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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 379 records · Page 21

Core/Combustor-Noise Baseline Measurements for the DGEN Aeropropulsion Research Turbofan

Contributions from the combustor to the overall propulsion noise of civilian transport aircraft are starting to become important due to turbofan design trends and advances in mitigation of other noise sources. Future propulsion systems for ultra-efficient commercial air vehicles are projected to be of increasingly higher bypass ratio from larger fans combined with much smaller cores, with ultra-clean burning fuel-flexible combustors. Unless effective noise-eduction strategies are developed, combustor noise is likely to become a prominent contributor to overall airport community noise in the future. The new NASA DGEN Aeropropulsion Research Turbofan (DART) is a cost-efficient testbed for the study of core-noise physics and mitigation. This paper describes the recently completed DART core/combustor-noise baseline test in the NASA GRC Aero-Acoustic Propulsion Laboratory (AAPL). Acoustic data was simultaneously acquired using the AAPL overhead microphone array in the engine aft quadrant far field, a single midfield microphone, and two semi-infinite-tube unsteady pressure sensors at the core-nozzle exit. Combustor-noise components of measured total-noise signatures were educed using a two-signal source-separation method and are found to occur in the expected frequency range. The acoustic data compares well with results from a limited 2014 feasibility test and will serve as a high-quality baseline for future research using the DART. The research described herein is aligned with the NASA Ultra-Efficient Commercial Transport strategic thrust and is supported by the NASA Advanced Air Vehicle Program, Advanced Air Transport Technology Project, under the Aircraft Noise Reduction Subproject.

Aeroacoustics↗

HabEx Baseline Optical Telescope Assembly

The Habitable Exoplanet Observatory Mission (HabEx) will image and spectroscopically characterize planetary systems in the habitable zone around nearby sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by 100 to 2500 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving the HabEx science goals is a large, ultra-stable telescope. The baseline HabEx telescope is a 4-m off-axis unobscured three-mirror-anastigmatic design with diffraction limited performance at 400 nm and wavefront stability of picometers per mK. These specifications are driven by science requirements. STOP (structural thermal optical performance) analysis predicts that the baseline telescope’s opto-mechanical design meets its specified performance tolerances.

Stahl, H Philip↗

Technology Development Roadmap for Habitable-Zone Exoplanet Observatory (HabEx) Baseline 4-M Primary Mirror

The Habitable Exoplanet Observatory (HabEx) is one of four mission concepts under study for the 2020 Astrophysics Decadal Survey. Its goal is to directly image and spectroscopically characterize planetary systems in the habitable zone around nearby sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by 115 to 2500 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving the HabEx science goals is a large, ultra-stable UV/Optical/Near-IR (UVOIR) telescope. The baseline HabEx telescope is 4-meter off-axis unobscured, diffraction limited at 400 nm with wavefront stability on the order of a few 10s of picometers. The technology readiness level (TRL) to manufacture and test the HabEx baseline primary mirror is assessed to be at TRL-6 for all but two TRL-4 technologies: 1) non-destructive process to quantify CTE homogeneity of a 4-m mirror substrate with a spatial sampling of at least 100 x 100 to better than +/- 1 ppb/K; and, 2) process to quantify self-weight gravity deflection to better than 4-nm rms over a 100 x 100 spatial sampling. This paper reviews the technology needs to manufacture the HabEx primary mirror, assesses their TRL and proposes a roadmap to mature the two remaining technologies to TRL-6.

Space Telescope Technology↗

Summary DSG-RQMT-004, Gateway Electromagnetic Environmental Effects (E3) Requirements Document, Initial Baseline

The Baseline Readiness Review presentation for DSG-RQMT-004 at a high level summarizes the differences between the originating standards (publicly available) and the Gateway-tailored standards (publicly available per DAA 72653). All data in the presentations are either derived from either MIL-STD-461G, SSP 30237, or SL-E-002 (Shuttle EMI spec). The Baseline Readiness Review presentation identifies why a tailored standard was necessary for Gateway (summarizes the changes made from the originating standard). Communicating this information should lead to IP and vendor Level 3 responders proposing substitute standards more in line with the Gateway requirements.

