Results for “well testing” — Page 36

NASA NTRS2022

Validation of the Mars 2020 Fault Protection Design: Navigating the Infinity of the Off-Nominal

On July 30th 2020, the Mars 2020 mission successfully launched out of Cape Canaveral, Florida, passed through the Earth’s shadow, and began its short cruise to Mars. Less than seven months later, the Perseverance rover touched down safely in Jezero Crater to begin its ambitious mission that includes looking for signs of ancient life and collecting samples for future return to Earth. Getting to the successful landing, or “Tango Delta Nominal,” could not have been achieved without also considering the off-nominal. One of the teams supporting this ambitious mission is the fault protection (FP) team. This team is tasked with assessing the various failures, or faults, that could prevent mission success and with ensuring that the autonomous behaviors built into the software and hardware can detect faults and recover the vehicle to a safe state. As part of its charter, the FP team designed a test campaign to provide confidence in the system’s robustness to off-nominal scenarios across all of Mars 2020’s mission phases. The greatest challenge associated with designing such a validation campaign was reducing the infinite number of anomalous scenarios into a finite test suite. In addition, the tests needed to be executed efficiently in order to utilize the team’s limited test venue access, but still needed to maintain a level of rigor that guaranteed confidence in the test outcomes. Given that each test scenario generated massive amounts of data, the team also developed methods for quickly ascertaining whether the autonomous fault protection behaviors maintained vehicle safety in the presence of an anomaly. This paper summarizes the processes that the Mars 2020 fault protection team employed to execute its off-nominal validation campaign. It captures both the methods of generating a suite of off-nominal tests, as well as reducing it to a subset that can be realistically executed within schedule and resource constraints. It also describes the various processes and philosophies that the team utilized to execute the tests efficiently, including creating a standardized procedure template, keeping the test cases modular so that they could be easily interchanged, and capturing common fault injections in a change-controlled database. Finally, it will describe the tools and processes for assessing the test data, focusing in particular on a tool that evaluated vehicle state using “secondary” sources of data to validate that the software had truly configured the spacecraft to the expected safe state.

Morantz, Chaz↗

DOE OSTI2016

Concept of an upright wearable positron emission tomography imager in humans

Abstract Background Positron Emission Tomography ( PET ) is traditionally used to image patients in restrictive positions, with few devices allowing for upright, brain‐dedicated imaging. Our team has explored the concept of wearable PET imagers which could provide functional brain imaging of freely moving subjects. To test feasibility and determine future considerations for development, we built a rudimentary proof‐of‐concept prototype (Helmet_ PET ) and conducted tests in phantoms and four human volunteers. Methods Twelve Silicon Photomultiplier‐based detectors were assembled in a ring with exterior weight support and an interior mechanism that could be adjustably fitted to the head. We conducted brain phantom tests as well as scanned four patients scheduled for diagnostic F 18‐ FDG PET / CT imaging. For human subjects the imager was angled such that field of view included basal ganglia and visual cortex to test for typical resting‐state pattern. Imaging in two subjects was performed ~4 hr after PET / CT imaging to simulate lower injected F 18‐ FDG dose by taking advantage of the natural radioactive decay of the tracer (F 18 half‐life of 110 min), with an estimated imaging dosage of 25% of the standard. Results We found that imaging with a simple lightweight ring of detectors was feasible using a fraction of the standard radioligand dose. Activity levels in the human participants were quantitatively similar to standard PET in a set of anatomical ROI s. Typical resting‐state brain pattern activation was demonstrated even in a 1 min scan of active head rotation. Conclusion To our knowledge, this is the first demonstration of imaging a human subject with a novel wearable PET imager that moves with robust head movements. We discuss potential research and clinical applications that will drive the design of a fully functional device. Designs will need to consider trade‐offs between a low weight device with high mobility and a heavier device with greater sensitivity and larger field of view.

