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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.

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At least 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

Reduced-Gravity Simulator for Field Environments - Drone Augmented System

Astronauts need to go through extensive training on Earth before heading into space, and the more accurate the analogue, the better prepared they will be. NASA currently trains astronauts in simulated lower gravity environments in either the Neutral Buoyancy Laboratory or the Active Response Gravity Offload System (ARGOS), but neither of these systems allow for testing outdoors in field environments. NASA, in partnership with Aquiline Drones, mechanical engineering, biomedical engineering, and the Krenicki Arts and Engineering Institute, are working to develop a gravity offload device compatible with testing in field environments such as Desert Research and Technology Studies (Desert RATS). This report covers the technical requirements of the gravity offload device, the design choices and justifications, options for scalability, current progress, and future goals. Two separate teams were formed to respond to NASA’s solicitation, and this report covers the work of the weather balloon and drone side of the project. Using a weather balloon to passively offload the user’s weight and a drone to actively respond to changes using a series of sensors, this system should create a consistent and well balanced offloading force. The weather balloon and drone system is connected to a harness system to comfortably lift the user, offload at their center of gravity, and provide attachment points for some of the necessary sensors. Final testing proved the comfort of the harness, mobility of the user, and passive stability of the balloon offload to exceed all expectations of the team. The current system is a scaled model of what NASA would be able to implement with a maximum offload of 25 pounds. The ability to scale up to NASA’s desired value of 100 pounds is easily achievable with linear scaling of the current model. All systems should work similarly on scaled versions, but minor tweaking and enhanced controls would be needed for optimal performance.

Jason Lee↗
NASA NTRS2022

A Dynamic Nonlinear Subgrid-Scale Model for Large-Eddy Simulation of Complex Turbulent Flows

We present a new dynamic nonlinear subgrid-scale (SGS) model for large-eddy simulations (LES) and apply it to compute a flow involving pressure gradients, surface curvature and separation, for which data from a direct numerical simulation are available for comparison. The model, inspired by the triple model idea of Bardina et al. (“Improved Turbulence Models Based on Large Eddy Simulation of Homogeneous, Incompressible, Turbulent Flows,” Report No. TF-19, Thermosciences Division, Department of Mechanical Engineering, Stanford University, 1983), includes a Galilean-invariant term called the modified Leonard stress tensor, and two nonlinear terms comprised of the products of the strain-rate and rotation-rate tensors for an improved representation of the subgrid-scale dissipation, backscatter and anisotropy effects. The model does not employ any ad hoc averaging or clipping procedures, and does not require the specification of a characteristic length scale; hence, it naturally avoids the ambiguities associated with defining a proper length scale for anisotropic grids. Results from the wall-resolved LES of flow past a Gaussian bump using the new model demonstrate improved prediction of skin-friction, flow separation, mean flow profiles and turbulent quantities when compared to implicit LES as well as explicit LES using the Vreman SGS model on the same grid.

Turbulence↗
NASA NTRSDate not supplied

Corrected Recursive Equations for Vane Aperture Sizes and Locations in One- and Two-Stage Stray Light Baffle Systems

Front-end stray light baffles for optical imaging systems are used to limit the amount of out-of-field light that reaches the entrance pupil of the optical system. From star tracker baffles to the outer barrel of the Hubble Space Telescope, it is vital to design the locations and apertures of baffle vanes so that the inner walls of the baffle are not simultaneously visible to both stray light sources and the optical entrance pupil. Various designs have been presented for arbitrary cylindrical baffle tubes and explicitly specified conical tubes, but no working generalized algorithm has been presented where the baffle tube can take an arbitrary conical form. Haghshenas and Johari presented what should be a working recursive algorithm, but the published equations have two errors that result in incorrect output. Corrections to their equations are presented here. Additionally, tolerancing in the field of baffle design has typically been accomplished by slightly increasing the field-of-view of the baffle system to avoid clipping the optical field due to mechanical tolerance errors. A new way of incorporating fabrication, alignment, and environmental tolerancing is presented that is more consistent with typical mechanical engineering practice. Furthermore, it is included in the recursive equations with some demonstration of their impact.

tolerance↗
NASA NTRSDate not supplied

Corrected Recursive Equations for Vane Aperture Sizes and Locations in One- and Two-Stage Stray Light Baffle Systems

