scholarly journals SI-traceable Spectral Irradiance Radiometric Characterization and Absolute Calibration of the TSIS-1 Spectral Irradiance Monitor (SIM)

2020 ◽  
Vol 12 (11) ◽  
pp. 1818 ◽  
Author(s):  
Erik Richard ◽  
Dave Harber ◽  
Odele Coddington ◽  
Ginger Drake ◽  
Joel Rutkowski ◽  
...  
Keyword(s):  
Space Station ◽  
Standard Uncertainty ◽  
Space Physics ◽  
Operating Conditions ◽  
Spectral Irradiance ◽  
Absolute Calibration ◽  
Component Level ◽  
Current Implementation ◽  
Direct Laser ◽  
Operational Envelope

The current implementation for continuous, long-term solar spectral irradiance (SSI) monitoring is the Total and Spectral Solar Irradiance Sensor (TSIS-1) Spectral Irradiance Monitor (SIM) that began operations from the International Space Station (ISS) in March 2018 and nominally provides an SSI spectrum every 12 h. Advances in both instrument design and spectral irradiance calibration techniques have resulted in the TSIS-1 SIM achieving higher absolute accuracy than its predecessor instrument in the wavelength range (200–2400 nm). A comprehensive detector-based Spectral Radiometer Facility (SRF) was developed in collaboration with the US National Institute for Standards and Technology (NIST) to ensure the ties to spectral SI standards in power and irradiance. Traceability is achieved via direct laser calibration of a focal plane electrical substitution radiometer (ESR) against a cryogenic radiometer in power and also irradiance responsivity via calibrated apertures. The SIM accuracy definition followed an absolute sensor approach based on a full radiometric measurement equation where component-level performance characterizations and calibrations were quantified with an associated uncertainty error budget and verified by independent measurements for each parameter. Unit-level characterizations were completed over the full operational envelope of external driving factors (e.g., pointing and temperature ranges) and were allowed for the independent parameterization of sub-assembly performance for expected operating conditions. Validation and final instrument end-to-end absolute calibration in the Laboratory for Atmospheric and Space Physics (LASP)-SRF achieved low combined standard uncertainty (uc < 0.25%, k = 1) in spectral irradiance.

Counting Failure Events for a Support System

2012 ◽  
Author(s):  
Curtis Smith
Keyword(s):  
Support System ◽  
Distribution System ◽  
Support Systems ◽  
Cooling Water ◽  
Operating Conditions ◽  
System Failure ◽  
Repairable Systems ◽  
Component Level ◽  
System Failures ◽  
Operational Envelope

An initiating event is a departure from a desired operational envelope to a system state where a control response is required either by human or machine intervention. In the case of a support system such as a cooling water or electrical distribution system, failure of this system represents the departure from normal operating conditions. Initiating event frequencies for probabilistic risk assessments are generally based on data collection. For rare, but potentially high consequence initiators representing the failure of support systems, this approach has a number of shortcomings. For example, since events are rare, there may not be any complete system failure events in the available data sets. Consequently, there is a desire to model system failures of initiating events since component-level failure events in the support systems are more frequent. Therefore, what is needed is a suitable method for calculating the initiating event frequency (expected number of system failures over some operating mission) from the relatively well known component failure rates. In this paper, we explore ways to develop and quantify models that represent the rates of failures for support systems. These failures of repairable systems can be represented by focusing on observables. Specifically, we can either count the number of failures in time t or count the times of failure. As part of the analysis, we will describe and evaluate a couple of typical redundant support systems. Included in the analysis will be considerations of dependent failure mechanisms.

Preliminary Design of Variable Nozzle Turbines Based on Sensitive Parameters

2020 ◽  
Author(s):  
Sebastian Wittwer ◽  
Ivo Sandor
Keyword(s):  
Engine Performance ◽  
Optimal Solution ◽  
Operating Conditions ◽  
Experimental Results ◽  
Preliminary Design ◽  
Component Level ◽  
Gasoline Engines ◽  
Functional Parameters ◽  
Predictive Quality ◽  
Recent Developments

Abstract Recent developments in turbocharged gasoline engines have established new requirements for the turbine. A simple approach of scaling or optimizing existing turbines on component level might not be sufficient in terms of finding an optimal solution according to the multi-point, multi-disciplinary layout target. In the following paper nondimensional functional parameters are derived from turbomachinery analytics and rated on corresponding values of existing turbine stages. The influence of different parameters on aerodynamic performance is discussed based on CFD results and arranged according to their sensitivity for different engine relevant operating conditions. A metamodel for the preliminary design of variable nozzle turbine stages is derived from DoE (Design of Experiments) based CFD results. It is evaluated regarding its predictive quality on several exemplary turbine stages. Both, CFD and experimental results are therefore used while the experimental results are made up of hot gas stand measurements as well as measurements on engine test bench. Thus, not only the influence of functional parameters can be verified on turbine efficiency characteristics, but beyond that also the predictive quality of engine performance can be assessed.