60 APPLIED LIFE SCIENCES↗

NASA NTRS1990

A New Approximate Fracture Mechanics Analysis Methodology for Composites with a Crack or Hole

A new approximate theory which links the inherent flaw concept with the theory of crack tip stress singularities at a bi-material interface was developed. Three assumptions were made: (1) the existence of inherent flaw (i.e., damage zone) at the tip of the crack, (2) a fracture of the filamentary composites initiates at a crack lying in the matrix material at the interface of the matrix/filament, and (3) the laminate fails whenever the principal load-carrying laminae fails. This third assumption implies that for a laminate consisting of 0 degree plies, cracks into matrix perpendicular to the 0 degree filaments are the triggering mechanism for the final failure. Based on this theory, a parameter bar K sub Q which is similar to the stress intensity factor for isotropic materials but with a different dimension was defined. Utilizing existing test data, it was found that bar K sub Q can be treated as a material constant. Based on this finding a fracture mechanics analysis methodology was developed. The analytical results are correlated well with test results. This new approximate theory can apply to both brittle and metal matrix composite laminates with crack or hole.

Tsai, H. C.↗

NASA NTRS2001

High Speed PC Based Data Acquisition and Instrumentation for Measurement of Simulated Low Earth Orbit Thermally Induced Disturbances

The Hubble Space Telescope (HST) Disturbance Verification Test (DVT) was conducted to characterize responses of the Observatory's new set of rigid solar array's (SA3) to thermally induced 'creak' or stiction releases. The data acquired in the DVT were used in verification of the HST Pointing Control System on-orbit performance, post-Servicing Mission 3B (SM3B). The test simulated the on-orbit environment on a deployed SA3 flight wing. Instrumentation for this test required pretest simulations in order to select the correct sensitivities. Vacuum compatible, highly accurate accelerometers and force gages were used for this test. The complexity of the test, as well as a short planning schedule, required a data acquisition system that was easy to configure, highly flexible, and extremely robust. A PC Windows oriented data acquisition system meets these requirements, allowing the test engineers to minimize the time required to plan and perform complex environmental test. The SA3 DVT provided a direct practical and complex demonstration of the versatility that PC based data acquisition systems provide. Two PC based data acquisition systems were assembled to acquire, process, distribute, and provide real time processing for several types of transducers used in the SA3 DVT. A high sample rate digital tape recorder was used to archive the sensor signals. The two systems provided multi-channel hardware and software architecture and were selected based on the test requirements. How these systems acquire and processes multiple data rates from different transducer types is discussed, along with the system hardware and software architecture.

Sills, Joel W., Jr.↗

NASA NTRS2008

Developments in Test Facility and Data Networking for the Altitude Test Stand at the John C. Stennis Space Center: A General Overview

NASA/SSC's Mission in Rocket Propulsion Testing Is to Acquire Test Performance Data for Verification, Validation and Qualification of Propulsion Systems Hardware: Accurate, Reliable, Comprehensive, and Timely. Data Acquisition in a Rocket Propulsion Test Environment Is Challenging: a) Severe Temporal Transient Dynamic Environments; b) Large Thermal Gradients; c) Vacuum to high pressure regimes. A-3 Test Stand Development is equally challenging with respect to accommodating vacuum environment, operation of a CSG system, and a large quantity of data system and control channels to determine proper engine performance as well as Test Stand operation. SSC is currently in the process of providing modernized DAS, Control Systems, Video, and network systems for the A-3 Test Stand to overcome these challenges.

Hebert, Phillip W.↗

DOE OSTI2017

Reduced order methods for the improvement of control-oriented modelling of nuclear power plants - 185

In the development of the control system of a nuclear power plant, it is of primary importance to rely on simulation tools for its realization, testing and validation. These tools should provide an accurate description of the controlled response of the entire power plant in different scenarios. The classic control-oriented modelling based on 0D/1D approach is well suited for control purposes since it provides fast-running simulations and it is easy to linearize, but it may not be sufficient to deeply investigate the complexity of some systems, in particular when/where spatial phenomena have a remarkable impact on dynamics. Reduced Order Methods (ROMs) can offer the proper trade-off between computational cost and solution accuracy, combining the high-detail modelling (e.g., 3D modelling) usually adopted for design purposes with the requirements demanded for a control-oriented tool, firstly the computational efficiency. In this work, ROMs are used to improve a control-oriented plant simulator of a Lead-cooled Fast Reactor (LFR). In particular, the attention is focused on the reactor core neutronics, and on the thermal-hydraulics of the reactor pool as well. A test case regarding the design of a Kalman Filter is set up showing promising results for the application of ROM in the control context. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2015