MIL-STD-464↗

HabEx Baseline Telescope: Design & Predicted Performance

Habitable Exoplanet Observatory Mission (HabEx) will image & spectroscopically characterize planetary systems in the habitable zone around nearby sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by a 150 to 1700 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving the HabEx science goals is a large, ultra-stable telescope. The baseline HabEx telescope is a 4-m off-axis unobscured three-mirror-anastigmatic design with diffraction limited performance at 400 nm and wavefront stability of picometers per mK. These specifications are driven by science requirements. STOP (structural thermal optical performance) analysis predicts that the baseline telescope’s opto-mechanical design meets its specified performance tolerances.

Stahl, H. Philip↗

Summary DSG-RQMT-007, Initial Baseline

The Baseline Readiness Review presentations for DSG-RQMT-007 at a high level summarizes the differences between the originating standards (publicly available) and the Gateway-tailored standards (publicly available per DAA 72653). All data in the presentations are either derived from either MIL-STD-461G, SSP 30237, or SL-E-002 (Shuttle EMI spec). The Baseline Readiness Review presentation identifies why a tailored standard was necessary for Gateway (summarizes the changes made from the originating standard). Communicating this information should lead to IP and vendor Level 3 responders proposing substitute standards more in line with the Gateway requirements.

MIL-STD-461↗

Stowage Assessment of the Common Habitat Baseline Variants

This paper performs a stowage assessment of the four baseline variants of the Common Habitat, a SLS-derived long duration, multi-mission habitat. The Common Habitat can be utilized as a lunar surface outpost, a Mars surface outpost, or an in-space habitat for Mars transit flights. The paper will discuss the stowage philosophy applied to all baseline variants of the Common Habitat and will discuss the approaches taken to domain-specific stowage, bulk stowage, and fluid and gas stowage. Water and air stowage for the closed loop ECLS subsystem is described across the four variants. Stowage of other supplies, consumables, and equipment is also described across the four variants and based on logistics sizing studies, a self-contained mission endurance is predicted for each variant – e.g. how long a mission each can support without a docked logistics module. Finally, follow-on assessments, including a habitability evaluation, are discussed along with specific stowage issues relevant to these assessments.

Deep space habitat↗

The Origins Space Telescope: Trades and Decisions Leading to the Baseline Mission Concept

The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the universe today? How do habitable planets form? How common are life-bearing worlds? We describe how Origins was designed to answer these alluring questions. We discuss the key decisions taken by the Origins mission concept study team, the rationale for those choices, and how they led through an exploratory design process to the Origins baseline mission concept. To understand the concept solution space, we studied two distinct mission concepts and descoped the second concept, aiming to maximize science per dollar and hit a self-imposed cost target. We report on the study approach and describe the concept evolution. The resulting baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. The chosen architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch. The cryo-thermal system design leverages JamesWebb Space Telescope technology and experience.

Infrared↗

The Origins Space Telescope: Baseline Mission Concept

The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate atmid- and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20 μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588 μm, making wide-area and deep spectroscopic surveys with spectral resolving power R ∼ 300, and pointed observations at R ∼ 40;000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins’ natural background-limited sensitivity.

David Leisawitz↗

Design and Predicted Performance of 4-m Baseline Habitable-Zone Exoplanet Observatory Telescope

The Habitable Exoplanet Observatory Mission (HabEx) is one of four missions which NASA is studying. Its goal is to directly image and spectroscopically characterize planets in the habitable zone around nearby sun-like stars. Additionally, HabEx would perform a broad range of general astrophysics science enabled by 115 to 1700 nm spectral range and 3x3 arc-minute FOV instruments. Critical to achieving its science goals is a large, ultra-stable UV/Optical/Near-IR (UVOIR) telescope. The baseline HabEx telescope is a 4-meter off-axis unobscured three-mirror-anastigmatic, diffraction limited at 400 nm with wavefront stability on the order of a few 10s of picometers. This paper summarizes how science driven systems engineering (using science requirements to derive engineering specifications) resulting in the opto-mechanical design of the HabEx baseline optical telescope assembly. And, how Structural Thermal Optical Performance (STOP) modeling predicts tolerance compliance.

