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Sample records for beta propeller wdr72

  1. Mutations in the beta propeller WDR72 cause autosomal-recessive hypomaturation amelogenesis imperfecta.

    Science.gov (United States)

    El-Sayed, Walid; Parry, David A; Shore, Roger C; Ahmed, Mushtaq; Jafri, Hussain; Rashid, Yasmin; Al-Bahlani, Suhaila; Al Harasi, Sharifa; Kirkham, Jennifer; Inglehearn, Chris F; Mighell, Alan J

    2009-11-01

    Healthy dental enamel is the hardest and most highly mineralized human tissue. Though acellular, nonvital, and without capacity for turnover or repair, it can nevertheless last a lifetime. Amelogenesis imperfecta (AI) is a collective term for failure of normal enamel development, covering diverse clinical phenotypes that typically show Mendelian inheritance patterns. One subset, known as hypomaturation AI, is characterised by near-normal volumes of organic enamel matrix but with weak, creamy-brown opaque enamel that fails prematurely after tooth eruption. Mutations in genes critical to enamel matrix formation have been documented, but current understanding of other key events in enamel biomineralization is limited. We investigated autosomal-recessive hypomaturation AI in a consanguineous Pakistani family. A whole-genome SNP autozygosity screen identified a locus on chromosome 15q21.3. Sequencing candidate genes revealed a point mutation in the poorly characterized WDR72 gene. Screening of WDR72 in a panel of nine additional hypomaturation AI families revealed the same mutation in a second, apparently unrelated, Pakistani family and two further nonsense mutations in Omani families. Immunohistochemistry confirmed intracellular localization in maturation-stage ameloblasts. WDR72 function is unknown, but as a putative beta propeller is expected to be a scaffold for protein-protein interactions. The nearest homolog, WDR7, is involved in vesicle mobilization and Ca2+-dependent exocytosis at synapses. Vesicle trafficking is important in maturation-stage ameloblasts with respect to secretion into immature enamel and removal of cleaved enamel matrix proteins via endocytosis. This raises the intriguing possibility that WDR72 is critical to ameloblast vesicle turnover during enamel maturation.

  2. Spatiotemporal expression profile of a putative β propeller WDR72 in laying hens.

    Science.gov (United States)

    Liu, Zhangguo; Li, Bingyi

    2013-09-01

    The purpose of this study is to characterize the expression profile of a novel gene WDR72 in laying hens. Sixty-week old Hy-line Brown layers with similar laying sequence, egg weight, and shell strength, were selected and divided into 5 groups. The oviduct segments, such as magnum, white isthmus, and uterus, were sampled from each group of hens which were killed at 3 h post-oviposition (3 h P.O.), 4.15-4.5 h P.O., 8.5-9 h P.O., 12 h P.O. and 18 h P.O., respectively. To the 8.5-9 h P.O. hens, additional organs were also sampled besides oviduct tissues. Moreover, another group of hens with weak shell strength were selected and their oviduct segments were sampled at 12 h P.O. Then the expression profile of WDR72 was analyzed using real-time quantitative RT-PCR. The results showed as follows. (1) WDR72 transcripts specifically distributed in parts of organs investigated. At 8.5-9 h P.O., WDR72 appeared to be much more abundantly expressed in hens' oviduct sections, then followed in turn by brain, kidney, lung, glandular stomach and spleen. However, there were almost no WDR72 transcripts expressed in pectoral muscle, liver, heart and jejunum. (2) During the process of an "egg" passing through an oviduct, the expression of WDR72 in the magnum was greatly superior to that in the other two oviduct segments at 3 h P.O., 8.5-9 h P.O., and 12 h P.O.; while it was white isthmus in which WDR72 transcript levels were the highest at 4.15-4.5 h P.O. and 18 h P.O. (3) To any oviduct segment, not only uterus but also magnum and white isthmus, the expression of WDR72 in which was significantly up-regulated at the stages of active calcification. (4) WDR72 transcript levels in any oviduct segments of strong-shell hens were significantly higher than that of weak-shell layers (P hens has been characterized, which would facilitate to further probe into its functions.

  3. Identification of the first multi-exonic WDR72 deletion in isolated amelogenesis imperfecta, and generation of a WDR72-specific copy number screening tool.

    Science.gov (United States)

    Hentschel, Julia; Tatun, Dana; Parkhomchuk, Dmitri; Kurth, Ingo; Schimmel, Bettina; Heinrich-Weltzien, Roswitha; Bertzbach, Sabine; Peters, Hartmut; Beetz, Christian

    2016-09-15

    Amelogenesis imperfecta (AI) is a clinically and genetically heterogeneous disorder of tooth development which is due to aberrant deposition or composition of enamel. Both syndromic and isolated forms exist; they may be inherited in an X-linked, autosomal recessive, or autosomal dominant manner. WDR72 is one of ten currently known genes for recessive isolated AI; nine WDR72 mutations affecting single nucleotides have been described to date. Based on whole exome sequencing in a large consanguineous AI pedigree, we obtained evidence for presence of a multi-exonic WDR72 deletion. A home-made multiplex ligation-dependent probe amplification assay was used to confirm the aberration, to narrow its extent, and to identify heterozygous carriers. Our study extends the mutational spectrum for WDR72 to include large deletions, and supports a relevance of the previously proposed loss-of-function mechanism. It also introduces an easy-to-use and highly sensitive tool for detecting WDR72 copy number alterations.

  4. Propellants

    Directory of Open Access Journals (Sweden)

    Lt. Col. B. N Mitra

    1952-01-01

    Full Text Available There is little doubt that explosives had their origin in warfare. In the armed conflict between groups of individuals or of states, where each sought and still seeks to impose its will upon the other by force, it was inevitable that arms should grow and flourish. The sling, the bow and arrow, the sword and firearm typify evolution in warfare weapons. Bs a means of propelling missiles, the gun and gun powder were thought of. The history of explosives, therefore, may be said to begin with black powder.

  5. The diversity and abundance of phytase genes (beta-propeller phytases) in bacterial communities of the maize rhizosphere

    NARCIS (Netherlands)

    Cotta, S.R.; Cavalcante Franco Dias, A.; Seldin, L.; Andreote, F. D.; van Elsas, J. D.

    2016-01-01

    The ecology of microbial communities associated with organic phosphorus (P) mineralization in soils is still understudied. Here, we assessed the abundance and diversity of bacteria harbouring genes encoding beta-propeller phytases (BPP) in the rhizosphere of traditional and transgenic maize cultivat

  6. Optimization of five environmental factors to increase beta-propeller phytase production in Pichia pastoris and impact on the physiological response of the host.

    Science.gov (United States)

    Viader-Salvadó, José M; Castillo-Galván, Miguel; Fuentes-Garibay, José A; Iracheta-Cárdenas, María M; Guerrero-Olazarán, Martha

    2013-01-01

    Recently, we engineered Pichia pastoris Mut(s) strains to produce several beta-propeller phytases, one from Bacillus subtilis and the others designed by a structure-guided consensus approach. Furthermore, we demonstrated the ability of P. pastoris to produce and secrete these phytases in an active form in shake-flask cultures. In the present work, we used a design of experiments strategy (Simplex optimization method) to optimize five environmental factors that define the culture conditions in the induction step to increase beta-propeller phytase production in P. pastoris bioreactor cultures. With the optimization process, up to 347,682 U (82,814 U/L or 6.4 g/L culture medium) of phytase at 68 h of induction was achieved. In addition, the impact of the optimization process on the physiological response of the host was evaluated. The results indicate that the increase in extracellular phytase production through the optimization process was correlated with an increase in metabolic activity of P. pastoris, shown by an increase in oxygen demand and methanol consumption, that increase the specific growth rate. The increase in extracellular phytase production also occurred with a decrease in extracellular protease activity. Moreover, the optimized culture conditions increased the recombinant protein secretion by up to 88%, along with the extracellular phytase production efficiency per cell.

  7. Solid propellants.

    Science.gov (United States)

    Marsh, H. E., Jr.; Hutchison, J. J.

    1972-01-01

    The basic principles underlying propulsion by rocket motor are examined together with the configuration of a solid propellant motor. Solid propellants and their preparation are discussed, giving attention to homogeneous propellants, composite propellants, energetic considerations in choosing a solid propellant, the processing of composite propellants, and some examples of new developments. The performance of solid propellants is investigated, taking into account characteristics velocity, the specific impulse, and performance calculations. Aspects of propellant development considered include nonperformance requirements for solid propellants, the approach to development, propellant mechanical properties, and future trends.

