Low cost manned Mars mission based on indigenous propellant production

NASA Technical Reports Server (NTRS)

Bruckner, A. P.; Cinnamon, M.; Hamling, S.; Mahn, K.; Phillips, J.; Westmark, V.

1993-01-01

The paper describes a low-cost approach to the manned exploration of Mars (which involves an unmanned mission followed two years later by a manned mission) based on near-term technologies and in situ propellant production. Particular attention is given to the basic mission architecture and its major components, including the orbital analysis, the unmanned segment, the Earth Return Vehicle, the aerobrake design, life sciences, guidance, communications, power, propellant production, the surface rovers, and Mars science. Also discussed are the cost per mission over an assumed 8-yr initiative.

Chemical production on Mars using in situ propellant production technology

NASA Technical Reports Server (NTRS)

Ash, Robert L.

1986-01-01

In situ propellant production (ISPP) was examined in terms of its applicability to a manned Mars mission. Production of oxygen from Martian atmosphere was used as the baseline system for ISPP technology assessment. It was concluded that production of oxygen was an important element in a manned Mars mission which could be developed in terrestrial laboratories. Expert system methodology will be required to enable reliable, autonomous production of oxygen. Furthermore, while no major technical breakthroughs are required, this research requires a long lead time to permit its systematic evolution.

Mars Propellant Production with Ionic Liquids Project

NASA Technical Reports Server (NTRS)

Falker, John; Thompson, Karen; Zeitlin, Nancy; Muscatello, Anthony

2015-01-01

This project seeks to develop a single vessel for carbon dioxide (CO2) capture and electrolysis for in situ Mars propellant production by eliminating several steps of CO2 processing, two cryocoolers, a high temperature reactor, a recycle pump, and a water condenser; thus greatly reducing mass, volume, and power.

Regenerative Gas Dryer for In-Situ Propellant Production

NASA Technical Reports Server (NTRS)

Paz, Aaron

2017-01-01

Rocket propellant can be produced anywhere that water is found by splitting it into hydrogen and oxygen, potentially saving several tons of mass per mission and enabling the long term presence of humans in space beyond LEO. When water is split into hydrogen and oxygen, the gaseous products can be very humid (several thousand ppm). Propellant-grade gases need to be extremely dry before being converted into cryogenic liquids (less than 26 ppm water for grade B Oxygen). The primary objective of this project is to design, build and test a regenerative gas drying system that can take humid gas from a water electrolysis system and provide dry gas (less than 26ppm water) to the inlet of a liquefaction system for long durations. State of the art work in this area attempted to use vacuum as a means to regenerate desiccant, but it was observed that water would migrate to the dry zone without a sweep gas present to direct the desorbed vapor. Further work attempted to use CO2 as a sweep gas, but this resulted in a corrosive carbonic acid. In order for in-situ propellant production to work, we need a way to continuously dry humid gas that addresses these issues.

This overview displays the concentration of JPL solid propellant production ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

This overview displays the concentration of JPL solid propellant production buildings as seen looking directly north (6 degrees) from the roof of the Administration Building (4231-E-32). The structures closest to the camera contain the equipment for weighing, grinding, mixing, and casting solid propellant grain for motors. Structures in the distance generally house curing or inspection activities. - Jet Propulsion Laboratory Edwards Facility, Edwards Air Force Base, Boron, Kern County, CA

Experimental investigation of the combustion products in an aluminised solid propellant

NASA Astrophysics Data System (ADS)

Liu, Zhu; Li, Shipeng; Liu, Mengying; Guan, Dian; Sui, Xin; Wang, Ningfei

2017-04-01

Aluminium is widely used as an important additive to improve ballistic and energy performance in solid propellants, but the unburned aluminium does not contribute to the specific impulse and has both thermal and momentum two-phase flow losses. So understanding of aluminium combustion behaviour during solid propellant burning is significant when improving internal ballistic performance. Recent developments and experimental results reported on such combustion behaviour are presented in this paper. A variety of experimental techniques ranging from quenching and dynamic measurement, to high-speed CCD video recording, were used to study aluminium combustion behaviour and the size distribution of the initial agglomerates. This experimental investigation also provides the size distribution of the condensed phase products. Results suggest that the addition of an organic fluoride compound to solid propellant will generate smaller diameter condensed phase products due to sublimation of AlF3. Lastly, a physico-chemical picture of the agglomeration process was also developed based on the results of high-speed CCD video analysis.

Microreactor Development for Martian In-Situ Propellant Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holladay, Jamie D.; Brooks, Kriston P.; Wegeng, Robert S.

2007-01-30

The second part of the Martian In-situ Propellant Production (MIPPS) system reviews the development of the Sabatier Reactor (SR). The microchannel SR had integrated cooling channels as well as reaction channels. It was <100cc in volume. The reactor utilized a proprietary catalyst. When operated at 400oC 70-80% CO2 conversion was achieved which enabled ~0.0125 kg CH4/hr production, or 1/8th the target mission. The modular design of the microchannel reactors would enable simple scale up to full scale production for the proposed mission.

AP reclamation and reuse in RSRM propellant

NASA Technical Reports Server (NTRS)

Miks, Kathryn F.; Harris, Stacey A.

1995-01-01

A solid propellant ingredient reclamation pilot plant has been evaluated at the Strategic Operations of Thiokol Corporation, located in Brigham City, Utah. The plant produces AP wet cake (95 percent AP, 5 percent water) for recycling at AP vendors. AP has been obtained from two standard propellant binder systems (PBAN and HTPB). Analytical work conducted at Thiokol indicates that the vendor-recrystallized AP meets Space Shuttle propellant specification requirements. Thiokol has processed 1-, 5-, and 600-gallon propellant mixes with the recrystallized AP. Processing, cast, cure, ballistic, mechanical, and safety properties have been evaluated. Phillips Laboratory static-test-fired 70-pound and 800-pound BATES motors. The data indicate that propellant processed with reclaimed AP has nominal properties.

14 CFR 21.129 - Tests: propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Tests: propellers. 21.129 Section 21.129... PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate § 21.129 Tests: propellers. Each person manufacturing propellers under a type certificate must give each variable pitch propeller an acceptable...

Propellant combustion product analyses on an M16 rifle and a 105 mm caliber gun

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ase, P.; Eisenberg, W.; Gordon, S.

1985-01-01

Some of the propellant combustion products (particulates and gases) that are formed on firing an M16 rifle and 105 mm caliber gun have been subjected to qualitative, and to a more limited extent, quantitative chemical analyses. For both weapons, large numbers of trace gas species, 90 to 70 respectively, were identified in the combustion effluents from the small large bore weapons. Quantifiable data were obtained for 15 of these species in terms of mass of compound formed per unit mass of propellant burned. Polynuclear aromatic hydrocarbons, 11 and 4 respectively, were identified and quantified in the combustion products from themore » small and large bore weapons. Metal particulates in the respirable range in the combustion products from the M16 rifle were analyzed and quantified. Many of the chemical species identified in the study have known toxicological properties. Although the data base is limited, it appears that within the confines of the different propellants' stoichiometries, the amounts of combustion products formed are approximately directly proportional to the masses of propellant burned.« less

An ISRU Propellant Production System to Fully Fuel a Mars Ascent Vehicle

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie; Paz, Aaron

2017-01-01

ISRU of Mars resources was base lined in 2009 Design Reference Architecture (DRA) 5.0, but only for Oxygen production using atmospheric CO2The Methane (LCH4) needed for ascent propulsion of the Mars Ascent Vehicle (MAV) would need to be brought from Earth. HOWEVER: Extracting water from the Martian Regolith enables the production of both Oxygen and Methane from Mars resources Water resources could also be used for other applications including: Life support, radiation shielding, plant growth, etc. Water extraction was not base lined in DRA5.0 due to perceived difficulties and complexity in processing regolith. The NASA Evolvable Mars Campaign (EMC) requested studies to look at the quantitative benefits and trades of using Mars water ISRU Phase 1: Examined architecture scenarios for regolith water retrieval. Completed October 2015Phase 2: Deep dive of one architecture concept to look at end-to-end system size, mass, power of a LCH4LO2 ISRU production system.Evolvable Mars CampaignPre-deployed Mars ascent vehicle (MAV)4 crew membersPropellants: Oxygen MethaneGenerate a system model to roll up mass power of a full ISRU system and enable parametric trade studies. Leverage models from previous studies and technology development programs Anchor with mass power performance from existing hardware. Whenever possible used reference-able (published) numbers for traceability.Modular approach to allow subsystem trades and parametric studies. Propellant mass needs taken from most recently published MAV study:Polsgrove, T. et al. (2015), AIAA2015-4416MAV engines operate at mixture ratios (oxygen: methane) between 3:1 and 3.5:1, whereas the Sabatier reactor produces at a 4:1 ratio. Therefore:Methane production is the driving requirement-Excess Oxygen will be produced.

14 CFR 21.129 - Tests: propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Tests: propellers. 21.129 Section 21.129... PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate Only § 21.129 Tests: propellers. Each person manufacturing propellers under a type certificate only shall give each variable pitch propeller an...

21 CFR 700.14 - Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products.

Code of Federal Regulations, 2011 CFR

2011-04-01

... propellant of cosmetic aerosol products. 700.14 Section 700.14 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.14 Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products...

21 CFR 700.14 - Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products.

Code of Federal Regulations, 2013 CFR

2013-04-01

... propellant of cosmetic aerosol products. 700.14 Section 700.14 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.14 Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products...

21 CFR 700.14 - Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products.

Code of Federal Regulations, 2012 CFR

2012-04-01

... propellant of cosmetic aerosol products. 700.14 Section 700.14 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.14 Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products...

21 CFR 700.14 - Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products.

Code of Federal Regulations, 2014 CFR

2014-04-01

... propellant of cosmetic aerosol products. 700.14 Section 700.14 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.14 Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products...

Autonomously Propelled Motors for Value-Added Product Synthesis and Purification.

PubMed

Srivastava, Sarvesh K; Schmidt, Oliver G

2016-06-27

A proof-of-concept design for autonomous, self-propelling motors towards value-added product synthesis and separation is presented. The hybrid motor design consists of two distinct functional blocks. The first, a sodium borohydride (NaBH4 ) granule, serves both as a reaction prerequisite for the reduction of vanillin and also as a localized solid-state fuel in the reaction mixture. The second capping functional block consisting of a graphene-polymer composite serves as a hydrophobic matrix to attract the reaction product vanillyl alcohol (VA), resulting in facile separation of this edible value-added product. These autonomously propelled motors were fabricated at a length scale down to 400 μm, and once introduced in the reaction environment showed rapid bubble-propulsion followed by high-purity separation of the reaction product (VA) by the virtue of the graphene-polymer cap acting as a mesoporous sponge. The concept has excellent potential towards the synthesis/isolation of industrially important compounds, affinity-based product separation, pollutant remediation (such as heavy metal chelation/adsorption), as well as localized fuel-gradients as an alternative to external fuel dependency. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In-Space Propellant Production Using Water

NASA Technical Reports Server (NTRS)

Notardonato, William; Johnson, Wesley; Swanger, Adam; McQuade, William

2012-01-01

A new era of space exploration is being planned. Manned exploration architectures under consideration require the long term storage of cryogenic propellants in space, and larger science mission directorate payloads can be delivered using cryogenic propulsion stages. Several architecture studies have shown that in-space cryogenic propulsion depots offer benefits including lower launch costs, smaller launch vehicles, and enhanced mission flexibility. NASA is currently planning a Cryogenic Propellant Storage and Transfer (CPST) technology demonstration mission that will use existing technology to demonstrate long duration storage, acquisition, mass gauging, and transfer of liquid hydrogen in low Earth orbit. This mission will demonstrate key technologies, but the CPST architecture is not designed for optimal mission operations for a true propellant depot. This paper will consider cryogenic propellant depots that are designed for operability. The operability principles considered are reusability, commonality, designing for the unique environment of space, and use of active control systems, both thermal and fluid. After considering these operability principles, a proposed depot architecture will be presented that uses water launch and on orbit electrolysis and liquefaction. This could serve as the first true space factory. Critical technologies needed for this depot architecture, including on orbit electrolysis, zero-g liquefaction and storage, rendezvous and docking, and propellant transfer, will be discussed and a developmental path forward will be presented. Finally, use of the depot to support the NASA Science Mission Directorate exploration goals will be presented.

Trade Study of Five In-Situ Propellant Production System for a Mars Sample Return Mission

NASA Technical Reports Server (NTRS)

Green, S. T.; Deffenbaugh, D. M.; Miller, M. A.

1999-01-01

One of the goals of NASA''s HEDS enterprise is to establish a long-term human presence on Mars at a fraction of the cost of employing today''s technology. The most direct method of reducing mission cost is to reduce the launch mass of the spacecraft. If the propellants for the return phase of the mission are produced on Mars, the total spacecraft mass could be reduced significantly. An interim goal is a Mars Sample Return (MSR) mission, which is proposed to demonstrate the feasibility of in-situ propellant production (ISPP). Five candidate ISPP systems for producing two fuels and oxygen from the Martian atmosphere are considered in this design trade-off study:(1) Zirconia cell with methanol synthesis, (2) Reverse water gas shift (RWGS) with water electrolysis and methanol synthesis, (3) Sabatier process for methane production with water electrolysis, (4) Sabatier process with water electrolysis and partial methane pyrolysis, and (5) Sabatier/RWGS combination with water electrolysis. These systems have been the subject of numerous previous analytical studies and laboratory demonstrations. In this investigation, the systems are objectively compared on the basis of thermochemical performance models using a commonly used chemical plant analysis software package. The realistic effects of incomplete chemical conversion and gas phase separator performance are included in these models. This study focuses on the chemical processing and product separation subsystems. The CO2 compression upstream of the chemical plane and the liquefaction/storage components are not included here.

Liquid Oxygen Propellant Densification Production and Performance Test Results With a Large-Scale Flight-Weight Propellant Tank for the X33 RLV

NASA Technical Reports Server (NTRS)

Tomsik, Thomas M.; Meyer, Michael L.

2010-01-01

This paper describes in-detail a test program that was initiated at the Glenn Research Center (GRC) involving the cryogenic densification of liquid oxygen (LO2). A large scale LO2 propellant densification system rated for 200 gpm and sized for the X-33 LO2 propellant tank, was designed, fabricated and tested at the GRC. Multiple objectives of the test program included validation of LO2 production unit hardware and characterization of densifier performance at design and transient conditions. First, performance data is presented for an initial series of LO2 densifier screening and check-out tests using densified liquid nitrogen. The second series of tests show performance data collected during LO2 densifier test operations with liquid oxygen as the densified product fluid. An overview of LO2 X-33 tanking operations and load tests with the 20,000 gallon Structural Test Article (STA) are described. Tank loading testing and the thermal stratification that occurs inside of a flight-weight launch vehicle propellant tank were investigated. These operations involved a closed-loop recirculation process of LO2 flow through the densifier and then back into the STA. Finally, in excess of 200,000 gallons of densified LO2 at 120 oR was produced with the propellant densification unit during the demonstration program, an achievement that s never been done before in the realm of large-scale cryogenic tests.

Conceptual study of on orbit production of cryogenic propellants by water electrolysis

NASA Technical Reports Server (NTRS)

Moran, Matthew E.

1991-01-01

The feasibility is assessed of producing cryogenic propellants on orbit by water electrolysis in support of NASA's proposed Space Exploration Initiative (SEI) missions. Using this method, water launched into low earth orbit (LEO) would be split into gaseous hydrogen and oxygen by electrolysis in an orbiting propellant processor spacecraft. The resulting gases would then be liquified and stored in cryogenic tanks. Supplying liquid hydrogen and oxygen fuel to space vehicles by this technique has some possible advantages over conventional methods. The potential benefits are derived from the characteristics of water as a payload, and include reduced ground handling and launch risk, denser packaging, and reduced tankage and piping requirements. A conceptual design of a water processor was generated based on related previous studies, and contemporary or near term technologies required. Extensive development efforts would be required to adapt the various subsystems needed for the propellant processor for use in space. Based on the cumulative results, propellant production by on orbit water electrolysis for support of SEI missions is not recommended.

A review of in situ propellant production techniques for solar system exploration

NASA Technical Reports Server (NTRS)

Hoffman, S. J.

1983-01-01

Representative studies done in the area of extraterrestrial chemical production as it applies to solar system exploration are presented. A description of the In Situ Propellant Production (ISPP) system is presented. Various propellant combinations and direct applications along with the previously mentioned benefits and liens are discussed. A series of mission scenarios is presented which is studied in the greatest detail. A general description of the method(s) of analysis used to study each mission is provided. Each section will be closed by an assessment of the performance advantage, if any, that can be provided by ISPP. A final section briefly summarizes those missions which, as a result of the studies completed thus far, should see a sizable benefit from the use of ISPP.

In situ propellant production: Alternatives for Mars exploration

NASA Technical Reports Server (NTRS)

Stancati, Michael L.; Jacobs, Mark K.; Cole, Kevin J.; Collins, John T.

1991-01-01

Current planning for the Space Exploration Initiative (SEI) recognizes the need for extraterrestrial resources to sustain long-term human presence and to attain some degree of self-sufficiency. As a practical matter, reducing the need to carry large supplies of propellant from Earth will make space exploration more economical. For nearly every round trip planned with conventional propulsion, the actual payload is only a small fraction - perhaps 10-15 percent - of the mass launched from Earth. The objective of this study was to analyze the potential application for SEI missions of propellants made exclusively from lunar or martian resources. Using such propellants could minimize or eliminate the cost of carrying propellant for surface excursion vehicles and return transfers through two high-energy maneuvers: Earth launch and trans-Mars injection. Certain chemical mono- and bipropellants are candidates for this approach; they could be recovered entirely from in situ resources on the Moon and Mars, without requiring a continuing Earth-based resupply of propellant constituents (e.g., fuel to mix with a locally obtained oxidizer) and, perhaps, with minimal need to resupply consumables (e.g., reagents or catalyst for process reactions). A complete assessment of the performance potential of these propellants must include the requirements for installation, operations, maintenance, and resupply of the chemical processing facility.

Mars rover sample return mission utilizing in situ production of the return propellants

NASA Technical Reports Server (NTRS)

Bruckner, A. P.; Nill, L.; Schubert, H.; Thill, B.; Warwick, R.

1993-01-01

This paper presents an unmanned Mars sample return mission that utilizes propellants manufactured in situ from the Martian atmosphere for the return trip. A key goal of the mission is to demonstrate the considerable benefits that can be realized through the use of indigenous resources and to test the viability of this approach as a precursor to manned missions to Mars. Two in situ propellant combinations, methane/oxygen and carbon monoxide/oxygen, are compared to imported terrestrial hydrogen/oxygen within a single mission architecture, using a single Earth launch vehicle. The mission is assumed to be launched from Earth in 2003. Upon reaching Mars, the landing vehicle aerobrakes, deploys a small satellite, and lands on the Martian surface. Once on the ground, the propellant production unit is activated, and the product gases are liquefied and stored in the empty tanks of the Earth Return Vehicle (ERV). Power for these activities is provided by a dynamic isotope power system. A semiautonomous rover, powered by the indigenous propellants, gathers between 25 and 30 kg of soil and rock samples which are loaded aboard the ERV for return to Earth. After a surface stay time of approximately 1.5 years, the ERV leaves Mars for the return voyage to Earth. When the vehicle reaches the vicinity of Earth, the sample return capsule detaches, and is captured and circularized in LEO via aerobraking maneuvers.

An ISRU Propellant Production System to Fully Fuel a Mars Ascent Vehicle

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie E.; Paz, Aaron

2017-01-01

In-Situ Resource Utilization (ISRU) will enable the long term presence of humans beyond low earth orbit. Since 2009, oxygen production from the Mars atmosphere has been baselined as an enabling technology for Mars human exploration by NASA. However, using water from the Martian regolith in addition to the atmospheric CO2 would enable the production of both liquid Methane and liquid Oxygen, thus fully fueling a Mars return vehicle. A case study was performed to show how ISRU can support NASA's Evolvable Mars Campaign (EMC) using methane and oxygen production from Mars resources. A model was built and used to generate mass and power estimates of an end-to-end ISRU system including excavation and extraction water from Mars regolith, processing the Mars atmosphere, and liquefying the propellants. Even using the lowest yield regolith, a full ISRU system would weigh 1.7 mT while eliminating the need to transport 30 mT of ascent propellants from earth.

Architecture Studies for Commercial Production of Propellants From the Lunar Poles

NASA Astrophysics Data System (ADS)

Duke, Michael B.; Diaz, Javier; Blair, Brad R.; Oderman, Mark; Vaucher, Marc

2003-01-01

Two architectures are developed that could be used to convert water held in regolith deposits within permanently shadowed lunar craters into propellant for use in near-Earth space. In particular, the model has been applied to an analysis of the commercial feasibility of using lunar derived propellant to convey payloads from low Earth orbit to geosynchronous Earth orbit. Production and transportation system masses were estimated for each architecture and cost analysis was made using the NAFCOM cost model. Data from the cost model were analyzed using a financial analysis tool reported in a companion paper (Lamassoure et al., 2002) to determine under what conditions the architectures might be commercially viable. Analysis of the architectural assumptions is used to identify the principal areas for further research, which include technological development of lunar mining and water extraction systems, power systems, reusable space transportation systems, and orbital propellant depots. The architectures and commercial viability are sensitive to the assumed concentration of ice in the lunar deposits, suggesting that further lunar exploration to determine whether higher-grade deposits exist would be economically justified.

The use of designed experiments in the process development of continuous propellant mixing

NASA Technical Reports Server (NTRS)

Campbell, J. A.; Clemons, K. T.; Wong, M. K.

1993-01-01

A continuous mix pilot plant was constructed at Aerojet Propulsion Division in Sacramento, California to develop a robust propellant mixing process for the full scale plant that was to be built at the NASA Advanced Solid Rocket Motor facility Yellow Creek, Mississippi. The plant was used to conduct dozens of subsystem and full system mixing tests for evaluation of equipment, processing methods, and control schemes for later use at the production plant. As a culmination to this work, a series of designed experiments were conducted using an eight run Taguchi analysis with four factors at two levels each to determine the primary effect of processing parameters on propellant ballistic and mechanical properties. The factors examined in these runs included the propellant production rate (454 (1000) and 622 kg/hr (1371 Ib/hr)), the product temperature out of the mixer (49 (120) and 63 deg C (145 deg F)), mixer screw speed (75 and 90 rpm), and the deaerator excess capacity (20 and 80 percent). Measured response variables included the uncured and cured density, Crawford Bomb liquid strand burning rates, and selected mechanical properties. The experiment revealed that several of the response variables displayed significant changes from run-to-run with the product temperature being the single most important factor. After concluding this experiment, a twenty-six hour confirmation run was conducted to verify the conclusions reached in the designed experiment. The extended run produced over 12,250 kgs (27,000 lbs) of propellant meeting all of the pre-run targeted properties including density (1.803 g/cc (0.065 lb/in(exp 3)) with a 0.12 percent coefficient of variation (CV) at 25 deg C (77 deg F)), liquid strand burn rate (0.889 cm/s (0.350 in/s) with a 0.69 percent CV at 4210 KPa (610 psig), 15.6 deg C (60 deg F)), nominal maximum stress (828 KPa (120 psig) with a 2.84 percent CV, S&E at 25 deg C (77 deg F), 5.08 cm/min (2 in/min)), strain at nominal maximum (47.4 percent with a

The 2001 Mars In-Situ-Propellant-Production Precursor (MIP) Flight Demonstration

NASA Technical Reports Server (NTRS)

Kaplan, David I.; Baird, R. Scott; Ratliff, James E.; Baraona, Cosmo R.; Jenkins, Phillip P.; Landis, Geoffrey A.; Scheiman, David A.; Brinza, David E.; Johnson, Kenneth R.; Karlmann, Paul B.;

Simulation in production of open rotor propellers: from optimal surface geometry to automated control of mechanical treatment

NASA Astrophysics Data System (ADS)

Grinyok, A.; Boychuk, I.; Perelygin, D.; Dantsevich, I.

2018-03-01

A complex method of the simulation and production design of open rotor propellers was studied. An end-to-end diagram was proposed for the evaluating, designing and experimental testing the optimal geometry of the propeller surface, for the machine control path generation as well as for simulating the cutting zone force condition and its relationship with the treatment accuracy which was defined by the propeller elastic deformation. The simulation data provided the realization of the combined automated path control of the cutting tool.

Atmospheric Processing Module for Mars Propellant Production

NASA Technical Reports Server (NTRS)

Muscatello, Anthony; Gibson, Tracy; Captain, James; Athman, Robert; Nugent, Matthew; Parks, Steven; Devor, Robert

2013-01-01

The multi-NASA center Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methane/oxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) Applied Chemistry Laboratory is focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere containing the minor components nitrogen, argon, carbon monoxide, and water vapor at Martian pressures (8 torr) by using dual cryocoolers with alternating cycles of freezing and sublimation. The resulting pressurized CO2 is fed to a methanation subsystem where it is catalytically combined with hydrogen in a Sabatier reactor supplied by the Johnson Space Center (JSC) to make methane and water vapor. We first used a simplified once-through setup and later employed a HiCO2 recycling system to improve process efficiency. This presentation and paper will cover (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO2/hr for 14 hr, (3) the testing of the CO2 freezer subsystem, and (4) the integration and testing of the two subsystems to verify the desired production rate of 31.7 g CH4/hr and 71.3 g H20/hr along with verification of their purity. The resulting 2.22 kg of CH4/O2 propellant per 14 hr day (including O2 from electrolysis of water recovered from regolith, which also supplies the H2 for methanation) is of the scale needed for a Mars Sample Return mission. In addition, the significance of the project to NASA's new Mars exploration plans will be discussed.

Atmospheric Processing Module for Mars Propellant Production

NASA Technical Reports Server (NTRS)

Muscatello, Anthony; Gibson, Tracy; Captain, James; Athman, Robert; Nugent, Matthew; Parks, Steven; Devor, Robert

2013-01-01

The multi-NASA center Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methane/oxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) Applied Chemistry Laboratory is focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere containing the minor components nitrogen, argon, carbon monoxide, and water vapor at Martian pressures (approx.8 torr) by using dual cryocoolers with alternating cycles of freezing and sublimation. The resulting pressurized CO2 is fed to a methanation subsystem where it is catalytically combined with hydrogen in a Sabatier reactor supplied by the Johnson Space Center (JSC) to make methane and water vapor. We first used a simplified once-through setup and later employed a HiCO2 recycling system to improve process efficiency. This presentation and paper will cover (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO2/hr for 14 hr, (3) the testing of the CO2 freezer subsystem, and (4) the integration and testing of the two subsystems to verify the desired production rate of 31.7 g CH4/hr and 71.3 g H2O/hr along with verification of their purity. The resulting 2.22 kg of CH4/O2 propellant per 14 hr day (including O2 from electrolysis of water recovered from regolith, which also supplies the H2 for methanation) is of the scale needed for a Mars Sample Return mission. In addition, the significance of the project to NASA's new Mars exploration plans will be discussed.

14 CFR 21.129 - Tests: propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Tests: propellers. 21.129 Section 21.129... PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate § 21.129 Tests: propellers. Each person... functional test to determine if it operates properly throughout the normal range of operation. ...

14 CFR 21.129 - Tests: propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Tests: propellers. 21.129 Section 21.129... PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate § 21.129 Tests: propellers. Each person... functional test to determine if it operates properly throughout the normal range of operation. ...

21 CFR 700.23 - Chlorofluorocarbon propellants.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.23 Chlorofluorocarbon propellants. The use of chlorofluorocarbons in cosmetics as propellants in self-pressurized containers is prohibited as...

21 CFR 700.23 - Chlorofluorocarbon propellants.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.23 Chlorofluorocarbon propellants. The use of chlorofluorocarbons in cosmetics as propellants in self-pressurized containers is prohibited as...

21 CFR 700.23 - Chlorofluorocarbon propellants.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.23 Chlorofluorocarbon propellants. The use of chlorofluorocarbons in cosmetics as propellants in self-pressurized containers is prohibited as...

21 CFR 700.23 - Chlorofluorocarbon propellants.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.23 Chlorofluorocarbon propellants. The use of chlorofluorocarbons in cosmetics as propellants in self-pressurized containers is prohibited as...

21 CFR 700.23 - Chlorofluorocarbon propellants.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.23 Chlorofluorocarbon propellants. The use of chlorofluorocarbons in cosmetics as propellants in self-pressurized containers is prohibited as...

14 CFR 21.129 - Tests: propellers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: propellers. 21.129 Section 21.129... PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate Only § 21.129 Tests: propellers. Each... acceptable functional test to determine if it operates properly throughout the normal range of operation. ...

Recent Advancements in Propellant Densification

NASA Technical Reports Server (NTRS)

McNelis, Nancy B.; Tomsik, Thomas M.

1998-01-01

Next-generation launch vehicles demand several technological improvements to achieve lower cost and more reliable access to space. One technology area whose performance gains may far exceed others is densified propellants. The ideal rocket engine propellant is characterized by high specific impulse, high density, and low vapor pressure. A propellant combination of liquid hydrogen and liquid oxygen (LH2/LOX) is one of the highest performance propellants, but LH2 stored at standard conditions has a relatively low density and high vapor pressure. Propellant densification can significantly improve this propellant's properties relative to vehicle design and engine performance. Vehicle performance calculations based on an average of existing launch vehicles indicate that densified propellants may allow an increase in payload mass of up to 5 percent. Since the NASA Lewis Research Center became involved with the National Aerospace Plane program in the 1980's, it has been leading the way in making densified propellants a viable fuel for next-generation launch vehicles. Lewis researchers have been working to provide a method and critical data for continuous production of densified hydrogen and oxygen.

Examination of propeller sound production using large eddy simulation

NASA Astrophysics Data System (ADS)

Keller, Jacob; Kumar, Praveen; Mahesh, Krishnan

2018-06-01

The flow field of a five-bladed marine propeller operating at design condition, obtained using large eddy simulation, is used to calculate the resulting far-field sound. The results of three acoustic formulations are compared, and the effects of the underlying assumptions are quantified. The integral form of the Ffowcs-Williams and Hawkings (FW-H) equation is solved on the propeller surface, which is discretized into a collection of N radial strips. Further assumptions are made to reduce FW-H to a Curle acoustic analogy and a point-force dipole model. Results show that although the individual blades are strongly tonal in the rotor plane, the propeller is acoustically compact at low frequency and the tonal sound interferes destructively in the far field. The propeller is found to be acoustically compact for frequencies up to 100 times the rotation rate. The overall far-field acoustic signature is broadband. Locations of maximum sound of the propeller occur along the axis of rotation both up and downstream. The propeller hub is found to be a source of significant sound to observers in the rotor plane, due to flow separation and interaction with the blade-root wakes. The majority of the propeller sound is generated by localized unsteadiness at the blade tip, which is caused by shedding of the tip vortex. Tonal blade sound is found to be caused by the periodic motion of the loaded blades. Turbulence created in the blade boundary layer is convected past the blade trailing edge leading to generation of broadband noise along the blade. Acoustic energy is distributed among higher frequencies as local Reynolds number increases radially along the blades. Sound source correlation and spectra are examined in the context of noise modeling.

Reduced-Smoke Solid Propellant Combustion Products Analysis. Development of a Micromotor Combustor Technique.

DTIC Science & Technology

1976-10-01

A low-cost micromotor combustor technique has been devised to support the development of reduced-smoke solid propellant formulations. The technique...includes a simple, reusable micromotor capable of high chamber pressures, a combustion products collection system, and procedures for analysis of

Handbook on Hypergolic Propellant Discharges and Disposal

NASA Technical Reports Server (NTRS)

Bowman, T. E.; Sivik, H. E.; Thomas, J. J.

1977-01-01

The efficiency of all treatment methods formerly or currently used in treating chemical wastes is assessed with emphasis on the disposal of hypergolic propellants. Maximum focus is on the space shuttle propellants MMH and N2O4. Except for hydrogen peroxide oxidizers, all the propellants are nitrogen based and can be potentially reduced to valuable plant nutrients. In theory, all the propellants can be reduced to carbon, hydrogen, nitrogen, and oxygen, except of fuming nitric acid which contains a small amount of fluorine. Appendices cover: (1) a general design criteria for disposal ponds; (2) thermal aspects of reaction in dilute solution; (3) gas bubble growth, detachment, and rise (4) absorption scrubber fundamentals and descriptions; (5) separation of a propellant vapor from a helium stream by permeation; and (6) atmospheric emission limits.

Production and Assessment of Damaged High Energy Propellant Samples,

DTIC Science & Technology

1980-05-08

and (c) -69.8% ...... 14 3 Longitudinal Velocity one hour after Compressing Versus Applied Engineering Compressive Strain for Propellant Samples...LONGITUDINAL VELOCITY ONE HOUR AFTER COMPRESSING VERSUS APPLIED ENGINEERING COMPRESSIVE STRAIN FOR PROPELLANT SAMPLES (NOMINAL 40 mm DIA x 13 mm HIGH

In-Situ Cryogenic Propellant Liquefaction and Storage for a Precursor to a Human Mars Mission

NASA Astrophysics Data System (ADS)

Mueller, Paul; Durrant, Tom

The current mission plan for the first human mission to Mars is based on an in-situ propellant production (ISPP) approach to reduce the amount of propellants needed to be taken to Mars and ultimately to reduce mission cost. Recent restructuring of the Mars Robotic Exploration Program has removed ISPP from the early sample return missions. A need still exists to demonstrate ISPP technologies on one or more robotic missions prior to the first human mission. This paper outlines a concept for an ISPP-based precursor mission as a technology demonstration prior to the first human mission. It will also return Martian soil samples to Earth for scientific analysis. The mission will primarily demonstrate cryogenic oxygen and fuel production, liquefaction, and storage for use as propellants for the return trip. Hydrogen will be brought from Earth as a feedstock to produce the hydrocarbon fuel (most likely methane). The analysis used to develop the mission concept includes several different thermal control and liquefaction options for the cryogens. Active cooling and liquefaction devices include Stirling, pulse tube, and Brayton-cycle cryocoolers. Insulation options include multilayer insulation, evacuated microspheres, aerogel blankets, and foam insulation. The cooling capacity and amount of insulation are traded off against each other for a minimum-mass system. In the case of hydrogen feedstock, the amount of hydrogen boiloff allowed during the trip to Mars is also included in the tradeoff. The spacecraft concept includes a Lander (including the propellant production plant) with a Mars Ascent Vehicle (MAV) mounted atop it. An option is explored where the engines on the MAV are also used for descent and landing on the Martian surface at the beginning of the mission. So the MAV propellant tanks would contain oxygen and methane during the trip from Earth. This propellant would be consumed in descent to the Martian surface, resulting in nearly-empty MAV tanks to be filled by the

Mars Ascent Vehicle-Propellant Aging

NASA Technical Reports Server (NTRS)

Dankanich, John; Rousseau, Jeremy; Williams, Jacob

2015-01-01

This project is to develop and test a new propellant formulation specifically for the Mars Ascent Vehicle (MAV) for the robotic Mars Sample Return mission. The project was initiated under the Planetary Sciences Division In-Space Propulsion Technology (ISPT) program and is continuing under the Mars Exploration Program. The two-stage, solid motor-based MAV has been the leading MAV solution for more than a decade. Additional studies show promise for alternative technologies including hybrid and bipropellant options, but the solid motor design has significant propellant density advantages well suited for physical constraints imposed while using the SkyCrane descent stage. The solid motor concept has lower specific impulse (Isp) than alternatives, but if the first stage and payload remain sufficiently small, the two-stage solid MAV represents a potential low risk approach to meet the mission needs. As the need date for the MAV slips, opportunities exist to advance technology with high on-ramp potential. The baseline propellant for the MAV is currently the carboxyl terminated polybutadiene (CTPB) based formulation TP-H-3062 due to its advantageous low temperature mechanical properties and flight heritage. However, the flight heritage is limited and outside the environments, the MAV must endure. The ISPT program competed a propellant formulation project with industry and selected ATK to develop a new propellant formulation specifically for the MAV application. Working with ATK, a large number of propellant formulations were assessed to either increase performance of a CTPB propellant or improve the low temperature mechanical properties of a hydroxyl terminated polybutadiene (HTPB) propellant. Both propellants demonstrated potential to increase performance over heritage options, but an HTPB propellant formulation, TP-H-3544, was selected for production and testing. The test plan includes propellant aging first at high vacuum conditions, representative of the Mars transit

Atmospheric Processing Module for Mars Propellant Production

NASA Technical Reports Server (NTRS)

Muscatello, Anthony C.

2014-01-01

The multi-NASA center Mars Atmosphere and Regolith COllectorPrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methaneoxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) Applied Chemistry Laboratory is focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere containing the minor components nitrogen, argon, carbon monoxide, and water vapor at Martian pressures (8 torr) by using dual cryocoolers with alternating cycles of freezing and sublimation. The resulting pressurized CO(sub 2) is fed to a methanation subsystem where it is catalytically combined with hydrogen in a Sabatier reactor supplied by the Johnson Space Center (JSC) to make methane and water vapor. We first used a simplified once-through setup and later employed a H(sub 2)CO(sub 2) recycling system to improve process efficiency. This presentation and paper will cover (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO(sub 2) hr for 14 hr, (3) the testing of the CO(sub 2) freezer subsystem, and (4) the integration and testing of the two subsystems to verify the desired production rate of 31.7 g CH(sub 4) hr and 71.3 g H(sub 2)O hr along with verification of their purity. The resulting 2.22 kg of CH(sub 2)O(sub 2) propellant per 14 hr day (including O(sub 2) from electrolysis of water recovered from regolith, which also supplies the H(sub 2) for methanation) is of the scale needed for a Mars Sample Return mission. In addition, the significance of the project to NASAs new Mars exploration plans will be discussed.

Atmospheric Processing Module for Mars Propellant Production

NASA Technical Reports Server (NTRS)

Muscatello, A.; Devor, R.; Captain, J.

