refrigerated display cases comprise nearly 50% of total case lineups in a typical supermarket, with more than 80% of their cooling load attributed to infiltration of warm and moist air from the surrounding space. The infiltration takes place across the air curtain system of the display case. While the air curtain acts as a thermal shield and as a cooling mechanism to maintain product temperature, it also entrains large amounts of heat and moisture from the adjacent space. Additionally, from food safety and quality standpoints, these fixtures are vulnerable to electric outages and traditionally cannot participate in load flexibility events. This paper describes key features of an innovative design of a self-contained, water-cooled, medium-temperature, open-vertical display case. The novel concept will eliminate the inefficient air curtain system and incorporate a hybrid radiant and low-airflow convective cooling design with a thermal-energy-storage-coupled heat exchanger integrated into the refrigeration circuit. The focus of this paper is on evaluating the thermal performance of the novel hybrid design in maintaining target product temperature. It presents thermal performance findings from thermo-fluid system modeling and robust state-of-the-art laboratory experiments used to validate those models. Load flexibility attributes from thermal energy storage are not discussed. A controlled-environment chamber at the National Renewable Energy Laboratory was leveraged to validate the thermal performance of the novel technology. Final results from bench-scale experiments indicate the proposed design maintained mean product temperatures within food safety guidelines.

commercial refrigeration↗

Delivering Energy Efficiency and Grid Services for Commercial Buildings on an IoT-Platform: Field Evaluation Plan

In FY20, the Commercial Buildings Integration Program (CBI) within Building Technologies Office (BTO) has funded PNNL to conduct field evaluation of the AIRCx and intelligent load control (ILC) using an Internet-of-Things (IoT) platform, VOLTTRON. The primary goal of the project is to show that software solutions deployed and delivered through an IoT-platform can identify energy efficiency opportunities and manage peak load in commercial buildings. There are also two secondary goals: 1) show that the energy efficiency solutions will result in identification of significant savings (10% to 30%) opportunities as well as energy cost reductions (10% to 15%) by managing the peak load in commercial buildings, and 2) show that an IoT-based software solution is more cost-effective in meeting the Re-tuning mandates than traditional retro commissioning (RCx) and there is a pathway for broader adoption of this approach. This report details how the field evaluation will be conducted, including what enhancements will be made to the software technologies, how PNNL will recruit energy service providers, types of buildings where the technology will be evaluated, metric of success for the field evaluation, and how the metric of success will be measured.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

A methodology for generating reduced-order models for large-scale buildings using the Krylov subspace method

Developing a computationally efficient but accurate building energy simulation (BES) model is important for many purposes. Model order reduction (MOR) methods are attractive and much more reliable than identification approaches, since it directly extract a lower-dimensional model from a detailed physics-based model without any pre-simulations. However, because of computational and data storage requirements, there are challenges of applying these methods to a large-scale building. To overcome the problem, this work introduces the Krylov subspace method to the building science field. Technical issues of applying the method to building applications are addressed and a suitable algorithm that overcomes those challenges is presented. Furthermore, to demonstrate the reliability of the algorithm, comparisons between the resulted reduced-order model (ROM) and a high-fidelity model from a commercial BES software for a 60-zone case study building are provided. The ROM was a factor of 100 faster than the high fidelity model but with high accuracy.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

How Do Electricity Pricing Programs Impact the Selection of Energy Efficiency Measures? - A Case Study with U.S. Medium Office Buildings

Building owners usually select energy efficiency measures (EEMs) by referring to return on investment (ROI). Current studies tend to apply static energy price to estimate ROI. However, more and more buildings are adopting dynamic electricity pricing programs. To understand how electricity pricing programs impact the selection of EEMs, this paper presents an analysis of the ROIs of EEMs under different pricing programs using U.S. medium office buildings as an example. Eight EEMs in four typical cities are selected as case studies. Considering five electricity pricing programs scenarios (one static program and four dynamic programs), EEMs are selected based on their ROIs. The main findings are: (1) The ROIs of EEMs change under different pricing programs. (2) In Honolulu, Buffalo, and Denver, replacing interior fixtures with higher-efficiency fixtures has a significantly higher ROI than the rest EEMs under all five pricing programs. However, the ROI of this EEM in Honolulu ranges from 28% to 47% for different pricing programs. (3) Similarly, in Fairbanks, replace heating coil with higher-efficiency coil produce higher ROI than the rest under all five pricing programs. (4) For other EEMs, their ROI rankings vary according to electricity pricing programs.

demand response↗

Optimizing Price-Informed Operation of a Battery Storage System in an Office Building

New prescriptive efficiency requirements amended to US model energy codes historically have been evaluated using an average, blended electricity rate, which obscures demand charges. Post 2019, new measures can be evaluated using a representative time-of-use (TOU) tariff yet more sophisticated analysis methods are needed to consider a variety of TOU tariffs and assess price-informed control. To address these needs, this study couples building prototype simulation model with varying-in-sophistication battery storage operating strategies for different electricity TOU tariffs. The analysis compares the impact of operating a battery storage system following simpler rule-of-thumb methods versus a semi-optimized priced-informed heuristic approach. The investigation demonstrates that the heuristic approach results in greater electricity cost savings and is practical to implement.