Runaway of energetic test ions in a toroidal plasma

Ion runaway in the presence of a large-scale, reconnection-driven electric field has been conclusively measured in the Madison Symmetric Torus reversed-field pinch (RFP). Measurements of the acceleration of a beam of fast ions agree well with test particle and Fokker-Planck modeling of the runaway process. However, the runaway mechanism does not explain all measured ion heating in the RFP, particularly previous measurements of strong perpendicular heating. It is likely that multiple energization mechanisms occur simultaneously and with differing significance for magnetically coupled thermal ions and magnetically decoupled tail and beam ions.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

NASA NTRS1980

Time-temperature-stress capabilities of composite materials for advanced supersonic technology application, phase 1

Implementation of metal and resin matrix composites into supersonic vehicle usage is contingent upon accelerating the demonstration of service capacity and design technology. Because of the added material complexity and lack of extensive service data, laboratory replication of the flight service will provide the most rapid method of documenting the airworthiness of advanced composite systems. A program in progress to determine the time temperature stress capabilities of several high temperature composite materials includes thermal aging, environmental aging, fatigue, creep, fracture, and tensile tests as well as real time flight simulation exposure. The program has two parts. The first includes all the material property determinations and aging and simulation exposures up through 10,000 hours. The second continues these tests up to 50,000 cumulative hours. Results are presented of the 10,000 hour phase, which has now been completed.

Kerr, J. R.↗

NASA NTRSDate not supplied

Gateway Power Quality Lessons Learned

Power Quality is a physical description of the electrical characteristics that allow the system to function properly without significant loss of performance or life. This physical description includes steady state voltage limits, transient voltage limits in normal/abnormal conditions, ripple voltage, stability, fault conditions, and more. All which are vital for improving reliability, ensuring stable operation, defining proper fault recovery, and ensuring a ‘plug and play’ approach to design and integration. Typically, a specification for Power Quality is created based on expected system performance or an existing standard, such as the International Space Power System Interoperability Standards (ISPSIS). One example of such a specification is the Gateway Power Quality Specification. It defines the requirements and characteristics of the 120 Volt direct current electrical power system for the Gateway Electrical Power System (EPS) and the Gateway Electrical Power Consuming Equipment (EPCE). This specification also maintains a separate requirement verification section that defines test methods for requirement verification. The test methods include analysis, test, inspection, and demonstration. These test methodologies and requirements are used to ensure that the loads operate when connected to the specified power quality and performance as defined by this specification. The challenge with developing a specification is that desired system characteristics are not always fully matured before the specification is needed and many performance requirements may be application specific. This drives the need to utilize lessons learned through extensive analysis and testing as well as historical knowledge to finalize requirements. Some example requirements where this is important are Small and Large Signal Stability, Ripple Voltage, Inrush/Surge Currents, and Fault Containment. Lessons learned are also important in the testing, analysis, and verification to ensure consistent and accurate results to verify performance. This presentation will cover the lessons learned for power quality relative to ripple, inrush/surge, fault containment, testing/verification, and more.

Power Quality↗

DOE OSTI2017

Push-pull tests for estimating effective porosity: expanded analytical solution and in situ application

The analytical solution describing the one-dimensional displacement of the center of mass of a tracer during an injection, drift, and extraction test (push-pull test) was expanded to account for displacement during the injection phase. The solution was expanded to improve the in situ estimation of effective porosity. The truncated equation assumed displacement during the injection phase was negligible, which may theoretically lead to an underestimation of the true value of effective porosity. To experimentally compare the expanded and truncated equations, single-well push-pull tests were conducted across six test wells located in a shallow, unconfined aquifer comprised of unconsolidated and heterogeneous silty and clayey fill materials. The push-pull tests were conducted by injection of bromide tracer, followed by a non-pumping period, and subsequent extraction of groundwater. The values of effective porosity from the expanded equation (0.6–5.0%) were substantially greater than from the truncated equation (0.1–1.3%). The expanded and truncated equations were compared to data from previous push-pull studies in the literature and demonstrated that displacement during the injection phase may or may not be negligible, depending on the aquifer properties and the push-pull test parameters. The results presented here also demonstrated the spatial variability of effective porosity within a relatively small study site can be substantial, and the error-propagated uncertainty of effective porosity can be mitigated to a reasonable level (< ± 0.5%). The tests presented here are also the first that the authors are aware of that estimate, in situ, the effective porosity of fine-grained fill material.

