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Actuators used on the United States space shuttle fleet are lubricated with unspecified amounts of Braycote 601 (Castrol Braycote) grease consisting of a perfluoropolyalkyl ether (PFPAE) base oil thickened with a polytetrafluoroethylene (PTFE) filler. Each shuttle has four body flap actuators (BFAs) (two on each wing) on a common segmented shaft and four rudder speed brake (RSB) actuators. The actuators were designed to operate for 10 years and 100 flights without periodic relubrication....
Topics: NASA Technical Reports Server (NTRS), ACTUATORS, GREASES, POLYTETRAFLUOROETHYLENE, SPACE SHUTTLES,...
During the shuttle era NASA utilized a failure reporting system called the Problem Reporting and Corrective Action (PRACA) it purpose was to identify and track system non-conformance. The PRACA system over the years evolved from a relatively nominal way to identify system problems to a very complex tracking and report generating data base. The PRACA system became the primary method to categorize any and all anomalies from corrosion to catastrophic failure. The systems documented in the PRACA...
Topics: NASA Technical Reports Server (NTRS), COMPONENT RELIABILITY, FAILURE, FAILURE MODES, GROUND SUPPORT...
This paper will describe the methodology used to allocate Reliability and Maintainability (R&M) goals to Ground Systems Development and Operations (GSDO) subsystems currently being designed or upgraded.
Topics: NASA Technical Reports Server (NTRS), GROUND OPERATIONAL SUPPORT SYSTEM, MAINTAINABILITY,...
Space radiation in space systems present unique failure modes and considerations for reliability engineers. Radiation effects is not a one size fits all field. Threat conditions that must be addressed for a given mission depend on the mission orbital profile, the technologies of parts used in critical functions and on application considerations, such as supply voltages, temperature, duty cycle, and redundancy. In general, the threats that must be addressed are of two types-the cumulative...
Topics: NASA Technical Reports Server (NTRS), AEROSPACE SYSTEMS, EXTRATERRESTRIAL RADIATION, FAILURE MODES,...
We have previously conducted a number of data assimilation experiments using AIRS Version-5 quality controlled temperature profiles as a step toward finding an optimum balance of spatial coverage and sounding accuracy with regard to improving forecast skill. The data assimilation and forecast system we used was the Goddard Earth Observing System Model , Version-5 (GEOS-5) Data Assimilation System (DAS), which represents a combination of the NASA GEOS-5 forecast model with the National Centers...
Topics: NASA Technical Reports Server (NTRS), EARTH OBSERVING SYSTEM (EOS), TEMPERATURE MEASUREMENT,...
Understanding climate variability at regional scales is an important for research and societal needs. Atmospheric retrospective-analyses (or reanalyses) integrate multitudes of observing systems with numerical models to produce continuous data that include variables not easily observed, if at all. The breadth of variables as well as observational influence included in reanalyses make them ideal for investigating climate variability. In this paper, we assess NASA s Modern Era...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC TEMPERATURE, CLIMATE, SOUTHERN OSCILLATION,...
On the day-of-launch, the 45th Weather Squadron (45 WS) Launch Weather Officers (LWOs) monitor the upper-level winds for their launch customers to include NASA's Launch Services Program and NASA's Ground Systems Development and Operations Program. They currently do not have the capability to display and overlay profiles of upper-level observations and numerical weather prediction model forecasts. The LWOs requested the Applied Meteorology Unit (AMU) develop a tool in the form of a graphical...
Topics: NASA Technical Reports Server (NTRS), MATHEMATICAL MODELS, RADIOSONDES, SPACECRAFT LAUNCHING, WIND...
A mid-fidelity computational fluid dynamics tool called RotCFD - specifically developed to aid in rotorcraft conceptual design efforts - has been applied to the study of rotor wake interactions of civil tiltrotor aircraft in the immediate vicinity of vertiport/airport ground infrastructure. This issue has grown in importance as previous NASA studies have suggested that civil tiltrotor aircraft can potentially have a significant impact on commercial transport aviation. Current NASA reference...
Topics: NASA Technical Reports Server (NTRS), TILT ROTOR AIRCRAFT, COMPUTATIONAL FLUID DYNAMICS, ROTARY...
Multiple metrics are applied to the design of large civil rotorcraft, integrating minimum cost and minimum environmental impact. The design mission is passenger transport with similar range and capacity to a regional jet. Separate aircraft designs are generated for minimum empty weight, fuel burn, and environmental impact. A metric specifically developed for the design of aircraft is employed to evaluate emissions. The designs are generated using the NDARC rotorcraft sizing code, and rotor...
Topics: NASA Technical Reports Server (NTRS), ROTARY WING AIRCRAFT, DESIGN ANALYSIS, CIVIL AVIATION,...
An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Atmosphere Revitalization System for moderate duration missions of the Orion Multipurpose Crew Vehicle. In previous years at this conference, reports were presented on extensive Johnson Space Center testing of this technology in a sea-level pressure environment with simulated and actual human metabolic loads in both open and closed-loop...
Topics: NASA Technical Reports Server (NTRS), ADSORPTION, CARBON DIOXIDE, CREW EXPLORATION VEHICLE,...
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The International Space Station (ISS) has been designed as a laboratory for demonstrating technologies in a microgravity environment, benefitting exploration programs by reducing the overall risk of implementing such technologies in new spacecraft. At the beginning of fiscal year 2010, the ISS program manager requested that the amine-based, pressure-swing carbon dioxide and humidity absorption technology (designed by Hamilton Sundstrand, baselined for the Orion Multi-Purpose Crew Vehicle, and...
Topics: NASA Technical Reports Server (NTRS), AMINES, CABIN ATMOSPHERES, CARBON DIOXIDE, INTERNATIONAL...
Atmospheric pressure and oxygen concentration of human-occupied space vehicles and habitats are an important life support parameter. The atmosphere is critical in terms of not only safety but also in terms of maximizing human capabilities at the point of scientific discovery. Human exploration missions beyond low earth orbit (LEO) will include extravehicular activity (EVA). EVAs are carried out in low pressure (4.3 psi/29.6 kilopascals) space suits running at 100 percent oxygen. New suits...
Topics: NASA Technical Reports Server (NTRS), LOW EARTH ORBITS, SPACE MISSIONS, MANNED SPACE FLIGHT,...
As NASA works to develop an effective integrated portable life support system design for exploration Extravehicular activity (EVA), alternatives to the current system s electrical power and control architecture are needed to support new requirements for flexibility, maintainability, reliability, and reduced mass and volume. Experience with the current Extravehicular Mobility Unit (EMU) has demonstrated that the current architecture, based in a central power supply, monitoring and control unit,...
