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Dynamic pressure characteristics analysis for double-cavity model of air system

Beijing Hangkong Hangtian Daxue Xuebao/Journal of Beijing University of Aeronautics and Astronautics 2016年第4期42卷 654-661页

作者： Ding, Shuiting Che, Weiwei Liu, Chuankai Beijing Key Laboratory on Safety of Integrated Aircraft and Propulsion System Beijing100083 China Co-Innovation Center for Advanced Aero-Engine Beijing100083 China School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing100083 China School of Transportation Science and Engineering Beijing University of Aeronautics and Astronautics Beijing100083 China

When the engine slam accelerates or suddenly fails, the pressure wave formed by cavity effect and pipe fluid inertia in a short time will have negative impact on some components of air system. On the basis of the simulation program of the modular transient air system, the pressure variation of cavity and different parts of pipe in the double-cavity model is analyzed. The influence law analysis of the size of the key components for pressure wave is mainly considered. Results show that the pressure wave produced in the transient state is closely related to the geometric structure size of the air system. The analysis method of this model can be used as a basis for fast transient research of air system of the integrated engine. © 2016, Editorial Board of JBUAA. All right reserved.

关键词： Engines

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Enabling international data relay at Mars 14th

Enabling international data relay at Mars

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14th International Conference on Space Operations, SpaceOps 2016

作者： Wenkert, Daniel D. Gladden, Roy E. Edwards, Charles D. Schmitz, Peter Denis, Michel Winton, Alistair J. Cross Mission System Development and Implementation Group Jet Propulsion Laboratory California Institute of Technology Mail Stop 264-235 PasadenaCA90027 United States Jet Propulsion Laboratory California Institute of Technology Mail Stop 264-235 PasadenaCA90027 United States Solar and Planetary Missions Division OPS-OPE European Space Operations Center European Space Agency Darmstadt Germany Solar and Planetary Missions Division OPS-OPM European Space Operations Center European Space Agency Darmstadt Germany ExoMars Systems Engineering SRE-PEG European Space Research and Technology Centre European Space Agency Noordwijk Netherlands

ISBN: (数字)9781624104268

ISBN: (纸本)9781624104268

The most commonly used mode of communications between Earth and a Mars surface mission is ultra-high frequency (UHF) radio relay via a Mars orbiter. There are four orbiters and two surface rovers operating at Mars and by October there will be five orbiters and three landers or rovers. There has been some collaboration between ESA’s Mars Express orbiter and NASA’s rovers, but 2016 is when Mars relay becomes fully international. In October, ESA will deliver the ExoMars Trace Gas Orbiter (TGO) and Entry, Descent, and Landing (EDL) Demonstrator Module (EDM) lander to Mars. The ExoMars program includes both ESA and ROSCOSMOS, with NASA participation (the Electra UHF transceiver on TGO). NASA orbiters will provide relay for EDM and future ESA Mars landers and rovers. TGO will provide relay for NASA's current and future surface assets (as Mars Express will continue to do). International collaboration is enabled in several steps. At the instruction of the space agencies, the Mars mission projects negotiate and write a "Service Agreement." This describes at a high level how a new Mars orbiter will operate with its corresponding surface missions or how a new surface mission will operate with its corresponding orbiters. It includes the roles of the different projects, how the new mission will communicate with existing or planned missions, the general flow of data and commands, and the capabilities or requirements of the new mission. After completing the Service Agreement, the projects write Interface Control Documents (ICDs), each of which describes data and command flow in greater detail and quantitative aspects of the relay link and operations timeline between an orbiter and a corresponding lander/rover. Interfaces and operations are tested before a new mission arrives at Mars. Once at Mars, a new orbiter will perform some "practice" relay contacts with its partners. For a new lander (e.g. EDM), relay operations generally begin before atmospheric entry at Mars, with recordin

关键词： NASA

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Evaluation of radiative heating rate profiles in eight GCMs using A-train satellite observations

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AIP Conference Proceedings 2017年第1期1810卷

作者： Gregory Cesana D. E. Waliser T. L’Ecuyer X. Jiang J.-L. Li 1Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA 2University of Wisconsin—Madison Madison WI USA 3Joint Institute for Regional Earth System Science & Engineering University of California Los Angeles CA USA