Predicting the Behavior of Solar Dynamic Closed Brayton Cycle Power Conversion Systems

1988 ◽  
Vol 110 (4) ◽  
pp. 636-640 ◽  
Author(s):  
R. Bons ◽  
J. Hanlon ◽  
S. Spencer
Keyword(s):  
Power Conversion ◽  
Space Station ◽  
Operating Conditions ◽  
System Model ◽  
Design System ◽  
Brayton Cycle ◽  
Preliminary Design ◽  
The Sun ◽  
Design Performance ◽  
Conversion System

Since space power conversion systems must operate both in the sun and in the earth’s shadow, they seldom encounter design operating conditions. As a consequence, consideration of off-design performance is essential in the preliminary design of these systems. To illustrate the necessity and utility of an off-design system model, this paper presents the results of a study of the solar dynamic closed Brayton cycle power conversion system for use on the NASA Space Station.

Reliability and Lifing Methodologies for Microelectronic Systems

1998 ◽  
Vol 515 ◽  
Author(s):  
Ken Reifsnider
Keyword(s):  
Semiconductor Industry ◽  
Turn Of The Century ◽  
Operating Conditions ◽  
Interactive Effects ◽  
Design Development ◽  
Component Level ◽  
Composite Systems ◽  
Technology Roadmap ◽  
Mechanical Models ◽  
Chemical Conditions

ABSTRACTIntegration of core electronic functions is progressing at a remarkable rate. The high-end computers that we are using now may be available on a single die by the turn of the century. The effect of this, and other advances on semiconductor assembly and packaging has generated the need for integrated component-level electrical thermal, and mechanical models and simulation methods, as described in the Semiconductor Industry Association national Technology Roadmap for Semiconductors. Although corporate and university research and development in the semiconductor area is intense (there are eight major university-based packaging centers around the world, for example), design/development methodologies that consider the combined and interactive effects of mechanical, thermal and chemical conditions on the reliability and durability of integrated components have been slow to develop. However, such methodologies have been developed for applications of complex composite systems in various other technologies where the operating conditions are similar. The present paper will discuss those developments and the possibility of applying that technology to microelectronic systems.

Application of Miniaturized Experiments for Constitutive Modeling of Creep Relaxation of a Novel Textured Gasket Product

2018 ◽  
Author(s):  
Ali P. Gordon ◽  
John Albury ◽  
Matthew Lopez ◽  
Evren Tasci ◽  
Zachary Poust ◽  
...  
Keyword(s):  
Constitutive Modeling ◽  
Material Selection ◽  
Operating Conditions ◽  
Filler Material ◽  
Small Samples ◽  
Test Results ◽  
Component Level ◽  
Operating Environments ◽  
Test Platform ◽  
Viscoelastic Constitutive Model

The material attributes that are fundamental for developing a candidate textured, ceramic-filled PTFE gasket, such as texture style/dimensions, filler material, thickness and so on, create a set of potential combinations that are not practical to experimentally characterize at the component-level one-by-one. Optimizing gasket performance, however, is essential to the operation of bolted connections associated with pressurized vessels that transfer media from one location to another. Gaskets are essential for these systems since they confer high levels of leak mitigation across a range of operating environments. A balance of both compressibility and sealability must be displayed in an optimal candidate gasket to be subjected to aggressive operating conditions. A novel textured PTFE material (termed textured) characterized using a miniaturized test platform. This new-to-market viscoelastic material features a dual-face, raised honeycomb pattern. Experiments on both flat (termed Flat) and textured are used to identify viscoelastic constitutive model constants associated with Burger theories. Considering that the test platform contains an elastic bolt that is tightened to a prescribe torque level, the gasket is subjected to creep relaxation. Test results on the small samples contribute to constitutive modeling. The influence of parameters such as filler material selection, torque level, dwell period, etc. are presented.

The Measurement of Component Friction Losses in a Fired Engine: Part 2 — Experimental Results

2005 ◽  
Author(s):  
Riaz A. Mufti ◽  
Martin Priest
Keyword(s):  
Engine Performance ◽  
Cost Effective ◽  
Operating Conditions ◽  
Experimental Results ◽  
Engine Oil ◽  
Sensor Technology ◽  
Component Level ◽  
Component Design ◽  
Engine Part ◽  
Actual Use