Topics: NASA Technical Reports Server (NTRS), EXTRAVEHICULAR ACTIVITY, LIFE SUPPORT SYSTEMS, PORTABLE LIFE...
Application Specific Integrated Circuit (ASIC) design for space applications involves multiple challenges of maximizing performance, minimizing power and ensuring reliable operation in extreme environments. This is a complex multidimensional optimization problem which must be solved early in the development cycle of a system due to the time required for testing and qualification severely limiting opportunities to modify and iterate. Manual design techniques which generally involve simulation at...
Topics: NASA Technical Reports Server (NTRS), APPLICATION SPECIFIC INTEGRATED CIRCUITS, OPTIMIZATION,...
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by NASA Technical Reports Server (NTRS)
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While a great deal of effort goes into planning and executing successful mission operations, it is also important to consider the End of the Mission during the planning, design, and operations phases of any mission. Spacecraft and launch vehicles must be disposed of properly in order to limit the generation of orbital debris, and better preserve the orbital environment for all future missions. Figure 30-1 shows a 1990's projected growth of debris with and without the use of responsible disposal...
Topics: NASA Technical Reports Server (NTRS), SPACE MISSIONS, MISSION PLANNING, LOW EARTH ORBITS, SPACE...
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In the early days of spaceflight, the gBig Sky h theory was the near universally accepted paradigm for dealing with collisions of orbiting objects. This theory was also used during the early years of the aviation industry. Just as it did in aviation, the gBig Sky h theory breaks down as more and more objects accumulate in the environment. Fortunately, by the late 1970 fs some visionaries in NASA and the US Department of Defense (DoD) realized that trends in the orbital environment would...
Topics: NASA Technical Reports Server (NTRS), SPACE DEBRIS, SPACE FLIGHT, IN SITU MEASUREMENT, EARTH...
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A concept for a Universal Waste Management System (UWMS) has been developed based on the knowledge gained from over 50 years of space travel. It is being designed for Commercial Orbital Transportation Services (COTS) and Multi ]Purpose Crew Vehicle (MPCV) and is based upon the Extended Duration Orbiter (EDO) commode. The UMWS was modified to enhance crew interface and reduce volume and cost. The UWMS will stow waste in fecal canisters, similar to the EDO, and urine will be stowed in bags for in...
Topics: NASA Technical Reports Server (NTRS), WASTE MANAGEMENT, POTABLE WATER, WATER RECLAMATION,...
After nearly 16 years on orbit, the Wide Field Planetary Camera-2 (WFPC-2) was recovered from the Hubble Space Telescope in May 2009 during the 12 day shuttle mission designated STS-125. During that exposure to the low Earth orbit environment, the WFPC-2 radiator was struck by approximately 700 impactors producing crater features 300 micrometers and larger in size. Following an optical inspection of these features in 2009, an agreement was reached for the joint NASA-ESA examination and...
Topics: NASA Technical Reports Server (NTRS), CAMERAS, PLANETARY CRATERS, HYPERVELOCITY IMPACT, CORE...
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This paper will discuss the design and development of the Nitrogen Oxygen Recharge System (NORS) for the International Space Station (ISS). The emphasis of the paper is the collaborative effort between The Boeing Company and Cobham in the crafting of the architecture of the system to meet NASA's requirements. Specific examples to be discussed include the inclusion of the pneumatic isolation valve for compliance with safety requirement, the inclusion of a single stage regulator with flow limiter...
Topics: NASA Technical Reports Server (NTRS), INTERNATIONAL SPACE STATION, NITROGEN, OXYGEN SUPPLY...
The goal of this paper is to relate numerical dissipations that are inherited in high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities. For pointwise evaluation of the source term, previous studies indicated that the phenomenon of wrong propagation speed of discontinuities is connected with the smearing of the discontinuity caused by the discretization of the advection term. The smearing introduces a nonequilibrium state into the calculation. Thus as...
Topics: NASA Technical Reports Server (NTRS), DISCONTINUITY, DISSIPATION, REACTING FLOW, TRUNCATION ERRORS,...
Heat flux sensors are routinely used in arc jet facilities to determine heat transfer rates from plasma plume. The goal of this study is to assess the impact of surface composition changes on these heat flux sensors. Surface compositions can change due to oxidation and material deposition from the arc jet. Systematic surface analyses of the sensors were conducted before and after exposure to plasma. Currently copper is commonly used as surface material. Other surface materials were studied...
Topics: NASA Technical Reports Server (NTRS), CATALYSIS, ENTHALPY, HEAT FLUX, OXIDATION, STAGNATION POINT,...
This paper addresses the problem of estimating the reliability of a critical system function as well as its impact on the system reliability when limited information is available. The approach addresses the basic function reliability, and then the impact of multiple attempts to accomplish the function. The dependence of subsequent attempts on prior failure to accomplish the function is also addressed. The autonomous docking of two spacecraft was the specific example that generated the inquiry,...
Topics: NASA Technical Reports Server (NTRS), SPACECRAFT DOCKING, AUTONOMOUS DOCKING, DEGRADATION, FAILURE,...
The effects of geometric changes on the amplification of first mode instability waves in an external supersonic boundary layer were investigated using numerical techniques. Boundary layer stability was analyzed at Mach 6 conditions similar to freestream conditions obtained in quiet ground test facilities so that results obtained in this study may be applied to future test article design to measure first mode instability waves. The DAKOTA optimization software package was used to optimize an...
Topics: NASA Technical Reports Server (NTRS), AMPLIFICATION, STABILITY TESTS, SUPERSONIC BOUNDARY LAYERS,...
The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The...
Topics: NASA Technical Reports Server (NTRS), INTERNATIONAL SPACE STATION, HEAT EXCHANGERS, CABIN...
NASA began corrosion studies at the Kennedy Space Center (KSC) in 1966 during the Gemini/Apollo Programs with the evaluation of long-term corrosion protective coatings for carbon steel. KSC's Beachside Corrosion Test Site (BCTS), which has been documented by the American Society of Materials (ASM) as one of the most corrosive, naturally occurring, environments in the world, was established at that time. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions...
Topics: NASA Technical Reports Server (NTRS), PROTECTIVE COATINGS, CORROSION TESTS, CARBON STEELS,...
The Product Breakdown Structure is traditionally a method of identification of the products of a project in a tree structure. It is a tool used to assess, plan, document, and display the equipment requirements for a project. It is part of a product based planning technique, and attempts to break down all components of a project in as much detail as possible, so that nothing is overlooked. The PBS for ground systems at the Kennedy Space Center is being developed to encompass the traditional...