In this study, we take advantage of two modeling experiments and A-train satellite observations to characterize the impact of cloud biases in the vertical distribution of radiative heating rates in eight general circulation models General Circulation Models (GCMs). We compare the modeled vertical distribution of clouds against the GCM-Oriented Cloud-Aerosols Lidar and Infrared Pathfinder Satellite Observations Cloud Product (CALIPSO-GOCCP) using a simulator approach. Although the overall pattern of modeled zonal cloud frequency profiles is relatively good (r=0.92 for the multi-model mean), we show two main systematic biases in the cloud frequency profiles: a positive bias above 7km (up to 10%), particularly in the tropics; and a negative bias below 3km (up to −10%), which reaches a maximum over the stratocumulus cloud regions. Using radiative heating rate profiles calculated with constraints from CloudSat, CALIPSO and other satellite observations, we show that the excess of clouds in the upper troposphere (>7km) results in excess infrared and solar heating in the vicinity of the clouds as well as more infrared heating for the entire column below the cloud. On the other hand, the lack of clouds in the lower troposphere reduces the infrared cooling near the missing cloud levels and increases the absorption of solar radiation by water vapor below. The global radiative heating rate between 50°S and 50°N is too warm in the models (−0.81K/day vs. −1.01K/day). The representation of clouds in GCMs remains challenging, but reducing the cloud biases would lead to an improvement of the heating rate profiles, which in turn would help in improving other aspects of models’ simulations such as the dynamics, cloud feedbacks and surface-atmosphere interactions.

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A tool for model-based generation of scenario-driven electric power load profiles

A tool for model-based generation of scenario-driven electri...

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AIAA SPACE Conference and Exposition, 2015

作者： Rozek, Matthew L. Donahue, Kenneth M. Ingham, Michel D. Kaderka, Justin D. Jet Propulsion Laboratory - California Institute of Technology Flight System Systems Engineering Group 4800 Oak Grove Drive PasadenaCA91109 United States Jet Propulsion Laboratory - California Institute of Technology System Architectures and Behaviors Group 4800 Oak Grove Drive PasadenaCA91109 United States

ISBN: (数字)9781624103346

ISBN: (纸本)9781624103346

Power consumption during all phases of spacecraft flight is of great interest to the aerospace community. As a result, significant analysis effort is exerted to understand the rates of electrical energy generation and consumption under many operational scenarios of the system. Previously, no standard tool existed for creating and maintaining a power equipment list (PEL) of spacecraft components that consume power, and no standard tool existed for generating power load profiles based on this PEL information during mission design phases. This paper presents the Scenario Power Load Analysis Tool (SPLAT) as a model-based systems engineering tool aiming to solve those problems. SPLAT is a plugin for a commercial modeling tool that aids in creating and maintaining a PEL, and also generates a power and temporal variable constraint set based on specified operational scenarios. The constraint set can be solved to show electric load profiles (i.e. power consumption from loads over time). SPLAT creates these load profiles from three modeled inputs: 1) a list of system components and their respective power states, 2) a decomposition hierarchy of the system into these components, and 3) the specification of at least one scenario, which consists of temporal constraints on component power states. In order to demonstrate how this information is represented in a system model, a notional example of a spacecraft planetary flyby is introduced. This example is also used to explain the overall functionality of SPLAT, and how this is used to generate electric power load profiles. Lastly, a cursory review of the usage of SPLAT on the Cold Atom laboratory project is presented to show how the tool was used in an actual space hardware design application. © 2015, American Institute of Aeronautics and Astronautics Inc, AIAA. All rigts reserved.

关键词： Electric power utilization

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FabricSat

FabricSat

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AIAA Space and Astronautics Forum and Exposition, SPACE 2016

作者： Lyke, James C. Quadrelli, Marco Ma, Kelvin Forman, Glenn Edmondson, James 3550 Aberdeen Ave SE KAFB AlbuquerqueNM91109 United States Autonomous Systems Division Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109-8099 United States BioVeriCom 255 River St TroyNY12180 United States GE Global Research 1 River Road NiskayunaNY12309 United States Software Engineering Institute Carnegie Mellon University 4500 Fifth Avenue PittsburghPA15213-2612 United States