  8. Mobius propeller

    Directory of Open Access Journals (Sweden)

    Leonid I. Gretchihin

    2014-04-01

    Full Text Available The article gives a detailed molecular-kinetic theory of the Mobius propeller functioning and shows the implementation of its computer modelling in different exploitation conditions. The mechanisation of the Mobius propeller can be carried out in such a way that, under certain conditions, it enables using this type of propellers as a heat pump. The developed theory of the Mobius propeller functioning has been experimentally verified in laboratory conditions.

  9. Novel sequences propel familiar folds.

    Science.gov (United States)

    Jawad, Zahra; Paoli, Massimo

    2002-04-01

    Recent structure determinations have made new additions to a set of strikingly different sequences that give rise to the same topology. Proteins with a beta propeller fold are characterized by extreme sequence diversity despite the similarity in their three-dimensional structures. Several fold predictions, based in part on sequence repeats thought to match modular beta sheets, have been proved correct.

  10. Tip-modified Propellers

    DEFF Research Database (Denmark)

    Andersen, Poul

    1999-01-01

    The paper deals with tip-modified propellers and the methods which, over a period of two decades, have been applied to develop such propellers. The development is driven by the urge to increase the efficiency of propellers and can be seen as analogous to fitting end plates and winglets to aircraft...... wings. The literature on four different designs is reviewed: the end-plate propeller; the two-sided, shifted end-plate propeller; the tip-fin propeller; and the bladelet propeller. The conclusion is that it is indeed possible to design tip-modified propellers that, relative to an optimum conventional...

  11. Solid propellant rocket motor

    Science.gov (United States)

    Dowler, W. L.; Shafer, J. I.; Behm, J. W.; Strand, L. D. (Inventor)

    1973-01-01

    The characteristics of a solid propellant rocket engine with a controlled rate of thrust buildup to a desired thrust level are discussed. The engine uses a regressive burning controlled flow solid propellant igniter and a progressive burning main solid propellant charge. The igniter is capable of operating in a vacuum and sustains the burning of the propellant below its normal combustion limit until the burning propellant surface and combustion chamber pressure have increased sufficiently to provide a stable chamber pressure.

  12. Aircraft propeller control

    Science.gov (United States)

    Day, Stanley G. (Inventor)

    1990-01-01

    In the invention, the speeds of both propellers in a counterrotating aircraft propeller pair are measured. Each speed is compared, using a feedback loop, with a demanded speed and, if actual speed does not equal demanded speed for either propeller, pitch of the proper propeller is changed in order to attain the demanded speed. A proportional/integral controller is used in the feedback loop. Further, phase of the propellers is measured and, if the phase does not equal a demanded phase, the speed of one propeller is changed, by changing pitch, until the proper phase is attained.

  13. Solid propellant motor

    Science.gov (United States)

    Shafer, J. I.; Marsh, H. E., Jr. (Inventor)

    1978-01-01

    A case bonded end burning solid propellant rocket motor is described. A propellant with sufficiently low modulus to avoid chamber buckling on cooling from cure and sufficiently high elongation to sustain the stresses induced without cracking is used. The propellant is zone cured within the motor case at high pressures equal to or approaching the pressure at which the motor will operate during combustion. A solid propellant motor with a burning time long enough that its spacecraft would be limited to a maximum acceleration of less than 1 g is provided by one version of the case bonded end burning solid propellant motor of the invention.

  14. New Propellant Formulation Development

    Science.gov (United States)

    2013-01-30

    initiators, JA2 19-Perf Hex propellants and Hagedorn-Plastic manufactured Nitrocellulose with Alkohol - German manufacturer. STAR-ATO goal is to develop... propellants in the U.S. Army’s small, medium and large caliber munitions are all nitrocellulose -based. As the Army drives continuous improvement in both...understanding the influence of nitrocellulose properties on propellant performance. Projectiles are getting heavier, ammunition is being exposed to

  15. 78 FR 41283 - Airworthiness Directives; Dowty Propellers Propellers

    Science.gov (United States)

    2013-07-10

    ... 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... Ganley, Acting Assistant Manager, Engine & Propeller Directorate, Aircraft Certification Service....

  16. Propeller tone bursts

    Science.gov (United States)

    Succi, G. P.; Munro, D. H.; Ingard, K. U.

    1983-01-01

    Intense high frequency (25-38 kHz) tone bursts have been observed in acoustic tests of a scale model of a general aviation propeller. The amplitude of the tone burst is approximately equal to the amplitude of the propeller noise signature. The conditions necessary for the production of these tone bursts are described. The experiments indicate that the origin of these bursts is a periodic flow oscillation on the suction surface of the propeller blade tips which may be due to the interaction between an oscillating shock wave and a laminar boundary layer.

  17. High temperature propellant development

    Science.gov (United States)

    Anderson, F. A.

    1981-01-01

    It is reported that the neccessary technology has been developed and demonstrated for the manufacture of heat-sterilizable solid propellants which meet specific ballistic goals. It is shown that: (1) phosphate doping of ammonium perchlorate significantly enhances the thermal stability of the substance; (2) grinding the ammonium perchlorate to reduce particle size further increases thermal stability; and (3) unsaturated polymers such as the polybutadienes can be successfully used in a heat-sterilizable propellant system. Among the topics considered by the study are oxidizers, dopants, binders, and the thermal cycling of 70 lb and 600 lb propellant grains.

  18. Solid Propellant Flame Spectroscopy

    Science.gov (United States)

    1988-08-01

    400 jm to reach the maximum flame temperature, a distance that can be reduced by replacing the HTPB binder with a polyester or CMDB binder. The...the dark zone for propellants similar to HIX2 is 2-2.5 mm at 1.8 MPa (18 atm, 265 psia) (Ref. 22,187). In contrast, the dark zone for HMX CMDB ...propellants eliminates the dark zone is not surprising, since TMETN is a nitrate ester as was the double-base matrix of Kubota’s HMX CMDB propellant. A

  19. Propeller TAP flap

    DEFF Research Database (Denmark)

    Thomsen, Jørn Bo; Bille, Camilla; Wamberg, Peter;

    2013-01-01

    The aim of this study was to examine if a propeller thoracodorsal artery perforator (TAP) flap can be used for breast reconstruction. Fifteen women were reconstructed using a propeller TAP flap, an implant, and an ADM. Preoperative colour Doppler ultrasonography was used for patient selection...... major complications needing additional surgery. One flap was lost due to a vascular problem. Breast reconstruction can be performed by a propeller TAP flap without cutting the descending branch of the thoracodorsal vessels. However, the authors would recommend that a small cuff of muscle is left around...

  20. Hydrodynamics of Ship Propellers

    DEFF Research Database (Denmark)

    Breslin, John P.; Andersen, Poul

    This book deals with flows over propellers operating behind ships, and the hydrodynamic forces and moments which the propeller generates on the shaft and on the ship hull.The first part of the text is devoted to fundamentals of the flow about hydrofoil sections (with and without cavitation...... arising from operation in non-uniform hull wakes. First, by a number of simplifications, various aspects of the problem are dealt with separately until the full problem of a non-cavitating, wide-bladed propeller in a wake is treated by a new and completely developed theory. Next, the complicated problem...... of an intermittently cavitating propeller in a wake and the pressures and forces it exerts on the shaft and on the ship hull is examined. A final chapter discusses the optimization of efficiency of compound propulsors. The authors have taken care to clearly describe physical concepts and mathematical steps. Appendices...

  1. Propellers in yaw

    Science.gov (United States)

    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.

  2. Self-propelled droplets

    Science.gov (United States)

    Seemann, Ralf; Fleury, Jean-Baptiste; Maass, Corinna C.

    2016-11-01

    Self-propelled droplets are a special kind of self-propelled matter that are easily fabricated by standard microfluidic tools and locomote for a certain time without external sources of energy. The typical driving mechanism is a Marangoni flow due to gradients in the interfacial energy on the droplet interface. In this article we review the hydrodynamic prerequisites for self-sustained locomotion and present two examples to realize those conditions for emulsion droplets, i.e. droplets stabilized by a surfactant layer in a surrounding immiscible liquid. One possibility to achieve self-propelled motion relies on chemical reactions affecting the surface active properties of the surfactant molecules. The other relies on micellar solubilization of the droplet phase into the surrounding liquid phase. Remarkable cruising ranges can be achieved in both cases and the relative insensitivity to their own `exhausts' allows to additionally study collective phenomena.