Topics: NASA Technical Reports Server (NTRS), EQUIPMENT SPECIFICATIONS, GROUND OPERATIONAL SUPPORT SYSTEM,...
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Topics: NASA Technical Reports Server (NTRS), LOW EARTH ORBITS, SPACE DEBRIS, EARTH ORBITAL ENVIRONMENTS,...
The International Space Station (ISS) risk management methodology is an example of a mature and sustainable process. Risk management is a systematic approach used to proactively identify, analyze, plan, track, control, communicate, and document risks to help management make risk-informed decisions that increase the likelihood of achieving program objectives. The ISS has been operating in space for over 14 years and permanently crewed for over 12 years. It is the longest surviving habitable...
Topics: NASA Technical Reports Server (NTRS), INTERNATIONAL SPACE STATION, MANAGEMENT PLANNING, RISK, RISK...
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The software industry repeatedly observes cost growth of well over 100% even after decades of cost estimation research and well-known best practices, so "What's the problem?" In this paper we will provide an overview of the current state oj software cost estimation best practice. We then explore whether applying some of the methods used in software assurance might improve the quality of software cost estimates. This paper especially focuses on issues associated with model calibration,...
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, COST ESTIMATES, STATE ESTIMATION,...
The Oxygen and Volatile Extraction Node (OVEN) is a subsystem within the Regolith & Environment Science and Oxygen & Lunar Volatile Extraction (RESOLVE) project. The purpose of the OVEN subsystem is to release volatiles from lunar regolith and extract oxygen by means of a hydrogen reduction reaction. The complete process includes receiving, weighing, sealing, heating, and disposing of core sample segments while transferring all gaseous contents to the Lunar Advanced Volatile Analysis...
Topics: NASA Technical Reports Server (NTRS), LUNAR ROCKS, EXTRACTION, SEALING, HEATING, OXYGEN, HYDROGEN,...
Characterization of the launch abort system of the Multi-purpose Crew Vehicle (MPCV) for control design and accurate simulation has provided a significant challenge to aerodynamicists and design engineers. The design space of the launch abort vehicle (LAV) includes operational altitudes from ground level to approximately 300,000 feet, Mach numbers from 0-9, and peak dynamic pressure near 1300psf during transonic flight. Further complicating the characterization of the aerodynamics and the...
Topics: NASA Technical Reports Server (NTRS), FLIGHT CONTROL, AERODYNAMICS, ATTITUDE CONTROL, TRANSONIC...
Controlling Carbon Dioxide (CO2) partial pressure in the habitable vehicle environment is a critical part of operations on the International Space Station (ISS). On the United States segment of ISS, CO2 levels are primarily controlled by the Carbon Dioxide Removal Assembly (CDRA). There are two CDRAs on ISS; one in the United States Laboratory module, and one in the Node3 module. CDRA has been through several significant operational issues, performance issues and subsequent re-design of various...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE REMOVAL, INTERNATIONAL SPACE STATION, PARTIAL...
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Planar laser-induced fluorescence (PLIF) of nitric oxide (NO) was used to visualize the interaction of reaction-control-system (RCS) jet flows in the wake of a hypersonic capsule reentry vehicle. The tests were performed at the Calspan University at Buffalo Research Center's (CUBRC) LENS-I reflected shock tunnel facility. This was the first application of PLIF to study RCS jets in a large-scale pulsed hypersonic facility. The LENS-I facility allowed RCS jet flows to be studied while varying the...
Topics: NASA Technical Reports Server (NTRS), LASER INDUCED FLUORESCENCE, REENTRY VEHICLES, HYPERSONIC...
The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the prior year, covering the period of time between March 2011 and February 2012. The ISS continued permanent crew operations including the...
Topics: NASA Technical Reports Server (NTRS), ENVIRONMENTAL CONTROL, HABITABILITY, INTERNATIONAL SPACE...
The NASA strategic plan includes overarching strategies to inspire students through interactions with NASA people and projects, and to expand partnerships with industry and academia around the world. The NASA Johnson Space Center Crew and Thermal Systems Division (CTSD) actively supports these NASA initiatives. At the end of fiscal year 2011, CTSD created a strategic communications team to communicate CTSD capabilities, technologies, and personnel to internal NASA and external technical...
Topics: NASA Technical Reports Server (NTRS), EDUCATION, NASA PROGRAMS, COOPERATION, COMMERCE, STUDENTS,...
A new 20 K helium refrigerator installed at NASA Johnson Space Center's Space Environment Simulation Laboratory (SESL) was successfully commissioned and tested in 2012. The refrigerator is used to create a deep space environment within SESL s Chamber A to perform ground testing of the James Webb Space Telescope. The chamber previously and currently still has helium cryopumping panels (CPP) and LN2 shrouds used to create Low Earth Orbit environments. Now with the new refrigerator and new helium...
Topics: NASA Technical Reports Server (NTRS), AEROSPACE ENVIRONMENTS, REFRIGERATORS, JAMES WEBB SPACE...
It has been found previously, by measuring from active ]region magnetograms a proxy of the free energy in the active region fs magnetic field, (1) that there is a sharp upper limit to the free energy the field can hold that increases with the amount of magnetic field in the active region, the active region fs magnetic flux content, and (2) that most active regions are near this limit when their field explodes in a CME/flare eruption. That is, explosive active regions are concentrated in a main...
Topics: NASA Technical Reports Server (NTRS), FREE ENERGY, MAGNETIC FIELDS, SOLAR MAGNETIC FIELD, MAGNETIC...
This technical memorandum is to summarize the Formulation Study conducted during fiscal year 2012 on the High Temperature Boost (HTB) Power Processing Unit (PPU). The effort is authorized and supported by the Game Changing Technology Division, NASA Office of the Chief Technologist. NASA center participation during the formulation includes LaRC, KSC and JPL. The Formulation Study continues into fiscal year 2013. The formulation study has focused on the power processing unit. The team has...
Topics: NASA Technical Reports Server (NTRS), HIGH TEMPERATURE, SILICON CARBIDES, HIGH TEMPERATURE...
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The Damage Tolerance Assessment Branch evaluates the ability of a structure to perform reliably throughout its service life in the presence of a defect, crack, or other form of damage. Such assessment is fundamental to the use of structural materials and requires an integral blend of materials engineering, fracture testing and analysis, and nondestructive evaluation. The vision of the Branch is to increase the safety of manned space flight by improving the fracture control and the associated...