2014-01-01

The multi-NASA center Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methaneoxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) Applied Chemistry Laboratory is focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere containing the minor components nitrogen, argon, carbon monoxide, and water vapor at Martian pressures (approx. 8 torr) by using dual cryocoolers with alternating cycles of freezing and sublimation. The resulting pressurized CO(sub 2) is fed to a methanation subsystem where it is catalytically combined with hydrogen in a Sabatier reactor supplied by the Johnson Space Center (JSC) to make methane and water vapor. We first used a simplified once-through setup and later employed a H(sub 2)CO(sub 2) recycling system to improve process efficiency. This presentation and paper will cover (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO(sub 2) hr for 14 hr, (3) the testing of the CO(sub 2) freezer subsystem, and (4) the integration and testing of the two subsystems to verify the desired production rate of 31.7 g CH(sub 4) hr and 71.3 g H(sub 2)O hr along with verification of their purity. The resulting 2.22 kg of CH(sub 2)O(sub 2) propellant per 14 hr day (including O(sub 2) from electrolysis of water recovered from regolith, which also supplies the H(sub 2) for methanation) is of the scale needed for a Mars Sample Return mission. In addition, the significance of the project to NASAs new Mars exploration plans will be discussed.

A new look at oxygen production on Mars - In situ propellant production (ISPP)

NASA Technical Reports Server (NTRS)

Frisbee, Robert H.; French, James R., Jr.; Lawton, Emil A.

1987-01-01

Consideration is given to the technique of producing oxygen on Mars from CO2 in the Martian atmosphere via in situ propellent production (ISPP). Mission implications of ISPP for both manned and unmanned Mars missions are described as well as ways to improve system reliability. Technology options that improve reliability and reduce power requirements include the use of adsorption pumps and advanced zirconia membranes. It is concluded that both manned and unmanned missions will benefit greatly from ISPP, especially in the context of a permanent manned base on Mars.

A Study on New Composite Thermoplastic Propellant

NASA Astrophysics Data System (ADS)

Kahara, Takehiro; Nakayama, Masanobu; Hasegawa, Hiroshi; Katoh, Kazushige; Miyazaki, Shigehumi; Maruizumi, Haruki; Hori, Keiichi; Morita, Yasuhiro; Akiba, Ryojiro

Efforts have been paid to realize a new composite propellant using thermoplastics as a fuel binder and lithium as a metallic fuel. Thermoplastics binder makes it possible the storage of solid propellant in small blocks and to provide propellants blocks into rocket motor case at a quantity needed just before use, which enables the production facility of solid propellant at a minimum level, thus, production cost significantly lower. Lithium has been a candidate for a metallic fuel for the ammonium perchlorate based composite propellants owing to its capability to reduce the hydrogen chloride in the exhaust gas, however, never been used because lithium is not stable at room conditions and complex reaction products between oxygen, nitrogen, and water are formed at the surface of particles and even in the core. However, lithium particles whose surface shell structure is well controlled are rather stable and can be stored in thermoplastics for a long period. Evaluation of several organic thermoplastics whose melting temperatures are easily tractable was made from the standpoint of combustion characteristics, and it is shown that thermoplastics propellants can cover wide range of burning rate spectrum. Formation of well-defined surface shell of lithium particles and its kinetics are also discussed.

The Mars In-Situ-Propellant-Production Precursor (MIP) Flight Demonstration

NASA Technical Reports Server (NTRS)

Kaplan, D. I.; Ratliff, J. E.; Baird, R. S.; Sanders, G. B.; Johnson, K. R.; Karlmann, P. B.; Baraona, C. R.; Landis, G. A.; Jenkins, P. P.; Scheiman, D. A.

1999-01-01

Strategic planning for human missions of exploration to Mars has conclusively identified insitu propellant production (ISPP) as an enabling technology. A team of scientists and engineers from NASA's Johnson Space Center, Jet Propulsion Laboratory, and Glenn Research Center is preparing the MARS ISPP PRECURSOR (MIP) Flight Demonstration. The objectives of MIP are to characterize the performance of processes and hardware that are important to ISPP concepts and to demonstrate how these processes and hardware interact with the Mars environment. Operating this hardware in the actual Mars environment is extremely important due to (1) uncertainties in our knowledge of the Mars environment, and (2) conditions that cannot be adequately simulated on Earth. The MIP Flight Demonstration is a payload onboard the MARS SURVEYOR Lander and will be launched in April 2001. MIP will be the first hardware to utilize the indigenous resources of a planet or moon. Its successful operation will pave the way for future robotic and human missions to rely on propellants produced using Martian resources as feedstock.

The structure of Rauvolfia serpentina strictosidine synthase is a novel six-bladed beta-propeller fold in plant proteins.

PubMed

Ma, Xueyan; Panjikar, Santosh; Koepke, Juergen; Loris, Elke; Stöckigt, Joachim

2006-04-01

The enzyme strictosidine synthase (STR1) from the Indian medicinal plant Rauvolfia serpentina is of primary importance for the biosynthetic pathway of the indole alkaloid ajmaline. Moreover, STR1 initiates all biosynthetic pathways leading to the entire monoterpenoid indole alkaloid family representing an enormous structural variety of approximately 2000 compounds in higher plants. The crystal structures of STR1 in complex with its natural substrates tryptamine and secologanin provide structural understanding of the observed substrate preference and identify residues lining the active site surface that contact the substrates. STR1 catalyzes a Pictet-Spengler-type reaction and represents a novel six-bladed beta-propeller fold in plant proteins. Structure-based sequence alignment revealed a common repetitive sequence motif (three hydrophobic residues are followed by a small residue and a hydrophilic residue), indicating a possible evolutionary relationship between STR1 and several sequence-unrelated six-bladed beta-propeller structures. Structural analysis and site-directed mutagenesis experiments demonstrate the essential role of Glu-309 in catalysis. The data will aid in deciphering the details of the reaction mechanism of STR1 as well as other members of this enzyme family.

Propelled abrasive grit applications for weed management in transitional corn grain production systems

USDA-ARS?s Scientific Manuscript database

Weed control is challenging to farmers who are transitioning from production systems that use synthetic herbicides to organic systems. A two-year field study examined weed control efficacy and corn grain yield of air-propelled corncob grit abrasion for in-row weed control. Grits were applied based o...

Propeller torque load and propeller shaft torque response correlation during ice-propeller interaction

NASA Astrophysics Data System (ADS)

Polić, Dražen; Ehlers, Sören; Æsøy, Vilmar

2017-03-01

Ships use propulsion machinery systems to create directional thrust. Sailing in ice-covered waters involves the breaking of ice pieces and their submergence as the ship hull advances. Sometimes, submerged ice pieces interact with the propeller and cause irregular fluctuations of the torque load. As a result, the propeller and engine dynamics become imbalanced, and energy propagates through the propulsion machinery system until equilibrium is reached. In such imbalanced situations, the measured propeller shaft torque response is not equal to the propeller torque. Therefore, in this work, the overall system response is simulated under the ice-related torque load using the Bond graph model. The energy difference between the propeller and propeller shaft is estimated and related to their corresponding mechanical energy. Additionally, the mechanical energy is distributed among modes. Based on the distribution, kinetic and potential energy are important for the correlation between propeller torque and propeller shaft response.

Low acid producing solid propellants

NASA Technical Reports Server (NTRS)

Bennett, Robert R.

1995-01-01

The potential environmental effects of the exhaust products of conventional rocket propellants have been assessed by various groups. Areas of concern have included stratospheric ozone, acid rain, toxicity, air quality and global warming. Some of the studies which have been performed on this subject have concluded that while the impacts of rocket use are extremely small, there are propellant development options which have the potential to reduce those impacts even further. This paper discusses the various solid propellant options which have been proposed as being more environmentally benign than current systems by reducing HCI emissions. These options include acid neutralized, acid scavenged, and nonchlorine propellants. An assessment of the acid reducing potential and the viability of each of these options is made, based on current information. Such an assessment is needed in order to judge whether the potential improvements justify the expenditures of developing the new propellant systems.

Refueling with In-Situ Produced Propellants

NASA Technical Reports Server (NTRS)

Chato, David J.

2014-01-01

In-situ produced propellants have been identified in many architecture studies as key to implementing feasible chemical propulsion missions to destinations beyond lunar orbit. Some of the more noteworthy ones include: launching from Mars to return to Earth (either direct from the surface, or via an orbital rendezvous); using the Earth-Moon Lagrange point as a place to refuel Mars transfer stages with Lunar surface produced propellants; and using Mars Moon Phobos as a place to produce propellants for descent and ascent stages bound for the Mars surface. However successful implementation of these strategies require an ability to successfully transfer propellants from the in-situ production equipment into the propellant tankage of the rocket stage used to move to the desired location. In many circumstances the most desirable location for this transfer to occur is in the low-gravity environment of space. In support of low earth orbit propellant depot concepts, extensive studies have been conducted on transferring propellants in-space. Most of these propellant transfer techniques will be applicable to low gravity operations in other locations. Even ground-based transfer operations on the Moon, Mars, and especially Phobos could benefit from the propellant conserving techniques used for depot refueling. This paper will review the literature of in-situ propellants and refueling to: assess the performance benefits of the use in-situ propellants for mission concepts; review the parallels with propellant depot efforts; assess the progress of the techniques required; and provide recommendations for future research.

14 CFR 21.500 - Acceptance of aircraft engines and propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or jurisdiction meets the requirements for... product furnishes with each such aircraft engine or propeller imported into the United States, an export...

14 CFR 21.500 - Acceptance of aircraft engines and propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or jurisdiction meets the requirements for... product furnishes with each such aircraft engine or propeller imported into the United States, an export...

14 CFR 21.500 - Acceptance of aircraft engines and propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or jurisdiction meets the requirements for... product furnishes with each such aircraft engine or propeller imported into the United States, an export...

14 CFR 21.500 - Acceptance of aircraft engines and propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or jurisdiction meets the requirements for... product furnishes with each such aircraft engine or propeller imported into the United States, an export...

The Structure of Rauvolfia serpentina Strictosidine Synthase Is a Novel Six-Bladed β-Propeller Fold in Plant Proteins[W

PubMed Central

Ma, Xueyan; Panjikar, Santosh; Koepke, Juergen; Loris, Elke; Stöckigt, Joachim

2006-01-01

The enzyme strictosidine synthase (STR1) from the Indian medicinal plant Rauvolfia serpentina is of primary importance for the biosynthetic pathway of the indole alkaloid ajmaline. Moreover, STR1 initiates all biosynthetic pathways leading to the entire monoterpenoid indole alkaloid family representing an enormous structural variety of ∼2000 compounds in higher plants. The crystal structures of STR1 in complex with its natural substrates tryptamine and secologanin provide structural understanding of the observed substrate preference and identify residues lining the active site surface that contact the substrates. STR1 catalyzes a Pictet-Spengler–type reaction and represents a novel six-bladed β-propeller fold in plant proteins. Structure-based sequence alignment revealed a common repetitive sequence motif (three hydrophobic residues are followed by a small residue and a hydrophilic residue), indicating a possible evolutionary relationship between STR1 and several sequence-unrelated six-bladed β-propeller structures. Structural analysis and site-directed mutagenesis experiments demonstrate the essential role of Glu-309 in catalysis. The data will aid in deciphering the details of the reaction mechanism of STR1 as well as other members of this enzyme family. PMID:16531499

Propellant Readiness Level: A Methodological Approach to Propellant Characterization

NASA Technical Reports Server (NTRS)

Bossard, John A.; Rhys, Noah O.

2010-01-01

A methodological approach to defining propellant characterization is presented. The method is based on the well-established Technology Readiness Level nomenclature. This approach establishes the Propellant Readiness Level as a metric for ascertaining the readiness of a propellant or a propellant combination by evaluating the following set of propellant characteristics: thermodynamic data, toxicity, applications, combustion data, heat transfer data, material compatibility, analytical prediction modeling, injector/chamber geometry, pressurization, ignition, combustion stability, system storability, qualification testing, and flight capability. The methodology is meant to be applicable to all propellants or propellant combinations; liquid, solid, and gaseous propellants as well as monopropellants and propellant combinations are equally served. The functionality of the proposed approach is tested through the evaluation and comparison of an example set of hydrocarbon fuels.

Producing propellants from water in lunar soil using solar lasers

NASA Astrophysics Data System (ADS)

de Morais Mendonca Teles, Antonio

, collect soil and retract itself to put the material on the top of the spacecraft inside a hole which will be opened; 3) an infrared laser based on solar electrical energy -a "solar laser" -when the soil be inside the chamber inside the spacecraft, the solar laser will be turned on and it will strike against the soil, heating it up, and release all oxygen and hydrogen from it. The oxygen and hydrogen molecules will be separated from the rest of the material by a mass spectrometer and they will be liquefied by thermal and pressure internal control sub-systems of the spacecraft, and pumped to vessels in a way similar to a micro-industrial line production process; the vessels with the propellants will be then ready to be taken by astronauts, from a small door outside the LPM. The shape of this spacecraft must be conical in order to not unbalance it during the landing and roving maneuvers and soil cargoes, and it will be shielded externally from heat and radiation from the Sun, and micrometeoroids, to prevent the internal thermal conduction and electronic operations from damaging. A solar array externally deployed can produce 44 KW of electric soil energy for the production process. This miniature chemical-processing plant can possibly have an output of 100 Kg of liquid oxygen and 200 Kg of liquid hydrogen per day. Telecommunications with Earth will provide the onboard computer courses for roving to new mapped areas with richer propellants content in the soil. The spacecraft can weight approximately 6,000 Kg (at launch time from Earth). It will be necessary two LPMs for providing all the liquid oxygen and hydrogen needed to supply spacecrafts next to a semi-permanent small manned lunar base. With the Lunar Propellant Manufacturer it will solve the problem of not-expensively producing great quantities of propellants for a manned spacecraft to explore Mars and beyond In the Solar System.

Mars Sample Return mission utilizing in-situ propellant production

NASA Technical Reports Server (NTRS)

Zubrin, Robert; Price, Steve

1995-01-01

This report presents the results of a study examining the potential of in-situ propellant production (ISPP) on Mars to aid in achieving a low cost Mars Sample Return (MSR) mission. Two versions of such a mission were examined: a baseline version employing a dual string spacecraft, and a light weight version employing single string architecture with selective redundancy. Both systems employed light weight avionics currently being developed by Lockheed Martin, Jet Propulsion Lab and elsewhere in the aerospace community, both used a new concept for a simple, light weight parachuteless sample return capsule, both used a slightly modified version of the Mars Surveyor lander currently under development at Lockheed Martin for flight in 1998, and both used a combination of the Sabatier-electrolysis and reverse water gas shift ISPP systems to produce methane/oxygen propellant on Mars by combining a small quantity of imported hydrogen with the Martian CO2 atmosphere. It was found that the baseline mission could be launched on a Delta 7925 and return a 0.5 kg sample with 82 percent mission launch margin;over and beyond subsystem allocated contingency masses . The lightweight version could be launched on a Mid-Lite vehicle and return a 0.25 kg sample with 11 percent launch margin, over and above subsystem contingency mass allocations.

Mars In-Situ Propellant Production Precursor (MIP) Flight Demonstration Project: Overview

NASA Technical Reports Server (NTRS)

Kaplan, D. I.; Ratliff, J. E.; Baird, R. S.; Sanders, G. B.; Johnson, K. R.; Karlmann, P. B.; Juanero, K. J.; Baraona, C. R.; Landis, G. A.; Jenkins, P. P.;

Mars In-Situ Propellant Production Precursor (MIP) Flight Demonstration Project: Overview

NASA Technical Reports Server (NTRS)

Kaplan, D. I.; Ratliff, J. E.; Sanders, G. B.; Johnson, K. R.; Karlmann, P. B.; Juanero, K. J.; Barona, C. R.; Landis, G. A.; Jenkins, P. P.; Scheiman, D. A.

1999-01-01

Strategic planning for human missions of exploration to Mars has conclusively identified in-situ propellant production (ISPP) as an enabling technology. A team of scientists and engineers from NASA's Johnson Space Center, Jet Propulsion Laboratory, and Lewis Research Center is preparing the MARS ISPP Precursors (MIP) Flight Demonstration. The objectives of MIP are to characterize the performance of processes and hardware which are important to ISPP concepts and to demonstrate how these processes and hardware interact with the Mars environment. Operating this hardware in the actual Mars environment is extremely important due to both uncertainties in our knowledge of the Mars environment as well as because of conditions that cannot be adequately simulated on Earth. The MIP Flight Demonstration is a payload onboard the MARS SURVEYOR Lander and will be launched in April 2001. MIP will be the first hardware to utilize the indigenous resources of a planet or moon. Its successful operation will pave the way for future robotic and human missions to rely on propellants produced using Martian resources as feedstock.

Investigation of Propeller-power-plant Autoprecession Boundaries for a Dynamic-aeroelastic Model of a Four-engine Turboprop Transport Airplane

NASA Technical Reports Server (NTRS)

Abbott, Frank T., Jr.; Kelley, H. Neale; Hampton, Kenneth D.

1963-01-01

A flexibly mounted aircraft engine may under certain conditions experience a self-excited whirling instability involving a coupling between the gyroscopic and aerodynamic forces acting on the propeller, and the inertial, elastic, and damping forces contributed by the power plant, nacelle, and wing. This phenomenon has been called autoprecession, or whirl instability. An experimental investigation was made in the Langley transonic dynamics tunnel at Mach numbers below 0.3 to study some of the pertinent parameters influencing the phenomenon. These parameters included propeller rotational speed, stiffness of the power-plant assembly in the pitch and yaw planes and the ratio of pitch stiffness to yaw stiffness, structural damping of the power-plant assembly in the pitch and yaw planes, simulated fuel load in the wings, and the location and number of autoprecessing powerplant assemblies. A large dynamic-aeroelastic model of a four-engine turboprop transport airplane mounted on a vertical rod in a manner which provided several limited body degrees of freedom was used in the investigation. It was found that the boundary for autoprecession decreased markedly with Increasing proreduction of power-plant stiffness and/or damping, and to a lesser degree decreased with reduction of simulated fuel load in the wings. peller rotational speed generally lowered the autoprecession boundary. This effect was more pronounced as the stiffness was increased. An inboard power plant was found to be more susceptible to autoprecession than an outboard one. Combinations in which two or more power plants had the same level of reduced stiffness resulted in autoprecession boundaries considerably lower than that of a single power plant with the same level of reduced stiffness.

Demonstration of Critical Systems for Propellant Production on Mars for Science and Exploration Missions

NASA Technical Reports Server (NTRS)

Linne, Diane L.; Gaier, James R.; Zoeckler, Joseph G.; Kolacz, John S.; Wegeng, Robert S.; Rassat, Scot D.; Clark, D. Larry

2013-01-01

A Mars hopper has been proposed as a Mars mobility concept that will also demonstrate and advance in-situ resource utilization. The components needed in a Mars propellant production plant have been developed to various levels of technology maturity, but there is little experience with the systems in a Mars environment. Two systems for the acquisition and compression of the thin carbon dioxide atmosphere were designed, assembled, and tested in a Mars environment chamber. A microchannel sorption pump system was able to raise the pressure from 7 Torr to 450 Torr or from 12 Torr to over 700 Torr in two stages. This data now provides information needed to make additional improvements in the sorption pump technology to increase performance, although a system-level analysis might prove that some amount of pre- or post-compression may be a preferred solution. A mini cryofreezer system was also evaluated as an alternative method for carbon dioxide acquisition and compression. Finally, an electrolysis system was tested and successfully demonstrated start-up operation and thermal stability of all components during long-term operation in the chamber.

Simulating the Composite Propellant Manufacturing Process

NASA Technical Reports Server (NTRS)

Williamson, Suzanne; Love, Gregory

2000-01-01

There is a strategic interest in understanding how the propellant manufacturing process contributes to military capabilities outside the United States. The paper will discuss how system dynamics (SD) has been applied to rapidly assess the capabilities and vulnerabilities of a specific composite propellant production complex. These facilities produce a commonly used solid propellant with military applications. The authors will explain how an SD model can be configured to match a specific production facility followed by a series of scenarios designed to analyze operational vulnerabilities. By using the simulation model to rapidly analyze operational risks, the analyst gains a better understanding of production complexities. There are several benefits of developing SD models to simulate chemical production. SD is an effective tool for characterizing complex problems, especially the production process where the cascading effect of outages quickly taxes common understanding. By programming expert knowledge into an SD application, these tools are transformed into a knowledge management resource that facilitates rapid learning without requiring years of experience in production operations. It also permits the analyst to rapidly respond to crisis situations and other time-sensitive missions. Most importantly, the quantitative understanding gained from applying the SD model lends itself to strategic analysis and planning.

Solid propellant processing factor in rocket motor design

NASA Technical Reports Server (NTRS)

1971-01-01

The ways are described by which propellant processing is affected by choices made in designing rocket engines. Tradeoff studies, design proof or scaleup studies, and special design features are presented that are required to obtain high product quality, and optimum processing costs. Processing is considered to include the operational steps involved with the lining and preparation of the motor case for the grain; the procurement of propellant raw materials; and propellant mixing, casting or extrusion, curing, machining, and finishing. The design criteria, recommended practices, and propellant formulations are included.

Oxygen Generator System Mars In-Situ Propellant Production Precursor Flight

NASA Technical Reports Server (NTRS)

Sridhar, K. R.; Gottmann, M.; Baird, R. S.

1999-01-01

The 2001 Lander to Mars will carry the first ever ISRU payload to Mars. This payload, the Mars In-situ Propellant production Precursor (MIP), will demonstrate a variety of technologies that will be required for future ISRU Mars indigenous material processing plant designs. One of those technologies is that of extracting oxygen from the predominantly carbon dioxide atmosphere of Mars, a prerequisite for future sample return and human missions to Mars. The Oxygen Generator Subsystem (OGS) portion of the MIP will demonstrate this and is the focus of this paper. The primary objective of the OGS is to demonstrate the production of oxygen from Mars atmospheric gases. Secondary objectives are to measure the performance and reliability of oxygen generation hardware in actual mission environments over an extended time. Major constraints on the OGS design came from several sources. The Lander provides power to the system from solar power that is harnessed by photovoltaic arrays. This limited OGS to daytime only operations (six to eight hours) and a maximum power of 15W. The reliance on solar power necessitated thermal cycling of the OGS between Mars ambient and OGS operating temperatures. The Lander also limited the total mass of the MIP payload to 7.5 kg with a correspondingly small volume, and the OGS was one of six experiments in the MIP. Mass and volume were to be minimized. Another constraint was cost. Mission funding, as always, was tight. Cost was to be minimized. In short the OGS design had to be low power (<15 Watts), low mass (1 kg), low volume, low cost, and be capable of cyclical operations for an extended stay on Mars. After extensive research, a zirconia based solid oxide electrolyzer design was selected.

Oxygen Generator System Mars In-Situ Propellant Production Precursor Flight

NASA Technical Reports Server (NTRS)

Sridhar, K. R.; Gottmann, M.; Baird, R. S.

1999-01-01

The 2001 Lander to Mars will carry the first ever In situ Resource Utilization (ISRU) payload to Mars. This payload, the Mars In-situ Propellant production Precursor (MIP), will demonstrate a variety of technologies that will be required for future ISRU Mars indigenous material processing plant designs. One of those technologies is that of extracting oxygen from the predominantly carbon dioxide atmosphere of Mars, a prerequisite for future sample return and human missions to Mars. The Oxygen Generator Subsystem (OGS) portion of the MIP will demonstrate this and is the focus of this paper. The primary objective of the OGS is to demonstrate the production of oxygen from Mars atmospheric gases. Secondary objectives are to measure the performance and reliability of oxygen generation hardware in actual mission environments over an extended time. Major constraints on the OGS design came from several sources. The Lander provides power to the system from solar power that is harnessed by photovoltaic arrays. This limited OGS to daytime only operations (six to eight hours) and a maximum power of 15W. The reliance on solar power necessitated thermal cycling of the OGS between Mars ambient and OGS operating temperatures. The Lander also limited the total mass of the MIP payload to 7.5 kg with a correspondingly small volume, and the OGS was one of six experiments in the MIP Mass and volume were to be minimized. Another constraint was cost. Mission funding, as always, was tight. Cost was to be minimized. In short the OGS design had to be low power (<15 Watts), low mass (1 kg), low volume, low cost, and be capable of cyclical operations for an extended stay on Mars. After extensive research, a zirconia based solid oxide electrolyzer design was selected.

Trade Study of Five In-Situ Propellant Production Systems for a Mars Sample Return Mission

NASA Technical Reports Server (NTRS)

Green, S. T.; Deffenbaugh, D. M.; Miller, M. A.

1999-01-01

One of the goals of NASA's HEDS enterprise is to establish a long-term human presence on Mars at a fraction of the cost of employing today's technology. The most direct method of reducing mission cost is to reduce the launch mass of the spacecraft. If the propellants for the return phase of the mission are produced on Mars, the total spacecraft mass could be reduced significantly. An interim goal is a Mars Sample Return (MSR) mission, which is proposed to demonstrate the feasibility of in-situ propellant production (ISPP). Five candidate ISPP systems for producing two fuels and oxygen from the Martian atmosphere are considered in this design trade-off study: 1) Zirconia cell with methanol synthesis, 2) Reverse water gas shift with water electrolysis and methanol synthesis, 3) Sabatier process for methane product ion with water electrolysis, 4) Sabatier process with water electrolysis and partial methane pyrolysis, and 5) Sabatier/RWGS combination with water electrolysis.

AEROSOL INDUSTRY SUCCESS IN REDUCING CFC PROPELLANT USAGE

EPA Science Inventory

Part I of this report discusses the U.S. aerosol industry's experience in converting from chlorofluorocarbon (CFC) propellants to alternative aerosol formulations. Detailed examples of non-CFC formulations are provided for 28 categories of aerosol products. ydrocarbon propellants...

Modeling of Liquefaction of Cryogenic Propellant in a Tank

NASA Technical Reports Server (NTRS)

Hedayat, A.; Bolshinskiy, L. G.; Majumdar, A. K.

2017-01-01

Over the past decades NASA has been focusing to develop technology that would to allow for production of cryogenic propellants on the surface of Mars. The in-situ propellant production reduces the amount of propellants needed to be taken to Mars and ultimately to reduce mission cost. Utilizing Martian resources, the produced gaseous propellants (i.e., oxygen and methane) are liquefied and stored prior to use on the Mars ascent vehicle. In this paper, a model for the liquefaction process of gaseous propellants in a cryogenically refrigerated tank is presented. The tank is considered to be cylindrical with elliptical top and bottom domes. A multi-node transient model is developed based on the mass and energy conservation equations and wall-gas and liquid-gas interface mass and heat transfer correlations. Description of the model and predicted results will be presented in the final paper.

Materials characterization of propellants using ultrasonics

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Jones, David

1993-01-01

Propellant characteristics for solid rocket motors were not completely determined for its use as a processing variable in today's production facilities. A major effort to determine propellant characteristics obtainable through ultrasonic measurement techniques was performed in this task. The information obtained was then used to determine the uniformity of manufacturing methods and/or the ability to determine non-uniformity in processes.

In situ propellant production - A new potential for round-trip spacecraft

NASA Technical Reports Server (NTRS)

Stancati, M. L.; Niehoff, J. C.; Wells, W. C.; Ash, R. L.

1979-01-01

In situ propellant production (ISPP) greatly reduces the Earth escape requirements for some roundtrip missions, particularly Mars Sample Return. ISPP systems are described which produce oxygen or oxygen and methane from available atmospheric and surface materials. With ISPP, a 1 kg sample can be returned direct from Mars using a single Shuttle launch. Mars entry can be either direct or from orbit. Comet and asteroid sample return is also accomplished within a single Shuttle launch. Launch requirements for round-trip missions to Ganymede and Callisto are reduced by 15 to 40%.

SOLID PROPELLANT COMBUSTION MECHANISM STUDIES.

DTIC Science & Technology

SOLID ROCKET PROPELLANTS, BURNING RATE), LOW PRESSURE, COMBUSTION PRODUCTS, QUENCHING, THERMAL CONDUCTIVITY, KINETIC THEORY, SURFACE PROPERTIES, PHASE STUDIES, SOLIDS, GASES, PYROLYSIS, MATHEMATICAL ANALYSIS.

78 FR 9005 - Airworthiness Directives; Dowty Propellers Propellers

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-07

... the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For..., Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New... Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England...

Variable Pitch Propellers

NASA Technical Reports Server (NTRS)

1920-01-01

In this report are described four different types of propellers which appeared at widely separated dates, but which were exhibited together at the last Salon de l'Aeronautique. The four propellers are the Chaviere variable pitch propeller, the variable pitch propeller used on the Clement Bayard dirigible, the variable pitch propeller used on Italian dirigibles, and the Levasseur variable pitch propeller.

78 FR 41283 - Airworthiness Directives; Dowty Propellers Propellers

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-10

... service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington... Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England... Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England...

Proof-of-concept automation of propellant processing

NASA Technical Reports Server (NTRS)

Ramohalli, Kumar; Schallhorn, P. A.

1989-01-01

For space-based propellant production, automation of the process is needed. Currently, all phases of terrestrial production have some form of human interaction. A mixer was acquired to help perform the tasks of automation. A heating system to be used with the mixer was designed, built, and installed. Tests performed on the heating system verify design criteria. An IBM PS/2 personal computer was acquired for the future automation work. It is hoped that some the mixing process itself will be automated. This is a concept demonstration task; proving that propellant production can be automated reliably.

Cleanup/stimulation of a horizontal wellbore using propellants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rougeot, J.E.; Lauterbach, K.A.

1993-01-01

This report documents the stimulation/cleanup of a horizontal well bore (Wilson 25) using propellants. The Wilson 25 is a Bartlesville Sand well located in the Flatrock Field, Osage County, Oklahoma. The Wilson 25 was drilled to determine if horizontal drilling could be used as a means to economically recover primary oil that had been left in place in a mostly abandoned oil field because of the adverse effects of water coning. Pump testing of the Wilson 25 horizontal well bore before cleanup or stimulation produced 6 barrels of oil and .84 barrels of water per day. The high percentage ofmore » daily oil production to total daily fluid production indicated that the horizontal well bore had accessed potentially economical oil reserves if the fluid production rate could be increased by performing a cleanup/stimulation treatment. Propellants were selected as an inexpensive means to stimulate and cleanup the near well bore area in a uniform manner. The ignition of a propellant creates a large volume of gas which penetrates the formation, creating numerous short cracks through which hydrocarbons can travel into the well bore. More conventional stimulation/cleanup techniques were either significantly more expensive, less likely to treat uniformly, or could not be confined to the near well bore area. Three different propellant torpedo designs were tested with a total of 304' of horizontal well bore being shot and producible. The initial test shot caused 400' of the horizontal well bore to become plugged off, and subsequently it could not be production tested. The second and third test shots were production tested, with the oil production being increased 458% and 349%, respectively, on a per foot basis. The Wilson 25 results indicate that a propellant shot treatment is an economically viable means to cleanup/stimulate a horizontal well bore.« less

Installation effects on propeller wake/vortex induced structure-borne noise transmission

NASA Technical Reports Server (NTRS)

Unruh, J. F.

1989-01-01

A laboratory-based test apparatus was employed to investigate the effects of power-plant placement, engine/nacelle mass installation, and wing-to-fuselage attachment methods on propeller-induced structure-borne noise (SBN) transmission levels and their effects on noise-control measures. Data are presented showing SBN transmission is insensitive to propeller spanwise placement, however some sensitivity is seen in propeller-to-wing spacing. Installation of an engine/nacelle mass and variation in wing-to-fuselage attachments have measurable influences on SBN transmission and control measures.

Propellant production from the Martian atmosphere

NASA Technical Reports Server (NTRS)

Bowles, J. V.; Tauber, M. E.; Anagnost, A. J.; Whittaker, T.

1992-01-01

Results are presented from a calculation of the specific impulses that can be generated through the combustion of cryogenic CO and O2 over a range of fuel/oxidizer ratios, chamber pressures, nozzle expansion ratios, freestream pressures representative of Mars, and the limiting conditions of equilibrium and frozen nozzle flow. For an expansion ratio of 80 and 100-atm. chamber pressure, a specific impulse of 298 sec was obtained; this is comparable to the best solid rocket propellants.

Propeller Study. Part 2: the Design of Propellers for Minimum Noise

NASA Technical Reports Server (NTRS)

Ormsbee, A. I.; Woan, C. J.

1977-01-01

The design of propellers which are efficient and yet produce minimum noise requires accurate determinations of both the flow over the propeller. Topics discussed in relating aerodynamic propeller design and propeller acoustics include the necessary approximations and assumptions involved, the coordinate systems and their transformations, the geometry of the propeller blade, and the problem formulations including the induced velocity, required in the determination of mean lines of blade sections, and the optimization of propeller noise. The numerical formulation for the lifting-line model are given. Some applications and numerical results are included.

Effect of Propellant Composition to the Temperature Sensitivity of Composite Propellant

NASA Astrophysics Data System (ADS)

Aziz, Amir; Mamat, Rizalman; Amin, Makeen; Ali, Wan Khairuddin Wan

2012-09-01

The propellant composition is one of several parameter that influencing the temperature sensitivity of composite propellant. In this paper, experimental investigation of temperature sensitivity in burning rate of composite propellant was conducted. Four sets of different propellant compositions had been prepared with the combination of ammonium perchlorate (AP) as an oxidizer, aluminum (Al) as fuel and hydroxy-terminated polybutadiene (HTPB) as fuel and binder. For each mixture, HTPB binder was fixed at 15% and cured with isophorone diisocyanate (IPDI). By varying AP and Al, the effect of oxidizer- fuel mixture ratio (O/F) on the whole propellant can be determined. The propellant strands were manufactured using compression molded method and burnt in a strand burner using wire technique over a range of pressure from 1 atm to 31 atm. The results obtained shows that the temperature sensitivity, a, increases with increasing O/F. Propellant p80 which has O/F ratio of 80/20 gives the highest value of temperature sensitivity which is 1.687. The results shows that the propellant composition has significant effect on the temperature sensitivity of composite propellant

New high energetic composite propellants for space applications: refrigerated solid propellant

NASA Astrophysics Data System (ADS)

Franson, C.; Orlandi, O.; Perut, C.; Fouin, G.; Chauveau, C.; Gökalp, I.; Calabro, M.

2009-09-01

Cryogenic solid propellants (CSP) are a new kind of chemical propellants that use frozen products to ensure the mechanical resistance of the grain. The objective is to combine the high performances of liquid propulsion and the simplicity of solid propulsion. The CSP concept has few disadvantages. Storability is limited by the need of permanent cooling between motor loading and firing. It needs insulations that increase the dry mass. It is possible to limit significantly these drawbacks by using a cooling temperature near the ambient one. It will permit not to change the motor materials and to minimize the supplementary dry mass due to insulator. The designation "Refrigerated Solid Propellant" (RPS) is in that case more appropriate as "Cryogenic Solid Propellant." SNPE Matériaux Energétiques is developing new concept of composition e e with cooling temperature as near the ambient temperature as possible. They are homogeneous and the main ingredients are hydrogen peroxide, polymer and metal or metal hydride, they are called "HydroxalaneTM." This concept allows reaching a high energy level. The expected specific impulse is between 355 and 375 s against 315 s for hydroxyl-terminated polybutadiene (HTPB) / ammonium perchlorate (AP) / Al composition. However, the density is lower than for current propellants, between 1377 and 1462 kg/m3 compared to around 1800 kg/m3 . This is an handicap only for volume-limited application. Works have been carried out at laboratory scale to define the quality of the raw materials and the manufacturing process to realize sample and small grain in a safer manner. To assess the process, a small grain with an internal bore had been realized with a composition based on aluminum and water. This grain had shown very good quality, without any defect, and good bonding properties on the insulator.

Propellant for the NASA Standard Initiator

NASA Technical Reports Server (NTRS)

Hohmann, Carl; Tipton, Bill, Jr.; Dutton, Maureen

2000-01-01

This paper discusses processes employed in manufacturing zirconium-potassium perchlorate propellant for the NASA standard initiator. It provides both a historical background on the NSI device-detailing problem areas and their resolution--and on propellant blending techniques. Emphasis is placed on the precipitation blending method. The findings on mixing equipment, processing, and raw materials are described. Also detailed are findings on the bridgewire slurry operation, one of the critical steps in the production of the NASA standard initiator.

In-Space Cryogenic Propellant Depot Stepping Stone

NASA Technical Reports Server (NTRS)

Howell, Joe T.; Mankins, John C.; Fikes, John C.

2005-01-01

An In-Space Cryogenic Propellant Depot (ISCPD) is an important stepping stone to provide the capability to preposition, store, manufacture, and later use the propellants for Earth-Neighborhood campaigns and beyond. An in-space propellant depot will provide affordable propellants and other similar consumables to support the development of sustainable and affordable exploration strategies as well as commercial space activities. An in-space propellant depot not only requires technology development in key areas such as zero boil-off storage and fluid transfer, but in other areas such as lightweight structures, highly reliable connectors, and autonomous operations. These technologies can be applicable to a broad range of propellant depot concepts or specific to a certain design. In addition, these technologies are required for spacecraft and orbit transfer vehicle propulsion and power systems, and space life support. Generally, applications of this technology require long-term storage, on-orbit fluid transfer and supply, cryogenic propellant production from water, unique instrumentation and autonomous operations. This paper discusses the reasons why such advances are important to future affordable and sustainable operations in space. This paper also discusses briefly R&D objectives comprising a promising approach to the systems planning and evolution into a meaningful stepping stone design, development, and implementation of an In-Space Cryogenic Propellant Depot. The success of a well-planned and orchestrated approach holds great promise for achieving innovation and revolutionary technology development for supporting future exploration and development of space.

ISRU Propellant Selection for Space Exploration Vehicles

NASA Technical Reports Server (NTRS)

Chen, Timothy T.