  3. 78 FR 45052 - Airworthiness Directives; Hartzell Propeller, Inc. Propellers

    Science.gov (United States)

    2013-07-26

    ... Manager, Engine & Propeller Directorate, Aircraft Certification Service. BILLING CODE 4910-13-P ...-07-AD; Amendment 39-17520; AD 2013-15-04] RIN 2120-AA64 Airworthiness Directives; Hartzell Propeller, Inc. Propellers AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY:...

  4. Disposal of Liquid Propellants

    Science.gov (United States)

    1990-03-13

    SYNTHESIS OF LIQUID PROPELLANT Hydroxylammonium nitrate (HAN), prepared via the electrolysis of nitric acid, is commercially available as a high-purity...stack gases, and brine solution from the wet scrubber (82). 5 Applicability/Limitation Most types of solid, liquid, and gaseous organic wastes or

  5. Low toxicity rocket propellants

    NARCIS (Netherlands)

    Wink, J.

    2014-01-01

    Hydrazine (N2H4) and its hypergolic mate nitrogen tetroxide (N2O4) are used on virtually all spacecraft and on a large number of launch vehicles. In recent years however, there has been an effort in identifying and developing alternatives to replace hydrazine as a rocket propellant.

  6. Cryogenic Propellant Storage and Transfer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cryogenic Propellant Storage and Transfer project will demonstrate the capability to safely and efficiently store, transfer and measure cryogenic propellants,...

  7. Modelling of composite propellant properties

    NARCIS (Netherlands)

    Keizers, H.L.J.; Hordijk, A.C.; Vliet, L.D. van; Bouquet, F.

    2000-01-01

    State-of-the-art composite propellants are based on solid particles (AP, Aluminium) in a polymeric HTPB based binder system. The usability of a propellant for a particular application is dependent on a large number of properties. These different properties sometimes result in contradictory requireme

  8. Low acid producing solid propellants

    Science.gov (United States)

    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.

  9. Environmentally compatible solid rocket propellants

    Science.gov (United States)

    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).

  10. Ignition Studies on Aluminised Propellant.

    Directory of Open Access Journals (Sweden)

    K. A. Bhaskaran

    1996-12-01

    Full Text Available An experimental investigation on the ignition of metallised propellants (APIHTPB/AI has been carried out 10 determine the ignition delay, minimum ignition energy and corresponding heat flux,threshold heat flux for ignition and minimum ignition temperature, Ignition experiments were conductedusing a shock tube under convectiveheating conditions similar to those prevailingin a rocket motor. Heat flux at propellant location was measured by thin film heat flux gauge and also calculated from a ribbon thermocouple output under similar test conditions. The igntion delay was measured as the time lag between the arrival of hot gas at the propellant and the light emission due to actual ignition of the propellant. The experimental results indicate that the ignition delay characteristics are independent of pressure. The minimum energy for ignition obtained for the propellant is 1100J/m2 corresponding to the heat flux range of 80·120 WIcm2 for a gas velocity of 110 mls. The threshold heat flux required to ignite the propellant was 40 W/cm2 at a velocity of 110 mls. Heat flux corresponding to minimum ignition energy and the threshold heat flux increase with gas velocity. The threshold ignition temperature of the propellant was found to be 600 ± 20 K.

  11. Magnetic propeller in symbiotic stars

    OpenAIRE

    Panferov, Alexander; Mikolajewski, Maciej

    2000-01-01

    Rapidly spinning magnetic white dwarfs in symbiotic stars may pass through the propeller stage. It is believed that a magnetic propeller acts in two such stars CH Cyg and MWC 560. We review a diversity of manifestations of the propeller there. In these systems in a quiescent state the accretion onto a white dwarf from the strong enough wind of a companion star is suppressed by the magnetic field, and the hot component luminosity is low. Since the gas stored in the envelope eventually settles ...

  12. Design of Propellers for Motorsoarers

    Science.gov (United States)

    Larrabee, E. E.

    1979-01-01

    A method was developed for the design of propellers of minimum induced loss matched to an arbitrary operating point characterized by disc loading (thrust or power), air density, shaft speed, flight speed, and number of blades. A consistent procedure is outlined to predict the performance of these propellers under off design conditions, or to predict the performance of propellers of general geometry. The examples discussed include a man powered airplane, a hang glider with a 7.5 kW (10 hp) 8,000 rpm engine, and an airplane-like motorsoarer.

  13. Liquid Propellants for Advanced Gun Ammunitions

    Directory of Open Access Journals (Sweden)

    K. P. Rao

    1987-01-01

    Full Text Available With constant improvements, the conventional solid propellants for guns have almost reached their limit in performance. Liquid gun propellants are promising new comers capable of surpassing these performance limits and have numerous advantages over solid propellants. A method has been worked out to predict the internal ballistics of a liquid propellant gun and illustrated in a typical application.

  14. 14 CFR 35.22 - Feathering propellers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Feathering propellers. 35.22 Section 35.22 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.22 Feathering propellers. (a) Feathering propellers...

  15. 14 CFR 23.905 - Propellers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propellers. 23.905 Section 23.905 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft...

  16. Beta Thalassemia

    Science.gov (United States)

    Beta thalassemia is found in people of Mediterranean, Middle Eastern, African, South Asian (Indian, Pakistani, etc.), Southeast Asian and Chinese descent. 1 Beta Thalassemia ßß Normal beta globin genes found on chromosomes ...

  17. Propeller aircraft interior noise model

    Science.gov (United States)

    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.

  18. Alternate Propellant Thermal Rocket Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Alternate Propellant Thermal Rocket (APTR) is a novel concept for propulsion of space exploration or orbit transfer vehicles. APTR propulsion is provided by...

  19. DESIGN EKONOMIS UNTUK PROPELLER KAPAL

    Directory of Open Access Journals (Sweden)

    Hartono Hartono

    2012-02-01

    Full Text Available Increase of the price of world oil pushs liner to conduct action is economic from every operational unit in it’sship armada. One other most dominant in usage of fuel is Main engine is working to turn around propeller asship actuator. On that account ship owner wants design propeller which is economic for it’s ship to canreduce usage of fuel of 20% when sailing.

  20. Aircraft Propeller Hub Repair

    Energy Technology Data Exchange (ETDEWEB)

    Muth, Thomas R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peter, William H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-02-13

    The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spray coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.

  1. Aspects of Propeller Developements for a Submarine

    DEFF Research Database (Denmark)

    Andersen, Poul; kappel, Jens Julius; Spangenberg, Eugen

    2009-01-01

    Design and development of propellers for submarines are in some ways different from propellers for surface vessels. The most important demand is low acoustic signature that has priority over propeller efficiency, and the submarine propeller must be optimized with respect to acoustics rather than...... efficiency. Moreover the operating conditions of a submarine propeller are quite different. These aspects are discussed as well as the weighing of the various propeller parameters against the design objectives. The noise generated by the propeller can be characterized as thrust noise due to the inhomogeneous...... wake field of the submarine, trailing-edge noise and noise caused by turbulence in the inflow. The items discussed are demonstrated in a case study where a propeller of the Kappel type was developed. Three stages of the development are presented, including a design of an 8-bladed propeller where...

  2. Erosive burning of solid propellants

    Science.gov (United States)

    King, Merrill K.

    1993-01-01

    Presented here is a review of the experimental and modeling work concerning erosive burning of solid propellants (augmentation of burning rate by flow of product gases across a burning surface). A brief introduction describes the motor design problems caused by this phenomenon, particularly for low port/throat area ratio motors and nozzleless motors. Various experimental techniques for measuring crossflow sensitivity of solid propellant burning rates are described, with the conclusion that accurate simulation of the flow, including upstream flow development, in actual motors is important since the degree of erosive burning depends not only on local mean crossflow velocity and propellant nature, but also upon this upstream development. In the modeling area, a brief review of simplified models and correlating equations is presented, followed by a description of more complex numerical analysis models. Both composite and double-base propellant models are reviewed. A second generation composite model is shown to give good agreement with data obtained in a series of tests in which composite propellant composition and heterogeneity (particle size distribution) were systematically varied. Finally, the use of numerical models for the development of erosive burning correlations is described, and a brief discussion of scaling is presented.

  3. Combustion chemistry of solid propellants

    Science.gov (United States)

    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.