ISBN: (纸本)9781624104275

FabricSat considers a novel distributed implementation of critical and common satellite bus functions using a set of planar tiles, which could exist in a sheet-like (fabric) form. The tiles can be considered as "cells" (such as those in biological organisms), each having a number of subsystems (energy, communication, computation, sensory). While each tile can be thought of as a degenerate spacecraft, they would likely be used in ensembles to implement the essential infrastructure necessary for all spacecraft (additional payloads could be added). Cells are designed to cooperate and pool resources to the degree practical. The tiles possess both local and global order, as in the case of multicellular organisms, where functions occur inside of individual cells, but the collection is viewed as a distinct overall system. This paper considers the cellular interpretation of spacecraft systems, the FabricSat embodiment, and describes a near-term cubesat to demonstrate some of the key principles. © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

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Diurnal variation of dust and gas production in comet 67P/Churyumov-Gerasimenko at the inbound equinox as seen by OSIRIS and VIRTIS-M on board Rosetta

arXiv

引用

arXiv 2019年

作者： Tubiana, C. Rinaldi, G. Güttler, C. Snodgrass, C. Shi, X. Hu, X. Marschall, R. Fulle, M. Bockelée-Morvan, D. Naletto, G. Capaccioni, F. Sierks, H. Arnold, G. Barucci, M.A. Bertaux, J.-L. Bertini, I. Bodewits, D. Capria, M.T. Ciarniello, M. Cremonese, G. Crovisier, J. da Deppo, V. Debei, S. de Cecco, M. Deller, J. de Sanctis, M.C. Davidsson, B. Doose, L. Erard, S. Filacchione, G. Fink, U. Formisano, M. Fornasier, S. Gutiérrez, P.J. Ip, W.-H. Ivanovski, S. Kappel, D. Keller, H.U. Kolokolova, L. Koschny, D. Krueger, H. la Forgia, F. Lamy, P.L. Lara, L.M. Lazzarin, M. Levasseur-Regourd, A.C. Lin, Z.-Y. Longobardo, A. López-Moreno, J.J. Marzari, F. Migliorini, A. Mottola, S. Rodrigo, R. Taylor, F. Toth, I. Zakharov, V. Max Planck Institute for Solar System Research Göttingen Germany Istituto di Astrofisica e Planetologia Spaziali Istituto Nazionale di Astrofisica Rome Italy Institute for Astronomy University of Edinburgh Royal Observatory EdinburghEH9 3HJ United Kingdom Institute for Geodesy and Geoinformation Science Technical University Berlin Straße des 17. Juni 135 Berlin10623 Germany International Space Science Institute Bern Switzerland INAF – Osservatorio Astronomico Trieste Italy LESIA Observatoire de Paris PSL Research University CNRS Sorbonne Université Univ. Paris Diderot Sorbonne Paris Cité 5 place Jules Janssen MeudonF-92195 France Department of Physics Oxford University Oxford United Kingdom Institut für Planetenforschung Berlin Germany Lunar and Planetary Laboratory University of Arizona Tucson United States Physics Department Auburn University AuburnAL36849 United States Laboratoire Atmosphères Milieux et Observations Spatiales CNRS Université de Versailles Saint-Quentin-en-Yvelines 11 boulevard d’Alembert Guyancourt78280 France Centro de Astrobiologia CSIC-INTA Torrejon de ArdozMadrid Spain Science Support Office European Space Research and Technology Centre/ESA Keplerlaan 1 Postbus 299 NoordwijkZH2201 AZ Netherlands Jet Propulsion Laboratory M/S 183-401 4800 Oak Grove Drive PasadenaCA91109 United States LATMOS CNRS/UVSQ/IPSL 11 Boulevard d’Alembert Guyancourt78280 France University of Padova Department of Physics and Astronomy "Galileo Galilei" Vicolo dell’Osservatorio 3 Padova35122 Italy INAF Astronomical Observatory of Padova Vicolo dell’Osservatorio 5 Padova35122 Italy CNR-IFN UOS Padova LUXOR Via Trasea 7 Padova35131 Italy University of Padova Department of Industrial Engineering Via Venezia 1 Padova35131 Italy University of Trento Faculty of Engineering Via Mesiano 77 Trento38121 Italy c/ Glorieta de la Astronomia s/n Granada18008 Spain Institute of Physics and Astronomy University of Potsdam Potsdam