2013-01-01

Chemical propulsion remains the only viable solution as technically matured technology for the near term human space transportation to Lunar and Mars. Current mode of space travel requires us to "take everything we will need", including propellant for the return trip. Forcing the mission designers to carry propellant for the return trip limits payload mass available for mission operations and results in a large and costly (and often unaffordable) design. Producing propellant via In-Situ Resource Utilization (ISRU) will enable missions with chemical propulsion by the "refueling" of return-trip propellant. It will reduce vehicle propellant mass carrying requirement by over 50%. This mass reduction can translates into increased payload to enhance greater mission capability, reduces vehicle size, weight and cost. It will also reduce size of launch vehicle fairing size as well as number of launches for a given space mission and enables exploration missions with existing chemical propulsion. Mars remains the ultimate destination for Human Space Exploration within the Solar System. The Mars atmospheric consist of 95% carbon dioxide (CO2) and the presence of Ice (water) was detected on Mars surfaces. This presents a basic chemical building block for the ISRU propellant manufacturing. However, the rationale for the right propellant to produce via ISRU appears to be limited to the perception of "what we can produce" as oppose to "what is the right propellant". Methane (CH4) is often quoted as a logical choice for Mars ISRU propellant, however; it is believed that there are better alternatives available that can result in a better space transportation architecture. A system analysis is needed to determine on what is the right propellant choice for the exploration vehicle. This paper examines the propellant selection for production via ISRU method on Mars surfaces. It will examine propellant trades for the exploration vehicle with resulting impact on vehicle performance, size

Agglomerates, smoke oxide particles, and carbon inclusions in condensed combustion products of an aluminized GAP-based propellant

NASA Astrophysics Data System (ADS)

Ao, Wen; Liu, Peijin; Yang, Wenjing

2016-12-01

In solid propellants, aluminum is widely used to improve the performance, however the condensed combustion products especially the large agglomerates generated from aluminum combustion significantly affect the combustion and internal flow inside the solid rocket motor. To clarify the properties of the condensed combustion products of aluminized propellants, a constant-pressure quench vessel was adopted to collect the combustion products. The morphology and chemical compositions of the collected products, were then studied by using scanning electron microscopy coupled with energy dispersive (SEM-EDS) method. Various structures have been observed in the condensed combustion products. Apart from the typical agglomerates or smoke oxide particles observed before, new structures including the smoke oxide clusters, irregular agglomerates and carbon-inclusions are discovered and investigated. Smoke oxide particles have the highest amount in the products. The highly dispersed oxide particle is spherical with very smooth surface and is on the order of 1-2 μm, but due to the high temperature and long residence time, these small particles will aggregate into smoke oxide clusters which are much larger than the initial particles. Three types of spherical agglomerates have been found. As the ambient gas temperature is much higher than the boiling point of Al2O3, the condensation layer inside which the aluminum drop is burning would evaporate quickly, which result in the fact that few "hollow agglomerates" has been found compared to "cap agglomerates" and "solid agglomerates". Irregular agglomerates usually larger than spherical agglomerates. The formation of irregular agglomerates likely happens by three stages: deformation of spherical aluminum drops; combination of particles with various shape; finally production of irregular agglomerates. EDS results show the ratio of O to Al on the surface of agglomerates is lower in comparison to smoke oxide particles. C and O account for

Noise reduction for model counterrotation propeller at cruise by reducing aft-propeller diameter

NASA Technical Reports Server (NTRS)

Dittmar, James H.; Stang, David B.

1987-01-01

The forward propeller of a model counterrotation propeller was tested with its original aft propeller and with a reduced diameter aft propeller. Noise reductions with the reduced diameter aft propeller were measured at simulated cruise conditions. Reductions were as large as 7.5 dB for the aft-propeller passing tone and 15 dB in the harmonics at specific angles. The interaction tones, mostly the first, were reduced probably because the reduced-diameter aft-propeller blades no longer interacted with the forward propeller tip vortex. The total noise (sum of primary and interaction noise) at each harmonic was significantly reduced. The chief noise reduction at each harmonic came from reduced aft-propeller-alone noise, with the interaction tones contributing little to the totals at cruise. Total cruise noise reductions were as much as 3 dB at given angles for the blade passing tone and 10 dB for some of the harmonics. These reductions would measurably improve the fuselage interior noise levels and represent a definite cruise noise benefit from using a reduced diameter aft propeller.

Cleanup/stimulation of a horizontal wellbore using propellants. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rougeot, J.E.; Lauterbach, K.A.

1993-01-01

This report documents the stimulation/cleanup of a horizontal well bore (Wilson 25) using propellants. The Wilson 25 is a Bartlesville Sand well located in the Flatrock Field, Osage County, Oklahoma. The Wilson 25 was drilled to determine if horizontal drilling could be used as a means to economically recover primary oil that had been left in place in a mostly abandoned oil field because of the adverse effects of water coning. Pump testing of the Wilson 25 horizontal well bore before cleanup or stimulation produced 6 barrels of oil and .84 barrels of water per day. The high percentage ofmore » daily oil production to total daily fluid production indicated that the horizontal well bore had accessed potentially economical oil reserves if the fluid production rate could be increased by performing a cleanup/stimulation treatment. Propellants were selected as an inexpensive means to stimulate and cleanup the near well bore area in a uniform manner. The ignition of a propellant creates a large volume of gas which penetrates the formation, creating numerous short cracks through which hydrocarbons can travel into the well bore. More conventional stimulation/cleanup techniques were either significantly more expensive, less likely to treat uniformly, or could not be confined to the near well bore area. Three different propellant torpedo designs were tested with a total of 304` of horizontal well bore being shot and producible. The initial test shot caused 400` of the horizontal well bore to become plugged off, and subsequently it could not be production tested. The second and third test shots were production tested, with the oil production being increased 458% and 349%, respectively, on a per foot basis. The Wilson 25 results indicate that a propellant shot treatment is an economically viable means to cleanup/stimulate a horizontal well bore.« less

Viton's Impact on NASA Standard Initiator Propellant Properties

NASA Technical Reports Server (NTRS)

Hohmann, Carl; Tipton, Bill, Jr.

2000-01-01

This paper discusses some of the properties of Viton that are relevant to its use as a pyrotechnic binder in a NASA standard initiator (NSI) propellant. Nearly every aspect of NSI propellant manufacture and use is impacted by the binder system. The effect of Viton's molecular weight on solubility, solution viscosity, glass transition temperature, and strength characteristics as applied to NSI production and performance are reviewed. Emphasis is placed on the Viton fractionation that occurs during the precipitation cycle and its impact on bridgewire functions. Special consideration is given to the production of bridgewire slurry mixtures.

Atomic hydrogen propellants: Historical perspectives and future possibilities

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

1993-01-01

Atomic hydrogen, a very high density free-radical propellant, is anticipated to generate a specific impulse of 600-1500 lb-f sec/lb-mass performance; this may facilitate the development of unique launch vehicles. A development status evaluation is presently given for atomic hydrogen investigations. It is noted that breakthroughs are required in the production, storage, and transfer of atomic hydrogen, before this fuel can become a viable rocket propellant.

A Cis-Lunar Propellant Infrastructure for Flexible Path Exploration and Space Commerce

NASA Technical Reports Server (NTRS)

Oeftering, Richard C.

2012-01-01

This paper describes a space infrastructure concept that exploits lunar water for propellant production and delivers it to users in cis-lunar space. The goal is to provide responsive economical space transportation to destinations beyond low Earth orbit (LEO) and enable in-space commerce. This is a game changing concept that could fundamentally affect future space operations, provide greater access to space beyond LEO, and broaden participation in space exploration. The challenge is to minimize infrastructure development cost while achieving a low operational cost. This study discusses the evolutionary development of the infrastructure from a very modest robotic operation to one that is capable of supporting human operations. The cis-lunar infrastructure involves a mix of technologies including cryogenic propellant production, reusable lunar landers, propellant tankers, orbital transfer vehicles, aerobraking technologies, and electric propulsion. This cislunar propellant infrastructure replaces Earth-launched propellants for missions beyond LEO. It enables users to reach destinations with smaller launchers or effectively multiplies the user s existing payload capacity. Users can exploit the expanded capacity to launch logistics material that can then be traded with the infrastructure for propellants. This mutually beneficial trade between the cis-lunar infrastructure and propellant users forms the basis of in-space commerce.

A theoretical evaluation of aluminum gel propellant two-phase flow losses on vehicle performance

NASA Technical Reports Server (NTRS)

Mueller, Donn C.; Turns, Stephen R.

1993-01-01

A one-dimensional model of a hydrocarbon/Al/O2(gaseous) fueled rocket combustion chamber was developed to study secondary atomization effects on propellant combustion. This chamber model was coupled with a two dimensional, two-phase flow nozzle code to estimate the two-phase flow losses associated with solid combustion products. Results indicate that moderate secondary atomization significantly reduces propellant burnout distance and Al2O3 particle size; however, secondary atomization provides only moderate decreases in two-phase flow induced I(sub sp) losses. Despite these two-phase flow losses, a simple mission study indicates that aluminum gel propellants may permit a greater maximum payload than the hydrocarbon/O2 bi-propellant combination for a vehicle of fixed propellant volume. Secondary atomization was also found to reduce radiation losses from the solid combustion products to the chamber walls, primarily through reductions in propellant burnout distance.

Technical prospects for utilizing extraterrestrial propellants for space exploration

NASA Technical Reports Server (NTRS)

Linne, Diane L.; Meyer, Michael L.

1991-01-01

NASA's LeRC has supported several efforts to understand how lunar and Martian produced propellants can be used to their best advantage for space exploration propulsion. A discussion of these efforts and their results is presented. A Manned Mars Mission Analysis Study identified that a more thorough technology base for propellant production is required before the the net economic benefits of in situ propellants can be determined. Evaluation of the materials available on the moon indicated metal/oxygen combinations are the most promising lunar propellants. A hazard analysis determined that several lunar metal/LOX monopropellants could be safely worked with in small quantities, and a characterization study was initiated to determine the physical and chemical properties of potential lunar monopropellant formulations. A bipropellant metal/oxygen subscale test engine which utilizes pneumatic injection of powdered metal is being pursued as an alternative to the monopropellant systems. The technology for utilizing carbon monoxide/oxygen, a potential Martian propellant, was studied in subscale ignition and rocket performance experiments.

Recent Advances and Applications in Cryogenic Propellant Densification Technology

NASA Technical Reports Server (NTRS)

Tomsik, Thomas M.

2000-01-01

This purpose of this paper is to review several historical cryogenic test programs that were conducted at the NASA Glenn Research Center (GRC), Cleveland, Ohio over the past fifty years. More recently these technology programs were intended to study new and improved denser forms of liquid hydrogen (LH2) and liquid oxygen (LO2) cryogenic rocket fuels. Of particular interest are subcooled cryogenic propellants. This is due to the fact that they have a significantly higher density (eg. triple-point hydrogen, slush etc.), a lower vapor pressure and improved cooling capacity over the normal boiling point cryogen. This paper, which is intended to be a historical technology overview, will trace the past and recent development and testing of small and large-scale propellant densification production systems. Densifier units in the current GRC fuels program, were designed and are capable of processing subcooled LH2 and L02 propellant at the X33 Reusable Launch Vehicle (RLV) scale. One final objective of this technical briefing is to discuss some of the potential benefits and application which propellant densification technology may offer the industrial cryogenics production and end-user community. Density enhancements to cryogenic propellants (LH2, LO2, CH4) in rocket propulsion and aerospace application have provided the opportunity to either increase performance of existing launch vehicles or to reduce the overall size, mass and cost of a new vehicle system.

Aerodynamic and propeller performance characteristics of a propfan-powered, semispan model

NASA Technical Reports Server (NTRS)

Levin, Alan D.; Smith, Ronald C.; Wood, Richard D.

1985-01-01

A semispan wing/body model with a powered propeller was tested to provide data on a total powerplant installation drag penalty of advanced propfan-powered aircraft. The test objectives were to determine the total power plant installation drag penalty on a representative propfan aircraft; to study the effect of configuration modifications on the installed powerplant drag; and to determine performance characteristics of an advanced design propeller which was mounted on a representative nacelle in the presence of a wing.

Advanced propeller research

NASA Technical Reports Server (NTRS)

Groeneweg, John F.; Bober, Lawrence J.

1987-01-01

Resent results of aerodynamic and acoustic research on both single and counter-rotation propellers are reviewed. Data and analytical results are presented for three propellers: SR-7A, the single rotation design used in the NASA Propfan Test Assessment (PTA); and F7-A7, the 8+8 counterrotating design used in the proof-of-concept Unducted Fan (UDF) engine. In addition to propeller efficiencies, cruise and takeoff noise, and blade pressure data, off-design phenomena involving formation of leading edge vortices are described. Aerodynamic and acoustic computational results derived from three-dimensional Euler and acoustic radiation codes are presented. Research on unsteady flows, which are particularly important for understanding counterrotation interaction noise, unsteady loading effects on acoustics, and flutter or forced response is described. The first results of three-dimensional unsteady Euler solutions are illustrated for a single rotation propeller at an angle of attack and for a counterrotation propeller. Basic experimental and theoretical results from studies of the unsteady aerodynamics of oscillating cascades are outlined. Finally, advanced concepts involving swirl recovery vanes and ultra bypass ducted propellers are discussed.

The onsite manufacture of propellant oxygen from lunar resources

NASA Technical Reports Server (NTRS)

Rosenberg, Sanders D.; Beegle, Robert L., Jr.; Guter, Gerald A.; Miller, Frederick E.; Rothenberg, Michael

1992-01-01

The Aerojet carbothermal process for the manufacture of oxygen from lunar materials has three essential steps: the reduction of silicate with methane to form carbon monoxide and hydrogen; the reduction of carbon monoxide with hydrogen to form methane and water; and the electrolysis of water to form hydrogen and oxygen. The reactions and the overall process are shown. It is shown with laboratory experimentation that the carbothermal process is feasible. Natural silicates can be reduced with carbon or methane. The important products are carbon monoxide, metal, and slag. The carbon monoxide can be completely reduced to form methane and water. The water can be electrolyzed to produce hydrogen and oxygen. A preliminary engineering study shows that the operation of plants using this process for the manufacture of propellant oxygen has a large economic advantage when the cost of the plant and its operation is compared to the cost of delivering oxygen from Earth.

Pressure Oscillations in a Liquid Propellant Gun - Possible Dependence on Propellant Burning Rate

DTIC Science & Technology

1992-06-01

corresponding nitrone (Smith 1966), an undesirable side reaction. The dilute DEHAN solution thus obtained was concentrated to 93.64 weight-percent by water...0.3- 0.0- 0.1- 0- 0 20 40 60 80 100 120 140 160 180 200 TDER (=a) 460 :-- woM Figure 6. Gas Production From the Combustion of Propellants 4600 and

14 CFR 23.905 - Propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational... tests, that the propeller is capable of continuous safe operation. (h) All engine cowling, access doors... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propellers. 23.905 Section 23.905...

14 CFR 23.905 - Propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational... tests, that the propeller is capable of continuous safe operation. (h) All engine cowling, access doors... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propellers. 23.905 Section 23.905...

14 CFR 23.905 - Propellers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational... tests, that the propeller is capable of continuous safe operation. (h) All engine cowling, access doors... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propellers. 23.905 Section 23.905...

14 CFR 23.905 - Propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational... tests, that the propeller is capable of continuous safe operation. (h) All engine cowling, access doors... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propellers. 23.905 Section 23.905...

14 CFR 23.905 - Propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational... tests, that the propeller is capable of continuous safe operation. (h) All engine cowling, access doors... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propellers. 23.905 Section 23.905...

Aircraft propeller induced structure-borne noise

NASA Technical Reports Server (NTRS)

Unruh, James F.

1989-01-01

A laboratory-based test apparatus employing components typical of aircraft construction was developed that would allow the study of structure-borne noise transmission due to propeller induced wake/vortex excitation of in-wake structural appendages. The test apparatus was employed to evaluate several aircraft installation effects (power plant placement, engine/nacelle mass loading, and wing/fuselage attachment methods) and several structural response modifications for structure-borne noise control (the use of wing blocking mass/fuel, wing damping treaments, and tuned mechanical dampers). Most important was the development of in-flight structure-borne noise transmission detection techniques using a combination of ground-based frequency response function testing and in-flight structural response measurement. Propeller wake/vortex excitation simulation techniques for improved ground-based testing were also developed to support the in-flight structure-borne noise transmission detection development.

LES of propeller crashback

NASA Astrophysics Data System (ADS)

Kumar, Praveen; Mahesh, Krishnan

2014-11-01

Crashback is an operating condition to quickly stop a propelled vehicle, where the propeller is rotated in the reverse direction to yield a negative thrust. In crashback, the freestream interacts with the strong reverse flow from the propeller leading to massive flow separation and highly unsteady loads. We have used Large-Eddy Simulation (LES) in recent years to accurately simulate the flowfield in crashback around a stand-alone open propeller, hull-attached (posterior alone) open propeller and a ducted propeller with stator blades. This talk will discuss our work towards LES of crashback inclusive of the entire hull. The results will be compared to available experimental data, and the flow physics will be discussed. This work is supported by the Office of Naval Research.

Fundamental Understanding of Propellant/Nozzle Interaction for Rocket Nozzle Erosion Minimization Under Very High Pressure Conditions

DTIC Science & Technology

2005-08-31

conditions; with X-ray radiography for erosion rate measurements. A vortex combustor was also designed to simulate propellant product species and to...DATES COVERED Interim Progress Report, August 1, 2004 to July 31, 2005 4. TITLE AND SUBTITLE Fundamental Understanding of Propellant /Nozzle...nozzle erosion by solid- propellant combustion products. Several processes can affect the nozzle erosion rate at high pressure and temperature

75 FR 7934 - Airworthiness Directives; McCauley Propeller Systems 1A103/TCM Series Propellers

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... with cracks that do not meet acceptable limits, and rework of propellers with cracks that meet..., replacement of propellers with cracks that do not meet acceptable limits, and rework of propellers with cracks... propeller hub, removal from service of propellers with cracks that do not meet acceptable limits, and rework...

Modeling and Fault Simulation of Propellant Filling System

NASA Astrophysics Data System (ADS)

Jiang, Yunchun; Liu, Weidong; Hou, Xiaobo

2012-05-01

Propellant filling system is one of the key ground plants in launching site of rocket that use liquid propellant. There is an urgent demand for ensuring and improving its reliability and safety, and there is no doubt that Failure Mode Effect Analysis (FMEA) is a good approach to meet it. Driven by the request to get more fault information for FMEA, and because of the high expense of propellant filling, in this paper, the working process of the propellant filling system in fault condition was studied by simulating based on AMESim. Firstly, based on analyzing its structure and function, the filling system was modular decomposed, and the mathematic models of every module were given, based on which the whole filling system was modeled in AMESim. Secondly, a general method of fault injecting into dynamic system was proposed, and as an example, two typical faults - leakage and blockage - were injected into the model of filling system, based on which one can get two fault models in AMESim. After that, fault simulation was processed and the dynamic characteristics of several key parameters were analyzed under fault conditions. The results show that the model can simulate effectively the two faults, and can be used to provide guidance for the filling system maintain and amelioration.

Common In-Situ Consumable Production Plant for Robotic Mars Exploration

NASA Technical Reports Server (NTRS)

Sanders, G. B.; Trevathan, J. R.; Peters, T. A.; Baird, R. S.

2000-01-01

Utilization of extraterrestrial resources, or In-Situ Resource Utilization (ISRU), is viewed by the Human Exploration and Development of Space (HEDS) Enterprise as an enabling technology for the exploration and commercial development of space. A key subset of ISRU which has significant cost, mass, and risk reduction benefits for robotic and human exploration, and which requires a minimum of infrastructure, is In-Situ Consumable Production (ISCP). ISCP involves acquiring, manufacturing, and storing mission consumables from in situ resources, such as propellants, fuel cell reagents, and gases for crew and life support, inflation, science and pneumatic equipment. One of the four long-term goals for the Space Science Enterprise (SSE) is to 'pursue space science programs that enable and are enabled by future human exploration beyond low-Earth orbit - a goal exploiting the synergy with the human exploration of space'. Adequate power and propulsion capabilities are critical for both robotic and human exploration missions. Minimizing the mass and volume of these systems can reduce mission cost or enhance the mission by enabling the incorporation of new science or mission-relevant equipment. Studies have shown that in-situ production of oxygen and methane propellants can enhance sample return missions by enabling larger samples to be returned to Earth or by performing Direct Earth Return (DER) sample return missions instead of requiring a Mars Orbit Rendezvous (MOR). Recent NASA and Department of Energy (DOE) work on oxygen and hydrocarbon-based fuel cell power systems shows the potential of using fuel cell power systems instead of solar arrays and batteries for future rovers and science equipment. The development and use of a common oxygen/methane ISCP plant for propulsion and power generation can extend and enhance the scientific exploration of Mars while supporting the development and demonstration of critical technologies and systems for the human exploration of Mars.

Common In-Situ Consumable Production Plant for Robotic Mars Exploration

NASA Astrophysics Data System (ADS)

Sanders, G. B.; Trevathan, J. R.; Peters, T. A.; Baird, R. S.

2000-07-01

Utilization of extraterrestrial resources, or In-Situ Resource Utilization (ISRU), is viewed by the Human Exploration and Development of Space (HEDS) Enterprise as an enabling technology for the exploration and commercial development of space. A key subset of ISRU which has significant cost, mass, and risk reduction benefits for robotic and human exploration, and which requires a minimum of infrastructure, is In-Situ Consumable Production (ISCP). ISCP involves acquiring, manufacturing, and storing mission consumables from in situ resources, such as propellants, fuel cell reagents, and gases for crew and life support, inflation, science and pneumatic equipment. One of the four long-term goals for the Space Science Enterprise (SSE) is to 'pursue space science programs that enable and are enabled by future human exploration beyond low-Earth orbit - a goal exploiting the synergy with the human exploration of space'. Adequate power and propulsion capabilities are critical for both robotic and human exploration missions. Minimizing the mass and volume of these systems can reduce mission cost or enhance the mission by enabling the incorporation of new science or mission-relevant equipment. Studies have shown that in-situ production of oxygen and methane propellants can enhance sample return missions by enabling larger samples to be returned to Earth or by performing Direct Earth Return (DER) sample return missions instead of requiring a Mars Orbit Rendezvous (MOR). Recent NASA and Department of Energy (DOE) work on oxygen and hydrocarbon-based fuel cell power systems shows the potential of using fuel cell power systems instead of solar arrays and batteries for future rovers and science equipment. The development and use of a common oxygen/methane ISCP plant for propulsion and power generation can extend and enhance the scientific exploration of Mars while supporting the development and demonstration of critical technologies and systems for the human exploration of Mars.

Nitramine smokeless propellant research

NASA Technical Reports Server (NTRS)

Cohen, N. S.; Strand, L. P.

1977-01-01

A transient ballistics and combustion model is derived to represent the closed vessel experiment that is widely used to characterize propellants. A computer program is developed to solve the time-dependent equations, and is applied to explain aspects of closed vessel behavior. In the case of nitramine propellants the cratering of the burning surface associated with combustion above break-point pressures augments the effective burning rate as deduced from the closed vessel experiment. Low pressure combustion is significantly affected by the ignition process and, in the case of nitramine propellants, by the developing and changing surface structure. Thus, burning rates deduced from the closed vessel experiment may or may not agree with those measured in the equilibrium strand burner. Series of T burner experiments are performed to compare the combustion instability characteristics of nitramine (HMX) containing propellants and ammonium perchlorate (AP)propellants. Although ash produced by more fuel rich propellants could have provided mechanical suppression, results from clean-burning propellants permit the conclusion that HMX reduces the acoustic driving.

Microgravity liquid propellant management

NASA Technical Reports Server (NTRS)

Hung, R. J.

1990-01-01

The requirement to settle or to position liquid fluid over the outlet end of a spacecraft propellant tank prior to main engine restart, poses a microgravity fluid behavior problem. Resettlement or reorientation of liquid propellant can be accomplished by providing optimal acceleration to the spacecraft such that the propellant is reoriented over the tank outlet without any vapor entrainment, any excessive geysering, or any other undersirable fluid motion for the space fluid management under microgravity environment. The most efficient technique is studied for propellant resettling through the minimization of propellant usage and weight penalties. Both full scale and subscale liquid propellant tank of Space Transfer Vehicle were used to simulate flow profiles for liquid hydrogen reorientation over the tank outlet. In subscale simulation, both constant and impulsive resettling acceleration were used to simulate the liquid flow reorientation. Comparisons between the constant reverse gravity acceleration and impulsive reverse gravity acceleration to be used for activation of propellant resettlement shows that impulsive reverse gravity thrust is superior to constant reverse gravity thrust.

Portable propellant cutting assembly, and method of cutting propellant with assembly

NASA Technical Reports Server (NTRS)

Sharp, Roger A. (Inventor); Hoskins, Shawn W. (Inventor); Payne, Brett D. (Inventor)

2002-01-01

A propellant cutting assembly and method of using the assembly to cut samples of solid propellant in a repeatable and consistent manner is disclosed. The cutting assembly utilizes two parallel extension beams which are shorter than the diameter of a central bore of an annular solid propellant grain and can be loaded into the central bore. The assembly is equipped with retaining heads at its respective ends and an adjustment mechanism to position and wedge the assembly within the central bore. One end of the assembly is equipped with a cutting blade apparatus which can be extended beyond the end of the extension beams to cut into the solid propellant.

Mutagenicity of burnt gun propellants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Felton, J.S.; Lewis, P.; Knize, M.G.

1989-08-02

The use of the Ames/Salmonella assay as a workplace monitoring method is a long-standing practice at LLNL. This practice has led to the discovery of very mutagenic soot in and around a 4 inch test gun. To the authors' knowledge this is the first finding of mutagenic components in the residue from gun propellants, although there have been numerous reports of mutagenic compounds associated with high explosives -- compounds of entirely different chemical composition (Won et al., 1976). In addition, Ase et al., 1985, analyzed the propellant combustion products of both a M16 rifle and a 105 mm caliber gunmore » with HPLC and GC/MS methods, and found a number of PAHs with known toxicological effects. No biological analysis was done on the residues. Further investigation in our laboratory found that direct acting mutagens where produced upon open burning of the propellants. Small gauge firearms when tested also showed mutagenic residue. Preliminary efforts to identify the mutagenic components estimate that 2-3 compounds are responsible for the biological activity. The identity of these compounds is under investigation. 8 refs., 4 tabs.« less

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2010 CFR

2010-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2013 CFR

2013-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2012 CFR

2012-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2011 CFR

2011-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2014 CFR

2014-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propellers. 25.905 Section 25.905...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propellers. 25.905 Section 25.905...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propellers. 25.905 Section 25.905...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propellers. 25.905 Section 25.905...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propellers. 25.905 Section 25.905...

78 FR 18255 - Airworthiness Directives; Hartzell Propeller, Inc. Propellers

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... engine oil leak. This proposed AD would require replacement of the propeller hydraulic bladder diaphragm. We are proposing this AD to prevent propeller hydraulic bladder diaphragm rupture, loss of engine oil, damage to the engine, and loss of the airplane. DATES: We must receive comments on this proposed AD by...

Investigation of Propellant Sloshing and Zero Gravity Equilibrium for the Orion Service Module Propellant Tanks

NASA Astrophysics Data System (ADS)

Kreppel, Samantha

A scaled model of the downstream Orion service module propellant tank was constructed to asses the propellant dynamics under reduced and zero-gravity conditions. Flight and ground data from the experiment is currently being used to validate computational models of propel-lant dynamics in Orion-class propellant tanks. The high fidelity model includes the internal structures of the propellant management device (PMD) and the mass-gauging probe. Qualita-tive differences between experimental and CFD data are understood in terms of fluid dynamical scaling of inertial effects in the scaled system. Propellant configurations in zero-gravity were studied at a range of fill-fractions and the settling time for various docking maneuvers was determined. A clear understanding of the fluid dynamics within the tank is necessary to en-sure proper control of the spacecraft's flight and to maintain safe operation of this and future service modules. Understanding slosh dynamics in partially-filled propellant tanks is essential to assessing spacecraft stability.

Propeller noise prediction

NASA Technical Reports Server (NTRS)

Zorumski, W. E.

1983-01-01

Analytic propeller noise prediction involves a sequence of computations culminating in the application of acoustic equations. The prediction sequence currently used by NASA in its ANOPP (aircraft noise prediction) program is described. The elements of the sequence are called program modules. The first group of modules analyzes the propeller geometry, the aerodynamics, including both potential and boundary layer flow, the propeller performance, and the surface loading distribution. This group of modules is based entirely on aerodynamic strip theory. The next group of modules deals with the actual noise prediction, based on data from the first group. Deterministic predictions of periodic thickness and loading noise are made using Farassat's time-domain methods. Broadband noise is predicted by the semi-empirical Schlinker-Amiet method. Near-field predictions of fuselage surface pressures include the effects of boundary layer refraction and (for a cylinder) scattering. Far-field predictions include atmospheric and ground effects. Experimental data from subsonic and transonic propellers are compared and NASA's future direction is propeller noise technology development are indicated.

Advanced propeller research

NASA Technical Reports Server (NTRS)

Groeneweg, John F.; Bober, Lawrence J.

1990-01-01

Recent results of aerodynamic and acoustic research on both single rotation and counterrotation propellers are reviewed. Data and analytical results are presented for three propellers: SR-7A, the single rotation design used in the NASA Propfan Test Assessment (PTA) flight program; CRP-X1, the initial 5+5 Hamilton Standard counterrotating design; and F7-A7, the 8+8 counterrotating G.E. design used in the proof of concept Unducted Fan (UDF) engine. In addition to propeller efficiencies, cruise and takeoff noise, and blade pressure data, off-design phenomena involving formation of leading edge vortexes are described. Aerodynamic and acoustic computational results derived from 3-D Euler and acoustic radiation codes are presented. Research on unsteady flows which are particularly important for understanding counterrotation interaction noise, unsteady loading effects on acoustics, and flutter or forced response is described. The first results of 3-D unsteady Euler solutions are illustrated for a single rotation propeller at angle of attack and for a counterrotation propeller. Basic experimental and theoretical results from studies on the unsteady aerodynamics of oscillating cascades are outlined.

Propeller flow visualization techniques

NASA Technical Reports Server (NTRS)

Stefko, G. L.; Paulovich, F. J.; Greissing, J. P.; Walker, E. D.

1982-01-01

Propeller flow visualization techniques were tested. The actual operating blade shape as it determines the actual propeller performance and noise was established. The ability to photographically determine the advanced propeller blade tip deflections, local flow field conditions, and gain insight into aeroelastic instability is demonstrated. The analytical prediction methods which are being developed can be compared with experimental data. These comparisons contribute to the verification of these improved methods and give improved capability for designing future advanced propellers with enhanced performance and noise characteristics.

Development and implementation of a propeller test capability for GL-10 "Greased Lightning" propeller design

NASA Astrophysics Data System (ADS)

Duvall, Brian Edward

Interest in small unmanned aerial vehicles has increased dramatically in recent years. Hybrid vehicles which allow forward flight as a fixed wing aircraft and a true vertical landing capability have always had applications. Management of the available energy and noise associated with electric propeller propulsion systems presents many challenges. NASA Langley has developed the Greased Lightning 10 (GL-10) vertical takeoff, unmanned aerial vehicle with ten individual motors and propellers. All are used for propulsion during takeoff and contribute to acoustic noise pollution which is an identified nuisance to the surrounding users. A propeller test capability was developed to gain an understanding of how the noise can be reduced while meeting minimum thrust requirements. The designed propeller test stand allowed for various commercially available propellers to be tested for potential direct replacement of the current GL-10 propellers and also supported testing of a newly designed propeller provided by the Georgia Institute of Technology. Results from the test program provided insight as to which factors affect the noise as well as performance characteristics. The outcome of the research effort showed that the current GL-10 propeller still represents the best choice of all the candidate propellers tested.

Performance Tests of a Liquid Hydrogen Propellant Densification Ground System for the X33/RLV

NASA Technical Reports Server (NTRS)

Tomsik, Thomas M.

1997-01-01

A concept for improving the performance of propulsion systems in expendable and single-stage-to-orbit (SSTO) launch vehicles much like the X33/RLV has been identified. The approach is to utilize densified cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX) propellants to fuel the propulsion stage. The primary benefit for using this relatively high specific impulse densified propellant mixture is the subsequent reduction of the launch vehicle gross lift-off weight. Production of densified propellants however requires specialized equipment to actively subcool both the liquid oxygen and liquid hydrogen to temperatures below their normal boiling point. A propellant densification unit based on an external thermodynamic vent principle which operates at subatmospheric pressure and supercold temperatures provides a means for the LH2 and LOX densification process to occur. To demonstrate the production concept for the densification of the liquid hydrogen propellant, a system comprised of a multistage gaseous hydrogen compressor, LH2 recirculation pumps and a cryogenic LH2 heat exchanger was designed, built and tested at the NASA Lewis Research Center (LeRC). This paper presents the design configuration of the LH2 propellant densification production hardware, analytical details and results of performance testing conducted with the hydrogen densifier Ground Support Equipment (GSE).

Field evaluation of a self-propelled sprayer and effects of the application rate on spray deposition and losses to the ground in greenhouse tomato crops.

PubMed

Sánchez-Hermosilla, Julián; Rincón, Víctor J; Páez, Francisco; Agüera, Francisco; Carvajal, Fernando

2011-08-01

In the greenhouses of south-eastern Spain, plant protection products are applied using mainly sprayers at high pressures and high volumes. This results in major losses on the ground and less than uniform spray deposition on the canopy. Recently, self-propelled vehicles equipped with vertical spray booms have appeared on the market. In this study, deposition on the canopy and the losses to the ground at different spray volumes have been compared, using a self-propelled vehicle with vertical spray booms versus a gun sprayer. Three different spray volumes have been tested with a boom sprayer, and two with a spray gun. The vehicle with the vertical spray boom gave similar depositions to those made with the gun, but at lower application volumes. Also, the distribution of the vertical spray boom was more uniform, with lower losses to the ground. The vertical spray booms used in tomato crops improve the application of plant protection products with respect to the spray gun, reducing the application volumes and the environmental risks of soil pollution. Copyright © 2011 Society of Chemical Industry.

Earth-to-orbit propellant transportation overview

NASA Technical Reports Server (NTRS)

Fester, D.

1984-01-01

The transportation of large quantities of cryogenic propellants which are needed to support Space Station/OTV operation is discussed. Two ways to send propellants into space are: transporting them in dedicated tankers or scavenging unused STS propellant. Scavenging propellant, both with and without an aft cargo carrier system is examined. An average of two to four flights per year can be saved by scavenging and manifesting propellant as payload. Addition of an aft cargo carrier permits loading closer to maximum, reduces the required number of flights, and reduces the propellant available for scavenging. Sufficient propellant remains, however, for OTV needs.

Performance optimization of marine propellers

NASA Astrophysics Data System (ADS)

Lee, Chang-Sup; Choi, Young-Dal; Ahn, Byoung-Kwon; Shin, Myoung-Sup; Jang, Hyun-Gil

2010-12-01

Recently a Wide Chord Tip (WCT) propeller has been developed and applied to a commercial ship by STX Offshore & Shipbuilding. It is reported that the WCT propeller significantly reduces pressure fluctuations and also ship's noise and vibration. On the sea trial, vibration magnitude in the accommodations at NCR was measured at 0.9mm/sec which is only 10% of international allowable magnitude of vibration (9mm/sec). In this paper, a design method for increasing performance of the marine propellers including the WCT propeller is suggested. It is described to maximize the performance of the propeller by adjusting expanded areas of the propeller blade. Results show that efficiency can be increased up to over 2% through the suggested design method.

Mobile propeller dynamometer validation

NASA Astrophysics Data System (ADS)

Morris, Mason Wade

With growing interest in UAVs and OSU's interest in propeller performance and manufacturing, evaluating UAV propeller and propulsion system performance has become essential. In attempts to evaluate these propellers a mobile propeller dynamometer has been designed, built, and tested. The mobile dyno has been designed to be cost effective through the ability to load it into the back of a test vehicle to create simulated forward flight characteristics. This allows much larger propellers to be dynamically tested without the use of large and expensive wind tunnels. While evaluating the accuracy of the dyno, several improvements had to be made to get accurate results. The decisions made to design and improve the mobile propeller dyno will be discussed along with attempts to validate the dyno by comparing its results against known sources. Another large part of assuring the accuracy of the mobile dyno is determining if the test vehicle will influence the flow going into the propellers being tested. The flow into the propeller needs to be as smooth and uniform as possible. This is determined by characterizing the boundary layer and accelerated flow over the vehicle. This evaluation was accomplished with extensive vehicle aerodynamic measurements with the use of full-scale tests using a pitot-rake and the actual test vehicle. Additional tests were conducted in Oklahoma State University's low speed wind tunnel with a 1/8-scale model using qualitative flow visualization with smoke. Continuing research on the mobile dyno will be discussed, along with other potential uses for the dyno.

Propellers in Saturn's rings

NASA Astrophysics Data System (ADS)

Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

2013-12-01

Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~<500m in size) have been indirectly identified in Saturn's A ring through their propeller signature in the images. Furthermore, recent Cassini observations indicate the possible existence of objects embedded even in Saturn's B and C ring. In this paper we present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B

A Detailed Historical Review of Propellant Management Devices for Low Gravity Propellant Acquisition

NASA Technical Reports Server (NTRS)

Hartwig, Jason W.

2016-01-01

This paper presents a comprehensive background and historical review of Propellant Management Devices (PMDs) used throughout spaceflight history. The purpose of a PMD is to separate liquid and gas phases within a propellant tank and to transfer vapor-free propellant from a storage tank to a transfer line en route to either an engine or receiver depot tank, in any gravitational or thermal environment. The design concept, basic flow physics, and principle of operation are presented for each type of PMD. The three primary capillary driven PMD types of vanes, sponges, and screen channel liquid acquisition devices are compared and contrasted. For each PMD type, a detailed review of previous applications using storable propellants is given, which include space experiments as well as space missions and vehicles. Examples of previous cryogenic propellant management are also presented.