  4. Chaotic dynamics of propeller singing

    Institute of Scientific and Technical Information of China (English)

    YU Dapeng; ZHAO Deyou; WANG Yu

    2012-01-01

    The system of propeller singing is proved for the first time to have the character of chaotic dynamics through the study of the signal time series. The estimation of the topolog- ical dimension, the confirmation of the number of independent variable and the description of the character of attractor trajectory in reconstructed phase space are implemented during the analysis of the system. The result indicates that the system of propeller singing can be recon- structed by the optional delay time tD = 1, the minimal embedding dimension dE = 8, and the reconstructed topological parameter with the fractional correlation dimension D2 = 5.1579 and the positive maximum Lyapunov exponent λtD=0.0771. The results provide a new approach to the further study of the propeller singing phenomenon.

  5. Solid Propellant Grain Structural Integrity Analysis

    Science.gov (United States)

    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.

  6. Solid propellants for rockets. Rocket suishin yaku

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, N. (Defense Agency, Tokyo (Japan). Technical Research and Development Inst.)

    1991-12-31

    Physical and chemical ProPerties and combustion characteristics of propellants differ according to the combination of oxidizers and fuel components. Composite smoke propellant, having crystalline ammonium perchlorate as an oxidizer and hydrocarbon Polymer as a fuel, has higher specific impulse and improved mechanical properties compared to smokeless double base propellant consisting of nitroglycerin and nirocellulose. Double base propellants with low specific impulse are combined with nitramines( RDX or HMX ) to make composite modified double based( CMDB ) propellants, as a result the smokeless property of double base propellant is preserved and the combustion efficiency is increased. With the combination of oxidizing agents and fuels, formation of various high functional propellants has been possible and energetic azide polymers have provided possibilities for fuels of propellants. 3 refs., 6 figs., 3 tabs.

  7. 78 FR 78290 - Airworthiness Directives; Dowty Propellers

    Science.gov (United States)

    2013-12-26

    ..., Boston Aircraft Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park... Aircraft Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Dowty...

  8. Characteristics of Five Propellers in Flight

    Science.gov (United States)

    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)

  9. Mars Integrated Propellant Production System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Integrated Mars In-Situ Propellant Production System (IMISPPS) is an end-to-end system that will produce rocket propellant on Mars from CO2 in the Martian...

  10. 76 FR 7101 - Airworthiness Directives; Hamilton Sundstrand Propellers Model 247F Propellers

    Science.gov (United States)

    2011-02-09

    ... Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park... Propellers Model 247F Propellers AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule... requires removing affected propeller blades from service. This AD was prompted by reports of blades...

  11. Unconventional Propeller Tip Design - Hydrodynamic Study

    OpenAIRE

    Ommundsen, Andreas

    2015-01-01

    Winglets have been successful in the aircraft industry, but have not yet seen widespread use on marine propellers. Three different propellers (one conventional and two equipped with winglets) have been modelled and analysed with the CFD software STAR-CCM+. The winglet propellers achieved up to 40 % greater thrust than the conventional propeller at the operational propulsion point, but the torque increased even more - meaning that the overall open water efficiency was reduced by as much as...

  12. Innovative boron nitride-doped propellants

    Institute of Scientific and Technical Information of China (English)

    Thelma MANNING; Henry GRAU; Paul MATTER; Michael BEACHY; Christopher HOLT; Samuel SOPOK; Richard FIELD; Kenneth KLINGAMAN; Michael FAIR; John BOLOGNINI; Robin CROWNOVER; Carlton P. ADAM; Viral PANCHAL; Eugene ROZUMOV

    2016-01-01

    The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride (BN) is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants (US patent pending 2015-026P). Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower flame temperatures for gun barrels. Further, boron can dope steel, which drastically improves its strength and wear resistance, and can block the formation of softer carbides. A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed. Even dispersion of the nano-particles in a double-base propellant has been demonstrated using a solvent-based processing approach. Stability of a composite propellant with the BN additive was verified. In this paper, results from propellant testing of boron nitride nano-composite propellants are presented, including closed bomb and wear and erosion testing. Detailed characterization of the erosion tester substrates before and after firing was obtained by electron microscopy, inductively coupled plasma and x-ray photoelectron spectroscopy. This promising boron nitride additive shows the ability to improve gun wear and erosion resistance without any destabilizing effects to the propellant. Potential applications could include less erosive propellants in propellant ammunition for large, medium and small diameter fire arms.

  13. 14 CFR 25.925 - Propeller clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 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...

  14. 14 CFR 25.905 - Propellers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propellers. 25.905 Section 25.905 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must...

  15. 14 CFR 35.2 - Propeller configuration.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller configuration. 35.2 Section 35.2 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS General § 35.2 Propeller configuration. The applicant must provide a list of all...

  16. Innovative boron nitride-doped propellants

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2016-04-01

    Full Text Available The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride (BN is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants (US patent pending 2015-026P. Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower flame temperatures for gun barrels. Further, boron can dope steel, which drastically improves its strength and wear resistance, and can block the formation of softer carbides. A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed. Even dispersion of the nano-particles in a double-base propellant has been demonstrated using a solvent-based processing approach. Stability of a composite propellant with the BN additive was verified. In this paper, results from propellant testing of boron nitride nano-composite propellants are presented, including closed bomb and wear and erosion testing. Detailed characterization of the erosion tester substrates before and after firing was obtained by electron microscopy, inductively coupled plasma and x-ray photoelectron spectroscopy. This promising boron nitride additive shows the ability to improve gun wear and erosion resistance without any destabilizing effects to the propellant. Potential applications could include less erosive propellants in propellant ammunition for large, medium and small diameter fire arms.

  17. 14 CFR 25.929 - Propeller deicing.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller deicing. 25.929 Section 25.929... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.929 Propeller deicing. (a) For airplanes... combustible fluid is used for propeller deicing, §§ 25.1181 through 25.1185 and 25.1189 apply....

  18. The propeller and the frog

    CERN Document Server

    Pan, Margaret

    2010-01-01

    "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 Bl\\'eriot in Saturn's A ring, our theory predicts a libration period of ~4 years, similar to the ~3.7 yea...

  19. Plasma ignition of LOVA propellants

    NARCIS (Netherlands)

    Driel, C.A. van; Boluijt, A.G.; Schilt, A.

    2010-01-01

    Ignition experiments were performed using a gun simulator which is equipped with a burst disk. This equipment facilitates the application of propellant loading densities which are comparable to those applied in regular ammunitions. For this study the gun simulator was equipped with a plasma jet igni

  20. Liquid Bismuth Propellant Flow Sensor

    Science.gov (United States)

    Polzin, Kurt A.; Stanojev, B. J.; Korman, V.

    2007-01-01

    Quantifying the propellant mass flow rate in liquid bismuth-fed electric propulsion systems has two challenging facets. First, the flow sensors must be capable of providing a resolvable measurement at propellant mass flow rates on the order of 10 mg/see with and uncertainty of less that 5%. The second challenge has to do with the fact that the materials from which the flow sensors are fabricated must be capable of resisting any of the corrosive effects associated with the high-temperature propellant. The measurement itself is necessary in order to properly assess the performance (thrust efficiency, Isp) of thruster systems in the laboratory environment. The hotspot sensor[I] has been designed to provide the bismuth propellant mass flow rate measurement. In the hotspot sensor, a pulse of thermal energy (derived from a current pulse and associated joule heating) is applied near the inlet of the sensor. The flow is "tagged" with a thermal feature that is convected downstream by the flowing liquid metal. Downstream, a temperature measurement is performed to detect a "ripple" in the local temperature associated with the passing "hotspot" in the propellant. By measuring the time between the upstream generation and downstream detection of the thermal feature, the flow speed can be calculated using a "time of flight" analysis. In addition, the system can be calibrated by measuring the accumulated mass exiting the system as a-function of time and correlating this with the time it takes the hotspot to convect through the sensor. The primary advantage of this technique is that it doesn't depend on an absolute measurement of temperature but, instead, relies on the observation of thermal features. This makes the technique insensitive to other externally generated thermal fluctuations. In this paper, we describe experiments performed using the hotspot flow sensor aimed at quantifying the resolution of the sensor technology. Propellant is expelled onto an electronic scale to

  1. High-Speed Propeller for Aircraft

    Science.gov (United States)

    Sagerser, D. A.; Gatzen, B. S.

    1986-01-01

    Engine efficiency increased. Propeller blades required to be quite thin and highly swept to minimize compressibility losses and propeller noise during high-speed cruise. Use of 8 or 10 blades with highpropeller-power loading allows overall propeller diameter to be kept relatively small. Area-ruled spinner and integrated nacelle shape reduce compressibility losses in propeller hub region. Finally, large modern turboshaft engine and gearbox provide power to advanced propeller. Fuel savings of 30 to 50 percent over present systems anticipated. Propfan system adaptable to number of applications, such as highspeed (subsonic) business and general-aviation aircraft, and military aircraft including V/STOL.