Topics: NASA Technical Reports Server (NTRS), DAMAGE, SAFETY, SERVICE LIFE, TOLERANCES (MECHANICS),...
Hidden connections between regression models of wind tunnel strain-gage balance calibration data are investigated. These connections become visible whenever balance calibration data is supplied in its design format and both the Iterative and Non-Iterative Method are used to process the data. First, it is shown how the regression coefficients of the fitted balance loads of a force balance can be approximated by using the corresponding regression coefficients of the fitted strain-gage outputs....
Topics: NASA Technical Reports Server (NTRS), STRAIN GAGES, WIND TUNNEL APPARATUS, REGRESSION ANALYSIS,...
One of the high risk operations on the International Space Station (ISS) is conducting a space walk, or an Extra Vehicular Activity (EVA). Threats to the space walking crew include airlock failures, space suit failures, and strikes from micro ]meteoroids and orbital debris (MM/OD). There are risks of becoming untethered from the space station, being pinched between the robotic arm and a piece of equipment, tearing your suit on a sharp edge, and other human errors that can be catastrophic. For...
Topics: NASA Technical Reports Server (NTRS), EXTRAVEHICULAR ACTIVITY, SPACECREWS, RISK, SAFETY, HAZARDS,...
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Before there is a funded space mission, there must be a present need for the mission. Space science and exploration are expensive, and without a well-defined and justifiable need, no one is going to commit significant funding for any space endeavor. However, as discussed in Chapter 1, applications of space technology and many and broad, hence there are many ways to determine and establish a mission need. Robotic science missions are justified by their science return. To be selected for flight,...
Topics: NASA Technical Reports Server (NTRS), SPACE MISSIONS, SYSTEMS ENGINEERING, SPACE TRANSPORTATION,...
Launch vehicle ascent is a time of high risk for an onboard crew. There is a large fraction of possible failures for which time is of the essence and a successful abort is possible if the detection and action happens quickly enough. This paper focuses on abort determination based on data already available from the Guidance, Navigation, and Control system. This work is the result of failure analysis efforts performed during the Ares I launch vehicle development program. The two primary areas of...
Topics: NASA Technical Reports Server (NTRS), LAUNCH VEHICLES, FAILURE ANALYSIS, ASCENT, GUIDANCE (MOTION),...
Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions. This chapter describes a thermal hydraulics design and analysis methodology developed at the NASA Marshall Space Flight Center, in support of the nuclear thermal propulsion development effort. The objective of this campaign is to bridge the design methods in the Rover/NERVA era, with a modern computational fluid dynamics and heat transfer methodology, to predict thermal, fluid, and hydrogen...
Topics: NASA Technical Reports Server (NTRS), NUCLEAR ROCKET ENGINES, THRUST CHAMBERS, COMPUTATIONAL FLUID...
A baseline load schedule for the manual calibration of a force balance was developed that takes current capabilities at the NASA Ames Balance Calibration Laboratory into account. The load schedule consists of 18 load series with a total of 194 data points. It was designed to satisfy six requirements: (i) positive and negative loadings should be applied for each load component; (ii) at least three loadings should be applied between 0 % and 100 % load capacity; (iii) normal and side force...
Topics: NASA Technical Reports Server (NTRS), LOADS (FORCES), BALANCE, CALIBRATING, ROLLING MOMENTS,...
The presented research validates the capability of a loosely-coupled computational fluid dynamics (CFD) and comprehensive rotorcraft analysis (CRA) code to calculate the flowfield around a rotor and test stand mounted inside a wind tunnel. The CFD/CRA predictions for the full-scale UH-60A Airloads Rotor inside the National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Foot Wind Tunnel at NASA Ames Research Center are compared with the latest measured airloads and performance data. The...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC LOADS, COMPUTATIONAL FLUID DYNAMICS, ROTARY WING...
Fission fragment direct energy conversion has been considered in the past for the purpose of increasing nuclear power plant efficiency and for advanced space propulsion. Since the fragments carry electric charge (typically in the order of 20 e) and have 100 MeV-range kinetic energy, techniques utilizing very high-voltage DC electrodes have been considered. This study is focused on a different approach: the kinetic energy of the charged fission fragments is converted into alternating current by...
Topics: NASA Technical Reports Server (NTRS), ENERGY CONVERSION, FRAGMENTS, TRAVELING WAVES, PARTICLE...
Future human and robotic sample return missions will require isolation containment systems with strict protocols and procedures for reducing inorganic and organic contamination. Robotic handling and manipulation of astromaterials may be required for preliminary examination inside such an isolation containment system. In addition, examination of astromaterials in microgravity will require constant contact to secure samples during manipulation. The National Space Grant Foundation exploration...
Topics: NASA Technical Reports Server (NTRS), SAMPLE RETURN MISSIONS, MICROGRAVITY, ROBOT ARMS,...
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A new analog for the giant polygons in the Chryse-Acidalia area suggests that those features may have formed in a major body of water - likely a Late Hesperian to Early Amazonian ocean. This analog -terrestrial polygons in subsea, passive margin basins derives from 3D seismic data that show similar-scale, polygonal fault systems in the subsurface of more than 50 terrestrial offshore basins. The terrestrial and martian polygons share similar sizes, basin-wide distributions, tectonic settings,...
Topics: NASA Technical Reports Server (NTRS), MARS (PLANET), OCEANS, POLYGONS, SEDIMENTS, TECTONICS,...
The lunar maria were formed by effusive fissure flows of low-viscosity basalt. Regional pyroclastic deposits were formed by deep-sourced fire-fountain eruptions dominated by basaltic glass. Basaltic material is also erupted from small vents within floor-fractured impact craters. These craters are characterized by shallow, flat floors cut by radial, concentric and/or polygonal fractures. Schultz [1] identified and classified over 200 examples. Low albedo pyroclastic deposits originate from...
Topics: NASA Technical Reports Server (NTRS), LUNAR MARIA, BASALT, CRATERS, FISSURES (GEOLOGY), MINERALOGY,...
There are several hypotheses on the origin of Gale Crater s central mound. These include ground water upwelling [1], aeolian, ice, volcanic [1-3], lacustrine [1-3], hydrothermal [1-3], and polar deposits [2]. The Mars Science Laboratory rover, Curiosity, landed in Gale Crater on August 6, 2012. It is currently analyzing samples along its traverse towards a channel and layered deposits that will provide insight into the sedimentary history of the crater [4]. Located at 5S, 138E, Gale is a 155km...