Considerations on propeller efficiency

NASA Technical Reports Server (NTRS)

Betz, A

1928-01-01

The propeller cannot be considered alone, but the mutual interference between propeller and airplane must be considered. These difficulties are so great when the joint action of propeller and airplane is considered, that the aerodynamic laboratory at Gottingen originally abandoned the idea of applying the efficiency conception of the test results. These difficulties and the methods by which they are overcome are outlined in this report.

Combustion characteristics of SMX and SMX based propellants

NASA Astrophysics Data System (ADS)

Reese, David A.

density and performance, smokeless combustion products, and stable combustion, SMX appears to be a viable replacement for existing energetic ingredients in a wide variety of propellant, explosive, and pyrotechnic applications.

Iron nutrition, biomass production, and plant product quality.

PubMed

Briat, Jean-François; Dubos, Christian; Gaymard, Frédéric

2015-01-01

One of the grand challenges in modern agriculture is increasing biomass production, while improving plant product quality, in a sustainable way. Of the minerals, iron (Fe) plays a major role in this process because it is essential both for plant productivity and for the quality of their products. Fe homeostasis is an important determinant of photosynthetic efficiency in algae and higher plants, and we review here the impact of Fe limitation or excess on the structure and function of the photosynthetic apparatus. We also discuss the agronomic, plant breeding, and transgenic approaches that are used to remediate Fe deficiency of plants on calcareous soils, and suggest ways to increase the Fe content and bioavailability of the edible parts of crops to improve human diet. Copyright © 2014 Elsevier Ltd. All rights reserved.

Propeller Belts of Saturn

NASA Image and Video Library

2017-05-10

This view from NASA's Cassini spacecraft is the sharpest ever taken of belts of the features called propellers in the middle part of Saturn's A ring. The propellers are the small, bright features that look like double dashes, visible on both sides of the wave pattern that crosses the image diagonally from top to bottom. The original discovery of propellers in this region in Saturn's rings was made using several images taken from very close to the rings during Cassini's 2004 arrival at Saturn. Those discovery images were of low resolution and were difficult to interpret, and there were few clues as to how the small propellers seen in those images were related to the larger propellers Cassini observed later in the mission. This image, for the first time, shows swarms of propellers of a wide range of sizes, putting the ones Cassini observed in its Saturn arrival images in context. Scientists will use this information to derive a "particle size distribution" for propeller moons, which is an important clue to their origins. The image was taken using the Cassini spacecraft's narrow-angle camera on April 19. The view was has an image scale of 0.24 mile (385 meters) per pixel, and was taken at a sun-ring-spacecraft angle, or phase angle, of 108 degrees. The view looks toward a point approximately 80,000 miles (129,000 kilometers) from Saturn's center. https://photojournal.jpl.nasa.gov/catalog/PIA21448

The "Tokyo" consensus on propeller flaps.

PubMed

Pignatti, Marco; Ogawa, Rei; Hallock, Geoffrey G; Mateev, Musa; Georgescu, Alexandru V; Balakrishnan, Govindasamy; Ono, Shimpei; Cubison, Tania C S; D'Arpa, Salvatore; Koshima, Isao; Hyakusoku, Hikko

2011-02-01

Over the past few years, the use of propeller flaps, which base their blood supply on subcutaneous tissue or isolated perforators, has become increasingly popular. Because no consensus has yet been reached on terminology and nomenclature of the propeller flap, different and confusing uses of the term can be found in the literature. In this article, the authors report the consensus on the definition and classification of propeller flaps reached by the authors that gathered at the First Tokyo Meeting on Perforator and Propeller Flaps in June of 2009. Some peculiar aspects of the surgical technique are discussed. A propeller flap can be defined as an "island flap that reaches the recipient site through an axial rotation." The classification is based on the nourishing pedicle (subcutaneous pedicled propeller flap, perforator pedicled propeller flap, supercharged propeller flap), the degrees of skin island rotation (90 to 180 degrees) and, when possible, the artery of origin of the perforator. The propeller flap is a useful reconstructive tool that can achieve good cosmetic and functional results. A flap should be called a propeller flap only if it fulfils the definition above. The type of nourishing pedicle, the source vessel (when known), and the degree of skin island rotation should be specified for each flap.

Improving the Performance of Multi-engined Airplanes by Means of Idling Propellers : the "free-wheel" Propeller

NASA Technical Reports Server (NTRS)

Pillard, M

1930-01-01

In order to demonstrate the importance of free-wheeling propellers, this report considers the braking effect of a propeller on a stopped engine when the propeller is rigidly connected with the engine shaft and also when mounted on a free-wheel hub. The cases of propellers of asymmetric and symmetric section are discussed. The author describes the mechanism of the free-wheel propeller as constructed for this test. The results obtained with the device mounted on a 1,000 horsepower two-engine airplane are given.

Ignition characterization of the GOX/ethanol propellant combination

NASA Technical Reports Server (NTRS)

Lawver, B. R.; Rousar, D. C.; Boyd, W. C.

1984-01-01

This paper describes the results of a study to define the ignition characteristics and thruster pulse mode capabilities of the GOX/ethanol propellant combination. Ignition limits were defined in terms of mixture ratio and cold flow pressure using a spark initiated torch igniter. Igniter tests were run over a wide range of cold flow pressure, propellant temperature and mixture ratio. The product of cold flow pressure and igniter chamber diameter was used to correlate mixture ratio regimes of ignition and nonignition. Engine ignition reliability and pulse mode capability were demonstrated using a 620 lbF thruster with an integrated torch igniter. The nominal chamber pressure and mixture ratio were 150 psia and 1.8, respectively, thruster tests were run over a wide range of chamber pressures and mixture ratios. The feasibility of thruster pulse mode operation with the non-hypergolic GOX/ethanol propellant combination was demonstrated.

Characteristics of Five Propellers in Flight

NASA Technical Reports Server (NTRS)

Crowley, J W , Jr; Mixson, R E

1928-01-01

This investigation was made for the purpose of determining the characteristics of five full-scale propellers in flight. The equipment consisted of five propellers in conjunction with a VE-7 airplane and a Wright E-2 engine. The propellers were of the same diameter and aspect ratio. Four of them differed uniformly in thickness and pitch and the fifth propeller was identical with one of the other four with exception of a change of the airfoil section. The propeller efficiencies measured in flight are found to be consistently lower than those obtained in model tests. It is probable that this is mainly a result of the higher tip speeds used in the full-scale tests. The results show also that because of differences in propeller deflections it is difficult to obtain accurate comparisons of propeller characteristics. From this it is concluded that for accurate comparisons it is necessary to know the propeller pitch angles under actual operating conditions. (author)

Nitramine smokeless propellant research

NASA Technical Reports Server (NTRS)

1977-01-01

A transient ballistics and combustion model was derived to represent the closed vessel experiment that is widely used to characterize propellants. The model incorporates the nitramine combustion mechanisms. A computer program was developed to solve the time dependent equations, and was applied to explain aspects of closed vessel behavior. It is found that the rate of pressurization in the closed vessel is insufficient at pressures of interest to augment the burning rate by time dependent processes. Series of T-burner experiments were performed to compare the combustion instability characteristics of nitramine (HMX) containing propellants and ammonium perchlorate (AP) propellants. It is found that the inclusion of HMX consistently renders the propellant more stable.

Badger Army Ammunition Plant groundwater data management system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansen, J.P.

1994-12-31

At the Badger Army Ammunition Plant (Badger), there are currently over 200 wells that are monitored on a quarterly basis. Badger has had three active production periods since its construction in 1942. During these periods, various nitrocellulose based propellants were produced including single base artillery propellants were produced including single base artillery propellant, double base rocket propellant and BALL POWDER{reg_sign} propellant. Intermediate materials used in the manufacture of these propellants were also produced, including nitroglycerine, and sulfuric and nitric acids. To meet the challenge of managing the data in-house, a groundwater data management system (GDMS) was developed. Although such systemsmore » are commercially available, they were not able to provide the specific capabilities necessary for data management and reporting at Badger. The GDMS not only provides the routine database capabilities of data sorts and queries, but has provided an automated data reporting system as well. The reporting function alone has significantly reduced the time and efforts that would normally be associated with this task. Since the GDMS was developed at Badger, the program can be continually adapted to site specific needs. Future planned modifications include automated reconciliation, improved transfer of data to graphics software, and statistical analysis and interpretation of the data.« less

Development of a Two-Stage Mars Ascent Vehicle Using In-Situ Propellant Production

NASA Technical Reports Server (NTRS)

Paxton, Laurel; Vaughan, David

2014-01-01

Mars Sample Return (MSR) and Mars In-Situ Resource Utilization (ISRU) present two main challenges for the advancement of Mars science. MSR would demonstrate Mars lift-off capability, while ISRU would test the ability to produce fuel and oxidizer using Martian resources, a crucial step for future human missions. A two-stage Mars Ascent Vehicle (MAV) concept was developed to support sample return as well as in-situ propellant production. The MAV would be powered by a solid rocket first stage and a LOX-propane second stage. A liquid second-stage provides higher orbit insertion reliability than a solid second stage as well as a degree of complexity eventually required for manned missions. Propane in particular offers comparable performance to methane without requiring cryogenic storage. The total MAV mass would be 119.9 kg to carry an 11 kg payload to orbit. The feasibility of in-situ fuel and oxidizer production was also examined. Two potential schemes were evaluated for production capability, size and power requirements. The schemes examined utilize CO2 and water as starting blocks to produce LOX and a propane blend. The infrastructure required to fuel and launch the MAV was also explored.

Large-Eddy Simulation of Propeller Crashback

NASA Astrophysics Data System (ADS)

Kumar, Praveen; Mahesh, Krishnan

2013-11-01

Crashback is an operating condition to quickly stop a propelled vehicle, where the propeller is rotated in the reverse direction to yield negative thrust. The crashback condition is dominated by the interaction of free stream flow with strong reverse flow. Crashback causes highly unsteady loads and flow separation on blade surface. This study uses Large-Eddy Simulation to predict the highly unsteady flow field in propeller crashback. Results are shown for a stand-alone open propeller, hull-attached open propeller and a ducted propeller. The simulations are compared to experiment, and used to discuss the essential physics behind the unsteady loads. This work is supported by the Office of Naval Research.

Propellant Reuse/Recovery Technology

DTIC Science & Technology

1988-08-31

viscosity of the nitrocellulose (NC) determine the solvent/solvent and solvent/propellant ratios required to properly resolvate the propellant. It was also...plasticization. An 11-min drying cycle was required to remove the excess solvent from the over-solvated propellant. To improve plasticization using...solvent, and (4) 15-min mix cycle. To eliminate the drying cycle and determine that a 15-min mix cycle will resolvate the propellart, an additional 1 h

Energy release properties of amorphous boron and boron-based propellant primary combustion products

NASA Astrophysics Data System (ADS)

Liang, Daolun; Liu, Jianzhong; Xiao, Jinwu; Xi, Jianfei; Wang, Yang; Zhang, Yanwei; Zhou, Junhu

2015-07-01

The microstructure of amorphous boron and the primary combustion products of boron-based fuel-rich propellant (hereafter referred to as primary combustion products) was analyzed by scanning electron microscope. Composition analysis of the primary combustion products was carried out by X-ray diffraction and X-ray photoelectron spectroscopy. The energy release properties of amorphous boron and the primary combustion products were comparatively studied by laser ignition experimental system and thermogravimetry-differential scanning calorimetry. The primary combustion products contain B, C, Mg, Al, B4C, B13C2, BN, B2O3, NH4Cl, H2O, and so on. The energy release properties of primary combustion products are different from amorphous boron, significantly. The full-time spectral intensity of primary combustion products at a wavelength of 580 nm is ~2% lower than that of amorphous boron. The maximum spectral intensity of the former at full wave is ~5% higher than that of the latter. The ignition delay time of primary combustion products is ~150 ms shorter than that of amorphous boron, and the self-sustaining combustion time of the former is ~200 ms longer than that of the latter. The thermal oxidation process of amorphous boron involves water evaporation (weight loss) and boron oxidation (weight gain). The thermal oxidation process of primary combustion products involves two additional steps: NH4Cl decomposition (weight loss) and carbon oxidation (weight loss). CL-20 shows better combustion-supporting effect than KClO4 in both the laser ignition experiments and the thermal oxidation experiments.

7 CFR 302.2 - Movement of plants and plant products.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 5 2011-01-01 2011-01-01 false Movement of plants and plant products. 302.2 Section 302.2 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DISTRICT OF COLUMBIA; MOVEMENT OF PLANTS AND PLANT PRODUCTS...

7 CFR 302.2 - Movement of plants and plant products.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Movement of plants and plant products. 302.2 Section 302.2 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DISTRICT OF COLUMBIA; MOVEMENT OF PLANTS AND PLANT PRODUCTS...

7 CFR 302.2 - Movement of plants and plant products.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 5 2013-01-01 2013-01-01 false Movement of plants and plant products. 302.2 Section 302.2 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DISTRICT OF COLUMBIA; MOVEMENT OF PLANTS AND PLANT PRODUCTS...

7 CFR 302.2 - Movement of plants and plant products.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 5 2012-01-01 2012-01-01 false Movement of plants and plant products. 302.2 Section 302.2 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DISTRICT OF COLUMBIA; MOVEMENT OF PLANTS AND PLANT PRODUCTS...

7 CFR 302.2 - Movement of plants and plant products.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 5 2014-01-01 2014-01-01 false Movement of plants and plant products. 302.2 Section 302.2 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DISTRICT OF COLUMBIA; MOVEMENT OF PLANTS AND PLANT PRODUCTS...

Deflagration of thermite - ammonium nitrate based propellant mixture

NASA Astrophysics Data System (ADS)

Duraes, Luisa; Morgado, Joel; Portugal, Antonio; Campos, Jose

2001-06-01

Reaction between iron oxide (Fe2O3) and aluminum (Al) is the reference of the classic thermite compositions. The efficency of the reaction, for a given initial composition of Fe2O3 and Al, is evaluated by the final temperature and by the mass ratio of Al2O3 /AlO in products of combustion (in condensed phase). In order to increase pressure in products of thermite reaction, the original composition is mixed, with an original twin screw extruder, with a propellant binder composed of ammonium and sodium nitrates, initialy solved in formamide (CH3NO) and mixed with a polyurethane solution. The products of combustion and pyrolysis of this binder, reacting with thermite products, generates high pressure and high temperature conditions. These experimental conditions are also predicted using THOR code. The study presents DSC and TGA results of components and mixtures, and correlates them to the ignition phenomena and reaction properties. The regression rate of combustion and final attained temperature and pressure, in a closed confinement, as a function of composition of thermite components/propellant binder, are presented and discussed. They show the influence of gaseous combustion and pyrolysis products of binder in final reaction.

Experimental Investigation of the Interaction of Electrothermal Plasmas with Solid Propellants

DTIC Science & Technology

2007-09-14

formation increases propellant burning rate (Koleczko, et al . 2001). The experiments described here were designed to create time and spatially resolved...Pesce-Rodriguez 2004, Koleczko, et al . 2001). Most tests involving plasma propellant interactions involve higher plasma energies than the 3.1 kJ of...product that scatters light. The large jump in pressurization seen in closed bomb plasma ignition tests (Lieb, et al . 2001) during the plasma discharge

Laboratory test methods for combustion stability properties of solid propellants

NASA Technical Reports Server (NTRS)

Strand, L. D.; Brown, R. S.

1992-01-01

An overview is presented of experimental methods for determining the combustion-stability properties of solid propellants. The methods are generally based on either the temporal response to an initial disturbance or on external methods for generating the required oscillations. The size distribution of condensed-phase combustion products are characterized by means of the experimental approaches. The 'T-burner' approach is shown to assist in the derivation of pressure-coupled driving contributions and particle damping in solid-propellant rocket motors. Other techniques examined include the rotating-valve apparatus, the impedance tube, the modulated throat-acoustic damping burner, and the magnetic flowmeter. The paper shows that experimental methods do not exist for measuring the interactions between acoustic velocity oscillations and burning propellant.

Application of theory to propeller design

NASA Technical Reports Server (NTRS)

Cox, G. G.; Morgan, W. B.

1974-01-01

The various theories concerning propeller design are discussed. The use of digital computers to obtain specific blade shapes to meet appropriate flow conditions is emphasized. The development of lifting-line and lifting surface configurations is analyzed. Ship propulsive performance and basic propeller design considerations are investigated. The characteristics of supercavitating propellers are compared with those of subcavitating propellers.

14 CFR 35.2 - Propeller configuration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller configuration. 35.2 Section 35.2... STANDARDS: PROPELLERS General § 35.2 Propeller configuration. The applicant must provide a list of all the... design of the propeller to be approved under § 21.31 of this chapter. [Amdt. No. 35-8, 73 FR 63346, Oct...

14 CFR 35.2 - Propeller configuration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller configuration. 35.2 Section 35.2... STANDARDS: PROPELLERS General § 35.2 Propeller configuration. The applicant must provide a list of all the... design of the propeller to be approved under § 21.31 of this chapter. [Amdt. No. 35-8, 73 FR 63346, Oct...

14 CFR 35.2 - Propeller configuration.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller configuration. 35.2 Section 35.2... STANDARDS: PROPELLERS General § 35.2 Propeller configuration. The applicant must provide a list of all the... design of the propeller to be approved under § 21.31 of this chapter. [Amdt. 35-8, 73 FR 63346, Oct. 24...

14 CFR 35.2 - Propeller configuration.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller configuration. 35.2 Section 35.2... STANDARDS: PROPELLERS General § 35.2 Propeller configuration. The applicant must provide a list of all the... design of the propeller to be approved under § 21.31 of this chapter. [Amdt. 35-8, 73 FR 63346, Oct. 24...

14 CFR 35.2 - Propeller configuration.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller configuration. 35.2 Section 35.2... STANDARDS: PROPELLERS General § 35.2 Propeller configuration. The applicant must provide a list of all the... design of the propeller to be approved under § 21.31 of this chapter. [Amdt. 35-8, 73 FR 63346, Oct. 24...

Space Transportatioin System (STS) propellant scavenging system study. Volume 3: Cost and work breakdown structure-dictionary

NASA Technical Reports Server (NTRS)

1985-01-01

Fundamentally, the volumes of the oxidizer and fuel propellant scavenged from the orbiter and external tank determine the size and weight of the scavenging system. The optimization of system dimensions and weights is stimulated by the requirement to minimize the use of partial length of the orbiter payload bay. Thus, the cost estimates begin with weights established for the optimum design. Both the design, development, test, and evaluation and theoretical first unit hardware production costs are estimated from parametric cost weight scaling relations for four subsystems. For cryogenic propellants, the widely differing characteristics of the oxidizer and the fuel lead to two separate tank subsystems, in addition to the electrical and instrumentation subsystems. Hardwares costs also involve quantity, as an independent variable, since the number of production scavenging systems is not firm. For storable propellants, since the tankage volume of the oxidizer and fuel are equal, the hardware production costs for developing these systems are lower than for cryogenic propellants.

Bleriot Propeller Close-up

NASA Image and Video Library

2017-05-10

This view from NASA's Cassini spacecraft shows Cassini's best image of the propeller feature known informally as Bleriot. The propeller is named after Louis Bleriot, the French engineer and aviator who in 1909 was the first person to fly across the English Channel. This is the third and final propeller to be targeted for a close flyby observation during Cassini's ring-grazing orbits (the period from Nov. 2016 to April 2017 when Cassini's orbit passed just outside the main rings). Because propellers are seen in the outermost parts of the main rings, the ring-grazing orbits provided Cassini's best opportunity to see them up close. Many small, bright specks and linear, scratch-like artifacts are visible in the image. These artifacts are due to cosmic rays and particles of radiation near the planet striking the camera detector during the exposure. Bleriot is the largest of the propellers in Saturn's rings. The wavy features embedded in the propeller structure indicate that its central moonlet is some 60 percent wider than that of Santos-Dumont, which means the Bleriot moonlet is about four times more massive. Cassini scientists have been tracking the orbit of this object for the past decade, tracing the effect that the ring has upon it. Because it is the biggest propeller, it is more easily seen in lower-resolution images than other propellers, and thus it can be spotted in the most images by far. Here, as Cassini moved in close to the rings as part of its ring-grazing orbits, it was able to obtain this extreme close-up view of the propeller, which enables researchers to examine its effects on the ring as never before. These views, and others like them, will inform models and studies in new ways going forward. This image was taken on the unilluminated side of the rings, where sunlight filters through the backlit ring. Like a frosted window, Saturn's rings look different depending on whether they are seen fully sunlit or backlit. On the lit side, the rings look darker

SRM propellant, friction/ESD testing

NASA Technical Reports Server (NTRS)

Campbell, L. A.

1989-01-01

Following the Pershing 2 incident in 1985 and the Peacekeeper ignition during core removal in 1987, it was found that propellant can be much more sensitive to Electrostatic Discharges (ESD) than ever before realized. As a result of the Peacekeeper motor near miss incident, a friction machine was designed and fabricated, and used to determine friction hazards during core removal. Friction testing with and electrical charge being applied across the friction plates resulted in propellant ignitions at low friction pressures and extremely low ESD levels. The objective of this test series was to determine the sensitivity of solid rocket propellant to combined friction pressure and electrostatic stimuli and to compare the sensitivity of the SRM propellant to Peacekeeper propellant. The tests are fully discussed, summarized and conclusions drawn.

Ion-thruster propellant utilization

NASA Technical Reports Server (NTRS)

Kaufman, H. R.

1971-01-01

The evaluation and understanding of maximum propellant utilization, with mercury used as the propellant are presented. The primary-electron region in the ion chamber of a bombardment thruster is analyzed at maximum utilization. The results of this analysis, as well as experimental data from a range of ion-chamber configurations, show a nearly constant loss rate for unionized propellant at maximum utilization over a wide range of total propellant flow rate. The discharge loss level of 1000 eV/ion was used as a definition of maximum utilization, but the exact level of this definition has no effect on the qualitative results and little effect on the quantitative results. There are obvious design applications for the results of this investigation, but the results are particularly significant whenever efficient throttled operation is required.

The effect of front-to-rear propeller spacing on the interaction noise at cruise conditions of a model counterrotation propeller having a reduced diameter aft propeller

NASA Technical Reports Server (NTRS)

Dittmar, James H.; Gordon, Eliott B.; Jeracki, Robert J.

1988-01-01

The effect of forward-to-aft propeller spacing on the interaction noise of a counterrotation propeller with reduced aft diameter was measured at cruise conditions. In general, the tones at 100 percent speed decreased from close to nominal spacing as expected from a wake decay model. However, when the spacing was further increased to the far position, the noise did not decrease as expected and in some cases increased. The behavior at the far spacing was attributed to changing forward propeller performance, which produced larger wakes. The results of this experiment indicate that simple wake decay model is sufficient to describe the behavior of the interaction noise only if the aerodynamic coupling of the two propellers does not change with spacing. If significant coupling occurs such that the loading of the forward propeller is altered, the interaction noise does not necessarily decrease with larger forward-to-aft propeller spacing.

Resonance vibrations of aircraft propellers

NASA Technical Reports Server (NTRS)

Liebers, Fritz

1932-01-01

On the basis of the consideration of various possible kinds of propeller vibrations, the resonance vibrations caused by unequal impacts of the propeller blades appear to be the most important. Their theoretical investigation is made by separate analysis of torsional and bending vibrations. This method is justified by the very great difference in the two natural frequencies of aircraft propeller blades. The calculated data are illustrated by practical examples. Thereby the observed vibration phenomenon in the given examples is explained by a bending resonance, for which the bending frequency of the propeller is equal to twice the revolution speed.

Pusher propeller noise directivity and trends

NASA Technical Reports Server (NTRS)

Block, P. J. W.

1986-01-01

The effects of pylon wake interaction on far-field propeller noise are studied using a model scale SR-2 propeller in a low-speed anechoic wind tunnel. The variation in the pusher noise penalty with axial angle theta and circumferential angle phi is compared to that of the tractor noise penalty; and the former exhibits minima occurring in the propeller plane and maxima occurring toward the propeller axis. The magnitude of the pusher installation noise penalty decreased with in increase in shaft horsepower and tip Mach number. Directivity comparisons revealed that both a noise reduction and a directivity pattern change resulted when the pylon was moved farther from the propeller. Noise emerging from the wake interaction was distinguished from that of the propeller by means of a modal decomposition.

TDAP: Island versus propeller.

PubMed

Angrigiani, Claudio; Rancati, Alberto; Artero, Guillermo; Escudero, Ezequiel; Khouri, Roger K

2016-04-01

Thoracodorsal artery perforator (TDAP) island flap is a safe and reliable method for breast reconstruction. TDAP propeller flap has been described as a modification of the conventional island technique that saves time and does not require microsurgical skills. However, a substantial portion of the propeller flap remains under the axilla and is not used for breast augmentation. The aim of this study is to identify the differences in the reaching distances between the propeller and island TDAP flaps. In five cadaveric specimens and 10 breast reconstruction patients, an initial propeller flap was harvested and rotated to the anterior thorax; the distance from the tip of the flap to the anterior midline was recorded as the "midline-reaching deficit;" the flap was then converted into a conventional island flap, and the new midline-reaching deficit was recorded. Differences between groups were compared with paired two-tailed t-tests (α = 0.05). In the cadaveric specimens, the mean midline-reaching deficit was 4.8 ± 2.4 cm with the propeller TDAP and -0.6 ± 2.0 cm with the conventional island TDAP (P < 0.001). In the clinical cases, the mean midline-reaching deficit was 8.1 ± 1.0 cm with the propeller TDAP and -0.3 ± 1.1 cm with the island TDAP (P < 0.000000001). We observed that the midline-reaching deficit could be reduced by 7-9 cm with the conventional island TDAP in comparison to the propeller TDAP. This should be considered when reconstructing the medial inner part of the breast. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Environmentally compatible solid rocket propellants

NASA Technical Reports Server (NTRS)

Jacox, James L.; Bradford, Daniel J.

1995-01-01

Hercules' clean propellant development research is exploring three major types of clean propellant: (1) chloride-free formulations (no chlorine containing ingredients), being developed on the Clean Propellant Development and Demonstration (CPDD) contract sponsored by Phillips Laboratory, Edwards Air Force Base, CA; (2) low HCl scavenged formulations (HCl-scavenger added to propellant oxidized with ammonium perchlorate (AP)); and (3) low HCl formulations oxidized with a combination of AN and AP (with or without an HCl scavenger) to provide a significant reduction (relative to current solid rocket boosters) in exhaust HCl. These propellants provide performance approaching that of current systems, with less than 2 percent HCl in the exhaust, a significant reduction (greater than or equal to 70 percent) in exhaust HCl levels. Excellent processing, safety, and mechanical properties were achieved using only readily available, low cost ingredients. Two formulations, a sodium nitrate (NaNO3) scavenged HTPB and a chloride-free hydroxy terminated polyether (HTPE) propellant, were characterized for ballistic, mechanical, and rheological properties. In addition, the hazards properties were demonstrated to provide two families of class 1.3, 'zero-card' propellants. Further characterization is planned which includes demonstration of ballistic tailorability in subscale (one to 70 pound) motors over the range of burn rates required for retrofit into current Hercules space booster designs (Titan 4 SRMU and Delta 2 GEM).

Propeller from Unlit Side

NASA Image and Video Library

2010-07-08

A propeller-shaped structure created by an unseen moon appears dark in this image obtained by NASA Cassini spacecraft of the unilluminated side of Saturn rings. The propeller is marked with a red arrow in the top left.

Aeroacoustics of advanced propellers

NASA Technical Reports Server (NTRS)

Groeneweg, John F.

1990-01-01

The aeroacoustics of advanced, high speed propellers (propfans) are reviewed from the perspective of NASA research conducted in support of the Advanced Turboprop Program. Aerodynamic and acoustic components of prediction methods for near and far field noise are summarized for both single and counterrotation propellers in uninstalled and configurations. Experimental results from tests at both takeoff/approach and cruise conditions are reviewed with emphasis on: (1) single and counterrotation model tests in the NASA Lewis 9 by 15 (low speed) and 8 by 6 (high speed) wind tunnels, and (2) full scale flight tests of a 9 ft (2.74 m) diameter single rotation wing mounted tractor and a 11.7 ft (3.57 m) diameter counterrotation aft mounted pusher propeller. Comparisons of model data projected to flight with full scale flight data show good agreement validating the scale model wind tunnel approach. Likewise, comparisons of measured and predicted noise level show excellent agreement for both single and counterrotation propellers. Progress in describing angle of attack and installation effects is also summarized. Finally, the aeroacoustic issues associated with ducted propellers (very high bypass fans) are discussed.

Propellers in yaw

NASA Technical Reports Server (NTRS)

Ribner, Herbert S

1945-01-01

It was realized as early as 1909 that a propeller in yaw develops a side force like that of a fin. In 1917, R. G. Harris expressed this force in terms of the torque coefficient for the unyawed propeller. Of several attempts to express the side force directly in terms of the shape of the blades, however, none has been completely satisfactory. An analysis that incorporates induction effects not adequately covered in previous work and that gives good agreement with experiment over a wide range of operating conditions is presented. The present analysis shows that the fin analogy may be extended to the form of the side-force expression and that the effective fin area may be taken as the projected side area of the propeller.

Development of HAN-based Liquid Propellant Thruster

NASA Astrophysics Data System (ADS)

Hisatsune, K.; Izumi, J.; Tsutaya, H.; Furukawa, K.

2004-10-01

Many of propellants that are applied to the conventional spacecraft propulsion system are toxic propellants. Because of its toxicity, considering the environmental pollution or safety on handling, it will be necessary to apply the "green" propellant to the spacecraft propulsion system. The purpose of this study is to apply HAN based liquid propellant (LP1846) to mono propellant thruster. Compared to the hydrazine that is used in conventional mono propellant thruster, HAN based propellant is not only lower toxic but also can obtain higher specific impulse. Moreover, HAN based propellant can be decomposed by the catalyst. It means there are the possibility of applying to the mono propellant thruster that can leads to the high reliability of the propulsion system.[1],[2] However, there are two technical subjects, to apply HAN based propellant to the mono propellant thruster. One is the high combustion temperature. The catalyst will be damaged under high temperature condition. The other is the low catalytic activity. It is the serious problem on application of HAN based propellant to the mono propellant thruster that is used for attitude control of spacecraft. To improve the catalytic activity of HAN based propellant, it is necessary to screen the best catalyst for HAN based propellant. The adsorption analysis is conducted by Monte Carlo Simulation to screen the catalyst metal for HAN and TEAN. The result of analysis shows the Iridium is the best catalyst metal for HAN and TEAN. Iridium is the catalyst metal that is used at conventional mono propellant thruster catalyst Shell405. Then, to confirm the result of analysis, the reaction test about catalyst is conducted. The result of this test is the same as the result of adsorption analysis. That means the adsorption analysis is effective in screening the catalyst metal. At the evaluating test, the various types of carrier of catalyst are also compared to Shell 405 to improve catalytic activity. The test result shows the

Lead-Free Double-Base Propellant for the 2.75 Inch Rocket Motor

NASA Technical Reports Server (NTRS)

Magill, B. T.; Nauflett, G. W.; Furrow, K. W.

2000-01-01

The current MK 66 2.75 inch Rocket Motor double-base propellant contains the lead-based ballistic modifier LC-12-15 to achieve the desired plateau and mesa burning rate characteristics. The use of lead compounds poses a concern for the environment and for personal safety due to the metal's toxic nature when introduced into the atmosphere by propellant manufacture, rocket motor firing, and disposal. Copper beta-resorcylate (copper 2,4-di-hydroxy-benzoate) was successfully used in propellant as a simple modifier in the mid 1970's. This and other compounds have also been mixed with lead salts to obtain more beneficial ballistic results. Synthesized complexes of lead and copper compounds soon replaced the mixtures. The complexes incorporate the lead, copper lack of organic liquids, which allows for easier propellant processing. About ten years ago, the Indian Head Division, Naval Surface Warfare Center (NSWC), initiated an effort to develop a lead-free propellant for use in missile systems. Several lead-free propellant candidate formulations were developed. About five years ago, NSWC, in conjunction with Alliant Techsystems, Radford Army Ammunition Plant, continued ballistic modifier investigations. A four component ballistic modifier system without lead for double-base propellants that provide adequate plateau and mesa burn rate characteristics was developed and patented. The ballistic modifier's system contains bismuth subsalicylate, 1.5 percent; copper salicylate, 1.0 percent, copper stannate, 0.77 percent; and carbon black, 0.1 percent. Action time and impulse data obtained through multiple static firings indicate that the new lead-free double-base propellant, while not a match for NOSIH-AA-2, will be a very suitable replacement in the 2.75 inch Rocket Motor. Accelerated aging of the double-base propellant containing the lead-free ballistic modifier showed that it had a much higher rate of stabilizer depletion than the AA-2. A comprehensive study showed that an

14 CFR 35.43 - Propeller hydraulic components.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller hydraulic components. 35.43... AIRWORTHINESS STANDARDS: PROPELLERS Tests and Inspections § 35.43 Propeller hydraulic components. Applicants must show by test, validated analysis, or both, that propeller components that contain hydraulic...

14 CFR 35.43 - Propeller hydraulic components.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller hydraulic components. 35.43... AIRWORTHINESS STANDARDS: PROPELLERS Tests and Inspections § 35.43 Propeller hydraulic components. Applicants must show by test, validated analysis, or both, that propeller components that contain hydraulic...

14 CFR 35.43 - Propeller hydraulic components.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller hydraulic components. 35.43... AIRWORTHINESS STANDARDS: PROPELLERS Tests and Inspections § 35.43 Propeller hydraulic components. Applicants must show by test, validated analysis, or both, that propeller components that contain hydraulic...

14 CFR 35.43 - Propeller hydraulic components.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller hydraulic components. 35.43... AIRWORTHINESS STANDARDS: PROPELLERS Tests and Inspections § 35.43 Propeller hydraulic components. Applicants must show by test, validated analysis, or both, that propeller components that contain hydraulic...

14 CFR 35.43 - Propeller hydraulic components.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller hydraulic components. 35.43... AIRWORTHINESS STANDARDS: PROPELLERS Tests and Inspections § 35.43 Propeller hydraulic components. Applicants must show by test, validated analysis, or both, that propeller components that contain hydraulic...

Kirsten-boeing Propeller

NASA Technical Reports Server (NTRS)

Sachse, H

1926-01-01

The advantages of the Kirsten-Boeing propeller consist essentially in the adjustability of the thrust in any desired direction, in the plane perpendicular to the axis of rotation of the system, and in its high efficiency. The propeller, which greatly resembles the paddle wheels used on river steamers, differs fundamentally from the latter, in that all the blades work simultaneously in the fluid medium (air or water).

14 CFR 23.1153 - Propeller feathering controls.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller feathering controls. 23.1153... Powerplant Controls and Accessories § 23.1153 Propeller feathering controls. If there are propeller feathering controls installed, it must be possible to feather each propeller separately. Each control must...

14 CFR 23.1153 - Propeller feathering controls.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller feathering controls. 23.1153... Powerplant Controls and Accessories § 23.1153 Propeller feathering controls. If there are propeller feathering controls installed, it must be possible to feather each propeller separately. Each control must...

14 CFR 23.1153 - Propeller feathering controls.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller feathering controls. 23.1153... Powerplant Controls and Accessories § 23.1153 Propeller feathering controls. If there are propeller feathering controls installed, it must be possible to feather each propeller separately. Each control must...

14 CFR 23.1153 - Propeller feathering controls.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller feathering controls. 23.1153... Powerplant Controls and Accessories § 23.1153 Propeller feathering controls. If there are propeller feathering controls installed, it must be possible to feather each propeller separately. Each control must...

14 CFR 23.1153 - Propeller feathering controls.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller feathering controls. 23.1153... Powerplant Controls and Accessories § 23.1153 Propeller feathering controls. If there are propeller feathering controls installed, it must be possible to feather each propeller separately. Each control must...

[Characteristics and mechanism of boat propeller injuries].

PubMed

Yu, Song; Shen, Yi-Wen; Xue, Ai-Min

2008-02-01

To summarize the characteristics and investigate the mechanisms of boat propeller injuries so as to explore the identification methods between boat propeller injuries and corpse dismemberment. More than 100 autopsy cases of boat propeller injuries were collected in a period between 1994 and 2005 in Huzhou district, Zhejiang province. The characteristics of injuries caused by propeller, including abrasion, wound, fracture and severed wound, and the characteristics of clothing, were retrospectively studied and summarized. The severed cross wound section of boat propeller injuries was compared with that caused by corpse dismemberment. The boat propeller injuries were resulted from high-speed propellers with enormous splitting power and mechanical cutting, while corpse dismemberment were resulted from cutting and dismembering the body with sharp instruments. Due to the different mechanisms, the different strength of force and recoil force, the severed wound cross section had different characteristics. Wounds caused by boat propeller injuries have their unique characteristics, distinguished from wounds of dismembered corpse.

In-Situ Propellant Supplied Lunar Lander Concept

NASA Astrophysics Data System (ADS)

Donahue, Benjamin; Maulsby, Curtis

2008-01-01

Future NASA and commercial Lunar missions will require innovative spacecraft configurations incorporating reliable, sustainable propulsion, propellant storage, power and crew life support technologies that can evolve into long duration, partially autonomous systems that can be used to emplace and sustain the massive supplies required for a permanently occupied lunar base. Ambitious surface science missions will require efficient Lunar transfer systems to provide the consumables, science equipment, energy generation systems, habitation systems and crew provisions necessary for lengthy tours on the surface. Lunar lander descent and ascent stages become significantly more efficient when they can be refueled on the Lunar surface and operated numerous times. Landers enabled by Lunar In-Situ Propellant Production (ISPP) facilities will greatly ease constraints on spacecraft mass and payload delivery capability, and may operate much more affordably (in the long term) then landers that are dependant on Earth supplied propellants. In this paper, a Lander concept that leverages ISPP is described and its performance is quantified. Landers, operating as sortie vehicles from Low Lunar Orbit, with efficiencies facilitated by ISPP will enable economical utilization and enhancements that will provide increasingly valuable science yields from Lunar Bases.