  2. Drag and Torque on Locked Screw Propeller

    Directory of Open Access Journals (Sweden)

    Tomasz Tabaczek

    2014-09-01

    Full Text Available Few data on drag and torque on locked propeller towed in water are available in literature. Those data refer to propellers of specific geometry (number of blades, blade area, pitch and skew of blades. The estimation of drag and torque of an arbitrary propeller considered in analysis of ship resistance or propulsion is laborious. The authors collected and reviewed test data available in the literature. Based on collected data there were developed the empirical formulae for estimation of hydrodynamic drag and torque acting on locked screw propeller. Supplementary CFD computations were carried out in order to prove the applicability of the formulae to modern moderately skewed screw propellers.

  3. Manufacture and deflagration of an atomic hydrogen propellant

    Science.gov (United States)

    Rosen, G.

    1974-01-01

    It is observed that the use of very low temperatures (in the range from 0.1 to 1.5 K) produced by advanced cryogenic apparatus and the use of very strong magnetic fields (in the range from 50 to 100 kG) produced by superconducting magnets can yield a significant improvement in the atomic hydrogen trapping effectiveness of an H2 matrix. The use of a radioactive beta-ray emiter isotope may yield H-H2 propellants (with a specific impulse of about 740 sec) by secondary electron impact dissociations of H2 in an impregnated matrix maintained below 1 K in a strong magnetic field. Another method for manufacturing an H-H2 propellant involves bombardment of supercooled solid H2 with a cyclotron-produced beam of 10-MeV hydrogen atoms. The matrix-isolated atomic hydrogen must be used directly without prior melting as a solid propellant, and an analysis of the steady deflagration is presented.

  4. Processing solid propellants for recycling

    Energy Technology Data Exchange (ETDEWEB)

    Whinnery, L.L.; Griffiths, S.K.; Handrock, J.L.; Lipkin, J.

    1994-05-01

    Rapid evolution in the structure of military forces worldwide is resulting in the retirement of numerous weapon systems. Many of these systems include rocket motors containing highly energetic propellants based on hazardous nitrocellulose/nitroglycerin (NC/NG) mixtures. Even as the surplus quantities of such material increases, however, current disposal methods -- principally open burning and open detonation (OB/OD) -- are coming under close scrutiny from environmental regulators. Environmentally conscious alternatives to disposal of propellant and explosives are thus receiving renewed interest. Recycle and reuse alternatives to OB/OD appear particularly attractive because some of the energetic materials in the inventories of surplus weapon systems represent potentially valuable resources to the commercial explosives and chemical industries. The ability to reclaim such resources is therefore likely to be a key requirement of any successful technology of the future in rocket motor demilitarization. This document consists of view graphs from the poster session.

  5. Multi-propeller drive system

    Science.gov (United States)

    Belenger, Robert V.

    1995-05-01

    A multipropeller drive system having a single input shaft for connection to an engine system, a differential gear assembly for dividing the driving force from the input drive shaft between a pair of output shafts, and a pair of laterally spaced propellers driven by the output shafts of the differential gear assembly is disclosed. The differential gear assembly operates in a manner wherein one output shaft, if required, is permitted to revolve at a different rate than the other output shaft. A pair of brake mechanisms acting on the output shafts of the differential gear assembly enable an operator to control the rotational speed of the respective propellers without modifying the engine speed or transmission settings.

  6. Kinetics Modeling of Hypergolic Propellants

    Science.gov (United States)

    2013-07-01

    reaction OH + NO + M −−→ HONO + M as a function of temperature and pressure in the presence of argon, sf6 , and n2 bath gas . Chemical physics, 171(1-2...understand fundamental processes such as gas phase ignition, vaporization and liquid phase chemistry for characterizing ignition. Such understanding will be...critical for future design efforts targeting rapidly repeatable cyclic ignition of these propellants. Three test cases are considered: gas and liquid

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

    Science.gov (United States)

    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

  8. Design of Multi-Propellant Star Grains for Solid Propellant Rockets

    Directory of Open Access Journals (Sweden)

    S. Krishnan

    1980-01-01

    Full Text Available A new approach to solve the geometry-problem of solid propellant star is presented. The basis of the approach is to take the web-thickness (a ballistic as well as a geometrical property as the characteristic length. The nondimensional characteristic parameters representing diameter, length, slenderness-ratio, and ignitor accommodation of the grain are all identified. Many particular cases of star configurations (from the configurations of single propellant to those of four different propellants can be analysed through the identified characteristic parameters. A better way of representing the single-propellant-star-performance in a design graph is explained. Two types of dual propellant grains are analysed in detail. The first type is characterised by its two distinct stages of burning (initially by single propellant burning and then by dual propellant burning; the second type has the dual propellant burning throughout. Suitability of the identified characteristic parameters to an optimisation study is demonstrated through examples.

  9. High Performance Binder for EMCDB Propellants

    Directory of Open Access Journals (Sweden)

    V. K. Bhat

    1995-01-01

    Full Text Available A novel block polymer has been synthesised from caprolactone using hydroxy terminated polybutadiene as ring opening initiator. Usefulness of this polymer as propellant binder has been studied by generating data on physico-chemical properties of the polymer. The polymer exhibited high miscibility with nitrate ester and high solid loading capability. Preliminary data generated on typical propellant formulation indicated higher performance as compared to composite propellant.

  10. Measuring Combustion Advance in Solid Propellants

    Science.gov (United States)

    Yang, L. C.

    1986-01-01

    Set of gauges on solid-propellant rocket motor with electrically insulating case measures advance of combustion front and local erosion rates of propellant and insulation. Data furnished by gauges aid in motor design, failure analysis, and performance prediction. Technique useful in determining propellant uniformity and electrical properties of exhaust plum. Gauges used both in flight and on ground. Foilgauge technique also useful in basic research on pulsed plasmas or combustion of solids.

  11. Propeller Test Facilities Â

    Data.gov (United States)

    Federal Laboratory Consortium — Description: Three electrically driven whirl test stands are used to determine propeller (or other rotating device) performance at various rotational speeds. These...

  12. High Seed Compressor for Propellant Densification Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Propellant densification systems particularly for H2 require compression systems developing very large amounts of head. Development of this head requires multiple...

  13. FORMULATION AND EVALUATION OF LIQUID PROPELLANT DISPERSIONS.

    Science.gov (United States)

    STRESSES, DECOMPOSITION, PRODUCTION , GAS CHROMATOGRAPHY (U) ALUMINUM, THIXOTROPIC ROCKET PROPELLANTS, HYDRAZINE, BENZENE, AMINES, CARBOXYMETHYLCELLULOSE , ALUMINUM ALLOYS, STAINLESS STEEL, AMMONIA, HYDROGEN, NITROGEN

  14. Cars Spectroscopy of Propellant Flames

    Science.gov (United States)

    1983-11-01

    Harris, K. Aron, and J. Fendell "N2 and 00 Vibrational CARS and H2 Rotational CARS Spectroscopy of CHI/N20 Flames," Proceedings of the Nineteenth...JANNAF Combustion Meeting, CIIA Publication No. 366, 1982, p 123. 21. K. Aron, L. E. Harris, and J. Fendell , "N and CO Vibrational CARS and H2 Rotational...9 6 5 . p 3 8 4 . . . . . 23. J. Fendell , L. E, Harris, and K. Aron, "Theoretical Calculation of 11 CARS S-Branches for Propellant Flames

  15. Cavitation simulation on marine propellers

    DEFF Research Database (Denmark)

    Shin, Keun Woo

    flows on a 2D hydrofoil are compared with the experimental results. In the current implementation, three models with a vapor transport equation show numerical stability and equivalently good accuracy in simulating steady and unsteady sheet cavitation. More validations for cavitating flows on 3D...... hydrofoils and conventional/highly-skewed propellers are performed with one of three cavitation models proven in 2D analysis. 3D cases also show accuracy and robustness of numerical method in simulating steady and unsteady sheet cavitation on complicated geometries. Hydrodynamic characteristics of cavitation...

  16. Method of injecting fluid propellants into a rocket combustion chamber

    Science.gov (United States)

    Schneider, Steven J. (Inventor)

    1991-01-01

    A rocket injector is provided with multiple sets of manifolds for supplying propellants to injector elements. Sensors transmit the temperatures of the propellants to a suitable controller which is operably connected to valves between these manifolds and propellant storage tanks. Additional valves are opened to furnish propellants to more of the manifolds when cryogenic propellant temperatures are sensed. Only a portion of the valves are opened to furnish propellants to some of the manifolds when lower temperatures are sensed.