Lei, Xuechen↗

Measuring Impact: Evaluating Thermal Zoning Simplification on Energy Efficiency Measures Analysis

Building Energy Modeling (BEM) is a versatile tool for designing, retrofitting, ensuring code compliance, obtaining certifications, qualifying for incentives, and enabling real-time building control. However, capturing all the details of building geometry for thermal zoning can be time-consuming, costly, and sometimes computationally challenging. As a result, modelers have been applying zoning simplification based on factors such as space functions and internal loads, as well as relying on their experience and judgment while adhering to zoning rules outlined in industry standards. Despite the prevalence of this common practice, a notable gap exists in the literature regarding studies quantifying the influence of simplified thermal zoning on the evaluation of Energy Efficiency Measures (EEMs). Recognizing this gap, this paper seeks to contribute to the field by enhancing the understanding of how the simplification of thermal zoning influences the evaluation of EEMs against a baseline design. The study utilized a medium office prototype model with a detailed floor plan featuring over 20 zones per floor covering diverse functional spaces with varying internal loads and occupancy schedules. A standard thermal zoning strategy outlined in ASHRAE Standard 90.1 Appendix G was employed as the simplified zoning method. This strategy condenses the zoning into a core zone and four perimeter zones per floor. It was compared with the detailed zoning approach, which involves one zone per space. Common Energy EEMs, such as enhanced envelope, high-efficiency appliances and equipment, and HVAC controls, were individually implemented and evaluated. The results indicate that the performance comparison between the two zoning methods varies depending on the type of measures considered. Basic measures, such as adding wall insulation, demonstrate similar energy impacts, while advanced HVAC control measures, such as static pressure reset, exhibit a more substantial difference that cannot be overlooked.

Xie, Jiarong↗

A Guide for Creating a Building-Level Action Plan to Improve Energy Efficiency and Reduce Carbon Emissions

Action plans are tools for commercial building owners to create pathways for reducing energy use and decarbonize, hence reducing carbon emissions. This template and associated direction manual provides a method for creating an action plan. Originally created for the Better Buildings Low Carbon Pilot, it can also be applied to the Better Buildings Climate Challenge and for any building owner striving towards lower carbon footprints.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Efficiency and Demand Flexibility in Large Office Buildings: The Potential for Cost Savings and CO 2 Reductions from Lighting and Cooling Measures

This report presents the estimated impact of lighting and cooling efficiency and demand flexibility measures in large office buildings in each state in the contiguous United States. It provides modeled results for three different metrics: bill savings, regional grid operational costs savings, and carbon dioxide (CO 2 ) emissions reductions. Lighting efficiency and demand flexibility are estimated to reduce load by up to 80 MWh/yr in a single large office building. These load reductions result in customer bill savings of up to $8,800/yr per building, with the highest savings in southern and midwestern states. Grid operating cost savings are estimated at up to $3,240/yr/building, with greatest benefit in southern and northeastern states. CO 2 emissions reduction potential is highest in the Dakotas, Nebraska, across the Midwest, in West Virginia, and in Mississippi (<48,200 kg/yr/building). Comparatively, cooling measures are found to have less load reduction potential (<28.5 MWh/yr/building), with the greatest potential in southern states including Texas, which ranks top of the list across several of the metrics studied. In numerous states, shifting cooling load to off-peak hours is found to increase costs and CO 2 emissions because precooling results in increased load during high-cost or high-CO 2 emissions periods. In general, focusing on cooling efficiency and load shedding has the potential for more savings. In all cases, the specific rate structure is a significant determinant in actual bill savings, which are up to $4,000/yr/building. To realize the full potential for bill savings through an energy measure, building operators must identify how the measure will change the building load pattern and the interaction of this load change with the applicable rate tariff. To realize CO 2 emissions reductions, industry and state coordination is needed to verify which fuel source is on the margin and then to create incentives for end users to reduce load during high-CO 2 emissions hours. Regular updates to data sets and analyses are critical. Regulators and policymakers are well positioned to facilitate the necessary coordination between the electric industry and building energy managers to develop appropriate price signals and incentives.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

A product data network to enable faster, easier, and better planning of building envelopes

The building envelopes contributes significantly to the energy-efficiency of the building. Building performance simulation has made it possible to compare façade technologies regarding energy demand, daylighting, thermal and visual comfort in detail. Planners, such as architects and engineers, need experience to find product data with the right quality and level of detail, and to process the data to fit the calculation and the application. In the available time, planners can compare only a limited number of products, which means that better solutions could go unnoticed. This paper presents a new concept for making product data easily accessible for building façade planning. The concept consists of a network of databases for the efficient exchange and use of optical and calorimetric data of glazing units, shading devices, and combinations of both. The paper presents the research questions, an analysis of the current challenges, six design goals for the product data network and its implementation together with a discussion. Many product data sources can be connected to many planning software applications via the specified application programming interface. When planning software connects to the product data network, the planning of building envelopes can be much faster because planners do not need to spend so much time to search and process product data manually. The planning of building envelopes can also become much easier, especially for planners with limited experience. They do not need to understand all the details about which data fits which calculation if the software company implements this. The planning of building envelopes can become much more reliable when software companies validate their use of the product data network, because the current manual process is prone to errors. The planning of building envelopes can also improve because more products can be compared in the available time, allowing better solutions to be found.

Maurer, Christoph↗