Combustion Mechanisms of Wide Distribution Propellants

DTIC Science & Technology

1988-06-01

trimodal propellants were formulated. Each set contains an HTPB binder and duplicate formulations were made with either a IPDI or a DDI curative. The...Distinctive Mechanisms Previous studies [12,131 have shown that HTPB * propellants with wide AP distributions burn at rates much different than predictions...propellants. 17 .- = i.= i i i il =.. .l=limim mll ili= =.l i@ w. -’- 87% 400/20/ 3 MICRON,AP/ HTPB PROPELLANT 2.0 Z -1.0 --- 0--.-7- 0 CALCULATIONO0

14 CFR 25.1153 - Propeller feathering controls.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller feathering controls. 25.1153... Accessories § 25.1153 Propeller feathering controls. (a) There must be a separate propeller feathering control for each propeller. The control must have means to prevent its inadvertent operation. (b) If...

14 CFR 25.1153 - Propeller feathering controls.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller feathering controls. 25.1153... Accessories § 25.1153 Propeller feathering controls. (a) There must be a separate propeller feathering control for each propeller. The control must have means to prevent its inadvertent operation. (b) If...

14 CFR 25.1153 - Propeller feathering controls.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller feathering controls. 25.1153... Accessories § 25.1153 Propeller feathering controls. (a) There must be a separate propeller feathering control for each propeller. The control must have means to prevent its inadvertent operation. (b) If...

14 CFR 25.1153 - Propeller feathering controls.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller feathering controls. 25.1153... Accessories § 25.1153 Propeller feathering controls. (a) There must be a separate propeller feathering control for each propeller. The control must have means to prevent its inadvertent operation. (b) If...

14 CFR 25.1153 - Propeller feathering controls.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller feathering controls. 25.1153... Accessories § 25.1153 Propeller feathering controls. (a) There must be a separate propeller feathering control for each propeller. The control must have means to prevent its inadvertent operation. (b) If...

14 CFR 23.1027 - Propeller feathering system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Oil System § 23.1027 Propeller feathering system. (a) If the propeller feathering system uses engine... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller feathering system. 23.1027... made to prevent sludge or other foreign matter from affecting the safe operation of the propeller...

14 CFR 23.1027 - Propeller feathering system.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Oil System § 23.1027 Propeller feathering system. (a) If the propeller feathering system uses engine... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller feathering system. 23.1027... made to prevent sludge or other foreign matter from affecting the safe operation of the propeller...

14 CFR 23.1027 - Propeller feathering system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Oil System § 23.1027 Propeller feathering system. (a) If the propeller feathering system uses engine... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller feathering system. 23.1027... made to prevent sludge or other foreign matter from affecting the safe operation of the propeller...

14 CFR 23.1027 - Propeller feathering system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Oil System § 23.1027 Propeller feathering system. (a) If the propeller feathering system uses engine... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller feathering system. 23.1027... made to prevent sludge or other foreign matter from affecting the safe operation of the propeller...

14 CFR 23.1027 - Propeller feathering system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Oil System § 23.1027 Propeller feathering system. (a) If the propeller feathering system uses engine... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller feathering system. 23.1027... made to prevent sludge or other foreign matter from affecting the safe operation of the propeller...

Advanced propeller aerodynamic analysis

NASA Technical Reports Server (NTRS)

Bober, L. J.

1980-01-01

The analytical approaches as well as the capabilities of three advanced analyses for predicting propeller aerodynamic performance are presented. It is shown that two of these analyses use a lifting line representation for the propeller blades, and the third uses a lifting surface representation.

14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller...

14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller...

14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller...

14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller...

14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller...

Cars Spectroscopy of Propellant Flames

DTIC Science & Technology

1983-11-01

applicability of CARS in studies of the combustion of propellants and other reactive systems. Broadband CARS spectra were obtained from both the reaction zone...ref 12). When ienited vith a flame, propellant burned in air with a luainous flame. A-e Ignittou with i hot wire resulted in flameless burning (fizz...ester). Current models of nitramine propellant combustion are essentially models of HMX (cyclotetranithylene tetranitramine) and RDX deflagration. The

14 CFR 35.16 - Propeller critical parts.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller critical parts. 35.16 Section 35... AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.16 Propeller critical parts. The integrity of each propeller critical part identified by the safety analysis required by § 35.15 must be established...

Effect of propellant deformation on ignition and combustion processes in solid propellant cracks

NASA Technical Reports Server (NTRS)

Kumar, M.; Kuo, K. K.

1980-01-01

A comprehensive theoretical model was formulated to study the development of convective burning in a solid propellant crack which continually deforms due to burning and pressure loading. In the theoretical model, the effect of interrelated structural deformation and combustion processes was taken into account by considering (1) transient, one dimensional mass, momentum, and energy conservation equations in the gas phase; (2) a transient, one dimensional heat conduction equation in the solid phase; and (3) quasi-static deformation of the two dimensional, linear viscoelastic propellant crack caused by pressure loading. Partial closures may generate substantial local pressure peaks along the crack, implying a strong coupling between chamber pressurization, crack combustion, and propellant deformation, especially when the cracks are narrow and the chamber pressurization rates high. The maximum pressure in the crack cavity is generally higher than that in the chamber. The initial flame-spreading process is not affected by propellant deformation.

Propeller aircraft interior noise model

NASA Technical Reports Server (NTRS)

Pope, L. D.; Wilby, E. G.; Wilby, J. F.

1984-01-01

An analytical model was developed to predict the interior noise of propeller-driven aircraft. The fuselage model is that of a cylinder with a structurally-integral floor. The cabin sidewall is stiffened by stringers and ring frames, and the floor by longitudinal beams. The cabin interior is covered with a sidewall treatments consisting of layers of porous material and an impervious trim septum. Representation of the propeller pressure field is utilized as input data in the form of the propeller noise signature at a series of locations on a grid over the fuselage structure. Results obtained from the analytical model are compared with test data measured by NASA in a scale model cylindrical fuselage excited by a model propeller.

The acoustics of ducted propellers

NASA Astrophysics Data System (ADS)

Ali, Sherif F.

The return of the propeller to the long haul commercial service may be rapidly approaching in the form of advanced "prop fans". It is believed that the advanced turboprop will considerably reduce the operational cost. However, such aircraft will come into general use only if their noise levels meet the standards of community acceptability currently applied to existing aircraft. In this work a time-marching boundary-element technique is developed, and used to study the acoustics of ducted propeller. The numerical technique is developed in this work eliminated the inherent instability suffered by conventional approaches. The methodology is validated against other numerical and analytical results. The results show excellent agreement with the analytical solution and show no indication of unstable behavior. For the ducted propeller problem, the propeller is modeled by a rotating source-sink pairs, and the duct is modeled by rigid annular body of elliptical cross-section. Using the model and the developed technique, the effect of different parameters on the acoustic field is predicted and analyzed. This includes the effect of duct length, propeller axial location, and source Mach number. The results of this study show that installing a short duct around the propeller can reduce the noise that reaches an observer on a side line.

14 CFR 25.925 - Propeller clearance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most adverse...

14 CFR 23.925 - Propeller clearance.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the most...

14 CFR 23.925 - Propeller clearance.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the most...

14 CFR 23.925 - Propeller clearance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the most...

14 CFR 25.925 - Propeller clearance.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most adverse...

14 CFR 25.925 - Propeller clearance.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most adverse...

14 CFR 25.925 - Propeller clearance.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most adverse...

14 CFR 23.925 - Propeller clearance.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the most...

Propeller injuries.

PubMed

Mann, R J

1976-05-01

Water skiing, boat racing, skin and scuba diving, and pleasure boat cruising are increasing in popularity. As a result the incidence of injuries secondary to motor propellers is becoming more frequent. In a ten-year period from 1963 to 1973, I collected a total of nine cases. In some amputations were necessary, and in other cases amputations occurred at the time of injury. Problems with bacterial flora occurring in open sea water versus salt water enclosed near docks and fresh lake water are discussed. A review of the orthopedic literature revealed sparse information regarding propeller injuries.

Experimental verification of propeller noise prediction

NASA Technical Reports Server (NTRS)

Succi, G. P.; Munro, D. H.; Zimmer, J. A.

1980-01-01

Results of experimental measurements of the sound fields of 1/4-scale general aviation propellers are presented and experimental wake surveys and pressure signatures obtained are compared with theoretical predictions. Experiments were performed primarily on a 1C160 propeller model mounted in front of a symmetric body in an anechoic wind tunnel, and measured the thrust and torque produced by propeller at different rotation speeds and tunnel velocities, wakes at three axial distances, and sound pressure at various azimuths and tip speeds with advance ratio or tunnel velocity constant. Aerodynamic calculations of blade loading were performed using airfoil section characteristics and a modified strip analysis procedure. The propeller was then modeled as an array of point sound sources with each point characterized by the force and volume of the corresponding propeller section in order to obtain the acoustic characteristics. Measurements are found to agree with predictions over a wide range of operating conditions, tip speeds and propeller nacelle combinations, without the use of adjustable constants.

Catalytic Decomposition of Propellant Hydrazines, N-Nitrosodimethylamine, and N-Nitrodimethylamine

NASA Technical Reports Server (NTRS)

Greene, Ben; Johnson, Harry T.

2000-01-01

Remediation of propellant hydrazine spills, waste treatment, or cleanup of water contaminated with these propellants and/or their oxidation products is a subject of great concern for safety and the environment. Current remediation technologies typically employ oxidative methods, such as chlorination or ozonation. Methylated hydrazines, in particular 1,1-dimethythydrazine (UDMH) and to some degree monomethy1hydrazine (MMH), form N-Nitrosodimethylamine (NDMA) and N-Nitrodimethylamine (DMNM) during oxidation. These compounds are highly toxic and may persist if oxidative conditions are not sufficiently harsh. Since NDMA and DMNM may also be formed from exposure of MMH or UDMH to air, a need exists for a method that will remediate hydrazine, MMH, UDMH, NDMA, and DMNM. In this work, aqueous solutions of propellant hydrazines, NDMA, and DMNM were found to degrade by catalytic reduction with nickel-aluminum (Ni-Al) alloy under basic conditions. The reaction is based upon dissolution of At from Ni-Al alloy in aqueous media to form aluminum ion and hydrogen gas; and the resultant finely divided nickel catalyzes reduction of the hydrazine, nitrosoamine, or nitroamine by the hydrogen produced. Greater than 99 percent of hydrazine, MMH, UDMH, NDMA, and DMNM in aqueous solutions were degraded under laboratory conditions when reacted with Ni-Al alloy. UDMH was identified as an intermediate reduction product of NDMA and DNNM. NDMA and UDMH were identified as intermediate reduction products of DMNM. Control experiments without nickel showed no degradation of hydrazine, MMH or UDMH, while NDMA and DMNM were reduced to UDMH. Spill pillows containing Ni-Al alloy and solid sodium hydroxide were also found effective in absorption and degradation of UDMH. The application of chemical reduction as a means to propellant hydrazines, NDMA, and DMNM spill remediation, waste treatment, and water decontamination appears highly attractive.

New Propellants and Cryofuels

NASA Technical Reports Server (NTRS)

Palasezski, Bryan; Sullivan, Neil S.; Hamida, Jaha; Kokshenev, V.

2006-01-01

The proposed research will investigate the stability and cryogenic properties of solid propellants that are critical to NASA s goal of realizing practical propellant designs for future spacecraft. We will determine the stability and thermal properties of a solid hydrogen-liquid helium stabilizer in a laboratory environment in order to design a practical propellant. In particular, we will explore methods of embedding atomic species and metallic nano-particulates in hydrogen matrices suspended in liquid helium. We will also measure the characteristic lifetimes and diffusion of atomic species in these candidate cryofuels. The most promising large-scale advance in rocket propulsion is the use of atomic propellants; most notably atomic hydrogen stabilized in cryogenic environments, and metallized-gelled liquid hydrogen (MGH) or densified gelled hydrogen (DGH). The new propellants offer very significant improvements over classic liquid oxygen/hydrogen fuels because of two factors: (1) the high energy-release, and (ii) the density increase per unit energy release. These two changes can lead to significant reduced mission costs and increased payload to orbit weight ratios. An achievable 5 to 10 percent improvement in specific impulse for the atomic propellants or MGH fuels can result in a doubling or tripling of system payloads. The high-energy atomic propellants must be stored in a stabilizing medium such as solid hydrogen to inhibit or delay their recombination into molecules. The goal of the proposed research is to determine the stability and thermal properties of the solid hydrogen-liquid helium stabilizer. Magnetic resonance techniques will be used to measure the thermal lifetimes and the diffusive motions of atomic species stored in solid hydrogen grains. The properties of metallic nano-particulates embedded in hydrogen matrices will also be studied and analyzed. Dynamic polarization techniques will be developed to enhance signal/noise ratios in order to be able to

Removing hydrochloric acid exhaust products from high performance solid rocket propellant using aluminum-lithium alloy.

PubMed

Terry, Brandon C; Sippel, Travis R; Pfeil, Mark A; Gunduz, I Emre; Son, Steven F

2016-11-05

Hydrochloric acid (HCl) pollution from perchlorate based propellants is well known for both launch site contamination, as well as the possible ozone layer depletion effects. Past efforts in developing environmentally cleaner solid propellants by scavenging the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., a salt instead of HCl). While this technique can potentially reduce HCl formation, it also results in reduced ideal specific impulse (ISP). Here, we show using thermochemical calculations that using aluminum-lithium (Al-Li) alloy can reduce HCl formation by more than 95% (with lithium contents ≥15 mass%) and increase the ideal ISP by ∼7s compared to neat aluminum (using 80/20 mass% Al-Li alloy). Two solid propellants were formulated using 80/20 Al-Li alloy or neat aluminum as fuel additives. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments (75.5±4.8% reduction in pH, ∝ [HCl], when compared to neat aluminum). Additionally, no measurable HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption. Copyright © 2016 Elsevier B.V. All rights reserved.

The Theory of Propellers I : Determination of the Circulation Function and the Mass Coefficient for Dual-Rotating Propellers

NASA Technical Reports Server (NTRS)

Theodorsen, Theodore

1944-01-01

Values of the circulation function have been obtained for dual-rotating propellers. Numerical values are given for four, eight, and twelve-blade dual-rotating propellers and for advance ratios from 2 to about 6. In addition, the circulation function has been determine for single-rotating propellers for the higher values of the advance ratio. The mass coefficient, another quantity of significance in propeller theory, has been introduced.

Thrust Deduction in Contrarotating Propellers

DTIC Science & Technology

1974-11-01

nuder gavc At = 0.056 Design CR propellers (Table 2) At = 0.029 Single Screw. Stromn-Tejsen 14 Very good agreement between the experimental and... design experimental points do not lie on the theoretical curve. This is believed to be due to either experimental test accuracy. or tile rudder effect, or...propellers. Con trarotating propellers operating at off- design loading and spacing as well as the contribution of a rudder were investigated. Theli

[Transgenic plants as medicine production systems].

PubMed

Okada, Y

1997-10-01

Transgenic plants are emerging as an important system for the expression of many recombinant proteins, especially those intended for therapeutic purpose. The production of foreign proteins in plants has several advantages. In terms of required equipment and cost, mass production in plants is far easier to achieve than techniques involving animal cells. Successful production of several proteins in plants, including human serum albumin, haemoglobin, monoclonal antibodies, viral antigens (vaccines), enkephalin, and trichosanthin, has been reported. Particularly, the demonstration that vaccine antigens can be produced in plants in their native, immunogenic forms opens exciting possibilities for the "bio-farming" of vaccines. If the antigens are orally active, food-based "edible vaccines" could allow economical production. In this review, I will discuss the progress that has been made by several groups in what is now an expanding area of medicine research that utilizes transgenic plants.

3-D viscous flow CFD analysis of the propeller effect on an advanced ducted propeller subsonic inlet

NASA Technical Reports Server (NTRS)

Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

1993-01-01

The time-marching Navier-Stokes code PARC3D was used to study the 3D viscous flow associated with an advanced ducted propeller subsonic inlet at take-off operating conditions. At a free stream Mach number of 0.2, experimental data for the inlet-with-propeller test model indicated that the airflow was attached on the cowl windward lip at an angle of attack of 25 deg became unstable at 29 deg, and separated at 30 deg. An experimental study with a similar inlet and without propeller (through-flow) indicated that flow separation occurred at an angle of attack a few degrees below the value observed when the inlet was tested with the propeller, indicating the propeller's favorable effect on inlet performance. In the present numerical study, flow blockage analogous to the propeller was modeled via a PARC3D computational boundary condition (BC), the 'screen BC', based on 1-1/2 dimension actuator disk theory. The application of the screen BC in this numerical study provided results similar to those of past experimental efforts in which either the blockage device or the propeller was used.

The theory of the screw propeller

NASA Technical Reports Server (NTRS)

Betz, A

1922-01-01

Given here is a brief review of the fundamental principles of the propeller slip-stream theory and its further development through later researches, which demonstrate the connection between the propeller slip-stream theory and Frounde's so-called 'propeller blade theory.' The propeller slip-stream theory, especially in its improved form, now gives us the basis for determining the mutual influence of the parts of the blade, so that, in calculating the shape of the blade, we can get along with certain section characteristics, which have been determined once and for all. It is argued that new theories present the possibility of investigating the phenomena in the vicinity of the propeller, allowing us to calculate its action on the basis of fewer experimental values.

Earhart Propeller in Saturn A Ring

NASA Image and Video Library

2017-03-30

The propeller informally named "Earhart" is seen in this view from NASA's Cassini spacecraft at much higher resolution than ever before. This view, obtained on March 22, 2017, is the second time Cassini has deliberately targeted an individual propeller for close-up viewing during its ring-grazing orbits, after its images of Santos-Dumont (PIA21433) a month earlier. The biggest known propeller, informally named "Bleriot," is slated for the third and final propeller close-up in April 2017. Propellers are disturbances in the ring caused by a central moonlet. The moonlet itself would be a few pixels wide in this view, but it is difficult to distinguish from (and may be obscured by) the disturbed ring material that surrounds it. (See PIA20525 for more info on propellers.) The detailed structure of the Earhart propeller, as seen here, differs from that of Santos-Dumont. It is not clear whether these differences have to do with intrinsic differences between Earhart and Santos-Dumont, or whether they have to do with different viewing angles or differences in where the propellers were imaged in their orbits around Saturn. Earhart is situated very close to the 200-mile-wide (320-kilometer-wide) Encke Gap, which is held open by the much larger moon Pan. In this view, half of the Encke Gap is visible as the dark region at right. The gap and the propeller are a study in contrasts. The propeller is nothing more than Earhart's attempt to open a gap like Encke using its gravity. However, Earhart's attempt is thwarted by the mass of the ring, which fills in the nascent gap before it can extend very far. Pan is a few thousand times more massive than Earhart, which enables it to maintain a gap that extends all the way around the ring. To the left of the propeller are wave features in the rings caused by the moons Pandora, Prometheus and Pan. The visible-light image was acquired by the Cassini narrow-angle camera at a distance of 69,183 miles (111,340 kilometers) from the propeller

Evaluating shrinkage of wood propellers in a high-temperature environment

Treesearch

Richard Bergman; Robert J. Ross

2008-01-01

Minimizing wood shrinkage is a priority for many wood products in use, particularly engineered products manufactured to close tolerances, such as wood propellers for unmanned surveillance aircraft used in military operations. Those currently in service in the Middle East are experiencing performance problems as a consequence of wood shrinking during long-term storage...

Turboprop: improved PROPELLER imaging.

PubMed

Pipe, James G; Zwart, Nicholas

2006-02-01

A variant of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) MRI, called turboprop, is introduced. This method employs an oscillating readout gradient during each spin echo of the echo train to collect more lines of data per echo train, which reduces the minimum scan time, motion-related artifact, and specific absorption rate (SAR) while increasing sampling efficiency. It can be applied to conventional fast spin-echo (FSE) imaging; however, this article emphasizes its application in diffusion-weighted imaging (DWI). The method is described and compared with conventional PROPELLER imaging, and clinical images collected with this PROPELLER variant are shown. Copyright 2006 Wiley-Liss, Inc.

JANNAF 28th Propellant Development and Characterization Subcommittee and 17th Safety and Environmental Protection Subcommittee Joint Meeting. Volume 1

NASA Technical Reports Server (NTRS)

Cocchiaro, James E. (Editor); Mulder, Edwin J. (Editor); Gomez-Knight, Sylvia J. (Editor)

1999-01-01

This volume contains 37 unclassified/unlimited-distribution technical papers that were presented at the JANNAF 28th Propellant Development & Characterization Subcommittee (PDCS) and 17th Safety & Environmental Protection Subcommittee (S&EPS) Joint Meeting, held 26-30 April 1999 at the Town & Country Hotel and the Naval Submarine Base, San Diego, California. Volume II contains 29 unclassified/limited-distribution papers that were presented at the 28th PDCS and 17th S&EPS Joint Meeting. Volume III contains a classified paper that was presented at the 28th PDCS Meeting on 27 April 1999. Topics covered in PDCS sessions include: solid propellant rheology; solid propellant surveillance and aging; propellant process engineering; new solid propellant ingredients and formulation development; reduced toxicity liquid propellants; characterization of hypergolic propellants; and solid propellant chemical analysis methods. Topics covered in S&EPS sessions include: space launch range safety; liquid propellant hazards; vapor detection methods for toxic propellant vapors and other hazardous gases; toxicity of propellants, ingredients, and propellant combustion products; personal protective equipment for toxic liquid propellants; and demilitarization/treatment of energetic material wastes.

Catalytic ignitor for regenerative propellant gun

NASA Technical Reports Server (NTRS)

Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)

1994-01-01

An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the ignitor and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.

Catalytic Ignitor for Regenerative Propellant Gun

NASA Technical Reports Server (NTRS)

Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)

1997-01-01

An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the igniter and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.

14 CFR 35.22 - Feathering propellers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... control systems that use engine oil to feather must incorporate a method to allow the propeller to feather if the engine oil system fails. (c) Feathering propellers must be designed to be capable of... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Feathering propellers. 35.22 Section 35.22...

14 CFR 35.22 - Feathering propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... control systems that use engine oil to feather must incorporate a method to allow the propeller to feather if the engine oil system fails. (c) Feathering propellers must be designed to be capable of... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Feathering propellers. 35.22 Section 35.22...

14 CFR 35.22 - Feathering propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... control systems that use engine oil to feather must incorporate a method to allow the propeller to feather if the engine oil system fails. (c) Feathering propellers must be designed to be capable of... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Feathering propellers. 35.22 Section 35.22...

14 CFR 35.22 - Feathering propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... control systems that use engine oil to feather must incorporate a method to allow the propeller to feather if the engine oil system fails. (c) Feathering propellers must be designed to be capable of... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Feathering propellers. 35.22 Section 35.22...

14 CFR 35.22 - Feathering propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... control systems that use engine oil to feather must incorporate a method to allow the propeller to feather if the engine oil system fails. (c) Feathering propellers must be designed to be capable of... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Feathering propellers. 35.22 Section 35.22...

Launch Vehicle Performance for Bipropellant Propulsion Using Atomic Propellants With Oxygen

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2000-01-01

Atomic propellants for bipropellant launch vehicles using atomic boron, carbon, and hydrogen were analyzed. The gross liftoff weights (GLOW) and dry masses of the vehicles were estimated, and the 'best' design points for atomic propellants were identified. Engine performance was estimated for a wide range of oxidizer to fuel (O/F) ratios, atom loadings in the solid hydrogen particles, and amounts of helium carrier fluid. Rocket vehicle GLOW was minimized by operating at an O/F ratio of 1.0 to 3.0 for the atomic boron and carbon cases. For the atomic hydrogen cases, a minimum GLOW occurred when using the fuel as a monopropellant (O/F = 0.0). The atomic vehicle dry masses are also presented, and these data exhibit minimum values at the same or similar O/F ratios as those for the vehicle GLOW. A technology assessment of atomic propellants has shown that atomic boron and carbon rocket analyses are considered to be much more near term options than the atomic hydrogen rockets. The technology for storing atomic boron and carbon has shown significant progress, while atomic hydrogen is not able to be stored at the high densities needed for effective propulsion. The GLOW and dry mass data can be used to estimate the cost of future vehicles and their atomic propellant production facilities. The lower the propellant's mass, the lower the overall investment for the specially manufactured atomic propellants.

14 CFR 35.23 - Propeller control system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... propeller effect under the intended operating conditions. (4) The failure or corruption of data or signals... corruption of airplane-supplied data does not result in hazardous propeller effects. (e) The propeller...

14 CFR 35.23 - Propeller control system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... propeller effect under the intended operating conditions. (4) The failure or corruption of data or signals... corruption of airplane-supplied data does not result in hazardous propeller effects. (e) The propeller...

Non-cavitating propeller noise modeling and inversion

NASA Astrophysics Data System (ADS)

Kim, Dongho; Lee, Keunhwa; Seong, Woojae

2014-12-01

Marine propeller is the dominant exciter of the hull surface above it causing high level of noise and vibration in the ship structure. Recent successful developments have led to non-cavitating propeller designs and thus present focus is the non-cavitating characteristics of propeller such as hydrodynamic noise and its induced hull excitation. In this paper, analytic source model of propeller non-cavitating noise, described by longitudinal quadrupoles and dipoles, is suggested based on the propeller hydrodynamics. To find the source unknown parameters, the multi-parameter inversion technique is adopted using the pressure data obtained from the model scale experiment and pressure field replicas calculated by boundary element method. The inversion results show that the proposed source model is appropriate in modeling non-cavitating propeller noise. The result of this study can be utilized in the prediction of propeller non-cavitating noise and hull excitation at various stages in design and analysis.

Propeller flaps in eyelid reconstruction.

PubMed

Rajak, Saul N; Huilgol, Shyamala C; Murakami, Masahiro; Selva, Dinesh

2018-03-14

Propeller flaps are island flaps that reach the recipient site through an axial rotation. The flap has a subcutaneous pedicle on which it pivots, thereby resembling a helicopter propeller. We present our series of propeller flaps for the reconstruction of large eyelid defects. This is a retrospective review of the clinical case notes of eight patients that underwent tumour excision with reconstruction with a cutaneous propeller flap supplied by a non-perforator orbicularis pedicle between July and December 2016. Propeller flaps were used in the reconstruction of five lower lid defects (size range 19 × 5 mm to 25 × 8 mm), one medial canthus defect (13 mm diameter), one complete upper lid defect (42 × 19 mm diameter) and one lid sparing extenteration defect. The flaps were recruited from nasolabial, lateral canthal, temple or medial upper cheek skin. Post-operatively one case had 'trapdooring' which required flap revision at 4 months and one had persistent oedema that settled without intervention. The reconstruction of large eyelid defects is challenging in part because of the paucity of locally available skin. Propeller flaps are a paradigm shift in periocular reconstruction in which the subcutaneous pedicle enables the recruitment of large and highly mobile skin flaps from a wide area of regional tissue.

The Effect of Propellant Optical Properties on Composite Solid Propellant Combustion

DTIC Science & Technology

1991-01-01

i a J’i A tkkkeport of Research to NOffice of Naval Research "The Effect of Propellant Optical Properties on Composite Solid Propellant Combustion...87-0547 _ Period (original): July 1987 - June 1990 (with extension): July 1987- December 1990 January 1991 19 . 2 04 090 a Summary of Research ...Results The results of this research program are summarized below in five categories. Only a brief synopsis of the results and their significance are given

Effects of plants and plant products on the testis

PubMed Central

D'Cruz, Shereen Cynthia; Vaithinathan, Selvaraju; Jubendradass, Rajamanickam; Mathur, Premendu Prakash

2010-01-01

For centuries, plants and plant-based products have been used as a valuable and safe natural source of medicines for treating various ailments. The therapeutic potential of most of these plants could be ascribed to their anticancer, antidiabetic, hepatoprotective, cardioprotective, antispasmodic, analgesic and various other pharmacological properties. However, several commonly used plants have been reported to adversely affect male reproductive functions in wildlife and humans. The effects observed with most of the plant and plant-based products have been attributed to the antispermatogenic and/or antisteroidogenic properties of one or more active ingredients. This review discusses the detrimental effects of some of the commonly used plants on various target cells in the testis. A deeper insight into the molecular mechanisms of action of these natural compounds could pave the way for developing therapeutic strategies against their toxicity. PMID:20562897

Numerical analysis of propeller induced ground vortices by actuator disk model.

PubMed

Yang, Y; Veldhuis, L L M; Eitelberg, G

2018-01-01

During the ground operation of aircraft, the interaction between the propulsor-induced flow field and the ground may lead to the generation of ground vortices. Utilizing numerical approaches, the source of vorticity entering ground vortices is investigated. The results show that the production of wall-parallel components of vorticity has a strong contribution from the wall-parallel components of the pressure gradient on the wall, which is generated by the action of the propulsor. This mechanism is a supplementation for the vorticity transported from the far-field boundary layer, which has been assumed the main vorticity source in a number of previous publications. Furthermore, the quantitative prediction of the occurrence of ground vortices is performed from the numerical results. As the distance of the propeller form the ground decreases, and as the thrust of the propeller increases, ground vortices are generated from the ground and enter the propeller. In addition, the vortices which exist near the ground but does not enter the propeller plane are observed and visualized by three-dimensional data.

Reactivities of Precision Cleaning Solvents with Hypergolic Propellants

NASA Technical Reports Server (NTRS)

Davis, Dennis D.; Delgado, Rafael H.; Williams, James H.

1999-01-01

The reactivities of several selected halogenated precision cleaning solvents with hypergolic propellants has been determined by analysis of the rates of formation of halide ion decomposition products. The solvents were Asahiklin AK 225, Asahiklin AK 225 AES, HFE 7100, HFE 7100 DE, Vertrel XF, Vertrel MCA, Vertrel MCA Plus, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and trans-1,2-dichloroethylene (DCE). The propellants were hydrazine (HZ), monomethylhydrazine (MMH), and mixed oxides of nitrogen (MON-3). The Vertrel solvents showed significant reactivity with HZ. All of the solvents except DCE exhibited significant reactivity with MMH, particularly HFE 7100 DE and CFC-113. HFE 7100 DE, Vertrel MCA, and Vertrel MCA Plus also showed significant reactivity with MON-3 oxidizer.

Modeling of pulsed propellant reorientation

NASA Technical Reports Server (NTRS)

Patag, A. E.; Hochstein, J. I.; Chato, D. J.

1989-01-01

Optimization of the propellant reorientation process can provide increased payload capability and extend the service life of spacecraft. The use of pulsed propellant reorientation to optimize the reorientation process is proposed. The ECLIPSE code was validated for modeling the reorientation process and is used to study pulsed reorientation in small-scale and full-scale propellant tanks. A dimensional analysis of the process is performed and the resulting dimensionless groups are used to present and correlate the computational predictions for reorientation performance.

The Effect of Nacelle-Propeller Diameter Ratio on Body Interference and on Propeller and Cooling Characteristics

NASA Technical Reports Server (NTRS)

Mchugh, James G; Derring, Eldridge H

1939-01-01

Report presents the results of an investigation conducted in the NACA 20-foot tunnel to determine the slipstream drag, the body interference, and the cooling characteristics of nacelle-propeller diameter. Four combinations of geometrically similar propellers and nacelles, mounted on standard wing supports, were tested with values of the ratio of nacelle diameter to propeller diameter of 0.25, 0.33, and 0.44.

Noise generated by a propeller in a wake

NASA Technical Reports Server (NTRS)

Block, P. J. W.

1984-01-01

Propeller performance and noise were measured on two model scale propellers operating in an anechoic flow environment with and without a wake. Wake thickness of one and three propeller chords were generated by an airfoil which spanned the full diameter of the propeller. Noise measurements were made in the relative near field of the propeller at three streamwise and three azimuthal positions. The data show that as much as 10 dB increase in the OASPL results when a wake is introduced into an operating propeller. Performance data are also presented for completeness.

Random sphere packing model of heterogeneous propellants

NASA Astrophysics Data System (ADS)

Kochevets, Sergei Victorovich

It is well recognized that combustion of heterogeneous propellants is strongly dependent on the propellant morphology. Recent developments in computing systems make it possible to start three-dimensional modeling of heterogeneous propellant combustion. A key component of such large scale computations is a realistic model of industrial propellants which retains the true morphology---a goal never achieved before. The research presented develops the Random Sphere Packing Model of heterogeneous propellants and generates numerical samples of actual industrial propellants. This is done by developing a sphere packing algorithm which randomly packs a large number of spheres with a polydisperse size distribution within a rectangular domain. First, the packing code is developed, optimized for performance, and parallelized using the OpenMP shared memory architecture. Second, the morphology and packing fraction of two simple cases of unimodal and bimodal packs are investigated computationally and analytically. It is shown that both the Loose Random Packing and Dense Random Packing limits are not well defined and the growth rate of the spheres is identified as the key parameter controlling the efficiency of the packing. For a properly chosen growth rate, computational results are found to be in excellent agreement with experimental data. Third, two strategies are developed to define numerical samples of polydisperse heterogeneous propellants: the Deterministic Strategy and the Random Selection Strategy. Using these strategies, numerical samples of industrial propellants are generated. The packing fraction is investigated and it is shown that the experimental values of the packing fraction can be achieved computationally. It is strongly believed that this Random Sphere Packing Model of propellants is a major step forward in the realistic computational modeling of heterogeneous propellant of combustion. In addition, a method of analysis of the morphology of heterogeneous

Production of recombinant allergens in plants

PubMed Central

2010-01-01

A large percentage of allergenic proteins are of plant origin. Hence, plant-based expression systems are considered ideal for the recombinant production of certain allergens. First attempts to establish production of plant-derived allergens in plants focused on transient expression in Nicotiana benthamiana infected with recombinant viral vectors. Accordingly, allergens from birch and mugwort pollen, as well as from apple have been expressed in plants. Production of house dust mite allergens has been achieved by Agrobacterium-mediated transformation of tobacco plants. Beside the use of plants as production systems, other approaches have focused on the development of edible vaccines expressing allergens or epitopes thereof, which bypasses the need of allergen purification. The potential of this approach has been convincingly demonstrated for transgenic rice seeds expressing seven dominant human T cell epitopes derived from Japanese cedar pollen allergens. Parallel to efforts in developing recombinant-based diagnostic and therapeutic reagents, different gene-silencing approaches have been used to decrease the expression of allergenic proteins in allergen sources. In this way hypoallergenic ryegrass, soybean, rice, apple, and tomato were developed. PMID:21258627

Production of recombinant allergens in plants.

PubMed

Schmidt, Georg; Gadermaier, Gabriele; Pertl, Heidi; Siegert, Marc; Oksman-Caldentey, Kirsi-Marja; Ritala, Anneli; Himly, Martin; Obermeyer, Gerhard; Ferreira, Fatima

2008-10-01

A large percentage of allergenic proteins are of plant origin. Hence, plant-based expression systems are considered ideal for the recombinant production of certain allergens. First attempts to establish production of plant-derived allergens in plants focused on transient expression in Nicotiana benthamiana infected with recombinant viral vectors. Accordingly, allergens from birch and mugwort pollen, as well as from apple have been expressed in plants. Production of house dust mite allergens has been achieved by Agrobacterium-mediated transformation of tobacco plants. Beside the use of plants as production systems, other approaches have focused on the development of edible vaccines expressing allergens or epitopes thereof, which bypasses the need of allergen purification. The potential of this approach has been convincingly demonstrated for transgenic rice seeds expressing seven dominant human T cell epitopes derived from Japanese cedar pollen allergens. Parallel to efforts in developing recombinant-based diagnostic and therapeutic reagents, different gene-silencing approaches have been used to decrease the expression of allergenic proteins in allergen sources. In this way hypoallergenic ryegrass, soybean, rice, apple, and tomato were developed.

The pasty propellant rocket engine development

NASA Astrophysics Data System (ADS)

Kukushkin, V. I.; Ivanchenko, A. N.

1993-06-01

The paper describes a newly developed pasty propellant rocket engine (PPRE) and the combustion process and presents results of performance tests. It is shown that, compared with liquid propellant rocket engines, the PPREs can regulate the thrust level within a wider range, are safer ecologically, and have better weight characteristics. Compared with solid propellant rocket engines, the PPREs may be produced with lower costs and more safely, are able to regulate thrust performance within a wider range, and are able to offer a greater scope for the variation of the formulation components and propellant characteristics. Diagrams of the PPRE are included.

Deflection of Propeller Blades While Running

NASA Technical Reports Server (NTRS)

Katzmayr, R

1922-01-01

The forces acting on the blades of a propeller proceed from the mass of the propeller and the resistance of the surrounding medium. The magnitude, direction and point of application of the resultant to the propeller blade is of prime importance for the strength calculation. Since it was obviously impracticable to bring any kind of testing device near the revolving propeller, not so much on account of the element of danger as on account of the resulting considerable disturbance of the air flow, the deflection in both cases was photographically recorded and subsequently measured at leisure.

The design of propeller blade roots

NASA Technical Reports Server (NTRS)

Cordes, G

1942-01-01

Predicated on the assumption of certain normal conditions for engine and propeller, simple expressions for the static and dynamic stresses of propeller blade roots are evolved. They, in combination with the fatigue strength diagram of the employed material, afford for each engine power one certain operating point by which the state of stress serving as a basis for the design of the root is defined. Different stress cases must be analyzed, depending on the vibration tendency of engine and use of propeller. The solution affords an insight into the possible introduction of different size classes of propeller.

Influence of yaw on propeller aerodynamic characteristics

NASA Astrophysics Data System (ADS)

Nguyen, Van Bang; Rozehnal, Dalibor; Hnidka, Jakub; Pham, Vu Uy

2018-06-01

Between the propeller axis and free stream direction, it can still be a non-zero yaw angle. This paper introduces some propeller experiments, in which the propeller aerodynamic characteristics have been determined in various yaw angle and different rotational speeds. The experimental aerodynamic characteristics are acquired dynamic values, from which the influence of yaw conditions on the frequency and the amplitude of propeller thrust and torque can be obtained.