Topics: NASA Technical Reports Server (NTRS), CRATERS, GROUND WATER, MARS SURFACE, PALEONTOLOGY, VOLCANOES,...
Wi-Fi devices operated inside a metallic enclosure have been investigation in the recent years. A motivation for this study is to investigate wave propagation inside an enclosed environment such as elevator, car, aircraft, and spacecraft. There are performances and safety concerned that when the RF transmitters are used in the metallic enclosed environments. In this paper, the field distributions inside a confined room were investigated with multiple portable Wi-Fi devices. Computer simulations...
Topics: NASA Technical Reports Server (NTRS), ELECTRIC FIELDS, RADIO FREQUENCIES, RADIO WAVES,...
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Designing a spacecraft, or any other complex engineering system, requires extensive simulation and analysis work. Oftentimes, the large amounts of simulation data generated are very difficult and time consuming to analyze, with the added risk of overlooking potentially critical problems in the design. The authors have developed a generic data analysis tool that can quickly sort through large data sets and point an analyst to the areas in the data set that cause specific types of failures. The...
Topics: NASA Technical Reports Server (NTRS), MONTE CARLO METHOD, SIMULATION, RISK, COMPLEX SYSTEMS,...
NASA has created the Environmentally Responsible Aviation (ERA) Project to explore and document the feasibility, benefits and technical risk of advanced vehicle configurations and enabling technologies that will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations that have higher lift-to-drag ratios, reduced drag, and lower community...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT STRUCTURES, COMPOSITE STRUCTURES, COMPOSITE...
Aeroacoustic measurements of the 11 % scale full-span AMELIA CESTOL model with leading- and trailing-edge slot blowing circulation control (CCW) wing were obtained during a recent test in the Arnold Engineering Development Center 40- by 80-Ft. Wind Tunnel at NASA Ames Research Center, Sound levels and spectra were acquired with seven in-flow microphones and a 48-element phased microphone array for a variety of vehicle configurations, CCW slot flow rates, and forward speeds, Corrections to the...
Topics: NASA Technical Reports Server (NTRS), AEROACOUSTICS, FLOW VELOCITY, TRAILING EDGES, NOISE...
This paper presents the findings of a study conducted tn 2010 by the NASA Innovation Fund Award project entitled "Elastically Shaped Future Air Vehicle Concept". The study presents three themes in support of meeting national and global aviation challenges of reducing fuel burn for present and future aviation systems. The first theme addresses the drag reduction goal through innovative vehicle configurations via non-planar wing optimization. Two wing candidate concepts have been...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, TRAILING EDGES, DRAG REDUCTION, CONTROL...
An experimental investigation was performed to study the propulsion airframe aeroacoustic installation effects of a separate flow jet nozzle with a Hybrid Wing Body aircraft configuration where the engine is installed above the wing. Prior understanding of the jet noise shielding effectiveness was extended to a bypass ratio ten application as a function of nozzle configuration, chevron type, axial spacing, and installation effects from additional airframe components. Chevron types included fan...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CONFIGURATIONS, JET AIRCRAFT NOISE, NOZZLE...
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This paper presents an analysis of the slat noise for Hybrid Wing Body (HWB) aircraft, based on a database from a 3% scale wind tunnel test. It is shown that the HWB slats are one of the dominant noise components, characterized by its broad spectral shape with a peak frequency that depends on both the mean flow velocity and the aircraft angle of attack, the former following the conventional Strouhal number scaling and the latter explainable by the dependence of the coherence length of the slat...
Topics: NASA Technical Reports Server (NTRS), LEADING EDGE SLATS, NOISE PREDICTION, ANGLE OF ATTACK, WIND...
System noise assessments of a state-of-the-art reference aircraft (similar to a Boeing 777-200ER with GE90-like turbofan engines) and several hybrid wing body (HWB) aircraft configurations were recently performed using NASA engine and aircraft system analysis tools. The HWB aircraft were sized to an equivalent mission as the reference aircraft and assessments were performed using measurements of airframe shielding from a series of propulsion airframe aeroacoustic experiments. The focus of this...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CONFIGURATIONS, AERODYNAMIC NOISE, NOISE...
The Mars Entry Atmospheric Data System is a part of the Mars Science Laboratory, Entry, Descent, and Landing Instrumentation project. These sensors are a system of seven pressure transducers linked to ports on the entry vehicle forebody to record the pressure distribution during atmospheric entry. These measured surface pressures are used to generate estimates of atmospheric quantities based on modeled surface pressure distributions. Specifically, angle of attack, angle of sideslip, dynamic...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, TRAJECTORY ANALYSIS, ATMOSPHERIC ENTRY, MARS...
This paper reviews five laser-induced fluorescence-based velocimetry techniques that have been used to study high-speed compressible flows at NASA Langley Research Center. The techniques discussed in this paper include nitric oxide (NO) molecular tagging velocimetry (MTV), nitrogen dioxide photodissociation (NO2-to-NO) MTV, and NO and atomic oxygen (O-atom) Doppler-shift-based velocimetry. Measurements of both single-component and two-component velocity have been performed using these...
Topics: NASA Technical Reports Server (NTRS), VELOCITY MEASUREMENT, LASER INDUCED FLUORESCENCE, MOLECULAR...
Computations are performed to study the flow past an isolated, spanwise symmetric roughness element in zero pressure gradient boundary layers at Mach 3.5 and 5.9, with an emphasis on roughness heights of less than 55 percent of the local boundary layer thickness. The Mach 5.9 cases include flow conditions that are relevant to both ground facility experiments and high altitude flight ("cold wall" case). Regardless of the Mach number, the mean flow distortion due to the roughness...
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYERS, SUPERSONIC SPEED, SURFACE ROUGHNESS, HIGH...
This paper describes the Advanced High Lift Leading Edge (AHLLE) task performed by Northrop Grumman Systems Corporation, Aerospace Systems (NGAS) for the NASA Subsonic Fixed Wing project in an effort to develop enabling high-lift technology for laminar flow wings. Based on a known laminar cruise airfoil that incorporated an NGAS-developed integrated slot design, this effort involved using Computational Fluid Dynamics (CFD) analysis and quality function deployment (QFD) analysis on several...
Topics: NASA Technical Reports Server (NTRS), LEADING EDGES, LIFT, LAMINAR FLOW, AERODYNAMIC...
As part of the Mars Science Laboratory (MSL) trajectory reconstruction effort at NASA Langley Research Center, free-flight aeroballistic experiments of instrumented MSL scale models was conducted at Aberdeen Proving Ground in Maryland. The models carried an inertial measurement unit (IMU) and a flush air data system (FADS) similar to the MSL Entry Atmospheric Data System (MEADS) that provided data types similar to those from the MSL entry. Multiple sources of redundant data were available,...