Context. On 27 April 2015, when 67P/Churyumov-Gerasimenko was at 1.76 au from the Sun and moving towards perihelion, the OSIRIS and VIRTIS-M instruments on board Rosetta simultaneously observed the evolving dust and gas coma during a complete rotation of the comet. Aims. We aim to characterize the dust, H2O and CO2 gas spatial distribution in the inner coma. To do this we performed a quantitative analysis of the release of dust and gas and compared the observed H2O production rate with the one calculated using a thermo-physical model. Methods. For this study we selected OSIRIS WAC images at 612 nm (dust) and VIRTIS-M image cubes at 612 nm, 2700 nm (H2O emission band) and 4200 nm (CO2 emission band). We measured the average signal in a circular annulus, to study spatial variation around the comet, and in a sector of the annulus, to study temporal variation in the sunward direction with comet rotation, both at a fixed distance of 3.1 km from the comet centre. Results. The spatial correlation between dust and water, both coming from the sun-lit side of the comet, shows that water is the main driver of dust activity in this time period. The spatial distribution of CO2 is not correlated with water and dust. There is no strong temporal correlation between the dust brightness and water production rate as the comet rotates. The dust brightness shows a peak at 0◦ sub-solar longitude, which is not pronounced in the water production. At the same epoch, there is also a maximum in CO2 production. An excess of measured water production, with respect to the value calculated using a simple thermo-physical model, is observed when the head lobe and regions of the Southern hemisphere with strong seasonal variations are illuminated (sub-solar longitude 270◦– 50◦). A drastic decrease in dust production, when the water production (both measured and from the model) displays a maximum, happens when typical Northern consolidated regions are illuminated and the Southern hemisphere regions wi

关键词： Comets

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Real-time terrain relative navigation test results from a relevant environment for mars landing

Real-time terrain relative navigation test results from a re...

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AIAA Guidance, Navigation, and Control Conference 2015, MGNC 2015 - Held at the AIAA SciTech Forum 2015

作者： Johnson, Andrew E. Cheng, Yang Montgomery, James Trawny, Nikolas Tweddle, Brent Zheng, Jason Guidance and Control Section Jet Propulsion Laboratory California Institute of Technology MS 198-235 4800 Oak Grove Dr. PasadenaCA91109 United States Mobility and Robotic System Section Jet Propulsion Laboratory California Institute of Technology MS 198-235 4800 Oak Grove Dr. PasadenaCA91109 United States Guidance and Control Section Jet Propulsion Laboratory California Institute of Technology MS 198-235 4800 Oak Grove Dr. PasadenaCA91109 United States Flight Electronics and Software Systems Section Jet Propulsion Laboratory California Institute of Technology MS 198-326 4800 Oak Grove Dr. PasadenaCA91109 United States

ISBN: (纸本)9781510801097

Terrain Relative Navigation (TRN) is an on-board GN&C function that generates a position estimate of a spacecraft relative to a map of a planetary surface. When coupled with a divert, the position estimate enables access to more challenging landing sites through pinpoint landing or large hazard avoidance. The Lander Vision system (LVS) is a smart sensor system that performs terrain relative navigation by matching descent camera imagery to a map of the landing site and then fusing this with inertial measurements to obtain high rate map relative position, velocity and attitude estimates. A prototype of the LVS was recently tested in a helicopter field test over Mars analog terrain at altitudes representative of Mars Entry Descent and Landing conditions. TRN ran in real-time on the LVS during the flights without human intervention or tuning. The system was able to compute estimates accurate to 40m (3 sigma) in 10 seconds on a flight like processing system. This paper describes the Mars operational test space definition, how the field test was designed to cover that operational envelope, the resulting TRN performance across the envelope and an assessment of test space coverage. © 2015, E-flow American Institute of Aeronautics and Astronautics (AIAA). All rights reserved.

关键词： Navigation

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Fault management ontology and modeling patterns

Fault management ontology and modeling patterns

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AIAA Space and Astronautics Forum and Exposition, SPACE 2016

作者： Castet, Jean-François Bareh, Magdy Nunes, Jeffery Jenkins, Steven Lee, Gene Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Autonomy & Fault Protection Group 4800 Oak Grove Drive M/S 321-560 PasadenaCA91109 United States Autonomy & Fault Protection Group 4800 Oak Grove Drive M/S 301-490 PasadenaCA91109 United States System Reliability Group 4800 Oak Grove Drive M/S 156-206 PasadenaCA91109 United States Engineering Development Office 4800 Oak Grove Drive M/S 301-237 PasadenaCA91109 United States Autonomy & Fault Protection Group 4800 Oak Grove Drive M/S 321-560 PasadenaCA91109 United States