Erosivity of LOVA Propellants

DTIC Science & Technology

1981-09-01

ant was a mixture of RDX with a KRATON binder. Two propellants (80% RDX-PU and 80% HMX- CTBN ) had heat inputs greater than the M735 projectile with a...LOVA propellants [80% RDX-PU and 80% HMX.- CTBN ) would require a wear-reducing additive to keep wear comparable to M735 and M774. The other LOVA

Thermal Vacuum Test Correlation of a Zero Propellant Load Case Thermal Capacitance Propellant Gauging Analytical Model

NASA Technical Reports Server (NTRS)

Mckim, Stephen A.

2016-01-01

This thesis describes the development and correlation of a thermal model that forms the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA's Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented are presented. The thermal model was correlated to within plus or minus 3 degrees Celsius of the thermal vacuum test data, and was determined sufficient to make future propellant predictions on MMS. The model was also found to be relatively sensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed to improve temperature predictions in the upper hemisphere of the propellant tank where predictions were found to be 2 to 2.5 C lower than the test data. A road map for applying the model to predict propellant loads on the actual MMS spacecraft toward its end of life in 2017-2018 is also presented.

Explosive laser light initiation of propellants

DOEpatents

Piltch, Martin S.

1993-01-01

A improved initiator for artillery shell using an explosively generated laser light to uniformly initiate the propellent. A small quantity of a high explosive, when detonated, creates a high pressure and temperature, causing the surrounding noble gas to fluoresce. This fluorescence is directed into a lasing material, which lases, and directs laser light into a cavity in the propellant, uniformly initiating the propellant.

Explosive laser light initiation of propellants

DOEpatents

Piltch, M.S.

1993-05-18

A improved initiator for artillery shell using an explosively generated laser light to uniformly initiate the propellent. A small quantity of a high explosive, when detonated, creates a high pressure and temperature, causing the surrounding noble gas to fluoresce. This fluorescence is directed into a lasing material, which lases, and directs laser light into a cavity in the propellant, uniformly initiating the propellant.

Micarta Propellers II : Method of Construction

NASA Technical Reports Server (NTRS)

Caldwell, F W; Clay, N S

1924-01-01

The methods used in manufacturing Micarta propellers differ considerably from those employed with wood propellers on account of the hardness of the materials. The propellers must be formed accurately to size in a mold and afterwards balanced without the customary trimming of the material from the tips. Described here are the pressing and molding processes, filing, boring, balancing, and curing.

Project Hyreus: Mars Sample Return Mission Utilizing in Situ Propellant Production

NASA Technical Reports Server (NTRS)

Bruckner, A. P.; Thill, Brian; Abrego, Anita; Koch, Amber; Kruse, Ross; Nicholson, Heather; Nill, Laurie; Schubert, Heidi; Schug, Eric; Smith, Brian

1993-01-01

Project Hyreus is an unmanned Mars sample return mission that utilizes propellants manufactured in situ from the Martian atmosphere for the return voyage. A key goal of the mission is to demonstrate the considerable benefits of using indigenous resources and to test the viability of this approach as a precursor to manned Mars missions. The techniques, materials, and equipment used in Project Hyreus represent those that are currently available or that could be developed and readied in time for the proposed launch date in 2003. Project Hyreus includes such features as a Mars-orbiting satellite equipped with ground-penetrating radar, a large rover capable of sample gathering and detailed surface investigations, and a planetary science array to perform on-site research before samples are returned to Earth. Project Hyreus calls for the Mars Landing Vehicle to land in the Mangala Valles region of Mars, where it will remain for approximately 1.5 years. Methane and oxygen propellant for the Earth return voyage will be produced using carbon dioxide from the Martian atmosphere and a small supply of hydrogen brought from Earth. This process is key to returning a large Martian sample to Earth with a single Earth launch.

Project Hyreus: Mars sample return mission utilizing in situ propellant production

NASA Technical Reports Server (NTRS)

Abrego, Anita; Bair, Chris; Hink, Anthony; Kim, Jae; Koch, Amber; Kruse, Ross; Ngo, Dung; Nicholson, Heather; Nill, Laurie; Perras, Craig

1993-01-01

Project Hyreus is an unmanned Mars sample return mission that utilizes propellants manufactured in situ from the Martian atmosphere for the return voyage. A key goal of the mission is to demonstrate the considerable benefits of using indigenous resources and to test the viability of this approach as a precursor to manned Mars missions. The techniques, materials, and equipment used in Project Hyreus represent those that are currently available or that could be developed and readied in time for the proposed launch date in 2003. Project Hyreus includes such features as a Mars-orbiting satellite equipped with ground-penetrating radar, a large rover capable of sample gathering and detailed surface investigations, and a planetary science array to perform on-site research before samples are returned to Earth. Project Hyreus calls for the Mars Landing Vehicle to land in the Mangala Valles region of Mars, where it will remain for approximately 1.5 years. Methane and oxygen propellant for the Earth return voyage will be produced using carbon dioxide from the Martian atmosphere and a small supply of hydrogen brought from Earth. This process is key to returning a large Martian sample to Earth with a single Earth launch.

Q-ball imaging with PROPELLER EPI acquisition.

PubMed

Chou, Ming-Chung; Huang, Teng-Yi; Chung, Hsiao-Wen; Hsieh, Tsyh-Jyi; Chang, Hing-Chiu; Chen, Cheng-Yu

2013-12-01

Q-ball imaging (QBI) is an imaging technique that is capable of resolving intravoxel fiber crossings; however, the signal readout based on echo-planar imaging (EPI) introduces geometric distortions in the presence of susceptibility gradients. This study proposes an imaging technique that reduces susceptibility distortions in QBI by short-axis PROPELLER EPI acquisition. Conventional QBI and PROPELLER QBI data were acquired from two 3T MR scans of the brains of five healthy subjects. Prior to the PROPELLER reconstruction, residual distortions in single-blade low-resolution b0 and diffusion-weighted images (DWIs) were minimized by linear affine and nonlinear diffeomorphic demon registrations. Subsequently, the PROPELLER keyhole reconstruction was applied to the corrected DWIs to obtain high-resolution PROPELLER DWIs. The generalized fractional anisotropy and orientation distribution function maps contained fewer distortions in PROPELLER QBI than in conventional QBI, and the fiber tracts more closely matched the brain anatomy depicted by turbo spin-echo (TSE) T2-weighted imaging (T2WI). Furthermore, for fixed T(E), PROPELLER QBI enabled a shorter scan time than conventional QBI. We conclude that PROPELLER QBI can reduce susceptibility distortions without lengthening the acquisition time and is suitable for tracing neuronal fiber tracts in the human brain. Copyright © 2013 John Wiley & Sons, Ltd.

Viscoelastic propellant effects on Space Shuttle Dynamics

NASA Technical Reports Server (NTRS)

Bugg, F.

1981-01-01

The program of solid propellant research performed in support of the space shuttle dynamics modeling effort is described. Stiffness, damping, and compressibility of the propellant and the effects of many variables on these properties are discussed. The relationship between the propellant and solid rocket booster dynamics during liftoff and boost flight conditions and the effects of booster vibration and propellant stiffness on free free solid rocket booster modes are described. Coupled modes of the shuttle system and the effect of propellant stiffness on the interfaces of the booster and the external tank are described. A finite shell model of the solid rocket booster was developed.

Information Technology and the Autonomous Control of a Mars In-Situ Propellant Production System

NASA Technical Reports Server (NTRS)

Gross, Anthony R.; Sridhar, K. R.; Larson, William E.; Clancy, Daniel J.; Peschur, Charles; Briggs, Geoffrey A.; Zornetzer, Steven F. (Technical Monitor)

1999-01-01

With the rapidly increasing performance of information technology, i.e., computer hardware and software systems, as well as networks and communication systems, a new capability is being developed that holds the clear promise of greatly increased exploration capability, along with dramatically reduced design, development, and operating costs. These new intelligent systems technologies, utilizing knowledge-based software and very high performance computer systems, will provide new design and development tools, scheduling mechanisms, and vehicle and system health monitoring capabilities. In addition, specific technologies such as neural nets will provide a degree of machine intelligence and associated autonomy which has previously been unavailable to the mission and spacecraft designer and to the system operator. One of the most promising applications of these new information technologies is to the area of in situ resource utilization. Useful resources such as oxygen, compressed carbon dioxide, water, methane, and buffer gases can be extracted and/or generated from planetary atmospheres, such as the Martian atmosphere. These products, when used for propulsion and life-support needs can provide significant savings in the launch mass and costs for both robotic and crewed missions. In the longer term the utilization of indigenous resources is an enabling technology that is vital to sustaining long duration human presence on Mars. This paper will present the concepts that are currently under investigation and development for mining the Martian atmosphere, such as temperature-swing adsorption, zirconia electrolysis etc., to create propellants and life-support materials. This description will be followed by an analysis of the information technology and control needs for the reliable and autonomous operation of such processing plants in a fault tolerant manner, as well as the approach being taken for the development of the controlling software. Finally, there will be a brief

Nitramine propellants. [gun propellant burning rate

NASA Technical Reports Server (NTRS)

Cohen, N. S.; Strand, L. D. (Inventor)

1978-01-01

Nitramine propellants without a pressure exponent shift in the burning rate curves are prepared by matching the burning rate of a selected nitramine or combination of nitramines within 10% of burning rate of a plasticized active binder so as to smooth out the break point appearance in the burning rate curve.

Propeller speed and phase sensor

NASA Technical Reports Server (NTRS)

Collopy, Paul D. (Inventor); Bennett, George W. (Inventor)

1992-01-01

A speed and phase sensor counterrotates aircraft propellers. A toothed wheel is attached to each propeller, and the teeth trigger a sensor as they pass, producing a sequence of signals. From the sequence of signals, rotational speed of each propeller is computer based on time intervals between successive signals. The speed can be computed several times during one revolution, thus giving speed information which is highly up-to-date. Given that spacing between teeth may not be uniform, the signals produced may be nonuniform in time. Error coefficients are derived to correct for nonuniformities in the resulting signals, thus allowing accurate speed to be computed despite the spacing nonuniformities. Phase can be viewed as the relative rotational position of one propeller with respect to the other, but measured at a fixed time. Phase is computed from the signals.

Material Compatibility with Space Storable Propellants. Design Guidebook

NASA Technical Reports Server (NTRS)

Uney, P. E.; Fester, D. A.

1972-01-01

An important consideration in the design of spacecraft for interplanetary missions is the compatibility of storage materials with the propellants. Serious problems can arise because many propellants are either extremely reactive or subject to catalytic decomposition, making the selection of proper materials of construction for propellant containment and control a critical requirement for the long-life applications. To aid in selecting materials and designing and evaluating various propulsion subsystems, available information on the compatibility of spacecraft materials with propellants of interest was compiled from literature searches and personal contacts. The compatibility of both metals and nonmetals with hydrazine, monomethyl hydrazine, nitrated hydrazine, and diborance fuels and nitrogen tetroxide, fluorine, oxygen difluoride, and Flox oxidizers was surveyed. These fuels and oxidizers encompass the wide variety of problems encountered in propellant storage. As such, they present worst case situations of the propellant affecting the material and the material affecting the propellant. This includes material attack, propellant decomposition, and the formation of clogging materials.

75 FR 13238 - Special Conditions: McCauley Propeller Systems, Model Propeller 3D15C1401/C80MWX-X

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-19

...-X AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed special conditions... for McCauley Propeller Systems for model propeller 3D15C1401/C80MWX-X. We are withdrawing the notice... McCauley Propeller Systems for model propeller 3D15C1401/C80MWX-X (71 FR 43674). On November 29, 2004...

Noise from Two-Blade Propellers

NASA Technical Reports Server (NTRS)

Stowell, E Z; Deming, A F

1936-01-01

The two-blade propeller, one of the most powerful sources of sound known, has been studied with the view of obtaining fundamental information concerning the noise emission. In order to eliminate engine noise, the propeller was mounted on an electric motor. A microphone was used to pick up the sound whose characteristics were studied electrically. The distribution of noise throughout the frequency range, as well as the spatial distribution about the propeller, was studied. The results are given in the form of polar diagrams. An appendix of common acoustical terms is included.

Green Propellant Landing Demonstration at U.S. Range

NASA Technical Reports Server (NTRS)

Mulkey, Henry W.; Miller, Joseph T.; Bacha, Caitlin E.

2016-01-01

The Green Propellant Loading Demonstration (GPLD) was conducted December 2015 at Wallops Flight Facility (WFF), leveraging work performed over recent years to bring lower toxicity hydrazine replacement green propellants to flight missions. The objective of this collaboration between NASA Goddard Space Flight Center (GSFC), WFF, the Swedish National Space Board (SNSB), and Ecological Advanced Propulsion Systems (ECAPS) was to successfully accept LMP-103S propellant at a U.S. Range, store the propellant, and perform a simulated flight vehicle propellant loading. NASA GSFC Propulsion (Code 597) managed all aspects of the operation, handling logistics, preparing the procedures, and implementing the demonstration. In addition to the partnership described above, Moog Inc. developed an LMP-103S propellant-compatible titanium rolling diaphragm flight development tank and loaned it to GSFC to act as the GPLD flight vessel. The flight development tank offered the GPLD an additional level of flight-like propellant handling process and procedures. Moog Inc. also provided a compatible latching isolation valve for remote propellant expulsion. The GPLD operation, in concert with Moog Inc. executed a flight development tank expulsion efficiency performance test using LMP-103S propellant. As part of the demonstration work, GSFC and WFF documented Range safety analyses and practices including all elements of shipping, storage, handling, operations, decontamination, and disposal. LMP-103S has not been previously handled at a U.S. Launch Range. Requisite for this activity was an LMP-103S Risk Analysis Report and Ground Safety Plan. GSFC and WFF safety offices jointly developed safety documentation for application into the GPLD operation. The GPLD along with the GSFC Propulsion historical hydrazine loading experiences offer direct comparison between handling green propellant versus safety intensive, highly toxic hydrazine propellant. These described motives initiated the GPLD operation

Green Propellant Loading Demonstration at U.S. Range

NASA Technical Reports Server (NTRS)

Mulkey, Henry W.; Miller, Joseph T.; Bacha, Caitlin E.

2016-01-01

The Green Propellant Loading Demonstration (GPLD) was conducted December 2015 at Wallops Flight Facility (WFF), leveraging work performed over recent years to bring lower toxicity hydrazine replacement green propellants to flight missions. The objective of this collaboration between NASA Goddard Space Flight Center (GSFC), WFF, the Swedish National Space Board (SNSB), and Ecological Advanced Propulsion Systems (ECAPS) was to successfully accept LMP-103S propellant at a U.S. Range, store the propellant, and perform a simulated flight vehicle propellant loading. NASA GSFC Propulsion (Code 597) managed all aspects of the operation, handling logistics, preparing the procedures, and implementing the demonstration. In addition to the partnership described above, Moog Inc. developed an LMP-103S propellant-compatible titanium rolling diaphragm flight development tank and loaned it to GSFC to act as the GPLD flight vessel. The flight development tank offered the GPLD an additional level of flight-like propellant handling process and procedures. Moog Inc. also provided a compatible latching isolation valve for remote propellant expulsion. The GPLD operation, in concert with Moog Inc. executed a flight development tank expulsion efficiency performance test using LMP-103S propellant. As part of the demonstration work, GSFC and WFF documented Range safety analyses and practices including all elements of shipping, storage, handling, operations, decontamination, and disposal. LMP-103S has not been previously handled at a U.S. Launch Range. Requisite for this activity was an LMP-103S Risk Analysis Report and Ground Safety Plan. GSFC and WFF safety offices jointly developed safety documentation for application into the GPLD operation. The GPLD along with the GSFC Propulsion historical hydrazine loading experiences offer direct comparison between handling green propellant versus safety intensive, highly toxic hydrazine propellant. These described motives initiated the GPLD operation

Return of the propeller

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1987-05-01

Resurrecting the propeller-driven airplane could help save fuel if there is another oil crisis like in the 1970s. This article discusses the new propeller engine, propfans, which are being developed for commercial airplanes. It discusses the three types of propfan engines and the advantages and disadvantages of each. It also tells about the propfan airplanes several companies are developing.

Active synchrophasing of propeller unbalance

NASA Technical Reports Server (NTRS)

Kaptein, Dick

1992-01-01

The results of a survey are presented to reduce the inflight propeller unbalance vibrations in the cabin of the Fokker 50 airplanes. Several approaches have been investigated. Active synchrophasing of the unbalance vibrations of both propellers appears to be successful.

Tests of Nacelle-Propeller Combinations in Various Positions with Reference to Wings VI : Wings and Nacelles with Pusher Propeller

NASA Technical Reports Server (NTRS)

Wood, Donald H; Bioletti, Carlton

1935-01-01

This report is the sixth of a series giving wind tunnel tests results on the interference drag and propulsive efficiency of nacelle-propeller-wing combinations. The present report gives the results of tests of a radial-engine nacelle with pusher propeller in 17 positions with reference to a Clark Y wing; tests of the same nacelle and propeller in three positions with reference to a thick wing; and tests of a body and pusher propeller with the thick wing, simulating the case of a propeller driven by an extension shaft from an engine within the wing. Some preliminary tests were made on pusher nacelles alone.

Motorboat propeller injuries.

PubMed

Di Nunno, N; Di Nunno, C

2000-07-01

The authors analyze the case of an Albanian refugee who was killed by the propellers of the outboard engine of a rubber dinghy while illegally attempting to reach Italy. The finding of multiple parallel, deep clear-cut injuries is uncommon, but highly characteristic of the object producing the lesions. These are typical and cannot be mistaken with those produced by sharp objects or shark bites. The description of the injuries is vital for establishing the position of the victim with regard to the propeller that struck him.

14 CFR 23.1149 - Propeller speed and pitch controls.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller speed and pitch controls. 23.1149... Powerplant Controls and Accessories § 23.1149 Propeller speed and pitch controls. (a) If there are propeller... propeller; and (2) Simultaneous control of all propellers. (b) The controls must allow ready synchronization...

14 CFR 23.1149 - Propeller speed and pitch controls.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller speed and pitch controls. 23.1149... Powerplant Controls and Accessories § 23.1149 Propeller speed and pitch controls. (a) If there are propeller... propeller; and (2) Simultaneous control of all propellers. (b) The controls must allow ready synchronization...

14 CFR 23.1149 - Propeller speed and pitch controls.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller speed and pitch controls. 23.1149... Powerplant Controls and Accessories § 23.1149 Propeller speed and pitch controls. (a) If there are propeller... propeller; and (2) Simultaneous control of all propellers. (b) The controls must allow ready synchronization...

Space Transportation Infrastructure Supported By Propellant Depots

NASA Technical Reports Server (NTRS)

Smitherman, David; Woodcock, Gordon

2011-01-01

A space transportation infrastructure is described that utilizes propellant depots to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicles such as the Delta IV Heavy, Atlas V, and Falcon 9, for all crew, cargo, and propellant launches to orbit. Propellant launches are made to a Low-Earth-Orbit (LEO) Depot and an Earth-Moon Lagrange Point 1 (L1) Depot to support new reusable in-space transportation vehicles. The LEO Depot supports missions to Geosynchronous Earth Orbit (GEO) for satellite servicing, and to L1 for L1 Depot missions. The L1 Depot supports Lunar, Earth-Sun L2 (ESL2), Asteroid, and Mars missions. A Mars Orbital Depot is also described to support ongoing Mars missions. New concepts for vehicle designs are presented that can be launched on current 5-meter diameter expendable launch vehicles. These new reusable vehicle concepts include a LEO Depot, L1 Depot, and Mars Orbital Depot based on International Space Station (ISS) heritage hardware. The high-energy depots at L1 and Mars orbit are compatible with, but do not require, electric propulsion tug use for propellant and/or cargo delivery. New reusable in-space crew transportation vehicles include a Crew Transfer Vehicle (CTV) for crew transportation between the LEO Depot and the L1 Depot, a new reusable Lunar Lander for crew transportation between the L1 Depot and the lunar surface, and a Deep Space Habitat (DSH) to support crew missions from the L1 Depot to ESL2, Asteroid, and Mars destinations. A 6 meter diameter Mars lander concept is presented that can be launched without a fairing based on the Delta IV heavy Payload Planners Guide, which indicates feasibility of a 6.5 meter fairing. This lander would evolve to re-usable operations when propellant production is established on Mars. Figure 1 provides a summary of the possible missions this infrastructure can support. Summary mission profiles are presented

14 CFR 121.225 - Propeller deicing fluid.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Propeller deicing fluid. 121.225 Section 121.225 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Propeller deicing fluid. If combustible fluid is used for propeller deicing, the certificate holder must...

14 CFR 121.225 - Propeller deicing fluid.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Propeller deicing fluid. 121.225 Section 121.225 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Propeller deicing fluid. If combustible fluid is used for propeller deicing, the certificate holder must...

14 CFR 121.225 - Propeller deicing fluid.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Propeller deicing fluid. 121.225 Section 121.225 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Propeller deicing fluid. If combustible fluid is used for propeller deicing, the certificate holder must...

14 CFR 121.225 - Propeller deicing fluid.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Propeller deicing fluid. 121.225 Section 121.225 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Propeller deicing fluid. If combustible fluid is used for propeller deicing, the certificate holder must...

14 CFR 121.225 - Propeller deicing fluid.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Propeller deicing fluid. 121.225 Section 121.225 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Propeller deicing fluid. If combustible fluid is used for propeller deicing, the certificate holder must...

Runtime and Pressurization Analyses of Propellant Tanks

NASA Technical Reports Server (NTRS)

Field, Robert E.; Ryan, Harry M.; Ahuja, Vineet; Hosangadi, Ashvin; Lee, Chung P.

2007-01-01

Multi-element unstructured CFD has been utilized at NASA SSC to carry out analyses of propellant tank systems in different modes of operation. The three regimes of interest at SSC include (a) tank chill down (b) tank pressurization and (c) runtime propellant draw-down and purge. While tank chill down is an important event that is best addressed with long time-scale heat transfer calculations, CFD can play a critical role in the tank pressurization and runtime modes of operation. In these situations, problems with contamination of the propellant by inclusion of the pressurant gas from the ullage causes a deterioration of the quality of the propellant delivered to the test article. CFD can be used to help quantify the mixing and propellant degradation. During tank pressurization under some circumstances, rapid mixing of relatively warm pressurant gas with cryogenic propellant can lead to rapid densification of the gas and loss of pressure in the tank. This phenomenon can cause serious problems during testing because of the resulting decrease in propellant flow rate. With proper physical models implemented, CFD can model the coupling between the propellant and pressurant including heat transfer and phase change effects and accurately capture the complex physics in the evolving flowfields. This holds the promise of allowing the specification of operational conditions and procedures that could minimize the undesirable mixing and heat transfer inherent in propellant tank operation. It should be noted that traditional CFD modeling is inadequate for such simulations because the fluids in the tank are in a range of different sub-critical and supercritical states and elaborate phase change and mixing rules have to be developed to accurately model the interaction between the ullage gas and the propellant. We show a typical run-time simulation of a spherical propellant tank, containing RP-1 in this case, being pressurized with room-temperature nitrogen at 540 R. Nitrogen

Cryogenic Propellant Management Device: Conceptual Design Study

NASA Technical Reports Server (NTRS)

Wollen, Mark; Merino, Fred; Schuster, John; Newton, Christopher

2010-01-01

Concepts of Propellant Management Devices (PMDs) were designed for lunar descent stage reaction control system (RCS) and lunar ascent stage (main and RCS propulsion) missions using liquid oxygen (LO2) and liquid methane (LCH4). Study ground rules set a maximum of 19 days from launch to lunar touchdown, and an additional 210 days on the lunar surface before liftoff. Two PMDs were conceptually designed for each of the descent stage RCS propellant tanks, and two designs for each of the ascent stage main propellant tanks. One of the two PMD types is a traditional partial four-screen channel device. The other type is a novel, expanding volume device which uses a stretched, flexing screen. It was found that several unique design features simplified the PMD designs. These features are (1) high propellant tank operating pressures, (2) aluminum tanks for propellant storage, and (3) stringent insulation requirements. Consequently, it was possible to treat LO2 and LCH4 as if they were equivalent to Earth-storable propellants because they would remain substantially subcooled during the lunar mission. In fact, prelaunch procedures are simplified with cryogens, because any trapped vapor will condense once the propellant tanks are pressurized in space.

46 CFR 50.05-20 - Steam-propelled motorboats.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Steam-propelled motorboats. 50.05-20 Section 50.05-20... Application § 50.05-20 Steam-propelled motorboats. (a) The requirements covering design of the propelling... than 40 feet in length and which are propelled by machinery driven by steam shall be in accordance with...

Air-propelled abrasive grit for postemergence in-row weed control in field corn

USDA-ARS?s Scientific Manuscript database

Organic growers need additional tools for weed control. A new technique involving abrasive grit propelled by compressed air was tested in field plots. Grit derived from corn cobs was directed at seedlings of summer annual weeds growing at the bases of corn plants when the corn was at differing early...

Research into the propeller strut for high speed outboard motor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shimizu, Takashi; Sunayama, Yoshihiko

1995-12-31

For better performance of outboard motors for high speed craft, improvement in the performance of the propeller strut located ahead of the propeller is indispensable in addition to ameliorating the performance of the screw propeller itself. Thus, it is extremely important to reduce the drag of the propeller strut, which accounts for the predominant portion of the submerged parts of the motor and hull when the craft is running at high speed and to improve the propeller efficiency in the wake of the propeller strut. This paper, taking up two different shapes of the propeller strut, compares the performances ofmore » the propeller placed in the wake of the propeller strut in tank tests, and discusses the drag of the propeller strut. The two propeller strut shapes are that of a 70% scaled down model of the propeller strut Suzuki`s 200 PS outboard motor and its improved version. The propeller used in the experiment is one having super cavitating blades with the Pseudo-Kirchhoff nose, whose performance the authors have been analyzing systematically. Detailed comparison was further made of the drags of the differently shaped propeller struts by means of computational fluid dynamics.« less

14 CFR 125.123 - Propeller deicing fluid.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Propeller deicing fluid. 125.123 Section 125.123 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Requirements § 125.123 Propeller deicing fluid. If combustible fluid is used for propeller deicing, the...

14 CFR 125.123 - Propeller deicing fluid.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Propeller deicing fluid. 125.123 Section 125.123 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Requirements § 125.123 Propeller deicing fluid. If combustible fluid is used for propeller deicing, the...

14 CFR 125.123 - Propeller deicing fluid.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Propeller deicing fluid. 125.123 Section 125.123 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Requirements § 125.123 Propeller deicing fluid. If combustible fluid is used for propeller deicing, the...

14 CFR 125.123 - Propeller deicing fluid.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Propeller deicing fluid. 125.123 Section 125.123 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Requirements § 125.123 Propeller deicing fluid. If combustible fluid is used for propeller deicing, the...

14 CFR 125.123 - Propeller deicing fluid.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Propeller deicing fluid. 125.123 Section 125.123 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Requirements § 125.123 Propeller deicing fluid. If combustible fluid is used for propeller deicing, the...

Disposal of Liquid Propellants

DTIC Science & Technology

1990-03-13

propellant includes an oxi- dizer (hydroxylammoniuin nitrate), a fuel (triethanolammonium nitrate), and water . In an- ticipation of widespread (both...are also included. 20. DISTRIBUTION/ AVAILABILIT ’." OF ABMTRACT 21 ABSTRACT SECURITY CLASSIF.CATICIN IUNCLASSIFIEDIUNLIMITED 0 SAME AS RPT. 0 OTIC...trieth- anolammoiur nitrate), anG water . In anticipation of widespread (both conti- nental U.S. and abroac) use of the propellant, USATHAMA began a

Space shuttle propellant constitutive law verification tests

NASA Technical Reports Server (NTRS)

Thompson, James R.

1995-01-01

As part of the Propellants Task (Task 2.0) on the Solid Propulsion Integrity Program (SPIP), a database of material properties was generated for the Space Shuttle Redesigned Solid Rocket Motor (RSRM) PBAN-based propellant. A parallel effort on the Propellants Task was the generation of an improved constitutive theory for the PBAN propellant suitable for use in a finite element analysis (FEA) of the RSRM. The outcome of an analysis with the improved constitutive theory would be more reliable prediction of structural margins of safety. The work described in this report was performed by Materials Laboratory personnel at Thiokol Corporation/Huntsville Division under NASA contract NAS8-39619, Mod. 3. The report documents the test procedures for the refinement and verification tests for the improved Space Shuttle RSRM propellant material model, and summarizes the resulting test data. TP-H1148 propellant obtained from mix E660411 (manufactured February 1989) which had experienced ambient igloo storage in Huntsville, Alabama since January 1990, was used for these tests.

14 CFR 25.1149 - Propeller speed and pitch controls.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller speed and pitch controls. 25.1149... Accessories § 25.1149 Propeller speed and pitch controls. (a) There must be a separate propeller speed and... synchronization of all propellers. (d) The propeller speed and pitch controls must be to the right of, and at...

14 CFR 25.1149 - Propeller speed and pitch controls.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller speed and pitch controls. 25.1149... Accessories § 25.1149 Propeller speed and pitch controls. (a) There must be a separate propeller speed and... synchronization of all propellers. (d) The propeller speed and pitch controls must be to the right of, and at...

A theoretical and experimental investigation of propeller performance methodologies

NASA Technical Reports Server (NTRS)

Korkan, K. D.; Gregorek, G. M.; Mikkelson, D. C.

1980-01-01

This paper briefly covers aspects related to propeller performance by means of a review of propeller methodologies; presentation of wind tunnel propeller performance data taken in the NASA Lewis Research Center 10 x 10 wind tunnel; discussion of the predominent limitations of existing propeller performance methodologies; and a brief review of airfoil developments appropriate for propeller applications.

The 3-D viscous flow CFD analysis of the propeller effect on an advanced ducted propeller subsonic inlet

NASA Technical Reports Server (NTRS)

Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

1993-01-01

A time marching Navier-Stokes code called PARC3D was used to study the 3-D viscous flow associated with an advanced ducted propeller (ADP) subsonic inlet at take-off operating conditions. At a free stream Mach number of 0.2, experimental data for the inlet-with-propeller test model indicated that the airflow was attached on the cowl windward lip at an angle of attack of 25 degrees became unstable at 29 degrees, and separated at 30 degrees. An experimental study with a similar inlet and with no propeller (through-flow) indicated that flow separation occurred at an angle of attack a few degrees below the value observed when the inlet was tested with the propeller. This tends to indicate that the propeller exerts a favorable effect on the inlet performance. During the through-flow experiment a stationary blockage device was used to successfully simulate the propeller effect on the inlet flow field at angles of attack. In the present numerical study, this flow blockage was modeled via a PARC3D computational boundary condition (BC) called the screen BC. The principle formulation of this BC was based on the one-and-half dimension actuator disk theory. This screen BC was applied at the inlet propeller face station of the computational grid. Numerical results were obtained with and without the screen BC. The application of the screen BC in this numerical study provided results which are similar to the results of past experimental efforts in which either the blockage device or the propeller was used.

14 CFR 25.1027 - Propeller feathering system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1027 Propeller feathering system. (a) If the propeller feathering system depends on engine oil, there must be means to trap... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller feathering system. 25.1027...

33 CFR 401.16 - Propeller direction alarms.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...

14 CFR 25.1027 - Propeller feathering system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1027 Propeller feathering system. (a) If the propeller feathering system depends on engine oil, there must be means to trap... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller feathering system. 25.1027...

14 CFR 25.1027 - Propeller feathering system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1027 Propeller feathering system. (a) If the propeller feathering system depends on engine oil, there must be means to trap... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller feathering system. 25.1027...

14 CFR 25.1027 - Propeller feathering system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1027 Propeller feathering system. (a) If the propeller feathering system depends on engine oil, there must be means to trap... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller feathering system. 25.1027...

14 CFR 25.1027 - Propeller feathering system.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1027 Propeller feathering system. (a) If the propeller feathering system depends on engine oil, there must be means to trap... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller feathering system. 25.1027...

33 CFR 401.16 - Propeller direction alarms.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...

33 CFR 401.16 - Propeller direction alarms.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...

33 CFR 401.16 - Propeller direction alarms.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...

33 CFR 401.16 - Propeller direction alarms.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...

Application of Theodorsen's Theory to Propeller Design

NASA Technical Reports Server (NTRS)

Crigler, John L

1948-01-01

A theoretical analysis is presented for obtaining by use of Theodorsen's propeller theory the load distribution along a propeller radius to give the optimum propeller efficiency for any design condition.The efficiencies realized by designing for the optimum load distribution are given in graphs, and the optimum efficiency for any design condition may be read directly from the graph without any laborious calculations. Examples are included to illustrate the method of obtaining the optimum load distributions for both single-rotating and dual-rotating propellers.

Application of Theodorsen's theory to propeller design

NASA Technical Reports Server (NTRS)

Crigler, John L

1949-01-01

A theoretical analysis is presented for obtaining, by use of Theodorsen's propeller theory, the load distribution along a propeller radius to give the optimum propeller efficiency for any design condition. The efficiencies realized by designing for the optimum load distribution are given in graphs, and the optimum efficiency for any design condition may be read directly from the graph without any laborious calculations. Examples are included to illustrate the method of obtaining the optimum load distributions for both single-rotating and dual-rotating propellers.

Cavitation noise studies on marine propellers

NASA Astrophysics Data System (ADS)

Sharma, S. D.; Mani, K.; Arakeri, V. H.

1990-04-01

Experimental observations are described of cavitation inception and noise from five model propellers, three basic and two modified, tested in the open jet section of the Indian Institute of Science high-speed water tunnel facility. Extensive experiments on the three basic propellers of different design, which included visualization of cavitation and measurements of noise, showed that the dominant type of cavitation was in the form of tip vortex cavitation, accompanied by leading edge suction side sheet cavitation in its close vicinity, and the resultant noise depended on parameters such as the advance coefficient, the cavitation number, and the propeller geometry. Of these, advance coefficient was found to have the maximum influence not only on cavitation noise but also on the inception of cavitation. Noise levels and frequencies of spectra obtained from all the three basic propellers at conditions near inception and different advance coefficient values, when plotted in the normalized form as suggested by Blake, resulted in a universal spectrum which would be useful for predicting cavitation noise at prototype scales when a limited extent of cavitation is expected in the same form as observed on the present models. In an attempt to delay the onset of tip vortex cavitation, the blades of two of the three basic propellers were modified by drilling small holes in the tip and leading edge areas. Studies on the modified propellers showed that the effectiveness of the blade modification was apparently stronger at low advance coefficient values and depended on the blade sectional profile. Measurements of cavitation noise indicated that the modification also improved the acoustic performance of the propellers as it resulted in a complete attenuation of the low-frequency spectral peaks, which were prominent with the basic propellers. In addition to the above studies, which were conducted under uniform flow conditions, one of the basic propellers was tested in the simulated

9 CFR 355.21 - Products entering inspected plants.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Products entering inspected plants... Products entering inspected plants. All products of a kind certified under this part or materials to be used in the preparation of such products when brought into an inspected plant shall be identified and...

9 CFR 355.21 - Products entering inspected plants.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Products entering inspected plants... Products entering inspected plants. All products of a kind certified under this part or materials to be used in the preparation of such products when brought into an inspected plant shall be identified and...

9 CFR 355.21 - Products entering inspected plants.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Products entering inspected plants... Products entering inspected plants. All products of a kind certified under this part or materials to be used in the preparation of such products when brought into an inspected plant shall be identified and...

9 CFR 355.21 - Products entering inspected plants.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Products entering inspected plants... Products entering inspected plants. All products of a kind certified under this part or materials to be used in the preparation of such products when brought into an inspected plant shall be identified and...

9 CFR 355.21 - Products entering inspected plants.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Products entering inspected plants... Products entering inspected plants. All products of a kind certified under this part or materials to be used in the preparation of such products when brought into an inspected plant shall be identified and...

Engine system assessment study using Martian propellants

NASA Technical Reports Server (NTRS)

Pelaccio, Dennis; Jacobs, Mark; Scheil, Christine; Collins, John

1992-01-01

A top-level feasibility study was conducted that identified and characterized promising chemical propulsion system designs which use two or more of the following propellant combinations: LOX/H2, LOX/CH4, and LOX/CO. The engine systems examined emphasized the usage of common subsystem/component hardware where possible. In support of this study, numerous mission scenarios were characterized that used various combinations of Earth, lunar, and Mars propellants to establish engine system requirements to assess the promising engine system design concept examined, and to determine overall exploration leverage of such systems compared to state-of-the-art cryogenic (LOX/H2) propulsion systems. Initially in the study, critical propulsion system technologies were assessed. Candidate expander and gas generator cycle LOX/H2/CO, LOX/H2/CH4, and LOX/CO/CH4 engine system designs were parametrically evaluated. From this evaluation baseline, tripropellant Mars Transfer Vehicle (MTV) LOX cooled and bipropellant Lunar Excursion Vehicle (LEV) and Mars Excursion Vehicle (MEV) engine systems were identified. Representative tankage designs for a MTV were also investigated. Re-evaluation of the missions using the baseline engine design showed that in general the slightly lower performance, smaller, lower weight gas generator cycle-based engines required less overall mission Mars and in situ propellant production (ISPP) infrastructure support compared to the larger, heavier, higher performing expander cycle engine systems.

Long-Term Cryogenic Propellant Storage on Mars with Hercules Propellant Storage Facility

NASA Technical Reports Server (NTRS)

Liu, Gavin

2017-01-01

This report details the process and results of roughly sizing the steady state, zero boil-off thermal and power parameters of the Hercules Propellant Storage Facility. For power analysis, isothermal and isobaric common bulkhead tank scenarios are considered. An estimated minimum power requirement of 8.3 kW for the Reverse Turbo-Brayton Cryocooler is calculated. Heat rejection concerns in soft vacuum Mars atmosphere are noted and potential solutions are proposed. Choice of coolant for liquid propellant conditioning and issues with current proposed cryocooler cycle are addressed; recommendations are made, e.g. adding a Joule-Thomson expansion valve after the Reverse Turbo-Brayton turbine in order to have two-phase, isothermal heat exchange through the Broad Area Cooling system. Issues with cross-country transfer lines from propellant storage to flight vehicle are briefly discussed: traditional vacuum jacketed lines are implausible, and Mars insulation needs to be developed.