Topics: NASA Technical Reports Server (NTRS), TRAJECTORY ANALYSIS, AERODYNAMICS, ANGLE OF ATTACK,...
Direct numerical simulations (DNS) are used to examine the pressure fluctuations generated by a Mach 6 turbulent boundary layer with nominal freestream Mach number of 6 and Reynolds number of Re(sub t) approx. =. 464. The emphasis is on comparing the primarily vortical pressure signal at the wall with the acoustic freestream signal under higher Mach number conditions. Moreover, the Mach-number dependence of pressure signals is demonstrated by comparing the current results with those of a...
Topics: NASA Technical Reports Server (NTRS), DIRECT NUMERICAL SIMULATION, PRESSURE OSCILLATIONS, TURBULENT...
Measurements of mean streamwise velocity, fluctuating streamwise velocity, and instantaneous streamwise velocity profiles in a hypersonic boundary layer were obtained over a 10-degree half-angle wedge model. A laser-induced fluorescence-based molecular tagging velocimetry technique was used to make the measurements. The nominal edge Mach number was 4.2. Velocity profiles were measured both in an untripped boundary layer and in the wake of a 4-mm diameter cylindrical tripping element centered...
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYERS, HYPERSONIC BOUNDARY LAYER, LAMINAR BOUNDARY...
A nonlinear simulation of the NASA Generic Transport Model was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of dynamic models identified from flight data. Measurements from a typical system identification maneuver were systematically and progressively deteriorated and then used to estimate stability and control derivatives within a Monte Carlo analysis. Based on the results, recommendations were provided for maximum...
Topics: NASA Technical Reports Server (NTRS), DYNAMIC MODELS, ERROR ANALYSIS, ACCURACY, MONTE CARLO METHOD,...
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We report recent advancements of the agglomerated multigrid methodology for complex flow simulations on fully unstructured grids. An agglomerated multigrid solver is applied to a wide range of test problems from simple two-dimensional geometries to realistic three- dimensional configurations. The solver is evaluated against a single-grid solver and, in some cases, against a structured-grid multigrid solver. Grid and solver issues are identified and overcome, leading to significant improvements...
Topics: NASA Technical Reports Server (NTRS), AGGLOMERATION, STRUCTURED GRIDS (MATHEMATICS), UNSTRUCTURED...
On August 5 , 2012, the Mars Science Laboratory (MSL) entry capsule successfully entered Mars' atmosphere and landed the Curiosity rover in Gale Crater. The capsule used a reaction control system (RCS) consisting of four pairs of hydrazine thrusters to fly a guided entry. The RCS provided bank control to fly along a flight path commanded by an onboard computer and also damped unwanted rates due to atmospheric disturbances and any dynamic instabilities of the capsule. A preliminary assessment of...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC HEATING, COMPUTATIONAL FLUID DYNAMICS, CRATERS,...
Non-intrusive hydroxyl radical (OH) planar laser-induced fluorescence (PLIF) measurements were obtained in configuration C of the University of Virginia supersonic combustion experiment. The combustion of hydrogen fuel injected through an unswept compression ramp into a supersonic cross-flow was imaged over a range of streamwise positions. Images were corrected for optical distortion, variations in the laser sheet profile, and different camera views. Results indicate an effect of fuel...
Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, SUPERSONIC COMBUSTION, LASER...
Nonlinear parabolized stability equations and secondary instability analyses are used to provide a computational assessment of the potential use of the discrete roughness elements (DRE) technology for extending swept-wing natural laminar flow at chord Reynolds numbers relevant to transport aircraft. Computations performed for the boundary layer on a natural laminar flow airfoil with a leading-edge sweep angle of 34.6deg, free-stream Mach number of 0.75 and chord Reynolds numbers of 17 x 10(exp...
Topics: NASA Technical Reports Server (NTRS), SWEPT WINGS, TURBULENT BOUNDARY LAYER, LAMINAR FLOW, BOUNDARY...
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Estimates of the eddy dissipation rate (EDR) were obtained from measurements made by a coherent pulsed lidar and compared with estimates from mesoscale model simulations and measurements from an in situ sonic anemometer at the Denver International Airport and with EDR estimates from the last observation time of the trailing vortex pair. The estimates of EDR from the lidar were obtained using two different methodologies. The two methodologies show consistent estimates of the vertical profiles....
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC TURBULENCE, MESOSCALE PHENOMENA, RADAR...
The main objective of this paper is to construct a turbulence model with a more reliable second equation simulating length scale. In the present paper, we assess the length scale equation based on Menter s modification to Rotta s two-equation model. Rotta shows that a reliable second equation can be formed in an exact transport equation from the turbulent length scale L and kinetic energy. Rotta s equation is well suited for a term-by-term modeling and shows some interesting features compared...
Topics: NASA Technical Reports Server (NTRS), TURBULENCE MODELS, NAVIER-STOKES EQUATION, REYNOLDS...
This paper presents the computational aeroelastic results generated in support of the first Aeroelastic Prediction Workshop for the Benchmark Supercritical Wing (BSCW) and the HIgh REynolds Number AeroStructural Dynamics (HIRENASD) configurations and compares them to the experimental data. The computational results are obtained using FUN3D, an unstructured grid Reynolds-averaged Navier-Stokes solver developed at NASA Langley Research Center. The analysis results for both configurations include...
Topics: NASA Technical Reports Server (NTRS), AEROELASTICITY, SUPERCRITICAL WINGS, REYNOLDS AVERAGING,...
A technique for predicting supersonic pitch damping of blunt axisymmetric bodies from static CFD data is presented. The contributions to static pitching moment due to forebody and aftbody pressure distributions are broken out and considered separately. The one-dimension moment equation is cast to model the separate contributions from forebody and aftbody pressures with no traditional damping term included. The aftbody contribution to pitching moment is lagged by a phase angle of the natural...
Topics: NASA Technical Reports Server (NTRS), BLUNT BODIES, COMPUTATIONAL FLUID DYNAMICS, PITCHING MOMENTS,...
Fully resolved simulation data of flow separation over 2-D humps has been used to analyze the modeling terms in second-moment closures of the Reynolds-averaged Navier- Stokes equations. Existing models for the pressure-strain and dissipation terms have been analyzed using a priori calculations. All pressure-strain models are incorrect in the high-strain region near separation, although a better match is observed downstream, well into the separated-flow region. Near-wall inhomogeneity causes...