H Philip Stahl↗

Normative Baseline Oculomotor Performance

Future missions to the moon or Mars will require the crew to monitor and assess their health and performance more autonomously, necessitating approaches that are easily useable and interpretable by non-clinicians. The eye-movement-based performance metrics (oculometrics) obtained from NASA-patented technology developed at the Visuomotor Control Laboratory can reliably detect and discriminate the source of mild neural impairment relative to an individual’s baseline visual and sensorimotor performance and can predict performance in manual control tasks. This study aims to develop a database of normative performance that can be used to enable the detection of impairment without a within-subject baseline and to facilitate power analyses for the design of future studies.

eye movements↗

Analysis and Optimization of Baseline Single Aisle Aircraft for Future Electrified Powertrain Flight Demonstrator Comparisons

The purpose of this study is to provide baseline single-aisle vehicles for future comparisons NASA’s Electrified Powertrain Flight Demonstrator (EPFD) turbofan powered Vision Systems. Both a large single-aisle (≈150 passenger) and a small single-aisle (≈100 passenger) vehicle will be analyzed using NASA’s General Aviation Synthesis Program and a modernized Python-based version of this program that enables efficient gradient-based optimization of both the airframe and propulsion that currently is being referred to as GASPy. A technology build-up will be conducted to bring the current State-of-the-art vehicles to a projected 2035 technology level by incorporating estimations for improvements in aerodynamics, structures, and propulsions. These vehicles can be used in NASA’s future EPFD project as baselines to measure the benefits of future hybrid and fully electric aircraft against. The advanced, large single-aisle will then be used to demonstrate the benefits of a coupled engine-airframe optimization for fuel burn reduction.

Carl J Recine↗

Status of the nuSTORM Facility and a Possible Extension for Long-Baseline $\nu$ Oscillation Experiments

Neutrino beams produced from the decay of muons in a racetrack-like decay ring (the so called Neutrino Factory) provide a powerful way to study neutrino oscillation physics and, in addition, provide unique beams for neutrino interaction studies. The Neutrinos from STORed Muons (nuSTORM) facility uses a neutrino factory-like design. Due to the particular nature of nuSTORM, it can also provide an intense, very pure, muon neutrino beam from pion decay. This so-called “Neo-conventional" muon neutrino beam from nuSTORM makes nuSTORM a hybrid neutrino factory. In this paper we describe the facility and give a detailed description of the neutrino beam fluxes that are available and the precision to which these fluxes can be determined. We then present sensitivity plots that indicated how well the facility can perform for short-baseline oscillation searches and show its potential for a neutrino interaction physics program. Finally, we comment on the performance potential of the "Neo-conventional" muon neutrino beam optimized for long- baseline neutrino-oscillation physics.

43 PARTICLE ACCELERATORS↗

2016 Annual Technology Baseline (ATB) - Webinar Presentation

This deck was presented for the 2016 Annual Technology Baseline Webinar. The presentation describes the Annual Technology Baseline, which is a compilation of current and future cost and performance data for electricity generation technologies.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

A model for manuscript submitted to the nth IIR conference on overview of the long-baseline neutrino facility cryogenic system

The Deep Underground Neutrino Experiment (DUNE) collaboration is developing a multi-kiloton Long-Baseline neutrino experiment that will be located one mile underground at the Sanford Underground Research Facility (SURF) in Lead, SD. In the present design, detectors will be located inside four cryostats filled with a total of 68,400 ton of ultrapure liquid argon, at the level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) is developing the conventional facilities and cryogenics infrastructure supporting this experiment. The cryogenics system is composed of several sub-systems: External/Infrastructure, Proximity, and Internal cryogenics. It will be engineered, manufactured, commissioned, and qualified by an international engineering team. This contribution highlights the main features of the LBNF cryogenic system. It presents its performance, functional requirements and modes of operations. As a result, it also details the status of the design, present and future needs.