  17. Effects of propellant composition variables on acceleration-induced burning-rate augmentation of solid propellants

    Science.gov (United States)

    Northam, G. B.

    1972-01-01

    This work was conducted to define further the effects of propellant composition variables on the acceleration-induced burning rate augmentation of solid propellants. The rate augmentation at a given acceleration was found to be a nonlinear inverse function of the reference burning rate and not controlled by binder or catalyst type at a given reference rate. A nonaluminized propellant and a low rate double-base propellant exhibited strong transient rate augmentation due to surface pitting resulting from the retention of hot particles on the propellant surface.

  18. Development of hydrazinium nitroformate based solid propellants

    NARCIS (Netherlands)

    Schöyer, H.F.R.; Schnorhk, A.J.; Korting, P.A.O.G.; Lit, P.J. van; Mul, J.M.; Gadiot, G.; Meulenbrugge, J.J.

    1995-01-01

    The development of new high-performance propellant combinations requires the establishment of safety and handling characteristics and thermodynamic decomposition and explosive properties. This paper addresses the early development phases of a new composite solid propellant based on HNF as oxidizer a

  19. Composite Solid Propellant Predictability and Quality Assurance

    Science.gov (United States)

    Ramohalli, Kumar

    1989-01-01

    Reports are presented at the meeting at the University of Arizona on the study of predictable and reliable solid rocket motors. The following subject areas were covered: present state and trends in the research of solid propellants; the University of Arizona program in solid propellants, particularly in mixing (experimental and analytical results are presented).

  20. Materials characterization of propellants using ultrasonics

    Science.gov (United States)

    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.

  1. 14 CFR 21.129 - Tests: propellers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: propellers. 21.129 Section 21.129 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate Only § 21.129 Tests: propellers....

  2. Calculation of Thermochemical Constants of Propellants

    Directory of Open Access Journals (Sweden)

    K. P. Rao

    1979-01-01

    Full Text Available A method for calculation of thermo chemical constants and products of explosion of propellants from the knowledge of molecular formulae and heats of formation of the ingredients is given. A computer programme in AUTOMATH-400 has been established for the method. The results of application of the method for a number of propellants are given.

  3. Green plasticizers for multibase gun propellants (Lecture)

    NARCIS (Netherlands)

    Schoolderman, C.; Driel, C.A. van; Zebregs, M.

    2007-01-01

    TNO Defence, Security and Safety has a long history of research on gun propellants. Areas investigated are formulating (new ingredients, optimization), manufacturing, charge design and lifetime assessment [1,2,3,4,5]. In conventional propellants inert plasticizers are used to alter performance, proc

  4. Storage of solid propellants in space

    Science.gov (United States)

    Udlock, D. E.

    1977-01-01

    A test program is described which determines the extent of physical property changes that result from extended space exposure. Primary emphasis was placed on determining the effects of space vacuum. Solid propellants were stored and their physical properties tested in a vacuum and in a dry environment. The storage caused significantly greater increases in the propellants' modulus and maximum tensile strength than occurred in parallel ambient stored samples. The data indicate that the loss of trace amounts of residual moisture from cured propellant is the apparent cause of the observed propellant property changes. Therefore, initial screening tests were carried out under dry storage conditions. Upon completion of the dry storage tests, appropriate propellant samples are exposed to an actual space environment using the Long Duration Exposure Facility (LDEF).

  5. Burning rate characteristics of CMDB propellants

    Energy Technology Data Exchange (ETDEWEB)

    Swaminathan, V.; Soosai Marian, M. (Vikram Sarabhai Space Centre, Trivandrum (India). Propellant Engineering Div.)

    1979-10-01

    The object of this paper is to obtain expressions for the burning rate pressure exponent and the temperature sensitivity of AP-based and HMX-based CMDB propellants in terms of the respective physical constants on the basis of a recently developed model of combustion for CMDB propellants and to examine the effects, if any, on these two parameters, of the changes in propellant composition, AP particle size and pressure. Computer programs were developed for this purpose and the results obtained for typical sets of input data presented in the paper. While the results of the calculation indicate a markedly strong dependence of the pressure exponent and the temperature sensitivity on pressure and composition for both AP-based and HMX-based CMDB propellants, the parameters are characterized by far lesser dependence on AP particle size for the AP-based propellant.

  6. MAST Propellant and Delivery System Design Methods

    Science.gov (United States)

    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.

  7. Runtime and Pressurization Analyses of Propellant Tanks

    Science.gov (United States)

    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

  8. Propellant isolation shutoff valve program

    Science.gov (United States)

    Merritt, F. L.

    1973-01-01

    An analysis and design effort directed to advancing the state-of-the-art of space storable isolation valves for control of flow of the propellants liquid fluorine/hydrazine and Flox/monomethylhydrazine is discussed. Emphasis is on achieving zero liquid leakage and capability of withstanding missions up to 10 years in interplanetary space. Included is a study of all-metal poppet sealing theory, an evaluation of candidate seal configurations, a valve actuator trade-off study and design description of a pneumo-thermally actuated soft metal poppet seal valve. The concepts and analysis leading to the soft seal approach are documented. A theoretical evaluation of seal leakage versus seal loading, related finishes and yield strengths of various materials is provided. Application of a confined soft aluminum seal loaded to 2 to 3 times yield strength is recommended. Use of either an electro-mechanical or pneumatic actuator appears to be feasible for the application.

  9. New Delivery Systems and Propellants

    Directory of Open Access Journals (Sweden)

    Myrna Dolovich

    1999-01-01

    Full Text Available The removal of chlorofluorocarbon (CFC propellants from industrial and household products has been agreed to by over 165 countires of which more than 135 are developing countries. The timetable for this process is outlined in the Montreal Protocol on Substances that Deplete the Ozone Layer document and in several subsequent amendments. Pressured metered dose inhalers (pMDIs for medical use have been granted temporary exemptions until replacement formulations, providing the same medication via the same route, and with the same efficacy and safety profiles, are approved for human use. Hydrofluoroalkanes (HFAs are the alternative propellants for CFCs-12 and -114. Their potential for damage to the ozone layer is nonexistent, and while they are greenhouse gases, their global warming potential is a fraction (one-tenth of that of CFCs. Replacement formulations for almost all inhalant respiratory medications have been or are being produced and tested; in Canada, it is anticipated that the transition to these HFA or CFC-free pMDIs will be complete by the year 2005. Initially, an HFA pMDI was to be equivalent to the CFC pMDI being replaced, in terms of aerosol properties and effective clinical dose. However, this will not necessarily be the situation, particularly for some corticosteroid products. Currently, only one CFC-free formulation is available in Canada – Airomir, a HFA salbutamol pMDI. This paper discusses the in vitro aerosol characteristics, in vivo deposition and clinical data for several HFA pMDIs for which there are data available in the literature. Alternative delivery systems to the pMDI, namely, dry powder inhalers and nebulizers, are briefly reviewed.

  10. Particle behavior in solid propellant rockets

    Science.gov (United States)

    Netzer, D. W.; Diloreto, V. D.; Dubrov, E.

    1980-01-01

    The use of holography, high speed motion pictures, light scattering measurements, and post-fire particle collection/scanning electron microscopic examination to study the combustion of composite solid propellants is discussed. The relative advantages and disadvantages of the different experimental techniques for obtaining two-phase flow characteristics within the combustion environment of a solid propellant grain are evaluated. Combustion bomb studies using high speed motion pictures and post-fire residue analysis were completed for six low metal content propellants. Resolution capabilities and the relationships between post-fire residue and motion picture data are determined. Initial testing using a holocamera together with a 2D windowed motor is also described.

  11. Particle size reduction of propellants by cryocycling

    Energy Technology Data Exchange (ETDEWEB)

    Whinnery, L.; Griffiths, S.; Lipkin, J. [and others

    1995-05-01

    Repeated exposure of a propellant to liquid nitrogen causes thermal stress gradients within the material resulting in cracking and particle size reduction. This process is termed cryocycling. The authors conducted a feasibility study, combining experiments on both inert and live propellants with three modeling approaches. These models provided optimized cycle times, predicted ultimate particle size, and allowed crack behavior to be explored. Process safety evaluations conducted separately indicated that cryocycling does not increase the sensitivity of the propellants examined. The results of this study suggest that cryocycling is a promising technology for the demilitarization of tactical rocket motors.