Bench testing can provide rapid and cost effective information for developing new lubricants. But there is general agreement that the only satisfactory means of evaluating the behaviour of engine oil is by actual use in engine. Also for detailed analysis of the tribological interaction it is important to analyse the engine performance at the component level. With the help of advance data acquisition system and sensor technology, experimental measurement of friction losses at the component level have been measured at realistic engine operating conditions, using the technique explained in Part 1. This paper describes the outcome of the experimental results at a range of engine operating conditions using mainly SAE 0W20 lubricant and some results from a friction-modified SAE 5W30 lubricant. The results clearly show considerable changes in the percentage contribution of power loss between low and high lubricant temperatures. The change in mode of lubricating regime from boundary to fluid film lubrication can be seen at the component level with increase in engine speed and decrease in lubricant temperature. This system can be used as a powerful tool for screening engine oils, analysing component design, validating friction models and studying the effect of different additives on the performance of each component under realistic operating conditions.

scholarly journals Closed Adsorption Heat Storage—A Life Cycle Assessment on Material and Component Levels

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3421 ◽  
Author(s):  
Björn Nienborg ◽  
Tobias Helling ◽  
Dominik Fröhlich ◽  
Rafael Horn ◽  
Gunther Munz ◽  
...  
Keyword(s):  
Life Cycle ◽  
Storage Capacity ◽  
Heat Storage ◽  
Operating Conditions ◽  
Assessment Criterion ◽  
Component Level ◽  
Reference Case ◽  
Relative Storage Capacity ◽  
Auxiliary Material ◽  
And Performance

Closed adsorption storages have been investigated in several projects for heat storage in building applications with focus on energy density and performance. This study complements this research with the assessment of the environmental impacts over the life cycle. Global warming potential (GWP) was chosen as the assessment criterion. Selected sorption materials in combination with water as the refrigerant were analyzed first by themselves and then embedded in a generic storage configuration. Sensible storage in water served as the reference benchmark. Results on material and component level showed that the relative storage capacity compared to water under realistic operating conditions reached values of below 4 and 2.5, respectively, in the best cases. Since the effort for producing the sorbents as well as the auxiliary material demand for assembling storage components was significantly higher than in the reference case, the specific environmental impact per storage capacity also turned out to be ~2.5 to ~100 times higher. We therefore suggest focusing sorption storage research on applications that (a) maximize the utilization of the uptake of sorbents, (b) do not compete with water storages, and (c) require minimal auxiliary parts.

scholarly journals A Solar Irradiance Climate Data Record

2016 ◽  
Vol 97 (7) ◽  
pp. 1265-1282 ◽  
Author(s):  
O. Coddington ◽  
J. L. Lean ◽  
P. Pilewskie ◽  
M. Snow ◽  
D. Lindholm
Keyword(s):  
Solar Irradiance ◽  
Sunspot Area ◽  
Space Physics ◽  
Spectral Irradiance ◽  
Multiple Time Scales ◽  
Naval Research ◽  
Multiple Time ◽  
Climate Data ◽  
Data Record ◽  
Climate Data Record

Abstract We present a new climate data record for total solar irradiance and solar spectral irradiance between 1610 and the present day with associated wavelength and time-dependent uncertainties and quarterly updates. The data record, which is part of the National Oceanic and Atmospheric Administration’s (NOAA) Climate Data Record (CDR) program, provides a robust, sustainable, and scientifically defensible record of solar irradiance that is of sufficient length, consistency, and continuity for use in studies of climate variability and climate change on multiple time scales and for user groups spanning climate modeling, remote sensing, and natural resource and renewable energy industries. The data record, jointly developed by the University of Colorado’s Laboratory for Atmospheric and Space Physics (LASP) and the Naval Research Laboratory (NRL), is constructed from solar irradiance models that determine the changes with respect to quiet sun conditions when facular brightening and sunspot darkening features are present on the solar disk where the magnitude of the changes in irradiance are determined from the linear regression of a proxy magnesium (Mg) II index and sunspot area indices against the approximately decade-long solar irradiance measurements of the Solar Radiation and Climate Experiment (SORCE). To promote long-term data usage and sharing for a broad range of users, the source code, the dataset itself, and supporting documentation are archived at NOAA’s National Centers for Environmental Information (NCEI). In the future, the dataset will also be available through the LASP Interactive Solar Irradiance Data Center (LISIRD) for user-specified time periods and spectral ranges of interest.

Spectral Irradiance Calibration in the Infrared. XV. Absolute Calibration of Standard Stars by Experiments on theMidcourse Space Experiment

2004 ◽  
Vol 128 (2) ◽  
pp. 889-910 ◽  
Author(s):  
S. D. Price ◽  
Charles Paxson ◽  
Charles Engelke ◽  
Thomas L. Murdock
Keyword(s):  
Space Experiment ◽  
Spectral Irradiance ◽  
Absolute Calibration

scholarly journals Spectral Irradiance Calibration in the Infrared. XIV. The Absolute Calibration of 2MASS

2003 ◽  
Vol 126 (2) ◽  
pp. 1090-1096 ◽  
Author(s):  
Martin Cohen ◽  
Wm. A. Wheaton ◽  
S. T. Megeath
Keyword(s):  
Spectral Irradiance ◽  
Absolute Calibration ◽  
The Absolute
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