43 PARTICLE ACCELERATORS↗

Design of the cryogenic systems for the Near and Far LAr-TPC detectors of the Short-Baseline Neutrino program (SBN) at Fermilab

The Short-Baseline Neutrino (SBN) physics program at Fermilab and Neutrino Platform (NP) at CERN are part of the international Neutrino Program leading to the development of Long-Baseline Neutrino Facility/Deep Underground Neutrino Experiment (LBNF/DUNE) science project. The SBN program consisting of three Liquid Argon Time Projection Chamber (LAr-TPC) detectors positioned along the Booster Neutrino Beam (BNB) at Fermilab includes an existing detector known as MicroBooNE (170-ton LAr-TPC) plus two new experiments known as SBN’s Near Detector (SBND, ~260 tons) and SBN’s Far Detector (SBN-FD, ~760 tons). All three detectors have distinctly different design of their cryostats thus defining specific requirements for the cryogenic systems. Fermilab has already built two new facilities to house SBND and SBN-FD detectors. The cryogenic systems for these detectors are in various stages of design and construction with CERN and Fermilab being responsible for delivery of specific sub-systems. This contribution presents specific design requirements and typical implementation solutions for each sub-system of the SBND and SBN-FD cryogenic systems.

43 PARTICLE ACCELERATORS↗

Laboratory-based validation of the baseline sensors of the ITER diagnostic residual gas analyzer

The divertor-specific ITER Diagnostic Residual Gas Analyzer (DRGA) will provide essential information relating to DT fusion plasma performance. This includes pulse-resolving measurements of the fuel isotopic mix reaching the pumping ducts, as well as the concentration of the helium generated as the ash of the fusion reaction. In the present baseline design, the cluster of sensors attached to this diagnostic's differentially pumped analysis chamber assembly includes a radiation compatible version of a commercial quadrupole mass spectrometer, as well as an optical gas analyzer using a plasma-based light excitation source. This paper reports on a laboratory study intended to validate the performance of this sensor cluster, with emphasis on the detection limit of the isotopic measurement. This validation study was carried out in a laboratory set-up that closely prototyped the analysis chamber assembly configuration of the baseline design. This includes an ITER-specific placement of the optical gas measurement downstream from the first turbine of the chamber's turbo-molecular pump to provide sufficient light emission while preserving the gas dynamics conditions that allow for \textasciitilde 1 s response time from the sensor cluster [1].

Biewer, Theodore↗

NOvA Short-Baseline Tau Neutrino Appearance Search

Standard three-flavor neutrino oscillations have well explained by a wide range of neutrino experiments. However, the anomalous results, such as electron-antineutrino excess seen by LSND and MiniBooNE do not fit the three-flavor paradigm. This can be explained by an additional fourth flavor sterile neutrino at a larger scale than the existing three flavor neutrinos. The NOvA experiment consists of two finely segmented, liquid scintillator detectors operating 14 .6 mrad off-axis from the NuMI muon-neutrino beam. The Near Detector is located on the Fermilab campus, 1 km from the NuMI target, while the Far Detector is located at Ash River, MN, 810 km from the NuMI target. The NOvA experiment is primarily designed to measure electron-neutrino appearance at the Far Detector using the Near Detector to control systematic uncertainties; however, the Near Detector is well suited for searching for anomalous short-baseline oscillations. This poster will present a novel method for selecting tau neutrino interactions with high purity at the Near Detector using a convolutional neural network. Using this method, the sensitivity to anomalous short-baseline tau-neutrino appearance due to sterile neutrino oscillations will be presented.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