Modeling and Analysis of the Reverse Water Gas Shift Process for In-Situ Propellant Production

NASA Technical Reports Server (NTRS)

Whitlow, Jonathan E.

2000-01-01

This report focuses on the development of mathematical models and simulation tools developed for the Reverse Water Gas Shift (RWGS) process. This process is a candidate technology for oxygen production on Mars under the In-Situ Propellant Production (ISPP) project. An analysis of the RWGS process was performed using a material balance for the system. The material balance is very complex due to the downstream separations and subsequent recycle inherent with the process. A numerical simulation was developed for the RWGS process to provide a tool for analysis and optimization of experimental hardware, which will be constructed later this year at Kennedy Space Center (KSC). Attempts to solve the material balance for the system, which can be defined by 27 nonlinear equations, initially failed. A convergence scheme was developed which led to successful solution of the material balance, however the simplified equations used for the gas separation membrane were found insufficient. Additional more rigorous models were successfully developed and solved for the membrane separation. Sample results from these models are included in this report, with recommendations for experimental work needed for model validation.

Green Propellant Infusion Mission

NASA Image and Video Library

2013-07-09

U.S. Senator Mark Udall (D-CO) speaks at a Green Propellant Infusion Mission press conference at the Reserve Officers Association, Tuesday, July 9, 2013 in Washington. The NASA GPIM program, led by Ball Aerospace in conjunction with Aerojet Rocketdyne, is demonstrating a high-performance "green" fuel in space. The propellant used on this mission offers nearly 50 percent better performance when compared to traditional hydrazine. Photo Credit: (NASA/Carla Cioffi)

Green Propellant Infusion Mission

NASA Image and Video Library

2013-07-09

Roger Myers, Executive Director, Aerojet Rocketdyne speaks at a Green Propellant Infusion Mission press conference at the Reserve Officers Association, Tuesday, July 9, 2013 in Washington. The NASA GPIM program, led by Ball Aerospace in conjunction with Aerojet Rocketdyne, is demonstrating a high-performance "green" fuel in space. The propellant used on this mission offers nearly 50 percent better performance when compared to traditional hydrazine. Photo Credit: (NASA/Carla Cioffi)

Propeller Flaps: A Literature Review.

PubMed

Sisti, Andrea; D'Aniello, Carlo; Fortezza, Leonardo; Tassinari, Juri; Cuomo, Roberto; Grimaldi, Luca; Nisi, Giuseppe

2016-01-01

Since their introduction in 1991, propeller flaps are increasingly used as a surgical approach to loss of substance. The aim of this study was to evaluate the indications and to verify the outcomes and the complication rates using this reconstructing technique through a literature review. A search on PubMed was performed using "propeller flap", "fasciocutaneous flap", "local flap" or "pedicled flap" as key words. We selected clinical studies using propeller flaps as a reconstructing technique. We found 119 studies from 1991 to 2015. Overall, 1,315 propeller flaps were reported in 1,242 patients. Most frequent indications included loss of substance following tumor excision, repair of trauma-induced injuries, burn scar contractures, pressure sores and chronic infections. Complications were observed in 281/1242 patients (22.6%) occurring more frequently in the lower limbs (31.8%). Partial flap necrosis and venous congestion were the most frequent complications. The complications' rate was significantly higher in infants (<10 years old) and in the older population (>70 years old) but there was not a significant difference between the sexes. Trend of complication rate has not improved during the last years. Propeller flaps showed a great success rate with low morbidity, quick recovery, good aesthetic outcomes and reduced cost. The quality and volume of the transferred soft tissue, the scar orientation and the possibility of direct donor site closure should be considered in order to avoid complications. Indications for propeller flaps are small- or medium-sized defects located in a well-vascularized area with healthy surrounding tissues. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

75 FR 18774 - Airworthiness Directives; McCauley Propeller Systems Model 4HFR34C653/L106FA Propellers

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-13

... (ECI) of the propeller hub for cracks. That proposed AD resulted from reports of 3 hubs found cracked... NPRM results from reports of 7 additional hubs found cracked during propeller overhaul, totaling 10 cracked hubs. We are proposing this supplemental AD to prevent failure of the propeller hub, which could...

Tests on thirteen navy type model propellers

NASA Technical Reports Server (NTRS)

Durand, W F

1927-01-01

The tests on these model propellers were undertaken for the purpose of determining the performance coefficients and characteristics for certain selected series of propellers of form and type as commonly used in recent navy designs. The first series includes seven propellers of pitch ratio varying by 0.10 to 1.10, the area, form of blade, thickness, etc., representing an arbitrary standard propeller which had shown good results. The second series covers changes in thickness of blade section, other things equal, and the third series, changes in blade area, other things equal. These models are all of 36-inch diameter. Propellers A to G form the series on pitch ratio, C, N. I. J the series on thickness of section, and K, M, C, L the series on area. (author)

Analytic Modeling of Pressurization and Cryogenic Propellant

NASA Technical Reports Server (NTRS)

Corpening, Jeremy H.

2010-01-01

An analytic model for pressurization and cryogenic propellant conditions during all mission phases of any liquid rocket based vehicle has been developed and validated. The model assumes the propellant tanks to be divided into five nodes and also implements an empirical correlation for liquid stratification if desired. The five nodes include a tank wall node exposed to ullage gas, an ullage gas node, a saturated propellant vapor node at the liquid-vapor interface, a liquid node, and a tank wall node exposed to liquid. The conservation equations of mass and energy are then applied across all the node boundaries and, with the use of perfect gas assumptions, explicit solutions for ullage and liquid conditions are derived. All fluid properties are updated real time using NIST Refprop.1 Further, mass transfer at the liquid-vapor interface is included in the form of evaporation, bulk boiling of liquid propellant, and condensation given the appropriate conditions for each. Model validation has proven highly successful against previous analytic models and various Saturn era test data and reasonably successful against more recent LH2 tank self pressurization ground test data. Finally, this model has been applied to numerous design iterations for the Altair Lunar Lander, Ares V Core Stage, and Ares V Earth Departure Stage in order to characterize Helium and autogenous pressurant requirements, propellant lost to evaporation and thermodynamic venting to maintain propellant conditions, and non-uniform tank draining in configurations utilizing multiple LH2 or LO2 propellant tanks. In conclusion, this model provides an accurate and efficient means of analyzing multiple design configurations for any cryogenic propellant tank in launch, low-acceleration coast, or in-space maneuvering and supplies the user with pressurization requirements, unusable propellants from evaporation and liquid stratification, and general ullage gas, liquid, and tank wall conditions as functions of time.

Space storable propellant acquisition system

NASA Technical Reports Server (NTRS)

Tegart, J. R.; Uney, P. E.; Anderson, J. E.; Fester, D. A.

1972-01-01

Surface tension propellant acquisition concepts for an advanced spacecraft propulsion system having a 10-year mission capability were investigated. Surface tension systems were specified because they were shown to be the best propellant acquisition technique for various interplanetery spacecraft in a prior study. A variety of surface tension concepts for accomplishing propellant acquisition were formulated for the baseline space storable propulsion module and Jupiter Orbiter mission. Analyses and evaluations were then conducted on each candidate concept to assess fabricability, performance capability, and spacecraft compatibility. A comparative evaluation of the results showed the Fruhof-class of low-g surface tension systems to be preferred for these interplanetary applications.

Rheology of composite solid propellants during motor casting

NASA Technical Reports Server (NTRS)

Rogers, C. J.; Smith, P. L.; Klager, K.

1978-01-01

In a study conducted to evaluate flow parameters of uncured solid composite propellants during motor casting, two motors (1.8M-lb grain wt) were cast with a PBAN propellant exhibiting good flow characteristics in a 260-in. dia solid rocket motor. Attention is given to the effects of propellant compositional and processing variables on apparent viscosity as they pertain to rheological behavior and grain defect formation during casting. It is noted that optimized flow behavior is impaired with solid propellant loading. Non-Newtonian pseudoplastic flow is observed, which is dependent upon applied shear stress and the age of the uncured propellant.

Propeller propulsion system integration: State of technology survey

NASA Technical Reports Server (NTRS)

Miley, S. J.; Vonlavante, E.

1985-01-01

A literature survey was performed to identify and review technical material applicable to the problem area of propeller propulsion system integration. The survey covered only aerodynamic interference aspects of the problem, and was restricted primarily to propeller effects on the airframe. The subject of airframe aerodynamic interference on the propeller was limited to the problem of vibration due to nonuniform inflow. The problem of airframe effects on propeller performance was not included. A total of 1121 references are given. The references are grouped into the subject areas of Aircraft Stability, Propulsive Efficiency, Aerodynamic Interference, Aerodynamic Interference-Propeller Vibration, and Miscellaneous.

Computational Predictions of the Performance Wright 'Bent End' Propellers

NASA Technical Reports Server (NTRS)

Wang, Xiang-Yu; Ash, Robert L.; Bobbitt, Percy J.; Prior, Edwin (Technical Monitor)

2002-01-01

Computational analysis of two 1911 Wright brothers 'Bent End' wooden propeller reproductions have been performed and compared with experimental test results from the Langley Full Scale Wind Tunnel. The purpose of the analysis was to check the consistency of the experimental results and to validate the reliability of the tests. This report is one part of the project on the propeller performance research of the Wright 'Bent End' propellers, intend to document the Wright brothers' pioneering propeller design contributions. Two computer codes were used in the computational predictions. The FLO-MG Navier-Stokes code is a CFD (Computational Fluid Dynamics) code based on the Navier-Stokes Equations. It is mainly used to compute the lift coefficient and the drag coefficient at specified angles of attack at different radii. Those calculated data are the intermediate results of the computation and a part of the necessary input for the Propeller Design Analysis Code (based on Adkins and Libeck method), which is a propeller design code used to compute the propeller thrust coefficient, the propeller power coefficient and the propeller propulsive efficiency.

Strength of Screw Propellers

DTIC Science & Technology

1975-07-07

development depends not, only on the ability of the material to resist hydraulic impacts in cavitation, but also on the correct design of the propeller. Study...9) z where k - correction of Goldstein-Prandtl, which takes into considera- tion the effect of the finite number of propeller blades on the amount... correction of Goldztcin-Prwxidtl is deteri~inedi by graphs in Fig. 10. An example of the calculation of hydrodynamic forces distribu- tion along a

Identification of β-propeller phytase-encoding genes in culturable Paenibacillus and Bacillus spp. from the rhizosphere of pasture plants on volcanic soils.

PubMed

Jorquera, Milko A; Crowley, David E; Marschner, Petra; Greiner, Ralf; Fernández, María Teresa; Romero, Daniela; Menezes-Blackburn, Daniel; De La Luz Mora, María

2011-01-01

Phytate is one of the most abundant sources of organic phosphorus (P) in soils, but must be mineralized by phytase-producing bacteria to release P for plant uptake. Microbial inoculants based on Bacillus spp. have been developed commercially, but few studies have evaluated the ecology of these bacteria in the rhizosphere or the types of enzymes that they produce. Here, we studied the diversity of aerobic endospore-forming bacteria (EFB) with the ability to mineralize phytate in the rhizosphere of pasture plants grown in volcanic soils of southern Chile. PCR methods were used to detect candidate phytase-encoding genes and to identify EFB bacteria that carry these genes. This study revealed that the phytate-degrading EFB populations of pasture plants included species of Paenibacillus and Bacillus, which carried genes encoding β-propeller phytase (BPP). Assays of enzymatic activity confirmed the ability of these rhizosphere isolates to degrade phytate. The phytase-encoding genes described here may prove valuable as molecular markers to evaluate the role of EFB in organic P mobilization in the rhizosphere. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

76 FR 27281 - Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-11

... Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller Assemblies AGENCY.../22 propeller assemblies with hub and driving center assembly part number (P/N) 601022105, 601022211, 601022294, 601021426, 601021858, or 601021859 installed, and type R251/4-30-4/49 propeller assemblies with...

The PROPEL Electrodynamic Tether Demonstration Mission

NASA Technical Reports Server (NTRS)

Bilen, Sven G.; Johnson, C. Les; Wiegmann, Bruce M.; Alexander, Leslie; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael

2012-01-01

The PROPEL ("Propulsion using Electrodynamics") mission will demonstrate the operation of an electrodynamic tether propulsion system in low Earth orbit and advance its technology readiness level for multiple applications. The PROPEL mission has two primary objectives: first, to demonstrate the capability of electrodynamic tether technology to provide robust and safe, near-propellantless propulsion for orbit-raising, de-orbit, plane change, and station keeping, as well as to perform orbital power harvesting and formation flight; and, second, to fully characterize and validate the performance of an integrated electrodynamic tether propulsion system, qualifying it for infusion into future multiple satellite platforms and missions with minimal modification. This paper provides an overview of the PROPEL system and design reference missions; mission goals and required measurements; and ongoing PROPEL mission design efforts.

Production of virus resistant plants

DOEpatents

Dougherty, W.G.; Lindbo, J.A.

1996-12-10

A method of suppressing virus gene expression in plants using untranslatable plus sense RNA is disclosed. The method is useful for the production of plants that are resistant to virus infection. 9 figs.

14 CFR 35.5 - Propeller ratings and operating limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller ratings and operating limitations... AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.5 Propeller ratings and operating limitations. (a) Propeller ratings and operating limitations must: (1) Be established by the applicant and approved by the...

14 CFR 35.5 - Propeller ratings and operating limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller ratings and operating limitations... AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.5 Propeller ratings and operating limitations. (a) Propeller ratings and operating limitations must: (1) Be established by the applicant and approved by the...

14 CFR 35.5 - Propeller ratings and operating limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller ratings and operating limitations... AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.5 Propeller ratings and operating limitations. (a) Propeller ratings and operating limitations must: (1) Be established by the applicant and approved by the...

14 CFR 35.5 - Propeller ratings and operating limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller ratings and operating limitations... AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.5 Propeller ratings and operating limitations. (a) Propeller ratings and operating limitations must: (1) Be established by the applicant and approved by the...

14 CFR 35.5 - Propeller ratings and operating limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller ratings and operating limitations... AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.5 Propeller ratings and operating limitations. (a) Propeller ratings and operating limitations must: (1) Be established by the applicant and approved by the...

Benefits of in situ propellant utilization for a Mars sample return mission

NASA Technical Reports Server (NTRS)

Wadel, Mary F.

1993-01-01

Previous Mars rover sample return mission studies have shown a requirement for Titan 4 or STS Space Shuttle launch vehicles to complete a sample return from a single Mars site. These studies have either used terrestrial propellants or considered in situ production of methane and oxygen for the return portion of the mission. Using in situ propellants for the return vehicles reduces the Earth launch mass and allows for a smaller Earth launch vehicle, since the return propellant is not carried from Earth. Carbon monoxide and oxygen (CO/O2) and methane and oxygen (CH4/O2) were investigated as in situ propellants for a Mars sample return mission and the results were compared to a baseline study performed by the Jet Propulsion Laboratory using terrestrial propellants. Capability for increased sample return mass, use of an alternate launch vehicle, and an additional mini-rover as payload were included. CO/O2 and CH4/O2 were found to decrease the baseline Earth launch mass by 13.6 and 9.2 percent, respectively. This resulted in higher payload mass margins for the baseline Atlas 2AS launch vehicle. CO/O2 had the highest mass margin. And because of this, it was not only possible to increase the sample return mass and carry an additional mini-rover, but was also possible to use the smaller Atlas 2A launch vehicle.

Solid Propellant Grain Structural Integrity Analysis

NASA Technical Reports Server (NTRS)

1973-01-01

The structural properties of solid propellant rocket grains were studied to determine the propellant resistance to stresses. Grain geometry, thermal properties, mechanical properties, and failure modes are discussed along with design criteria and recommended practices.

Ammonium nitrate as an oxidizer in solid composite propellants

NASA Astrophysics Data System (ADS)

Manelis, G. B.; Lempert, D. B.

2009-09-01

Despite the fact that ammonium nitrate (AN) has the highest hydrogen content and fairly high oxygen balance (compared to other oxidizers), its extremely low formation enthalpy and relatively low density makes it one of the worst power oxidizers in solid composite propellants (SCP). Nevertheless, AN has certain advantages - the combustion of the compositions containing AN is virtually safe, its combustion products are ecologically clean, it is very accessible and cheap, and also very thermostable (far more stable than ammonium dinitramide (ADN)). Besides, its low density stops being a disadvantage if the propellant has to be used in deep space and therefore, must be carried there with other rocket carriers. The low cost of AN may also become a serious advantage in the AN application even in lower stages of multistage space launchers as well as in one-stage space launchers with low mass fraction of the propellant. The main specific features relevant to the creation of AN-based SCPs with the optimal energetic characteristics are discussed. The use of metals and their hydrides and proper fuel-binders as well as the recent successes in phase stabilization of AN are described.

Ionic liquid propellants: future fuels for space propulsion.

PubMed

Zhang, Qinghua; Shreeve, Jean'ne M

2013-11-11

Use of green propellants is a trend for future space propulsion. Hypergolic ionic liquid propellants, which are environmentally-benign while exhibiting energetic performances comparable to hydrazine, have shown great potential to meet the requirements of developing nontoxic high-performance propellant formulations for space propulsion applications. This Concept article presents a review of recent advances in the field of ionic liquid propellants. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Predictions of wing and pylon forces caused by propeller installation

NASA Technical Reports Server (NTRS)

Martinez, Rudolph

1987-01-01

Replacement of current turbojets by high-efficiency unducted propfans could have the unfortunate side effect of increasing cabin noise, essentially because unsteady-aerodynamic mechanisms are likely to be introduced whereby some of the energy saved may be lost again, to the production of propeller noise and to wing/pylon vibrations coupling to the cabin as a sounding board. The present study estimates theoretically associated harmonic aerodynamic forces for two candidate configurations: a pusher propeller which chops through the mean wake of the pylon supporting it, and in the process generates a blade-rate force driving the structure, and a tractor wing-mounted propeller, whose trailing rotating wake induces an unsteady downwash field generating unsteady wing airloads. Reported predictions of such propfan aerodynamic sources of structure-borne sound, or vibration, could be the basis for devising means for their mechanical isolation, and thus for the effective interruption of the structural noise path into the cabin. Both mechanisms are analyzed taking advantage of the high subsonic Mach number and high reduced frequency of the interaction between the impinging flow and the affected aerodynamic element.

Approach Considerations in Aircraft with High-Lift Propeller Systems

NASA Technical Reports Server (NTRS)

Patterson, Michael D.; Borer, Nicholas K.

2017-01-01

NASA's research into distributed electric propulsion (DEP) includes the design and development of the X-57 Maxwell aircraft. This aircraft has two distinct types of DEP: wingtip propellers and high-lift propellers. This paper focuses on the unique opportunities and challenges that the high-lift propellers--i.e., the small diameter propellers distributed upstream of the wing leading edge to augment lift at low speeds--bring to the aircraft performance in approach conditions. Recent changes to the regulations related to certifying small aircraft (14 CFR x23) and these new regulations' implications on the certification of aircraft with high-lift propellers are discussed. Recommendations about control systems for high-lift propeller systems are made, and performance estimates for the X-57 aircraft with high-lift propellers operating are presented.

Green Propellant Infusion Mission

NASA Image and Video Library

2013-07-09

Dr. Michael Gazarik, Associate Administrator, NASA Space Technology Mission Directorate, answers a reporter's question at a Green Propellant Infusion Mission press conference at the Reserve Officers Association, Tuesday, July 9, 2013 in Washington. The NASA GPIM program, led by Ball Aerospace in conjunction with Aerojet Rocketdyne, is demonstrating a high-performance "green" fuel in space. The propellant used on this mission offers nearly 50 percent better performance when compared to traditional hydrazine. Photo Credit: (NASA/Carla Cioffi)

Study on unsteady hydrodynamic performance of propeller in waves

NASA Astrophysics Data System (ADS)

Zhao, Qingxin; Guo, Chunyu; Su, Yumin; Liu, Tian; Meng, Xiangyin

2017-09-01

The speed of a ship sailing in waves always slows down due to the decrease in efficiency of the propeller. So it is necessary and essential to analyze the unsteady hydrodynamic performance of propeller in waves. This paper is based on the numerical simulation and experimental research of hydrodynamics performance when the propeller is under wave conditions. Open-water propeller performance in calm water is calculated by commercial codes and the results are compared to experimental values to evaluate the accuracy of the numerical simulation method. The first-order Volume of Fluid (VOF) wave method in STAR CCM+ is utilized to simulate the three-dimensional numerical wave. According to the above prerequisite, the numerical calculation of hydrodynamic performance of the propeller under wave conditions is conducted, and the results reveal that both thrust and torque of the propeller under wave conditions reveal intense unsteady behavior. With the periodic variation of waves, ventilation, and even an effluent phenomenon appears on the propeller. Calculation results indicate, when ventilation or effluent appears, the numerical calculation model can capture the dynamic characteristics of the propeller accurately, thus providing a significant theory foundation for further studying the hydrodynamic performance of a propeller in waves.

Supplier's Status for Critical Solid Propellants, Explosive, and Pyrotechnic Ingredients

NASA Technical Reports Server (NTRS)

Sims, B. L.; Painter, C. R.; Nauflett, G. W.; Cramer, R. J.; Mulder, E. J.

2000-01-01

task. This paper is designed to emphasize the necessity of maintaining a JANNAF community supported database, which monitors PEP critical ingredient suppliers' status. The final product of this task is a user friendly, searchable database that provides a quick-view summary of critical ingredient supplier's information. This database must be designed to serve the needs of JANNAF and the propellant and energetic commercial manufacturing community as well. This paper provides a summary of the type of information to archive each critical ingredient.

Subcooling Cryogenic Propellants for Long Duration Space Exploration

NASA Technical Reports Server (NTRS)

Mustafi, Shuvo; Canavan, Edgar; Johnson, Wesley; Kutter, Bernard; Shull, Jeff

2009-01-01

The use of cryogenic propellants such as hydrogen and oxygen is crucial for exploration of the solar system because of their superior specific impulse capability. Future missions may require vehicles with the flexibility to remain in orbit or travel in space for months, necessitating long-term storage of these cryogens. One powerful technique for easing the challenge of cryogenic fluid storage is to remove energy from tlie cryogenic propellant by isobaricly subcooling them below their normal boiling point prior to launch. The isobaric subcooling of the cryogenic propellant will be performed by using a cold pressurant to maintain the tank pressure while the cryogen's temperature is simultaneously reduced. After launch, even with the use of the best insulation systems, heat will leak into the cold cryogenic propellant tank. However, the large heat capacity available in highly subcooled cryogenic propellants allows them to absorb the energy that leaks into the tank until the cryogen reaches its operational thermodynamic condition. During this period of heating of the subcooled cryogen there will be no loss of the propellant due to venting for pressure control. This simple technique can extend the operational life of a spacecraft or an orbital cryogenic depot many months with minimal mass penalty. Subcooling technologies for cryogenic propellants would thus provide the Exploration Systems Mission Directorate with an enhanced level of mission flexibility. However, there are a few challenges associated with subcooling cryogenic propellants since compact subcooling ground support equipment has not been demonstrated. This paper explores the beneficial impact of subcooling cryogenic propellants on the launch pad for long-term cryogenic propellant storage in space and proposes a novel method for implementing subcooling of cryogenic propellants for spacecraft such as the Ares V Earth Departure Stage (EDS). Analysis indicates that with a careful strategy to handle the

Simultaneous multi-slice combined with PROPELLER.

PubMed

Norbeck, Ola; Avventi, Enrico; Engström, Mathias; Rydén, Henric; Skare, Stefan

2018-08-01

Simultaneous multi-slice (SMS) imaging is an advantageous method for accelerating MRI scans, allowing reduced scan time, increased slice coverage, or high temporal resolution with limited image quality penalties. In this work we combine the advantages of SMS acceleration with the motion correction and artifact reduction capabilities of the PROPELLER technique. A PROPELLER sequence was developed with support for CAIPIRINHA and phase optimized multiband radio frequency pulses. To minimize the time spent on acquiring calibration data, both in-plane-generalized autocalibrating partial parallel acquisition (GRAPPA) and slice-GRAPPA weights for all PROPELLER blade angles were calibrated on a single fully sampled PROPELLER blade volume. Therefore, the proposed acquisition included a single fully sampled blade volume, with the remaining blades accelerated in both the phase and slice encoding directions without additional auto calibrating signal lines. Comparison to 3D RARE was performed as well as demonstration of 3D motion correction performance on the SMS PROPELLER data. We show that PROPELLER acquisitions can be efficiently accelerated with SMS using a short embedded calibration. The potential in combining these two techniques was demonstrated with a high quality 1.0 × 1.0 × 1.0 mm 3 resolution T 2 -weighted volume, free from banding artifacts, and capable of 3D retrospective motion correction, with higher effective resolution compared to 3D RARE. With the combination of SMS acceleration and PROPELLER imaging, thin-sliced reformattable T 2 -weighted image volumes with 3D retrospective motion correction capabilities can be rapidly acquired with low sensitivity to flow and head motion. Magn Reson Med 80:496-506, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Water Contaminant Mitigation in Ionic Liquid Propellant

NASA Technical Reports Server (NTRS)

Conroy, David; Ziemer, John

2009-01-01

Appropriate system and operational requirements are needed in order to ensure mission success without unnecessary cost. Purity requirements applied to thruster propellants may flow down to materials and operations as well as the propellant preparation itself. Colloid electrospray thrusters function by applying a large potential to a room temperature liquid propellant (such as an ionic liquid), inducing formation of a Taylor cone. Ions and droplets are ejected from the Taylor cone and accelerated through a strong electric field. Electrospray thrusters are highly efficient, precise, scaleable, and demonstrate low thrust noise. Ionic liquid propellants have excellent properties for use as electrospray propellants, but can be hampered by impurities, owing to their solvent capabilities. Of foremost concern is the water content, which can result from exposure to atmosphere. Even hydrophobic ionic liquids have been shown to absorb water from the air. In order to mitigate the risks of bubble formation in feed systems caused by water content of the ionic liquid propellant, physical properties of the ionic liquid EMI-Im are analyzed. The effects of surface tension, material wetting, physisorption, and geometric details of the flow manifold and electrospray emitters are explored. Results are compared to laboratory test data.

Microbial production of plant hormones: Opportunities and challenges.

PubMed

Shi, Tian-Qiong; Peng, Hui; Zeng, Si-Yu; Ji, Rong-Yu; Shi, Kun; Huang, He; Ji, Xiao-Jun

2017-03-04

Plant hormones are a class of organic substances which are synthesized during the plant metabolism. They have obvious physiological effect on plant growth at very low concentrations. Generally, plant hormones are mainly divided into 5 categories: auxins, cytokinins, ethylene, gibberellins (GAs) and abscisic acid (ABA). With the deepening of research, some novel plant hormones such as brassinosteroid and salicylates have been found and identified. The plant hormone products are mainly obtained through plant extraction, chemical synthesis as well as microbial fermentation. However, the extremely low yield in plants and relatively complex chemical structure limit the development of the former 2 approaches. Therefore, more attention has been paid into the microbial fermentative production. In this commentary, the developments and technological achievements of the 2 important plant hormones (GAs and ABA) have been discussed. The discovery, producing strains, fermentation technologies, and their accumulation mechanisms are first introduced. Furthermore, progresses in the industrial mass scale production are discussed. Finally, guidelines for future studies for GAs and ABA production are proposed in light of the current progress, challenges and trends in the field. With the widespread use of plant hormones in agriculture, we believe that the microbial production of plant hormones will have a bright future.

Enhanced alkaline hydrolysis and biodegradability studies of nitrocellulose-bearing missile propellant

NASA Technical Reports Server (NTRS)

Sidhoum, Mohammed; Christodoulatos, Christos; Su, Tsan-Liang; Redis, Mercurios

1995-01-01

Large amounts of energetic materials which have been accumulated over the years in various manufacturing and military installations must be disposed of in an environmentally sound manner. Historically, the method of choice for destruction of obsolete or aging energetic materials has been open burning or open detonation (OB/OD). This destruction approach has become undesirable due to air pollution problems. Therefore, there is a need for new technologies which will effectively and economically deal with the disposal of energetic materials. Along those lines, we have investigated a chemical/biological process for the safe destruction and disposal of a double base solid rocket propellant (AHH), which was used in several 8 inch projectile systems. The solid propellant is made of nitrocellulose and nitroglycerin as energetic components, two lead salts which act as ballistic modifiers, triacetin as a plasticizer and 2-Nitrodiphenylamine (2-NDPA) as a stabilizer. A process train is being developed to convert the organic components of the propellant to biodegradable products and remove the lead from the process stream. The solid propellant is first hydrolyzed through an enhanced alkaline hydrolysis process step. Following lead removal and neutralization, the digested liquor rich in nitrates and nitrites is found to be easily biodegradable. The digestion rate of the intact ground propellant as well as the release of nitrite and nitrate groups were substantially increased when ultrasound were supplied to the alkaline reaction medium compared to the conventional alkaline hydrolysis. The effects of reaction time, temperature, sodium hydroxide concentration and other relevant parameters on the digestion efficiency and biodegradability have been studied. The present work indicates that the AHH propellant can be disposed of safely with a combination of physiochemical and biological processes.

Propellant Depots: The Future of Space Exploration

NASA Astrophysics Data System (ADS)

Crenwelge, Drew

NASA is currently exploring several options for mankind's return to the lunar surface and beyond. The selected option must stimulate both commercial and international involvement, support future missions to the Moon and other destinations, and above all, fit within the current budget profile. Contrary to the current Constellation approach, this paper describes the option of using an in-space propellant depot architecture that can refuel or top-off visiting vehicles at EML1, and how it fits within NASA's new space exploration criteria. In addition to receiving and transferring fuel, the propellant depot will also provide cryogenic propellant storage and management that utilizes flight proven technologies in conjunction with technologies currently under development. The propellant depot system, propellant management and acquisition devices, thermodynamic analysis, and key enabling technologies are also discussed. Depot design concepts along with an overview of a future lunar mission sequence are also presented.

Interaction Between Air Propellers and Airplane Structures

NASA Technical Reports Server (NTRS)

Durand, W F

1927-01-01

The purpose of this investigation was the determination of the character and amount of interaction between air propellers as usually mounted on airplanes and the adjacent parts of the airplane structure - or, more specifically, those parts of the airplane structure within the wash of the propeller, and capable of producing any significant effect on propeller performance. In report no. 177 such interaction between air propellers and certain simple geometrical forms was made the subject of investigation and report. The present investigation aims to carry this general study one stage further by substituting actual airplane structures for the simple geometrical forms. From the point of view of the present investigation, the airplane structures, viewed as an obstruction in the wake of the propeller, must also be viewed as a necessary part of the airplane and not as an appendage which might be installed or removed at will. (author)

Summary of recent NASA propeller research

NASA Technical Reports Server (NTRS)

Mikkelson, D. C.; Mitchell, G. A.; Bober, L. J.

1985-01-01

Advanced high speed propellers offer large performance improvements for aircraft that cruise in the Mach 0.7 to 0.8 speed regime. At these speeds, studies indicate that there is a 15 to near 40 percent block fuel savings and associated operating cost benefits for advanced turboprops compared to equivalent technology turbofan powered aircraft. Recent wind tunnel results for five eight to ten blade advanced models are compared with analytical predictions. Test results show that blade sweep was important in achieving net efficiencies near 80 percent at Mach 0.8 and reducing nearfield cruise noise about 6 dB. Lifting line and lifting surface aerodynamic analysis codes are under development and some results are compared with propeller force and probe data. Also, analytical predictions are compared with some initial laser velocimeter measurements of the flow field velocities of an eight bladed 45 swept propeller. Experimental aeroelastic results indicate that cascade effects and blade sweep strongly affect propeller aeroelastic characteristics. Comparisons of propeller nearfield noise data with linear acoustic theory indicate that the theory adequately predicts nearfield noise for subsonic tip speeds, but overpredicts the noise for supersonic tip speeds.

Summary of recent NASA propeller research

NASA Technical Reports Server (NTRS)

Mikkelson, D. C.; Mitchell, G. A.; Bober, L. J.

1984-01-01

Advanced high-speed propellers offer large performance improvements for aircraft that cruise in the Mach 0.7 to 0.8 speed regime. At these speeds, studies indicate that there is a 15 to near 40 percent block fuel savings and associated operating cost benefits for advanced turboprops compared to equivalent technology turbofan powered aircraft. Recent wind tunnel results for five eight to ten blade advanced models are compared with analytical predictions. Test results show that blade sweep was important in achieving net efficiencies near 80 percent at Mach 0.8 and reducing nearfield cruise noise by about 6 dB. Lifting line and lifting surface aerodynamic analysis codes are under development and some results are compared with propeller force and probe data. Also, analytical predictions are compared with some initial laser velocimeter measurements of the flow field velocities of an eightbladed 45 swept propeller. Experimental aeroelastic results indicate that cascade effects and blade sweep strongly affect propeller aeroelastic characteristics. Comparisons of propeller near-field noise data with linear acoustic theory indicate that the theory adequately predicts near-field noise for subsonic tip speeds but overpredicts the noise for supersonic tip speeds.

Design and simulation on the morphing composite propeller (Conference Presentation)

NASA Astrophysics Data System (ADS)

Chen, Fanlong; Li, Qinyu; Liu, Liwu; Lan, Xin; Liu, Yanju; Leng, Jinsong

2017-04-01

As one of the most crucial part of the unmanned underwater vehicle (UUV), the composite propeller plays an important role on the UUV's performance. As the composite propeller behaves excellent properties in hydroelastic facet and acoustic suppression, it attracts increasing attentions all over the globe. This paper goes a step further based on this idea, and comes up with a novel concept of "morphing composite propeller" (MCP) to improve the performance of the conventional composite propeller (CCP) to anticipate the improved propeller can perform better to propel the UUV. Based on the new concept, a novel MCP is designed. Each blade of the propeller is assembled with an active rotatable flap (ARF) to change the blade's local camber with flap rotation. Then the transmission mechanism (TM) has been designed and housed in the propeller blade to push the ARF. With the ARF rotating, the UUV can be propelled by different thrusts under certain rotation velocities of the propeller. Based on the design, the Fluent is exploited to analyze the fluid dynamics around the propeller. Finally, based on the design and hydrodynamic analysis, the structural response for the novel morphing composite propeller is calculated. The propeller blade is simplified and layered with composite materials. And the structure response of an MCP is obtained with various rotation angle under the hydrodynamic pressure. This simulation can instruct the design and fabrication techniques of the MCP.

Light-activated self-propelled colloids

PubMed Central

Palacci, J.; Sacanna, S.; Kim, S.-H.; Yi, G.-R.; Pine, D. J.; Chaikin, P. M.

2014-01-01

Light-activated self-propelled colloids are synthesized and their active motion is studied using optical microscopy. We propose a versatile route using different photoactive materials, and demonstrate a multiwavelength activation and propulsion. Thanks to the photoelectrochemical properties of two semiconductor materials (α-Fe2O3 and TiO2), a light with an energy higher than the bandgap triggers the reaction of decomposition of hydrogen peroxide and produces a chemical cloud around the particle. It induces a phoretic attraction with neighbouring colloids as well as an osmotic self-propulsion of the particle on the substrate. We use these mechanisms to form colloidal cargos as well as self-propelled particles where the light-activated component is embedded into a dielectric sphere. The particles are self-propelled along a direction otherwise randomized by thermal fluctuations, and exhibit a persistent random walk. For sufficient surface density, the particles spontaneously form ‘living crystals’ which are mobile, break apart and reform. Steering the particle with an external magnetic field, we show that the formation of the dense phase results from the collisions heads-on of the particles. This effect is intrinsically non-equilibrium and a novel principle of organization for systems without detailed balance. Engineering families of particles self-propelled by different wavelength demonstrate a good understanding of both the physics and the chemistry behind the system and points to a general route for designing new families of self-propelled particles. PMID:25332383

[Imaging characteristics of PROPELLER T2-weighted imaging].

PubMed

Goto, Masami; Aoki, Shigeki; Hayashi, Naoto; Mori, Harushi; Watanabe, Yasushi; Ino, Kenji; Satake, Yoshirou; Nishida, Katuji; Sato, Haruo; Iida, Kyouhito; Mima, Kazuo; Ohtomo, Kuni

2004-11-01

As the PROPELLER sequence is a combination of the radial scan and fast-spin-echo (FSE) sequence, it can be considered an FSE sequence with a motion correlation. However, there are some differences between PROPELLER and FSE owing to differences in k-space trajectory. We clarified the imaging characteristics of PROPELLER T2-weighted imaging (T2WI) for different parameters in comparison with usual FSE T2WI. When the same parameters were used, PROPELLER T2WI showed a higher signal-to-noise ratio (SNR) and lower spatial resolution than usual FSE. Effective echo time (TE) changed with different echo train lengths (ETL) or different bandwidths on PROPELLER, and imaging contrast changed accordingly to be more effective.

NASA's Space Launch Initiative Targets Toxic Propellants

NASA Technical Reports Server (NTRS)

Hurlbert, Eric; McNeal, Curtis; Davis, Daniel J. (Technical Monitor)

2001-01-01

When manned and unmanned space flight first began, the clear and overriding design consideration was performance. Consequently, propellant combinations of all kinds were considered, tested, and, when they lifted the payload a kilometer higher, or an extra kilogram to the same altitude, they became part of our operational inventory. Cost was not considered. And with virtually all of the early work being performed by the military, safety was hardly a consideration. After all, fighting wars has always been dangerous. Those days are past now. With space flight, and the products of space flight, a regular part of our lives today, safety and cost are being reexamined. NASA's focus turns naturally to its Shuttle Space Transportation System. Designed, built, and flown for the first time in the 1970s, this system remains today America's workhorse for manned space flight. Without its tremendous lift capability and mission flexibility, the International Space Station would not exist. And the Hubble telescope would be a monument to shortsighted management, rather than the clear penetrating eye on the stars it is today. But the Shuttle system fully represents the design philosophy of its period: it is too costly to operate, and not safe enough for regular long term access to space. And one of the key reasons is the utilization of toxic propellants. This paper will present an overview of the utilization of toxic propellants on the current Shuttle system.