58 GEOSCIENCES↗

DOE OSTI2021

Precision tests of fundamental physics with η and η ' mesons

Decays of the neutral and long-lived $\eta$ and $\eta'$ mesons provide a unique, flavor-conserving laboratory to test low-energy Quantum Chromodynamics and search for new physics beyond the Standard Model. They have drawn world-wide attention in recent years and have inspired broad experimental programs in different high-intensity-frontier centers. Additionally, new experimental data will offer critical inputs to precisely determine the light quark mass ratios, $\eta$-$\eta'$ mixing parameters, and hadronic contributions to the anomalous magnetic moment of the muon. At the same time, it will provide a sensitive probe to test potential new physics. This includes searches for hidden photons, light Higgs scalars, and axion-like particles that are complementary to worldwide efforts to detect new light particles below the GeV mass scale, as well as tests of discrete symmetry violation. In this review, we give an update on theoretical developments, discuss the experimental opportunities, and identify future research needed in this field.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

NASA NTRS2014

Wald Sequential Probability Ratio Test for Space Object Conjunction Assessment

This paper shows how satellite owner/operators may use sequential estimates of collision probability, along with a prior assessment of the base risk of collision, in a compound hypothesis ratio test to inform decisions concerning collision risk mitigation maneuvers. The compound hypothesis test reduces to a simple probability ratio test, which appears to be a novel result. The test satisfies tolerances related to targeted false alarm and missed detection rates. This result is independent of the method one uses to compute the probability density that one integrates to compute collision probability. A well-established test case from the literature shows that this test yields acceptable results within the constraints of a typical operational conjunction assessment decision timeline. Another example illustrates the use of the test in a practical conjunction assessment scenario based on operations of the International Space Station.

Navigation↗

NASA NTRS2019

Test and Analysis Correlation for Sandwich Composite Longitudinal Joint Specimens

The NASA Composite Technology for Exploration (CTE) project is tasked with evaluating methods to analyze and manufacture composite joints for potential use in block upgrades to the Space Launch System (SLS) launch-vehicle structures such as the Payload Attach Fitting (PAF). To perform this task, the CTE project has initiated test and analysis correlation studies for composite joints under various loading conditions. Herein, NASA-developed numerical models are correlated with the experimental results from a series of tension tests. Pretest strain results matched the far-field test data well, but did not capture the nonlinear response in the vicinity of the joint. A refined pretest analytical model was modified to represent progressive failure of the specimens at failure locations observed during the experimental tests. The nonlinear strain response from this progressive failure model predicted the delamination failure load within 15% of the test data, but underpredicted the nonlinearity of the strain response. Further study of composite material models that account for the nonlinear shear response of fabric composites is recommended for the composite joint structures considered in this paper.

Mason, Brian H.↗

DOE OSTI2015

WE-F-201-00: Practical Guidelines for Commissioning Advanced Brachytherapy Dose Calculation Algorithms

With the recent introduction of heterogeneity correction algorithms for brachytherapy, the AAPM community is still unclear on how to commission and implement these into clinical practice. The recently-published AAPM TG-186 report discusses important issues for clinical implementation of these algorithms. A charge of the AAPM-ESTRO-ABG Working Group on MBDCA in Brachytherapy (WGMBDCA) is the development of a set of well-defined test case plans, available as references in the software commissioning process to be performed by clinical end-users. In this practical medical physics course, specific examples on how to perform the commissioning process are presented, as well as descriptions of the clinical impact from recent literature reporting comparisons of TG-43 and heterogeneity-based dosimetry. Learning Objectives: Identify key clinical applications needing advanced dose calculation in brachytherapy. Review TG-186 and WGMBDCA guidelines, commission process, and dosimetry benchmarks. Evaluate clinical cases using commercially available systems and compare to TG-43 dosimetry.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-F-201-01: Identify Key Clinical Applications Needing Advanced Dose Calculation in Brachytherapy

With the recent introduction of heterogeneity correction algorithms for brachytherapy, the AAPM community is still unclear on how to commission and implement these into clinical practice. The recently-published AAPM TG-186 report discusses important issues for clinical implementation of these algorithms. A charge of the AAPM-ESTRO-ABG Working Group on MBDCA in Brachytherapy (WGMBDCA) is the development of a set of well-defined test case plans, available as references in the software commissioning process to be performed by clinical end-users. In this practical medical physics course, specific examples on how to perform the commissioning process are presented, as well as descriptions of the clinical impact from recent literature reporting comparisons of TG-43 and heterogeneity-based dosimetry. Learning Objectives: Identify key clinical applications needing advanced dose calculation in brachytherapy. Review TG-186 and WGMBDCA guidelines, commission process, and dosimetry benchmarks. Evaluate clinical cases using commercially available systems and compare to TG-43 dosimetry.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-F-201-02: Review TG-186 and WGMBDCA Guidelines, Commission Process, and Dosimetry Benchmarks