Front-end stray light baffles for optical imaging systems are used to limit the amount of out-of-field light that reaches the entrance pupil of the optical system. From star tracker baffles to the outer barrel of the Hubble Space Telescope, it is vital to design the locations and apertures of baffle vanes so that the inner walls of the baffle are not simultaneously visible to both stray light sources and the optical entrance pupil. Various designs have been presented for arbitrary cylindrical baffle tubes and explicitly specified conical tubes, but no working generalized algorithm has been presented where the baffle tube can take an arbitrary conical form. Haghshenas and Johari presented what should be a working recursive algorithm, but the published equations have two errors that result in incorrect output. Corrections to their equations are presented here. Additionally, tolerancing in the field of baffle design has typically been accomplished by slightly increasing the fieldof-view of the baffle system to avoid clipping the optical field due to mechanical tolerance errors. A new way of incorporating fabrication, alignment, and environmental tolerancing is presented that is more consistent with typical mechanical engineering practice and margin against those fabrication errors is included in the recursive equations with demonstration of their benefit.

Stray light↗
DOE OSTI2020

Update on the United States Advanced Ultra-Supercritical Program with Full Scale Component Fabrication to Develop Utility Scale Power Plants with 760°C Steam Temperature

Following the successful completion of a 15-year effort to develop and test materials that would allow coal-fired power plants to be operated at advanced ultra-supercritical (A-USC) steam conditions, a United States-based consortium is presently engaged in Phase 2 of a project which includes an advanced manufacturing effort to complete US-based supply chain development for full commercial scale (800-850 MWe) A-USC components made of nickel-based alloys, components operating at up to 760°C. The project, funded under U.S. Department of Energy Award No. DE-FE0025064, falls under the US DOE overall goal to Develop cost-effective, reliable technologies to improve the efficiency of new and existing coal-fired power plants. A-USC steam cycles have the potential to improve cycle efficiency, reduce fuel costs, and reduce greenhouse gas emissions. Current development and demonstration efforts are focused on enabling the construction of A-USC plants, operating with steam temperatures as high as 1400°F (760°C) and steam pressures up to 5000 psi (35 MPa), which can potentially increase cycle efficiencies to 47% HHV (higher heating value), or approximately 50% LHV (lower heating value), and reduce CO 2 emissions by roughly 25%, compared to today’s U.S. fleet. A-USC technology provides a lower-cost method to reduce CO 2 emissions, compared to CO 2 capture technologies, while retaining a viable coal option for owners of coal generation assets. Among the specific goals of Phase 2 of the ComTest Project are to: validate that components made from advanced nickel-based alloys can operate and perform under A-USC conditions accelerate the development of a U.S.-based supply chain for the full complement of A-USC components close the remaining gaps and reduce the risks for manufacturing components from advanced materials for commercial demonstration fabricate full-scale versions of selected key components made of nickel-based alloys validate a qualified U.S. supply chain, to provide greater cost certainty for components obtain American Society of Mechanical Engineers (ASME) code approval for new materials, components and processes Additional benefit: Manufacturing technology will be applicable to other advanced fossil energy high temperature cycles, and can support increased flexibility of existing power plants The ComTest project is managed by Energy Industries of Ohio, and technically directed by the Electric Power Research Institute, Inc., with General Electric designing the A-USC components. As stated earlier, the current phase of the effort is primarily funded by the U.S. Department of Energy, through the National Energy Technology Laboratory. This presentation outlines the motivation for the project, explains the project’s structure and schedule, and provides some of the technical details on the design of the ComTest components.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2020

Update on the United States Advanced Ultra-Supercritical Program with Full Scale Component Fabrication to Develop Utility Scale Power Plants with 760°C Steam Temperature