Topics: NASA Technical Reports Server (NTRS), SEPARATED FLOW, BOUNDARY LAYER SEPARATION, NAVIER-STOKES...
Measurements have been conducted at the University of Virginia Supersonic Combustion Facility in configuration C of the dual-mode scramjet. This is a continuation of previously published works on configuration A. The scramjet is hydrogen fueled and operated at two equivalence ratios, one representative of the scram mode and the other of the ram mode. Dual-pump CARS was used to acquire the mole fractions of the major species as well as the rotational and vibrational temperatures of N2....
Topics: NASA Technical Reports Server (NTRS), SUPERSONIC COMBUSTION RAMJET ENGINES, RAMAN SPECTROSCOPY,...
Conceptual design is the most fluid phase of aircraft design. It is important to be able to perform large scale design space exploration of candidate concepts that can achieve the design intent to avoid more costly configuration changes in later stages of design. This also means that conceptual design is highly dependent on the disciplinary analysis tools to capture the underlying physics accurately. The required level of analysis fidelity can vary greatly depending on the application. Vehicle...
Topics: NASA Technical Reports Server (NTRS), DESIGN ANALYSIS, AIRCRAFT DESIGN, DESIGN OPTIMIZATION,...
The manual piloting requirements specified under the NASA Constellation Program involved Cooper-Harper ratings, which are a qualitative and subjective evaluation from experienced pilots. This type of verification entails a significant investment of resources to assess a completed design and is not one that can easily or meaningfully be applied upfront in the design phase. The evolution of the Multi-Purpose Crew Vehicle Program to include an independently developed propulsion system from an...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT PILOTS, CONSTELLATION PROGRAM, COOPER-HARPER...
The Supersonics Project of the NASA Fundamental Aeronautics Program organized an internal sonic boom workshop to evaluate near- and mid-field sonic boom prediction capability at the Fundamental Aeronautics Annual Meeting in Atlanta, Georgia on October 8, 2008. Workshop participants computed sonic boom signatures for three non-lifting bodies and two lifting configurations. A cone-cylinder, parabolic, and quartic bodies of revolution comprised the non-lifting cases. The lifting configurations...
Topics: NASA Technical Reports Server (NTRS), ANGLE OF ATTACK, SONIC BOOMS, LIFTING BODIES, BOUNDARY...
Results presented at the Fifth Drag Prediction Workshop using CFL3D, FUN3D, and NSU3D are described. These are calculations on the workshop provided grids and drag adapted grids. The NSU3D results have been updated to reflect an improvement to skin friction calculation on skewed grids. FUN3D results generated after the workshop are included for custom participant generated grids and a grid from a previous workshop. Uniform grid refinement at the design condition shows a tight grouping in...
Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL GRIDS, DRAG, PREDICTIONS, WIND TUNNEL TESTS,...
The National Transonic Facility (NTF) utilizes Inlet Guide Vanes (IGV) to provide precise, quick response Mach number control for the tunnel. During cryogenic operations, the massive IGV structure can experience large thermal gradients, measured as "Delta T or (Delta)T", between the IGV ring and its support structure called the transfer case. If these temperature gradients are too large, the IGV structure can be stressed beyond its safety limit and cease operation. In recent years,...
Topics: NASA Technical Reports Server (NTRS), GUIDE VANES, TEMPERATURE GRADIENTS, WIND TUNNELS, INTAKE...
Grid modification methods have been under development at NASA to enable better predictions of low boom pressure signatures from supersonic aircraft. As part of this effort, two new codes, Stretched and Sheared Grid - Modified (SSG) and Boom Grid (BG), have been developed in the past year. The CFD results from these codes have been compared with ones from the earlier grid modification codes Stretched and Sheared Grid (SSGRID) and Mach Cone Aligned Prism (MCAP) and also with the available...
Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, GRID GENERATION (MATHEMATICS),...
A graphical framework is used for statistical analysis of the results from an extensive N-version test of a collection of Reynolds-averaged Navier-Stokes computational fluid dynamics codes. The solutions were obtained by code developers and users from North America, Europe, Asia, and South America using a common grid sequence and multiple turbulence models for the June 2012 fifth Drag Prediction Workshop sponsored by the AIAA Applied Aerodynamics Technical Committee. The aerodynamic...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CONFIGURATIONS, DRAG, REYNOLDS AVERAGING,...
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The Aeroelastic Prediction Workshop brought together an international community of computational fluid dynamicists as a step in defining the state of the art in computational aeroelasticity. This workshop's technical focus was prediction of unsteady pressure distributions resulting from forced motion, benchmarking the results first using unforced system data. The most challenging aspects of the physics were identified as capturing oscillatory shock behavior, dynamic shock-induced separated flow...
Topics: NASA Technical Reports Server (NTRS), AEROELASTICITY, BOUNDARY LAYERS, DEFLECTION, PRESSURE...
"Changing the game" in space exploration involves changing the paradigm for the human exploration of the Solar System, e.g, changing the human exploration of Mars from a three-year epic event to an annual expedition. For the purposes of this assessment an "annual expedition" capability is defined as an in-space power & propulsion system which, with launch mass limits as defined in NASA s Mars Architecture 5.0, enables sending a crew to Mars and returning them after a...
Topics: NASA Technical Reports Server (NTRS), ENERGY CONVERSION, NUCLEAR FUSION, RANKINE CYCLE, NUCLEAR...
The Rendezvous and Proximity Operations Program (RPOP) is a laptop computer- based relative navigation tool and piloting aid that was developed during the Space Shuttle program. RPOP displays a graphical representation of the relative motion between the target and chaser vehicles in a rendezvous, proximity operations and capture scenario. After being used in over 60 Shuttle rendezvous missions, some of the RPOP display concepts have become recognized as a minimum standard for cockpit displays...
Topics: NASA Technical Reports Server (NTRS), NAVIGATION AIDS, COCKPITS, SPACE SHUTTLE MISSIONS, SPACE...
Future sample return missions will require strict protocols and procedures for reducing inorganic and organic contamination in isolation containment systems. In 2012, a baseline study was orchestrated to establish the current state of organic cleanliness in gloveboxes used by NASA JSC astromaterials curation labs [1, 2]. As part of this in-depth organic study, the current curatorial technical support procedure (TSP) 23 was used for cleaning the gloveboxes with ultra pure water (UPW) [3-5]....
Topics: NASA Technical Reports Server (NTRS), CLEANING, DECONTAMINATION, SAMPLE RETURN MISSIONS,...