With the recent introduction of heterogeneity correction algorithms for brachytherapy, the AAPM community is still unclear on how to commission and implement these into clinical practice. The recently-published AAPM TG-186 report discusses important issues for clinical implementation of these algorithms. A charge of the AAPM-ESTRO-ABG Working Group on MBDCA in Brachytherapy (WGMBDCA) is the development of a set of well-defined test case plans, available as references in the software commissioning process to be performed by clinical end-users. In this practical medical physics course, specific examples on how to perform the commissioning process are presented, as well as descriptions of the clinical impact from recent literature reporting comparisons of TG-43 and heterogeneity-based dosimetry. Learning Objectives: Identify key clinical applications needing advanced dose calculation in brachytherapy. Review TG-186 and WGMBDCA guidelines, commission process, and dosimetry benchmarks. Evaluate clinical cases using commercially available systems and compare to TG-43 dosimetry.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-F-201-03: Evaluate Clinical Cases Using Commercially Available Systems and Compare to TG-43 Dosimetry

With the recent introduction of heterogeneity correction algorithms for brachytherapy, the AAPM community is still unclear on how to commission and implement these into clinical practice. The recently-published AAPM TG-186 report discusses important issues for clinical implementation of these algorithms. A charge of the AAPM-ESTRO-ABG Working Group on MBDCA in Brachytherapy (WGMBDCA) is the development of a set of well-defined test case plans, available as references in the software commissioning process to be performed by clinical end-users. In this practical medical physics course, specific examples on how to perform the commissioning process are presented, as well as descriptions of the clinical impact from recent literature reporting comparisons of TG-43 and heterogeneity-based dosimetry. Learning Objectives: Identify key clinical applications needing advanced dose calculation in brachytherapy. Review TG-186 and WGMBDCA guidelines, commission process, and dosimetry benchmarks. Evaluate clinical cases using commercially available systems and compare to TG-43 dosimetry.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2012

An Evaluation of the Carbon Sequestration Potential of the Cambro-Ordovician Strata of the Illinois and Michigan Basins. Part 1. Evaluation of Phase 2 CO 2 Injection Testing in the Deep Saline Gunter Sandstone Reservoir (Cambro-Ordovician Knox Group), Marvin Blan No. 1 Hancock County, Kentucky Part 2. Time-lapse Three-Dimensional Vertical Seismic Profile (3D-VSP) of Sequestration Target Interval with Injected Fluids

Part 1 of this report focuses on results of the western Kentucky carbon storage test, and provides a basis for evaluating injection and storage of supercritical CO 2 in Cambro-Ordovician carbonate reservoirs throughout the U.S. Midcontinent. This test demonstrated that the Cambro- Ordovician Knox Group, including the Beekmantown Dolomite, Gunter Sandstone, and Copper Ridge Dolomite in stratigraphic succession from shallowest to deepest, had reservoir properties suitable for supercritical CO 2 storage in a deep saline reservoir hosted in carbonate rocks, and that strata with properties sufficient for long-term confinement of supercritical CO 2 were present in the deep subsurface. Injection testing with brine and CO 2 was completed in two phases. The first phase, a joint project by the Kentucky Geological Survey and the Western Kentucky Carbon Storage Foundation, drilled the Marvin Blan No. 1 carbon storage research well and tested the entire Knox Group section in the open borehole – including the Beekmantown Dolomite, Gunter Sandstone, and Copper Ridge Dolomite – at 1152–2255 m, below casing cemented at 1116 m. During Phase 1 injection testing, most of the 297 tonnes of supercritical CO 2 was displaced into porous and permeable sections of the lowermost Beekmantown below 1463 m and Gunter. The wellbore was then temporarily abandoned with a retrievable bridge plug in casing at 1105 m and two downhole pressure-temperature monitoring gauges below the bridge plug pending subsequent testing. Pressure and temperature data were recorded every minute for slightly more than a year, providing a unique record of subsurface reservoir conditions in the Knox. In contrast, Phase 2 testing, this study, tested a mechanically-isolated dolomitic-sandstone interval in the Gunter.

54 ENVIRONMENTAL SCIENCES↗