Following the successful completion of a 15-year effort to develop and test materials that would allow coal-fired power plants to be operated at advanced ultra-supercritical (A-USC) steam conditions, a United States-based consortium is presently engaged in Phase 2 of a project which includes an advanced manufacturing effort to complete US-based supply chain development for full commercial scale (800-850 MWe) A-USC components made of nickel-based alloys, components operating at up to 760°C. The project, funded under U.S. Department of Energy Award No. DE-FE0025064, falls under the US DOE overall goal to Develop cost-effective, reliable technologies to improve the efficiency of new and existing coal-fired power plants. A-USC steam cycles have the potential to improve cycle efficiency, reduce fuel costs, and reduce greenhouse gas emissions. Current development and demonstration efforts are focused on enabling the construction of A-USC plants, operating with steam temperatures as high as 1400°F (760°C) and steam pressures up to 5000 psi (35 MPa), which can potentially increase cycle efficiencies to 47% HHV (higher heating value), or approximately 50% LHV (lower heating value), and reduce CO 2 emissions by roughly 25%, compared to today’s U.S. fleet. A-USC technology provides a lower-cost method to reduce CO 2 emissions, compared to CO 2 capture technologies, while retaining a viable coal option for owners of coal generation assets. Among the specific goals of Phase 2 of the ComTest Project are to: validate that components made from advanced nickel-based alloys can operate and perform under A-USC conditions accelerate the development of a U.S.-based supply chain for the full complement of A-USC components close the remaining gaps and reduce the risks for manufacturing components from advanced materials for commercial demonstration fabricate full-scale versions of selected key components made of nickel-based alloys validate a qualified U.S. supply chain, to provide greater cost certainty for components obtain American Society of Mechanical Engineers (ASME) code approval for new materials, components and processes Additional benefit: Manufacturing technology will be applicable to other advanced fossil energy high temperature cycles, and can support increased flexibility of existing power plants The ComTest project is managed by Energy Industries of Ohio, and technically directed by the Electric Power Research Institute, Inc., with General Electric designing the A-USC components. As stated earlier, the current phase of the effort is primarily funded by the U.S. Department of Energy, through the National Energy Technology Laboratory. This presentation outlines the motivation for the project, explains the project’s structure and schedule, and provides some of the technical details on the design of the ComTest components.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2020

Status of INL Aged A709 Mechanical Testing

A709 was selected to be qualified in Section III, Division 5 of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code. Idaho National Laboratory (INL), Argonne National Laboratory and Oak Ridge National Laboratory are collaborating to develop and qualify A709 plate. Aging A709 to form beneficial precipitates prior to service is investigated. One tensile test, five creep-rupture tests, and eight cyclic tests have been completed on aged A709. Two creep-rupture tests are in progress.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Effects of Notches on the Intermediate Creep-Rupture Life of Alloy 617 Weldment

A Code Case has recently been completed that adds Alloy 617 to Section III, Division 5 of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, which covers high temperature nuclear components. However, additional information is needed to address concerns raised by the Nuclear Regulatory Commission that are not covered by the Code Case. The effects of notches (geometric discontinuities) and multiaxial stress on the expected creep life of a component are among these concerns. This report covers the current state of testing of Alloy 617 notched specimens at Idaho National Laboratory, with particular focus on intermediate length (8,000 – 20,000 hours) creep tests of Alloy 617 weld metal. While most of this testing is ongoing, the current state of the tests indicate that the multi-axial stress state imposed by the notch geometry does not negatively impact the creep rupture life of the Alloy 617 weld metal. While the weld metal is notch strengthening in short-term (1,000 – 2,000 hours) testing, it is not clear if this characteristic will continue to hold for intermediate and long-term testing. Ongoing tests will provide additional information to address this concern of a crossover from notch strengthening to notch weakening for intermediate and long-term creep lives.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Report Documenting Activity for Second Alloy 709 Commercial Heat

SUMMARY Qualification of the advanced austenitic stainless steel material Alloy 709 for use in Section III Division 5 of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code is being pursued by the US Department of Energy Advanced Reactor Technology Program. Qualification of this alloy will allow its use in design and construction of components for elevated temperature nuclear reactor systems. Code qualification requires extensive characterization of three commercial scale heats of the alloy. This report describes progress in procuring the second of three required heats of Alloy 709 plate from ATI Flat Rolled Products.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Long Reach Robotic Arm

The Accelerator Division at Fermilab began a robotics program, known as the AD Robotics Initiative. A multi-axis robotic arm was proposed to be included in the program. This summer internship, our team began the planning and design for this project, called the Long Reach Robotic Arm. The problem is that critical systems around the magnets require analysis when water leaks cause them to fail. However, the tightly compacted parts and the quadrupole magnet, weighing approximately 1,000 pounds, cause access viewing problems. The process of having to dismantle and remove the magnet is time-consuming; it is not an efficient solution. The goal for the Long Reach Robotic Arm was to extend and reach behind the component of the Main Injector while "snaking" around and avoiding obstructions. At the start of the project, my teammate, Amanda Hoeksema, and I coded a program in the C language that will determine the number of links and their respective lengths for the robot arm. After, we began the 3D CAD model of the robot arm, base, and counterweight system. The design of the Long Reach Robotic Arm provided a learning experience in learning how to code in the C programming language, using SDL libraries and understanding mechanical engineering.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Integrated FY21 Elevated Temperature Mechanical Testing Results for Alloy 709 Code Case