  12. 14 CFR 35.5 - Propeller ratings and operating limitations.

    Science.gov (United States)

    2010-01-01

    ... 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 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller ratings and operating...

  13. 46 CFR 50.05-20 - Steam-propelled motorboats.

    Science.gov (United States)

    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...

  14. 46 CFR 171.050 - Intact stability requirements for a mechanically propelled or a nonself-propelled vessel.

    Science.gov (United States)

    2010-10-01

    ... propelled or a nonself-propelled vessel. 171.050 Section 171.050 Shipping COAST GUARD, DEPARTMENT OF... PASSENGERS Large Vessels § 171.050 Intact stability requirements for a mechanically propelled or a nonself-propelled vessel. Each vessel must be shown by design calculations to have a metacentric height (GM) in...

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

    Science.gov (United States)

    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.

  16. DDT Behavior of Porous Propellant Models and Porous Samples of Commercial Propellants,

    Science.gov (United States)

    1980-03-13

    base ( CMDB ) propellant and is also referred to as a cross-linked double base (XLDB) propellant. EXPERIMENTAL INSTRUMENTATION AND PROCEDURES The...binary AP mixtures that might be expected in composite or CMDB propellants. Each of the three charges was 80% AP. AP/wax was fired at 56.6 and 67.0% TMD...either a CMDB or a composite propellant to which RDX has been added. The Ak content was 9 or 20% and each composition was tested at 70 and 90% TMD; all

  17. Some typical solid propellant rocket motors

    NARCIS (Netherlands)

    Zandbergen, B.T.C.

    2013-01-01

    Typical Solid Propellant Rocket Motors (shortly referred to as Solid Rocket Motors; SRM's) are described with the purpose to form a database, which allows for comparative analysis and applications in practical SRM engineering.

  18. High Speed Compressor for Subcooling Propellants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Propellant densification systems for LH2 require compression systems that develop significant head. In the past this has required multiple stages of compressors...

  19. Energy coefficients for a propeller series

    DEFF Research Database (Denmark)

    Olsen, Anders Smærup

    2004-01-01

    The efficiency for a propeller is calculated by energy coefficients. These coefficients are related to four types of losses, i.e. the axial, the rotational, the frictional, and the finite blade number loss, and one gain, i.e. the axial gain. The energy coefficients are derived by use of the poten......The efficiency for a propeller is calculated by energy coefficients. These coefficients are related to four types of losses, i.e. the axial, the rotational, the frictional, and the finite blade number loss, and one gain, i.e. the axial gain. The energy coefficients are derived by use...... of the potential theory with the propeller modelled as an actuator disk. The efficiency based on the energy coefficients is calculated for a propeller series. The results show a good agreement between the efficiency based on the energy coefficients and the efficiency obtained by a vortex-lattice method....

  20. High Speed Compressor for Subcooling Propellants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The most promising propellant subcooling systems for LH2 require compression systems that involve development of significant head. The inlet pressure for these...

  1. Gelled Propellants for Reduced Temperature Operation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is responsive to NASA 2004 SBIR objectives (under Topic X6.05) seeking gelled propellant formulations "for long-duration missions involving low-power...

  2. Partial Burn Laws in Propellant Erosive Burning

    Directory of Open Access Journals (Sweden)

    S.V. Finjakov

    1999-04-01

    Full Text Available Experimental and computer methods were developed for investigating the combustion phenomena in the propellants which burn in streams of hot gas flowing along the burn surfaces of the propellants. The experimental investigations allowed establishment of different dependencies for erosive burning. Computer solutions of the problem for double-base (DB propellants showed a good agreement with the experimental results. The suggested variant of modified theory considers the change of heat release in solids, the real burn surface roughness, the nonisothermality of boundary layer and the effect of gas mass blow from the propellant burn surface into the gas stream. This modified theory was used for studying burn laws at 30-1000 atm and up to gas stream sound velocities for different DB propellants. It was found that gas stream leads to splitting of the propellant burn laws, m = bp/sup v/. Pressure power (v, in this case depends on gas stream velocity (W, diameter of the propellant tube canal (d and gas stream temperature (T/sub w/. It is because of this that these burn laws were named partial burn laws. They have the form (m = bp/sup w(omega/ w,d,T/sub w/ -const. The dependencies w(omega = f(w,d,T/sub w/ were obtained by the modified theory. It was found that omega values mainly decrease when pressure increases beginning from ~200 to 400 atm and they can decrease up to w(omega = 0,1- 0,3. Similar results can be obtained for composite propellants.

  3. Composite Propellant combustion and Transition to Detonation.

    Science.gov (United States)

    1981-02-01

    I combustion BYU Brigham Young University I CMDB Composite-modified double-base propellant CPIA Chemical Propulsion Information Agency (at Johns...incorporate a model of active binder combustion and apply the model to composite-modified double-base ( CMDB ) propellants. The porous burner apparatus...Hercules composite-modified double-base ( CMDB ) pro- pellants, containing AP or HMX, but not containing aluminum. Qualita- tive effects of composition and

  4. Water Contaminant Mitigation in Ionic Liquid Propellant

    Science.gov (United States)

    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.

  5. 75 FR 7934 - Airworthiness Directives; McCauley Propeller Systems 1A103/TCM Series Propellers

    Science.gov (United States)

    2010-02-23

    ... inspections of steel reinforcement plates and gaskets. This AD results from 16 reports received of propeller..., inspections of steel reinforcement plates and gaskets, removal from service of propellers with cracks that do... not have a significant economic impact, positive or negative, on a substantial number of...

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

    Science.gov (United States)

    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.

  7. In-Space Propellant Production Using Water

    Science.gov (United States)

    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.

  8. Effect of Temperature on Mechanical Properties of Solid Rocket Propellants

    Directory of Open Access Journals (Sweden)

    Himanshu Shekhar

    2011-10-01

    Full Text Available Mechanical properties of solid rocket propellants are dependent on temperature. Any change in temperature brings significant change in the tensile strength, percentage elongation, and elastic modulus of the propellant. Different classes of operational solid rocket propellants namely extruded double-base propellants, composite, extruded composite and nitrarte ester polyester propellants were evaluated at different temperatures in the operating range of the rockets and missiles preferably in the range of –50 oC to +55 oC. It was observed that for each class of propellant, as temperature reduces, propellant becomes hard. This is depicted by increase in elastic modulus and tensile strength of the material. However, trend of percentage elongation is not very uniform. Extruded double-base propellants show less percentage elongation (around 1 per cent at reduced temperature (–50 oC probably due to brittleness. So is the trend with case-bonded composite propellants. However, reverse trend is exhibited by cartridge-loaded composite propellants and nitrate ester polyester propellants. Such propellants show higher percentage elongation (6 per cent for CLCP and 35 per cent for NEPE at reduced temperature (–50 oC. This makes such propellants tough and more area under stress-strain curve at reduced temperature is observed.Defence Science Journal, 2011, 61(6, pp.529-533, DOI:http://dx.doi.org/10.14429/dsj.61.774

  9. Development of a solvent processed insensitive propellant

    Science.gov (United States)

    Trask, R.; Costa, E.; Beardell, A. J.

    1980-01-01

    Two types of low vulnerability propellants are studied which are distinguished by whether the binder is a rubber, such as polyurethane or CTBN, or a plasticizable polymer such as ethyl cellulose or cellulose acetate. The former propellants are made by a partial cure extrusion process while the latter are made by the conventional solvent process. Emphasis is given to a cellulose binder (plasticizer) RDX composition. The type of binder used, the particle size of the RDX and the presence of small quantities of nitrocellulose in the solvent processed compositions have important influences on the mechanical and combustion characteristics of the propellant. The low temperature combustion is of particular concern because of potential breakup of the grains that can lead to instability.

  10. Electrostatic Discharge testing of propellants and primers

    Energy Technology Data Exchange (ETDEWEB)

    Berry, R.B.

    1994-02-01

    This report presents the results of testing of selected propellants and primers to Electrostatic Discharge (ESD) characteristic of the human body. It describes the tests and the fixturing built to accommodate loose material (propellants) and the packed energetic material of the primer. The results indicate that all powders passed and some primers, especially the electric primers, failed to pass established requirements which delineate insensitive energetic components. This report details the testing of components and materials to four ESD environments (Standard ESD, Severe ESD, Modified Standard ESD, and Modified Severe ESD). The purpose of this study was to collect data based on the customer requirements as defined in the Sandia Environmental Safety & Health (ES&H) Manual, Chapter 9, and to define static sensitive and insensitive propellants and primers.