ISBN: (数字)9781624104275

ISBN: (纸本)9781624104275

This paper presents a novel model-based approach to capture problematic behaviors and how they affect a system. Failure modes, failure causes and propagation are discussed, as well as redundancy and Fault Containment Regions. An application case of a Martian rover has been developed, featuring enough complexity to demonstrate the capabilities of the fault management ontology. A SysML profile reflecting the ontology concepts and relationships was produced to allow adding fault management information to SysML models. Finally, this ontology represents a foundational step to enable the automated creation of reliability artifacts such as Failure Modes, Effects and Criticality Analysis (FMECA), fault trees, or Fault Containment Region diagrams. Considerations and on-going work related to the auto-generation of these artifacts are discussed in this paper. © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Ontology

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A CALIBRATED 35 GHZ AIRBORNE SCATTEROMETER FOR NASA'S SURFACE WATER AND OCEAN TOPOGRAPHY MISSION 35th

A CALIBRATED 35 GHZ AIRBORNE SCATTEROMETER FOR NASA'S SURFAC...

引用

IEEE International Geoscience and Remote Sensing Symposium

作者： Gerard Ruiz Carregal Tom Hartley Paul Siqueira Jan-Willem De Bleser Mark S. Haynes Daniel Esteban-Fernandez Thomas Millette Microwave Remote Sensing Laboratory University of Massachusetts Radar System and Instrument Engineering Jet Propulsion Laboratory Department of Geography Mt. Holyoke College

ISBN: (纸本)9781479979301

In this paper, an airborne Ka-band (35 GHz) FMCW scatterometer and its preliminary results are presented. The paper describes the system, the calibration and the data processing needed to study the response of different targets to the scatterometer. The results obtained in the first flights include normalized radar cross-section measurements of inland water bodies and a tree height estimation algorithm.

关键词： Airborne radar Millimeter wave radar Scatterometer Radar cross-section topography airborne radar Radar cross section gigahertz surface water Millimeter wave radar Scatterometers

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Rule-based flight software cost estimation

Rule-based flight software cost estimation

引用

AIAA SPACE Conference and Exposition, 2015

作者： Stukes, Sherry A. Spagnuolo, John N. Jet Propulsion Laboratory California Institute of Technology United States Cross Mission System Development And Implementation 4800 Oak Grove Drive/301-270 PasadenaCA91109 United States Engineering Cost Estimation 4800 Oak Grove Drive/301-465 PasadenaCA91109 United States

ISBN: (数字)9781624103346

ISBN: (纸本)9781624103346

This paper discusses the fundamental process for the computation of Flight software (FSW) cost estimates. This process has been incorporated in a rule-based expert system [1] that can be used for Independent Cost Estimates (ICEs), Proposals, and for the validation of Cost Analysis Data Requirements (CADRe) submissions. A high-level directed graph (referred to here as a decision graph) illustrates the steps taken in the production of these estimated costs and serves as a basis of design for the expert system described in this paper. Detailed discussions are subsequently given elaborating upon the methodology, tools, charts, and caveats related to the various nodes of the graph. We present general principles for the estimation of FSW using SEER-SEM as an illustration of these principles when appropriate. Since Source Lines of Code (SLOC) is a major cost driver, a discussion of various SLOC data sources for the preparation of the estimates is given together with an explanation of how contractor SLOC estimates compare with the SLOC estimates used by JPL. Obtaining consistency in code counting will be presented as well as factors used in reconciling SLOC estimates from different code counters. When sufficient data is obtained, a mapping into the JPL Work Breakdown Structure (WBS) from the SEER-SEM output is illustrated. For across the board FSW estimates, as was done for the NASA Discovery Mission proposal estimates performed at JPL, a comparative highlevel summary sheet for all missions with the SLOC, data description, brief mission description and the most relevant SEER-SEM parameter values is given to illustrate an encapsulation of the used and calculated data involved in the estimates. The rule-based expert system described provides the user with inputs useful or sufficient to run generic cost estimation programs. This system’s incarnation is achieved via the C Language Integrated Production system (CLIPS) and will be addressed at the end of this paper. © 2015, Ameri

关键词： Directed graphs

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