The Aeroelastic Prediction Workshop brought together an international community of computational fluid dynamicists as a step in defining the state of the art in computational aeroelasticity. The Rectangular Supercritical Wing (RSW) was chosen as the first configuration to study due to its geometric simplicity, perceived simple flow field at transonic conditions and availability of an experimental data set containing forced oscillation response data. Six teams performed analyses of the RSW; they...
Topics: NASA Technical Reports Server (NTRS), AEROELASTICITY, LESSONS LEARNED, RECTANGULAR WINGS,...
A validation study of Computational Fluid Dynamics (CFD) for Supersonic Retropropulsion (SRP) was conducted using three Navier-Stokes flow solvers (DPLR, FUN3D, and OVERFLOW). The study compared results from the CFD codes to each other and also to wind tunnel test data obtained in the NASA Ames Research Center 90 70 Unitary PlanWind Tunnel. Comparisons include surface pressure coefficient as well as unsteady plume effects, and cover a range of Mach numbers, levels of thrust, and angles of...
Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, WIND TUNNEL TESTS, SUPERSONIC...
In this paper, the use of polyimide foam as a lining in double panel applications is considered. It is being investigated here as a replacement for aircraft grade glass fiber and has a number of attractive functional attributes, not the least of which is its high fire resistance. The test configuration studied here consisted of two 1mm (0.04 in.) thick, flat aluminum panels separated by 12.7 cm (5.0 in.) with a 7.6 cm (3.0 in.) thick layer of foam centered in that space. Random incidence...
Topics: NASA Technical Reports Server (NTRS), FOAMS, POLYIMIDES, LININGS, PANELS, MECHANICAL PROPERTIES,...
As a backup to the GPS-aided Kalman filter and the Barometric altimeter, an "adjusted" velocity trigger is used during entry to trigger the chain of events that leads to drogue chute deploy for the Orion Multi-Purpose Crew Vehicle (MPCV) Exploration Flight Test-1 (EFT-1). Even though this scenario is multiple failures deep, the Orion Guidance, Navigation, and Control (GN&C) software makes use of a clever technique that was taken from the Mars Science Laboratory (MSL) program,...
Topics: NASA Technical Reports Server (NTRS), CREW EXPLORATION VEHICLE, DRAG CHUTES, GLOBAL POSITIONING...
Boundary-layer receptivity and stability of Mach 6 flows over smooth and rough seven-degree half-angle sharp-tipped cones are numerically investigated. The receptivity of the boundary layer to slow acoustic disturbances, fast acoustic disturbances, and vortical disturbances is considered. The effects of three-dimensional isolated roughness on the receptivity and stability are also simulated. The results for the smooth cone show that the instability waves are generated in the leading edge region...
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER STABILITY, CONTINUOUS SPECTRA, SURFACE...
Results from the Fifth AIAA CFD Drag Prediction Workshop (DPW-V) are presented. As with past workshops, numerical calculations are performed using industry-relevant geometry, methodology, and test cases. This workshop focused on force/moment predictions for the NASA Common Research Model wing-body configuration, including a grid refinement study and an optional buffet study. The grid refinement study used a common grid sequence derived from a multiblock topology structured grid. Six levels of...
Topics: NASA Technical Reports Server (NTRS), BODY-WING CONFIGURATIONS, COMPUTATIONAL FLUID DYNAMICS,...
The National Aeronautics and Space Administration (NASA) manages a vast array of infrastructure assets across ten National Centers with a worth of at least 30 billion dollars. Eighty percent of this infrastructure is greater than 40 years old and is in degraded condition. Maintenance budgets are typically less than one percent of current replacement value (CRV), much less than the 2-4% recommended by the National Research Council. The maintenance backlog was 2.55 billion dollars in FY10 and...
Topics: NASA Technical Reports Server (NTRS), NASA PROGRAMS, MANAGEMENT PLANNING, BUDGETING, PREVENTIVE...
The development of aerospace and aeronautics products typically requires three distinct types of testing resources across research, development, test, and evaluation: experimental ground testing, computational "testing" and development, and flight testing. Over the last twenty plus years, computational methods have replaced some physical experiments and this trend is continuing. The result is decreased utilization of ground test capabilities and, along with market forces, industry...
Topics: NASA Technical Reports Server (NTRS), GROUND TESTS, TEST FACILITIES, RESEARCH AND DEVELOPMENT,...
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A novel method for determining the thermal efficiency of the SparkJet is proposed. A SparkJet is attached to the end of a pendulum. The motion of the pendulum subsequent to a single spark discharge is measured using a laser displacement sensor. The measured displacement vs time is compared with the predictions of a theoretical perfect gas model to estimate the fraction of the spark discharge energy which results in heating the gas (i.e., increasing the translational-rotational temperature). The...
Topics: NASA Technical Reports Server (NTRS), IDEAL GAS, ELECTRIC SPARKS, CAPACITANCE, THERMODYNAMIC...
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Basics of Nuclear Systems: Long history of use on Apollo and space science missions. 44 RTGs and hundreds of RHUs launched by U.S. during past 4 decades. Heat produced from natural alpha (a) particle decay of Plutonium (Pu-238). Used for both thermal management and electricity production. Used terrestrially for over 65 years. Fissioning 1 kg of uranium yields as much energy as burning 2,700,000 kg of coal. One US space reactor (SNAP-10A) flown (1965). Former U.S.S.R. flew 33 space reactors....
Topics: NASA Technical Reports Server (NTRS), NUCLEAR PROPULSION, URANIUM 235, PLUTONIUM 238, TEMPERATURE...
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Geometric modeling of aircraft during the Conceptual design phase is very different from that needed for the Preliminary or Detailed design phases. The Conceptual design phase is characterized by the rapid, multi-disciplinary analysis of many design variables by a small engineering team. The designer must walk a line between fidelity and productivity, picking tools and methods with the appropriate balance of characteristics to achieve the goals of the study, while staying within the available...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT DESIGN, DESIGN ANALYSIS, COMPUTER AIDED DESIGN,...
Active Flow Control (AFC) experiments performed at the Caltech Lucas Adaptive Wall Wind Tunnel on a 12%-thick, generic vertical tail model indicated that sweeping jets emanating from the trailing edge (TE) of the vertical stabilizer significantly increased the side force coefficient for a wide range of rudder deflection angles and yaw angles at free-stream velocities approaching takeoff rotation speed. The results indicated that 2% blowing momentum coefficient (C(sub mu) increased the side...
Topics: NASA Technical Reports Server (NTRS), TAIL ASSEMBLIES, ACTUATORS, AIRCRAFT CONTROL, CONTROL...