14 CFR 25.1149 - Propeller speed and pitch controls.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller speed and pitch controls. 25.1149... Accessories § 25.1149 Propeller speed and pitch controls. (a) There must be a separate propeller speed and pitch control for each propeller. (b) The controls must be grouped and arranged to allow— (1) Separate...

14 CFR 25.1149 - Propeller speed and pitch controls.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller speed and pitch controls. 25.1149... Accessories § 25.1149 Propeller speed and pitch controls. (a) There must be a separate propeller speed and pitch control for each propeller. (b) The controls must be grouped and arranged to allow— (1) Separate...

14 CFR 25.1149 - Propeller speed and pitch controls.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller speed and pitch controls. 25.1149... Accessories § 25.1149 Propeller speed and pitch controls. (a) There must be a separate propeller speed and pitch control for each propeller. (b) The controls must be grouped and arranged to allow— (1) Separate...

Thermal Vacuum Test Correlation of A Zero Propellant Load Case Thermal Capacitance Propellant Gauging Analytics Model

NASA Technical Reports Server (NTRS)

McKim, Stephen A.

2016-01-01

This thesis describes the development and test data validation of the thermal model that is the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA's Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented to validate the model are presented. The thermal model was correlated to within plus or minus 3 degrees Centigrade of the thermal vacuum test data, and was found to be relatively insensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed, however, to refine the thermal model to further improve temperature predictions in the upper hemisphere of the propellant tank. Temperatures predictions in this portion were found to be 2-2.5 degrees Centigrade lower than the test data. A road map to apply the model to predict propellant loads on the actual MMS spacecraft toward its end of life in 2017-2018 is also presented.

Performance analysis of mini-propellers based on FlightGear

NASA Astrophysics Data System (ADS)

Vogeltanz, Tomáš

2016-06-01

This paper presents a performance analysis of three mini-propellers based on the FlightGear flight simulator. Although a basic propeller analysis has to be performed before the use of FlightGear, for a complex and more practical performance analysis, it is advantageous to use a propeller model in cooperation with a particular aircraft model. This approach may determine whether the propeller has sufficient quality in respect of aircraft requirements. In the first section, the software used for the analysis is illustrated. Then, the parameters of the analyzed mini-propellers and the tested UAV are described. Finally, the main section shows and discusses the results of the performance analysis of the mini-propellers.

Effect of a rotating propeller on the separation angle of attack and distortion in ducted propeller inlets

NASA Technical Reports Server (NTRS)

Boldman, D. R.; Iek, C.; Hwang, D. P.; Larkin, M.; Schweiger, P.

1993-01-01

The present study represents an extension of an earlier wind tunnel experiment performed with the P&W 17-in. Advanced Ducted Propeller (ADP) Simulator operating at Mach 0.2. In order to study the effects of a rotating propeller on the inlet flow, data were obtained in the UTRC 10- by 15-Foot Large Subsonic Wind Tunnel with the same hardware and instrumentation, but with the propeller removed. These new tests were performed over a range of flow rates which duplicated flow rates in the powered simulator program. The flow through the inlet was provided by a remotely located vacuum source. A comparison of the results of this flow-through study with the previous data from the powered simulator indicated that in the conventional inlet the propeller produced an increase in the separation angle of attack between 4.0 deg at a specific flow of 22.4 lb/sec-sq ft to 2.7 deg at a higher specific flow of 33.8 lb/sec-sq ft. A similar effect on separation angle of attack was obtained by using stationary blockage rather than a propeller.

14 CFR 23.33 - Propeller speed and pitch limits.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller speed and pitch limits. 23.33... Propeller speed and pitch limits. (a) General. The propeller speed and pitch must be limited to values that... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p...

14 CFR 23.33 - Propeller speed and pitch limits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller speed and pitch limits. 23.33... Propeller speed and pitch limits. (a) General. The propeller speed and pitch must be limited to values that... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p...

Advanced space storable propellants for outer planet exploration

NASA Technical Reports Server (NTRS)

Thunnissen, Daniel P.; Guernsey, Carl S.; Baker, Raymond S.; Miyake, Robert N.

2004-01-01

An evaluation of the feasibility and mission performance benefits of using advanced space storable propellants for outer planet exploration was performed. For the purpose of this study, space storable propellants are defined to be propellants which can be passively stored without the need for active cooling.

30 CFR 57.4260 - Underground self-propelled equipment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Prevention and Control Firefighting Equipment § 57.4260 Underground self-propelled equipment. (a) Whenever self-propelled equipment is used underground, a fire extinguisher shall be on the equipment. This... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Underground self-propelled equipment. 57.4260...

14 CFR 25.907 - Propeller vibration and fatigue.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller vibration and fatigue. 25.907... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.907 Propeller vibration and fatigue. This section does not apply to fixed-pitch wood propellers of conventional design. (a...

14 CFR 25.907 - Propeller vibration and fatigue.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller vibration and fatigue. 25.907... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.907 Propeller vibration and fatigue. This section does not apply to fixed-pitch wood propellers of conventional design. (a...

Development of a solid propellant viscoelastic dynamic model

NASA Technical Reports Server (NTRS)

Hufferd, W. L.; Fitzgerald, J. E.

1976-01-01

The results of a one year study to develop a dynamic response model for the Space Shuttle Solid Rocket Motor (SRM) propellant are presented. An extensive literature survey was conducted, from which it was concluded that the only significant variables affecting the dynamic response of the SRM propellant are temperature and frequency. Based on this study, and experimental data on propellants related to the SRM propellant, a dynamic constitutive model was developed in the form of a simple power law with temperature incorporated in the form of a modified power law. A computer program was generated which performs a least-squares curve-fit of laboratory data to determine the model parameters and it calculates dynamic moduli at any desired temperature and frequency. Additional studies investigated dynamic scaling laws and the extent of coupling between the SRM propellant and motor cases. It was found, in agreement with other investigations, that the propellant provides all of the mass and damping characteristics whereas the case provides all of the stiffness.

Annoyance caused by propeller airplane flyover noise

NASA Technical Reports Server (NTRS)

Mccurdy, D. A.; Powell, C. A.

1984-01-01

Laboratory experiments were conducted to provide information on quantifying the annoyance response of people to propeller airplane noise. The items of interest were current noise metrics, tone corrections, duration corrections, critical band corrections, and the effects of engine type, operation type, maximum takeoff weight, blade passage frequency, and blade tip speed. In each experiment, 64 subjects judged the annoyance of recordings of propeller and jet airplane operations presented at d-weighted sound pressure levels of 70, 80, and 90 dB in a testing room which simulates the outdoor acoustic environment. The first experiment examined 11 propeller airplanes with maximum takeoff weights greater than or equal to 5700 kg. The second experiment examined 14 propeller airplanes weighting 5700 kg or less. Five jet airplanes were included in each experiment. For both the heavy and light propeller airplanes, perceived noise level and perceived level (Stevens Mark VII procedure) predicted annoyance better than other current noise metrics.

MAST Propellant and Delivery System Design Methods

NASA Technical Reports Server (NTRS)

Nadeem, Uzair; Mc Cleskey, Carey M.

2015-01-01

A Mars Aerospace Taxi (MAST) concept and propellant storage and delivery case study is undergoing investigation by NASA's Element Design and Architectural Impact (EDAI) design and analysis forum. The MAST lander concept envisions landing with its ascent propellant storage tanks empty and supplying these reusable Mars landers with propellant that is generated and transferred while on the Mars surface. The report provides an overview of the data derived from modeling between different methods of propellant line routing (or "lining") and differentiate the resulting design and operations complexity of fluid and gaseous paths based on a given set of fluid sources and destinations. The EDAI team desires a rough-order-magnitude algorithm for estimating the lining characteristics (i.e., the plumbing mass and complexity) associated different numbers of vehicle propellant sources and destinations. This paper explored the feasibility of preparing a mathematically sound algorithm for this purpose, and offers a method for the EDAI team to implement.

Motion Correction in PROPELLER and Turboprop-MRI

PubMed Central

Tamhane, Ashish A.; Arfanakis, Konstantinos

2009-01-01

PROPELLER and Turboprop-MRI are characterized by greatly reduced sensitivity to motion, compared to their predecessors, fast spin-echo and gradient and spin-echo, respectively. This is due to the inherent self-navigation and motion correction of PROPELLER-based techniques. However, it is unknown how various acquisition parameters that determine k-space sampling affect the accuracy of motion correction in PROPELLER and Turboprop-MRI. The goal of this work was to evaluate the accuracy of motion correction in both techniques, to identify an optimal rotation correction approach, and determine acquisition strategies for optimal motion correction. It was demonstrated that, blades with multiple lines allow more accurate estimation of motion than blades with fewer lines. Also, it was shown that Turboprop-MRI is less sensitive to motion than PROPELLER. Furthermore, it was demonstrated that the number of blades does not significantly affect motion correction. Finally, clinically appropriate acquisition strategies that optimize motion correction were discussed for PROPELLER and Turboprop-MRI. PMID:19365858

Combustion chemistry of solid propellants

NASA Technical Reports Server (NTRS)

Baer, A. D.; Ryan, N. W.

1974-01-01

Several studies are described of the chemistry of solid propellant combustion which employed a fast-scanning optical spectrometer. Expanded abstracts are presented for four of the studies which were previously reported. One study of the ignition of composite propellants yielded data which suggested early ammonium perchlorate decomposition and reaction. The results of a study of the spatial distribution of molecular species in flames from uncatalyzed and copper or lead catalyzed double-based propellants support previously published conclusions concerning the site of action of these metal catalysts. A study of the ammonium-perchlorate-polymeric-fuel-binder reaction in thin films, made by use of infrared absorption spectrometry, yielded a characterization of a rapid condensed-phase reaction which is likely important during the ignition transient and the burning process.

Biodiversity influences plant productivity through niche-efficiency.

PubMed

Liang, Jingjing; Zhou, Mo; Tobin, Patrick C; McGuire, A David; Reich, Peter B

2015-05-05

The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity-ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche-efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche-efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species' inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty.

Biodiversity influences plant productivity through niche–efficiency

PubMed Central

Liang, Jingjing; Zhou, Mo; Tobin, Patrick C.; McGuire, A. David; Reich, Peter B.

2015-01-01

The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity–ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche–efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche–efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species’ inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty. PMID:25901325

Biodiversity influences plant productivity through niche–efficiency

USGS Publications Warehouse

Liang, Jingjing; Zhou, Mo; Tobin, Patrick C.; McGuire, A. David; Reich, Peter B.

2015-01-01

The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity–ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche–efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche–efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species’ inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty.

Circulation control propellers for general aviation, including a BASIC computer program

NASA Technical Reports Server (NTRS)

Taback, I.; Braslow, A. L.; Butterfield, A. J.

1983-01-01

The feasibility of replacing variable pitch propeller mechanisms with circulation control (Coanada effect) propellers on general aviation airplanes was examined. The study used a specially developed computer program written in BASIC which could compare the aerodynamic performance of circulation control propellers with conventional propellers. The comparison of aerodynamic performance for circulation control, fixed pitch and variable pitch propellers is based upon the requirements for a 1600 kg (3600 lb) single engine general aviation aircraft. A circulation control propeller using a supercritical airfoil was shown feasible over a representative range of design conditions. At a design condition for high speed cruise, all three types of propellers showed approximately the same performance. At low speed, the performance of the circulation control propeller exceeded the performance for a fixed pitch propeller, but did not match the performance available from a variable pitch propeller. It appears feasible to consider circulation control propellers for single engine aircraft or multiengine aircraft which have their propellers on a common axis (tractor pusher). The economics of the replacement requires a study for each specific airplane application.

Lessons Learned with Metallized Gelled Propellants

NASA Technical Reports Server (NTRS)

1996-01-01

During testing of metallized gelled propellants in a rocket engine, many changes had to be made to the normal test program for traditional liquid propellants. The lessons learned during the testing and the solutions for many of the new operational conditions posed with gelled fuels will help future programs run more smoothly. The major factors that influenced the success of the testing were propellant settling, piston-cylinder tank operation, control of self pressurization, capture of metal oxide particles, and a gelled-fuel protective layer. In these ongoing rocket combustion experiments at the NASA Lewis Research Center, metallized, gelled liquid propellants are used in a small modular engine that produces 30 to 40 lb of thrust. Traditional liquid RP-1 and gelled RP-1 with 0-, 5-, and 55-wt% loadings of aluminum are used with gaseous oxygen as the oxidizer. The figure compares the thrust chamber efficiencies of different engines.

Project Genesis: Mars in situ propellant technology demonstrator mission

NASA Technical Reports Server (NTRS)

Acosta, Francisco Garcia; Anderson, Scott; Andrews, Jason; Deger, Matt; Hedman, Matt; Kipp, Jared; Kobayashi, Takahisa; Marcelo, Mohrli; Mark, Karen; Matheson, Mark

1994-01-01

Project Genesis is a low cost, near-term, unmanned Mars mission, whose primary purpose is to demonstrate in situ resource utilization (ISRU) technology. The essence of the mission is to use indigenously produced fuel and oxidizer to propel a ballistic hopper. The Mars Landing Vehicle/Hopper (MLVH) has an Earth launch mass of 625 kg and is launched aboard a Delta 117925 launch vehicle into a conjunction class transfer orbit to Mars. Upon reaching its target, the vehicle performs an aerocapture maneuver and enters an elliptical orbit about Mars. Equipped with a ground penetrating radar, the MLVH searches for subsurface water ice deposits while in orbit for several weeks. A deorbit burn is then performed to bring the MLVH into the Martian atmosphere for landing. Following aerobraking and parachute deployment, the vehicle retrofires to a soft landing on Mars. Once on the surface, the MLVH begins to acquire scientific data and to manufacture methane and oxygen via the Sabatier process. This results in a fuel-rich O2/CH4 mass ratio of 2, which yields a sufficiently high specific impulse (335 sec) that no additional oxygen need be manufactured, thus greatly simplifying the design of the propellant production plant. During a period of 153 days the MLVH produces and stores enough fuel and oxidizer to make a 30 km ballistic hop to a different site of scientific interest. At this new location the MLVH resumes collecting surface and atmospheric data with the onboard instrumentation. Thus, the MLVH is able to provide a wealth of scientific data which would otherwise require two separate missions or separate vehicles, while proving a new and valuable technology that will facilitate future unmanned and manned exploration of Mars. Total mission cost, including the Delta launch vehicle, is estimated to be $200 million.

External And Internal Work Of A T-6 Paraplegic Propelling A Wheelchair And Arm Cranking A Cycle Ergometer: Case Study

NASA Astrophysics Data System (ADS)

Novak, Charles W.

1982-02-01

In this, the International Year of the Disabled, attention is directed among other areas toward rehabilitation and sports participation of wheelchair users. As an application of movement analysis in medicine and rehabilitation and as an application of sports research using biomechanics, this investigation was performed to compare the results of two methods of gathering data on the stress of wheelchair propelling at equivalent work loads and to account for differences in physiological responses with a mechanical analysis of wheelchair propelling. Physiological data collected were heart rate, systolic blood pressure, and rate-pressure product. A biomechanical cinematography analysis was used to determine external work in wheelchair propelling and to determine the extent to which modifications in segment actionsoccurred during increasing magnitude of work. A cycle ergometer was adjusted to replicate external work loads performed during wheelchair propelling. A t-test of equivalent external work loads indicated that heart rate was not different between the two exercise modes at the .05 level of significance. The t-test did indicate a significant difference in systolic blood pressure and rate-pressure product at the .05 level of significance. The biomechanical analysis of wheelchair propelling established that an increase in external work was accomplished by a decrease in the range of motion and an increase in the speed of movement. During cycle ergometry the range and speed of movement remained the same while resistance was increased. Results of the study established that while heart rate for equivalent external work loads was the same for wheelchair propelling and arm cranking cycle ergometry, systolic blood pressure and rate-pressure product were not the same. The suggestion was that some means of propelling a wheelchair other than that which is con-sidered "standard" might be considered which produces less stressful responses in wheelchair users.

Analysis of noise measured from a propeller in a wake

NASA Technical Reports Server (NTRS)

Block, P. J. W.

1984-01-01

In this experimental study, the acoustic characteristics of a propeller operating in a wake were studied. The propeller performance and noise were measured from two 0.25 scale propellers operating in an open jet anechoic flow environment with and without a wake. One propeller had NACA 16 series sections; the other, ARA-D. Wake thicknesses of 1 and 3 propeller chords were generated by an airfoil which spanned the full diameter of the propeller. The airfoil wake profiles were measured. Noise measurements were made in and out of the flow. The propellers were operated at 40, 83, and 100 inf of thrust. The acoustic data are analyzed, and the effects on the overall sound pressure level (OASPL) and scaled A weighted sound level L sub A with propeller thrust, wake thickness, and observer location are presented. The analysis showed that, generally, the wake increased the overall noise (OASPL) produced by the propeller; increased the harmonic content of the noise, thus the scaled L sub a; and produced an azimuthal dependence. With few exceptions, both propellers generally produced the same trends in delta OASPL and delta L sub a with thrust and wake thickness.

Design of a mercury Propellant Storage and Distribution assembly

NASA Technical Reports Server (NTRS)

Holcomb, L. B.; Womack, J. R.

1973-01-01

A study has been conducted of a Propellant Storage and Distribution (PSD) assembly for a solar electric propulsion (SEP) thrust subsystem. As a result of the trade-off study an elastomeric diaphragm propellant tank with nitrogen blowdown pressurization was the method selected for propellant expulsion. This study included the following propellant management devices: surface tension, metallic bellows, and metallic and elastomeric diaphragms. Pressurant supply concepts investigated were blowdown, externally pressure regulated, vaporizing Freon 113, and heated CO2/Zeolite. The configuration selected consists of a single propellant tank, a single main propellant latching-solenoid valve, and individual thruster latching-solenoid valves. Stainless steel was the selected tankage material and AF-E-332 was the selected diaphragm material. The PSD design characteristics and interfaces are summarized.

Propeller installation effects on turboprop aircraft acoustics

NASA Astrophysics Data System (ADS)

Chirico, Giulia; Barakos, George N.; Bown, Nicholas

2018-06-01

Propeller installation options for a twin-engined turboprop aircraft are evaluated at cruise conditions, aiming to identify the quieter configuration. Computational fluid dynamics is used to investigate the near-field acoustics and transfer functions are employed to estimate the interior cabin noise. Co-rotating and counter-rotating installation options are compared. The effect of propeller synchrophasing is also considered. The employed method captures the complexity of the acoustic field generated by the interactions of the propeller sound fields among each other and with the airframe, showing also the importance of simulating the whole problem to predict the actual noise on a flying aircraft. Marked differences among the various layouts are observed. The counter-rotating top-in option appears the best in terms of acoustics, the top-out propeller rotation leading to louder noise because of inflow conditions and the occurrence of constructive acoustic interferences. Synchrophasing is shown to be beneficial for co-rotating propellers, specially regarding the interior noise, because of favorable effects in the interaction between the propeller direct sound field and the noise due to the airframe. An angle closer to the maximum relative blade shift was found to be the best choice, yielding, however, higher sound levels than those provided by the counter-rotating top-in layout.

Electromagnetic Pumps for Conductive-Propellant Feed Systems

NASA Technical Reports Server (NTRS)

Markusic, T. E.; Polzin, K. A.

2005-01-01

There has been a recent, renewed interest in high-power electric thrusters for application in nuclear-electric propulsion systems. Two of the most promising thrusters utilize liquid metal propellants: the lithium-fed magnetoplasmadynamic thruster and the bismuth-fed Hall thruster. An important element of part of the maturation of these thrusters will be the development of compact, reliable conductive-propellant feed system components. In the present paper we provide design considerations and experimental calibration data for electromagnetic (EM) pumps. The role of an electromagnetic pump in a liquid metal feed system is to establish a pressure gradient between the propellant reservoir and the thruster - to establish the requisite mass flow rate. While EM pumps have previously been used to a limited extent in nuclear reactor cooling loops, they have never been implemented in electric propulsion (EP) systems. The potential benefit of using EM pumps for EP are reliability (no moving parts) and the ability to precisely meter the propellant flow rate. We have constructed and tested EM pumps that use gallium, lithium, and bismuth propellants. Design details, test results (pressure developed versus current), and material compatibility issues are reported. It is concluded that EM pumps are a viable technology for application in both laboratory and flight EP conductive-propellant feed systems.

The Propeller and the Frog

NASA Astrophysics Data System (ADS)

Pan, Margaret; Chiang, Eugene

2010-10-01

"Propellers" in planetary rings are disturbances in ring material excited by moonlets that open only partial gaps. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass. The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the "frog" resonance, after the relevant term in equine hoof anatomy. For a ring surface density and gap geometry appropriate for the propeller Blériot in Saturn's A ring, our theory predicts a libration period of ~4 years, similar to the ~3.7 year period over which Blériot's orbital longitude is observed to vary. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

Current approaches toward production of secondary plant metabolites

PubMed Central

Hussain, Md. Sarfaraj; Fareed, Sheeba; Ansari, Saba; Rahman, Md. Akhlaquer; Ahmad, Iffat Zareen; Saeed, Mohd.

2012-01-01

Plants are the tremendous source for the discovery of new products with medicinal importance in drug development. Today several distinct chemicals derived from plants are important drugs, which are currently used in one or more countries in the world. Secondary metabolites are economically important as drugs, flavor and fragrances, dye and pigments, pesticides, and food additives. Many of the drugs sold today are simple synthetic modifications or copies of the naturally obtained substances. The evolving commercial importance of secondary metabolites has in recent years resulted in a great interest in secondary metabolism, particularly in the possibility of altering the production of bioactive plant metabolites by means of tissue culture technology. Plant cell and tissue culture technologies can be established routinely under sterile conditions from explants, such as plant leaves, stems, roots, and meristems for both the ways for multiplication and extraction of secondary metabolites. In vitro production of secondary metabolite in plant cell suspension cultures has been reported from various medicinal plants, and bioreactors are the key step for their commercial production. Based on this lime light, the present review is aimed to cover phytotherapeutic application and recent advancement for the production of some important plant pharmaceuticals. PMID:22368394

In-space propellant logistics and safety

NASA Technical Reports Server (NTRS)

1971-01-01

Preliminary guidelines for the basic delivery system and safety aspects of the space shuttle configuration in connection with the transport, handling, storage, and transfer of propellants are developed. It is shown that propellants are the major shuttle space load and influence shuttle traffic modeling significantly.

30 CFR 57.4230 - Surface self-propelled equipment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Prevention and Control Firefighting Equipment § 57.4230 Surface self-propelled equipment. (a)(1) Whenever a fire or its effects could impede escape from self-propelled equipment, a fire extinguisher shall be on... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Surface self-propelled equipment. 57.4230...

Holographic investigation of solid propellant particulates

NASA Astrophysics Data System (ADS)

Gillespie, T. R.

1981-12-01

The investigation completed the development process to establish a technique to obtain holographic recordings of particulate behavior during the combustion process of solid propellants in a two-dimensional rocket motor. Holographic and photographic recordings were taken in a crossflow environment using various compositions of metallized propellants. The reconstructed holograms are used to provide data on the behavior of aluminum/aluminum oxide particulates in a steady state combustion environment as a function of the initial aluminum size cast into the propellant. High speed, high resolution motion pictures were taken to compare the cinematic data with that available from the holograms.

Sunlit Propeller

NASA Image and Video Library

2010-07-08

A propeller-shaped structure created by an unseen moon is brightly illuminated on the sunlit side of Saturn rings in this image obtained by NASA Cassini spacecraft. The moon, which is too small to be seen, is marked with a red arrow.

Rheology of composite solid propellants during motor casting

NASA Technical Reports Server (NTRS)

Klager, K.; Rogers, C. J.; Smith, P. L.

1978-01-01

Results of casting studies are reviewed so as to define the viscosity criteria insuring the fabrication of defect-free grains. The rheology of uncured propellants is analyzed showing that a realistic assessment of a propellant's flow properties must include measurement of viscosity as a function of shear stress and time after curing agent. Methods for measuring propellant viscosity are discussed, with particular attention given to the Haake-Rotovisko rotational viscometer. The effects of propellant compositional and processing variables on apparent viscosity are examined, as are results relating rheological behavior to grain defect formation during casting.

Solid rocket propellant waste disposal/ingredient recovery study

NASA Technical Reports Server (NTRS)

Mcintosh, M. J.

1976-01-01

A comparison of facility and operating costs of alternate methods shows open burning to be the lowest cost incineration method of waste propellant disposal. The selection, development, and implementation of an acceptable alternate is recommended. The recovery of ingredients from waste propellant has the probability of being able to pay its way, and even show a profit, when large consistent quantities of composite propellant are available. Ingredients recovered from space shuttle waste propellant would be worth over $1.5 million. Open and controlled burning are both energy wasteful.

Performance and acoustic prediction of counterrotating propeller configurations

NASA Technical Reports Server (NTRS)

Denner, B. W.; Korkan, K. D.

1989-01-01

The Davidson (1981) numerical method is used to predict the performance of a counterrotating propeller configuration over a range of different front and back disk rotation speeds with constant-speed propellers; this has yielded such overall performance parameters as integrated thrust, torque, and power, as well as the radial variation of blade torque and thrust. Since the unsteady component of the noise from a counterrotating propeller configuration is minimal in the plane of the propeller disk, this approach is restricted to noise-level predictions for observer locations in this region.

Long-Term Cryogenic Propellant Storage for the TOPS Mission

NASA Technical Reports Server (NTRS)

Mustafi, Shuvo; Francis, John; Li, Xiaoyi; Purves, Lloyd; DeLee, Hudson; Riall, Sara; McGuinness, Dan; Willis, Dewey; Nixon, Conor; Devine Matt;

14 CFR 33.95 - Engine-propeller systems tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine-propeller systems tests. 33.95... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.95 Engine-propeller systems tests. If the engine is designed to operate with a propeller, the following tests must be made with a...

14 CFR 33.95 - Engine-propeller systems tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine-propeller systems tests. 33.95... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.95 Engine-propeller systems tests. If the engine is designed to operate with a propeller, the following tests must be made with a...

14 CFR 33.95 - Engine-propeller systems tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Engine-propeller systems tests. 33.95... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.95 Engine-propeller systems tests. If the engine is designed to operate with a propeller, the following tests must be made with a...

14 CFR 33.95 - Engine-propeller systems tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine-propeller systems tests. 33.95... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.95 Engine-propeller systems tests. If the engine is designed to operate with a propeller, the following tests must be made with a...

14 CFR 33.95 - Engine-propeller systems tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine-propeller systems tests. 33.95... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.95 Engine-propeller systems tests. If the engine is designed to operate with a propeller, the following tests must be made with a...

14 CFR 23.907 - Propeller vibration and fatigue.

Code of Federal Regulations, 2013 CFR

2013-01-01

... based on direct testing of the propeller on the airplane and engine installation for which approval is... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller vibration and fatigue. 23.907... General § 23.907 Propeller vibration and fatigue. This section does not apply to fixed-pitch wood...

14 CFR 23.907 - Propeller vibration and fatigue.

Code of Federal Regulations, 2014 CFR

2014-01-01

... based on direct testing of the propeller on the airplane and engine installation for which approval is... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller vibration and fatigue. 23.907... General § 23.907 Propeller vibration and fatigue. This section does not apply to fixed-pitch wood...

14 CFR 35.3 - Instructions for propeller installation and operation.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Instructions for propeller installation and... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.3 Instructions for propeller.... Those approved instructions must contain: (a) Instructions for installing the propeller, which: (1...

14 CFR 35.3 - Instructions for propeller installation and operation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Instructions for propeller installation and... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.3 Instructions for propeller.... Those approved instructions must contain: (a) Instructions for installing the propeller, which: (1...

14 CFR 35.3 - Instructions for propeller installation and operation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Instructions for propeller installation and... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.3 Instructions for propeller.... Those approved instructions must contain: (a) Instructions for installing the propeller, which: (1...

14 CFR 35.3 - Instructions for propeller installation and operation.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Instructions for propeller installation and... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.3 Instructions for propeller.... Those approved instructions must contain: (a) Instructions for installing the propeller, which: (1...

14 CFR 35.3 - Instructions for propeller installation and operation.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Instructions for propeller installation and... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.3 Instructions for propeller.... Those approved instructions must contain: (a) Instructions for installing the propeller, which: (1...

Characterizing high-energy-density propellants for space propulsion applications

NASA Astrophysics Data System (ADS)

Kokan, Timothy

There exists wide ranging research interest in high-energy-density matter (HEDM) propellants as a potential replacement for existing industry standard fuels for liquid rocket engines. The U.S. Air Force Research Laboratory, the U.S. Army Research Lab, the NASA Marshall Space Flight Center, and the NASA Glenn Research Center each either recently concluded or currently has ongoing programs in the synthesis and development of these potential new propellants. In order to perform conceptual designs using these new propellants, most conceptual rocket engine powerhead design tools (e.g. NPSS, ROCETS, and REDTOP-2) require several thermophysical properties of a given propellant over a wide range of temperature and pressure. These properties include enthalpy, entropy, density, viscosity, and thermal conductivity. Very little thermophysical property data exists for most of these potential new HEDM propellants. Experimental testing of these properties is both expensive and time consuming and is impractical in a conceptual vehicle design environment. A new technique for determining these thermophysical properties of potential new rocket engine propellants is presented. The technique uses a combination of three different computational methods to determine these properties. Quantum mechanics and molecular dynamics are used to model new propellants at a molecular level in order to calculate density, enthalpy, and entropy. Additivity methods are used to calculate the kinematic viscosity and thermal conductivity of new propellants. This new technique is validated via a series of verification experiments of HEDM compounds. Results are provided for two HEDM propellants: quadricyclane and 2-azido-N,N-dimethylethanamine (DMAZ). In each case, the new technique does a better job than the best current computational methods at accurately matching the experimental data of the HEDM compounds of interest. A case study is provided to help quantify the vehicle level impacts of using HEDM

Performance of a capillary propellant management device with hydrazine

NASA Technical Reports Server (NTRS)

Tegart, J. R.

1979-01-01

The propellant management device that was successfully used in the Viking Orbiter spacecraft was selected for the main propulsion system of the Teleoperator Retrieval System (TRS). Due to differences in the missions and different propellants, the operation of this sheet metal vane device required reverification for the TRS application. An analytical investigation was performed considering the adverse acceleration environment and the high contract angle of the hydrazine propellant. Drop tower tests demonstrated that the device would provide propellant acquisition while the TRS was docked with Skylab, but its operation would have to be supplemented through propellant settling when free-flying.

Investigations Into Tank Venting for Propellant Resupply

NASA Technical Reports Server (NTRS)

Hearn, H. C.; Harrison, Robert A. (Technical Monitor)

2002-01-01

Models and simulations have been developed and applied to the evaluation of propellant tank ullage venting, which is integral to one approach for propellant resupply. The analytical effort was instrumental in identifying issues associated with resupply objectives, and it was used to help develop an operational procedure to accomplish the desired propellant transfer for a particular storable bipropellant system. Work on the project was not completed, and several topics have been identified as requiring further study; these include the potential for liquid entrainment during the low-g and thermal/freezing effects in the vent line and orifice. Verification of the feasibility of this propellant venting and resupply approach still requires additional analyses as well as testing to investigate the fluid and thermodynamic phenomena involved.

Mars Propellant Liquefaction Modeling in Thermal Desktop

NASA Technical Reports Server (NTRS)

Desai, Pooja; Hauser, Dan; Sutherlin, Steven

2017-01-01

NASAs current Mars architectures are assuming the production and storage of 23 tons of liquid oxygen on the surface of Mars over a duration of 500+ days. In order to do this in a mass efficient manner, an energy efficient refrigeration system will be required. Based on previous analysis NASA has decided to do all liquefaction in the propulsion vehicle storage tanks. In order to allow for transient Martian environmental effects, a propellant liquefaction and storage system for a Mars Ascent Vehicle (MAV) was modeled using Thermal Desktop. The model consisted of a propellant tank containing a broad area cooling loop heat exchanger integrated with a reverse turbo Brayton cryocooler. Cryocooler sizing and performance modeling was conducted using MAV diurnal heat loads and radiator rejection temperatures predicted from a previous thermal model of the MAV. A system was also sized and modeled using an alternative heat rejection system that relies on a forced convection heat exchanger. Cryocooler mass, input power, and heat rejection for both systems were estimated and compared against sizing based on non-transient sizing estimates.

An assessment of propeller aircraft noise reduction technology

NASA Technical Reports Server (NTRS)

Metzger, F. Bruce

1995-01-01

This report is a review of the literature regarding propeller airplane far-field noise reduction. Near-field and cabin noise reduction are not specifically addressed. However, some of the approaches used to reduce far-field noise produce beneficial effects in the near-field and in the cabin. The emphasis is on propeller noise reduction but engine exhaust noise reduction by muffling is also addressed since the engine noise becomes a significant part of the aircraft noise signature when propeller noise is reduced. It is concluded that there is a substantial body of information available that can be used as the basis to reduce propeller airplane noise. The reason that this information is not often used in airplane design is the associated weight, cost, and performance penalties. It is recommended that the highest priority be given to research for reducing the penalties associated with lower operating RPM and propeller diameter while increasing the number of blades. Research to reduce engine noise and explore innovative propeller concepts is also recommended.

Conceptual design of a lunar oxygen pilot plant Lunar Base Systems Study (LBSS) task 4.2

NASA Technical Reports Server (NTRS)

1988-01-01

The primary objective was to develop conceptual designs of two pilot plants to produce oxygen from lunar materials. A lunar pilot plant will be used to generate engineering data necessary to support an optimum design of a larger scale production plant. Lunar oxygen would be of primary value as spacecraft propellant oxidizer. In addition, lunar oxygen would be useful for servicing nonregenerative fuel cell power systems, providing requirements for life support, and to make up oxygen losses from leakage and airlock cycling. Thirteen different lunar oxygen production methods are described. Hydrogen reduction of ilmenite and extraction of solar-wind hydrogen from bulk lunar soil were selected for conceptual design studies. Trades and sensitivity analyses were performed with these models.

Electromagnetic Pumps for Conductive-Propellant Feed Systems

NASA Technical Reports Server (NTRS)

Markusic, Thomas E.; Polzin, Kurt A.; Dehoyos, Amado

2005-01-01

Prototype electromagnetic pumps for use with lithium and bismuth propellants were constructed and tested. Such pumps may be used to pressurize future electric propulsion liquid metal feed systems, with the primary advantages being the compactness and simplicity versus alternative pressurization technologies. Design details for two different pumps are described: the first was designed to withstand (highly corrosive) lithium propellant, and t he second was designed to tolerate the high temperature required to pump liquid bismuth. Both qualitative and quantitative test results are presented. Open-loop tests demonstrated the capability of each device to electromagnetically pump its design propellant (lithium or bismuth). A second set of tests accurately quantified the pump pressure developed as a function of current. These experiments, which utilized a more easily handled material (gallium), demonstrated continuously-adjustable pump pressure levels ranging from 0-100 Torr for corresponding input current levels of 0-75 A. While the analysis and testing in this study specifically targeted lithium and bismuth propellants, the underlying design principles should be useful in implementing liquid metal pumps in any conductive-propellant feed system.

Implementation Options for the PROPEL Electrodynamic Tether Demonstration Mission

NASA Technical Reports Server (NTRS)

Bilen, Sven G.; Johnson, Les; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael P.; Stone, Nobie H.

2014-01-01

The PROPEL flight mission concept will demonstrate the safe use of an electrodynamic tether for generating thrust. PROPEL is being designed to be a versatile electrodynamic-tether system for multiple end users and to be flexible with respect to platform. As such, several implementation options are being explored, including a comprehensive mission design for PROPEL with a mission duration of six months; a space demonstration mission concept design with configuration of a pair of tethered satellites, one of which is the Japanese H-II Transfer Vehicle; and an ESPA-based system. We report here on these possible implementation options for PROPEL. electrodynamic tether; PROPEL demonstration mission; propellantless propulsion

Water-propellant resistojets for man-tended platforms

NASA Technical Reports Server (NTRS)

Louviere, Allen J.; Jones, Robert E.; Morren, W. Earl; Sovey, James S.

1987-01-01

The selection of a propulsion system for a man-tended platform has been influenced by the planned use of resistojets for drag make-up on the manned space station. For that application a resistojet has been designed that is capable of operation with a wide variety of propellants, including water. The reasons for the selection of water as the propellant and the performance of water as a propellant are discussed. The man-tended platform and its mission requirements are described.

Entropy production and optimization of geothermal power plants

NASA Astrophysics Data System (ADS)

Michaelides, Efstathios E.

2012-09-01

Geothermal power plants are currently producing reliable and low-cost, base load electricity. Three basic types of geothermal power plants are currently in operation: single-flashing, dual-flashing, and binary power plants. Typically, the single-flashing and dual-flashing geothermal power plants utilize geothermal water (brine) at temperatures in the range of 550-430 K. Binary units utilize geothermal resources at lower temperatures, typically 450-380 K. The entropy production in the various components of the three types of geothermal power plants determines the efficiency of the plants. It is axiomatic that a lower entropy production would improve significantly the energy utilization factor of the corresponding power plant. For this reason, the entropy production in the major components of the three types of geothermal power plants has been calculated. It was observed that binary power plants generate the lowest amount of entropy and, thus, convert the highest rate of geothermal energy into mechanical energy. The single-flashing units generate the highest amount of entropy, primarily because they re-inject fluid at relatively high temperature. The calculations for entropy production provide information on the equipment where the highest irreversibilities occur, and may be used to optimize the design of geothermal processes in future geothermal power plants and thermal cycles used for the harnessing of geothermal energy.

Propellant Technologies: A Persuasive Wave of Future Propulsion Benefits