This report provides the status of creep, fatigue, and creep-fatigue testing that transpired in Fiscal Year 2021 at Argonne National Laboratory, Idaho National Laboratory and Oak Ridge National Laboratory. This testing is being conducted to develop the data package to qualify Alloy 709 in Section III, Division 5 of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code. This would permit the use of Alloy 709 for elevated-temperature nuclear construction. Preliminary results continue to demonstrate the improved creep and fatigue resistance of Alloy 709 compared to 316H stainless steel.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Recommendation for Limiting Conditions for ASME BPVC Section III Division 5 Allowable Stress Criteria

Section III, Division 5 of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) specifies rules for elevated temperature nuclear reactors. Time dependent allowable stresses are an important aspect of the high temperature design models and are related to the time to 1% strain, time to rupture, and time to onset of tertiary creep. The time to onset of tertiary creep criterion has an overly strong negative influence on the allowable stresses for some structural materials, likely due to very limited datasets and misidentification of microstructural changes rather than onset of significant creep damage, as tertiary creep is meant to represent. It is recommended that the onset of tertiary creep be determined through an alloy specific ratio between onset of tertiary creep and creep rupture time, which would give access to the significantly larger creep rupture time datasets.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Assessment of Overmatched Filler (Alloy 617) to Improve Alloy 800H Stress Rupture Factors

Section III, Division 5 of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) specifies rules for elevated temperature nuclear reactors. Currently, only six metals are qualified in Section III, Division for construction of Class A metallic pressure boundary components for elevated-temperature service, one of these being Alloy 800H. There are only two permissible filler metals Alloy 800H is qualified to be welded with: Alloy A and Alloy 82. The stress rupture factors for these two filler metals are low near the maximum temperatures and service lives Alloy 800H is qualified for. This may preclude vendors from being able to use Alloy 800H for elevated-temperature nuclear construction. In this work, an overmatched filler metal, Alloy 617 is assessed to determine its potential to offer improved stress rupture factors. Scoping creep-rupture tests of cross-welds with Alloy 800H base metal and Alloy 617 filler metal were conducted. Preliminary results do not indicate that Alloy 617 will offer significantly improved stress rupture factors. Consequently, a matching filler metal, UTP A 2133, is now being investigated.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

Environmental and Energy Research at the Texas Center for Advanced Scientific Computing and Modeling (CASCaM)

The funding enabled the creation of the (University of North) Texas Center for Advanced Scientific Computing and Modeling (CASCaM). Due to its success, CASCaM has continued to grow beyond the initial team focused on the biological and environmental research discussed herein, with investments by the University of North Texas in new faculty and researchers who contribute to CASCaM research. CASCaM is now a sustainable effort, with researchers across multiple fields including chemistry, physics, biology, mechanical engineering, materials science, and other fields, with multiple researchers engaged in a broad variety of research, including other DOE projects. Over 20 PI’s and ~100 researchers are engaged in CASCaM research. The overall goal of the research effort was to provide greater understanding about carbon capture, storage, and utilization. As part of this effort, the development of computational methods and identification of novel strategies to support the CO2 and CO studies were necessary. Three primary themes were investigated: carbon dioxide and CO catalysis; protein- and amino acid-based strategies towards carbon dioxide capture, storage, and utilization; and, finally, the methodology improvements for modeling carbon dioxide chemistry

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Treatment Technology Assessment for Landfill Leachate

This presentation by NETL was given at the 2022 American Society of Mechanical Engineers conference in Pittsburgh, PA (July 18-21, 2022). The presentation gives an overview of an analysis of wastewater emissions associated with coal combustion residual leachate, including constituents present, variability according to coal type burned at the plant, national estimates of total volume of wastewater that requires treatment, and the cost to treat.

Able, Chad↗
DOE OSTI2022

Treatment Technology Assessment for Landfill Leachate (Video)

This presentation by NETL was given at the 2022 American Society of Mechanical Engineers conference in Pittsburgh, PA (July 18-21, 2022). The presentation gives an overview of an analysis of wastewater emissions associated with coal combustion residual leachate, including constituents present, variability according to coal type burned at the plant, national estimates of total volume of wastewater that requires treatment, and the cost to treat.

Able, Chad↗
DOE OSTI2022

NNSS Student Outreach Presentation

Student outreach presentation for recruitment at Texas Tech University in Lubbock, Texas. Specific interest in recruiting pulsed power and mechanical engineers.

42 ENGINEERING↗