  11. Propellant Grade Hydrazine in Mono/Bi-propellant Thrusters: Preparation and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    S. Krishnamachary

    2015-03-01

    Full Text Available Propellant grade hydrazine was prepared with 64 per cent yield and 95.5 per cent purity. Purity of the propellant grade hydrazine was determined using wet chemical, gas chromatographic (GC and eudiometric methods. It was observed that the compositions containing blends of hydrazine-methyl alcohol-ammonium nitrate and hydrazine-methyl alcohol-ammonium perchlorate were not found to be frozen even after cooling to -65 °C for 30 minutes. Mono and bi-propellant thrusters were designed and developed to demonstrate the performance of prepared propellant grade hydrazine as a promising rocket fuel. Five static tests with 22 N thruster and one static test with 1 N thruster were performed successfully in mono-propellant mode. The hurdles of chamber pressure oscillations were overcome by compact packing of the catalyst. The desired decomposition and chamber pressure were achieved. One static test was performed successfully with 60 N bi-propellant thruster. The desired chamber pressure and thrust were achieved. The combustion was smooth and C* achieved was higher than that of UH-25, N2O4 combination. The performance of prepared propellant grade hydrazine shows it as a promising rocket fuels.Defence Science Journal, Vol. 65, No. 1, January 2015, pp.31-38, DOI:http://dx.doi.org/10.14429/dsj.65.7986

  12. Sensitivity of solid rocket propellants for card gap test

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Eishu; Oyumi, Yoshio (Japan Defense Agency, Tokyo (Japan). Technical Research and Development Inst.)

    1999-05-01

    Card gap test, which is standardized in Japan Explosives Society, was modified in order to apply it to solid rocket propellants and carried out to evaluate sensitivities against shock stimuli. Solid propellants tested here were mainly azide polymer composite propellants, which contained ammonium nitrate (AN) as a main oxidizer. Double base propellant, composed nitroglycerin and nitrocellulose (NC), and ammonium perchlorate (AP)-based composite propellants. It is found that the sensitivity was dominated by the oxidizer characteristics. AP- and AN-based propellant had less sensitivity and HMX-based propellant showed higher sensitivity, and the adding of NC and TMETN contributed to worse sensitive for the card gap test. Good relationship was obtained between the card gap sensitivity and the oxygen balance of propellants tested here. (orig.)

  13. Innovative Swirl Injector for LOX and Hydrocarbon Propellants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Gases trapped in the propellant feed lines of space-based rocket engines due to cryogenic propellant boil-off or pressurant ingestion can result in poor combustion...

  14. The mixing of solid propellant by an artificial muscle actuator

    OpenAIRE

    岩崎, 祥大; 伴, 遼介; 吉浜, 舜; 中村, 太郎; 羽生, 宏人; Iwasaki, Akihiro; Ban, Ryosuke; Yoshihama, Shun; Nakamura, Taro; Habu, Hiroto

    2015-01-01

    This research aims to reduce the cost of the solid rocket motor production, mainly solid propellant. The production process of the solid rocket propellant are usually employed the multi-batch mixing. However, this study using a peristaltic pump as a mixer will lead to the continuous process. The pump system can mix the powder materials for propellant and we consider that it will make the slurry of the solid propellant efficiently by the mechanism of the fluid dynamics in the pump.

  15. Dissolution Rate of Propellant Energetics from Nitrocellulose Matrices

    Science.gov (United States)

    2012-09-01

    ER D C/ CR R EL T R -1 2 -9 ER-1691 Dissolution Rate of Propellant Energetics from Nitrocellulose Matrices C ol d R eg io n s R es ea...showing the heated edge of the propellant . ER-1691 ERDC/CRREL TR-12-9 September 2012 Dissolution Rate of Propellant Energetics from Nitrocellulose ...unfired propellants , are com- posed of nitrocellulose imbibed with either 2,4-DNT (single-base), nitroglycerin (NG) (double- base) or NG and

  16. Numerical Analysis of Ice Impacts on Azimuth Propeller

    Science.gov (United States)

    2013-09-01

    propeller for ice operation ships. A typical propeller profile was created using MATLAB and modeled in SolidWorks using realistic material properties...for ice operation ships. A typical propeller profile was created using MATLAB and modeled in SolidWorks using realistic material properties. The...OPENPROP in MATLAB The program allows for the 3-D graphical propeller design created in MATLAB to be exported to CAD programs such as Rhino or SolidWorks

  17. 14 CFR 420.65 - Handling of solid propellants.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Handling of solid propellants. 420.65....65 Handling of solid propellants. (a) A launch site operator shall determine the maximum total quantity of solid propellants and other solid explosives by class and division, in accordance with 49...

  18. 14 CFR 23.907 - Propeller vibration and fatigue.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller vibration and fatigue. 23.907... General § 23.907 Propeller vibration and fatigue. This section does not apply to fixed-pitch wood... evaluation of the propeller to show that failure due to fatigue will be avoided throughout the...

  19. CFD simulation on Kappel propeller with a hull wake field

    DEFF Research Database (Denmark)

    Shin, Keun Woo; Andersen, Poul; Møller Bering, Rasmus

    2013-01-01

    -water characteristics. The hull wake field is simulated without the propeller flow to check whether it is preserved at the propeller plane or not. Propeller flow simulations are made with mean axial wake varying only along the radius (i.e. circumferentially uniform), whole axial wake and upstream transverse wake...

  20. 14 CFR 21.500 - Approval of engines and propellers.

    Science.gov (United States)

    2010-01-01

    ... AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Approval of Engines, Propellers, Materials, Parts.... type certificate for an aircraft engine or propeller manufactured in a foreign country with which the... with each such aircraft engine or propeller imported into this country, a certificate of...

  1. 14 CFR 25.875 - Reinforcement near propellers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Reinforcement near propellers. 25.875... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Miscellaneous § 25.875 Reinforcement near propellers. (a) Each part of the airplane near the propeller tips must...

  2. 14 CFR 35.43 - Propeller hydraulic components.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller hydraulic components. 35.43 Section 35.43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Tests and Inspections § 35.43 Propeller hydraulic components....

  3. 14 CFR 35.23 - Propeller control system.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller control system. 35.23 Section 35.23 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.23 Propeller control system. The...

  4. 14 CFR 35.21 - Variable and reversible pitch propellers.

    Science.gov (United States)

    2010-01-01

    ... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.21 Variable and reversible pitch propellers. (a) No single failure or malfunction in the propeller system will result in... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Variable and reversible pitch...

  5. 14 CFR 25.907 - Propeller vibration and fatigue.

    Science.gov (United States)

    2010-01-01

    ... 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 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller vibration and fatigue....

  6. Changing of ballistic parameters from aged gun propellants

    NARCIS (Netherlands)

    Klerk, W.P.C. de; Driel, C.A. van

    2003-01-01

    The various properties of an SB and a DB gun propellant were investigated before and after artificial ageing. It was found that the decrease of nitrocellulose (NC) molecular weight, due to ageing of gun propellants, leads to a decrease of the mechanical integrity of the propellant grains. The effect

  7. 14 CFR 121.225 - Propeller deicing fluid.

    Science.gov (United States)

    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...

  8. 14 CFR 125.123 - Propeller deicing fluid.

    Science.gov (United States)

    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,...

  9. 30 CFR 57.4260 - Underground self-propelled equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground self-propelled equipment. 57.4260... 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....

  10. 30 CFR 57.4230 - Surface self-propelled equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Surface self-propelled equipment. 57.4230... 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...

  11. 30 CFR 56.4230 - Self-propelled equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Self-propelled equipment. 56.4230 Section 56... Control Firefighting Equipment § 56.4230 Self-propelled equipment. (a)(1) Whenever a fire or its effects could impede escape from self-propelled equipment, a fire extinguisher shall be on the equipment....

  12. Assessment of stability of propellants and safe lifetimes

    NARCIS (Netherlands)

    Klerk, W.P.C. de

    2015-01-01

    The surveillance of gun propellants is basically performed either by an investigation into the thermal behavior of the propellant or by the determination of its remaining effective stabilizer content. Over the years it is shown that the surveillance of NC based gun propellants is necessary. NC based

  13. Cryogenic Propellant Storage and Transfer (CPST) Technology Demonstration Mission (TDM)

    Science.gov (United States)

    Chojnacki, Kent

    2013-01-01

    Objectives: 1) Store cryogenic propellants in a manner that maximizes their availability for use regardless of mission duration. 2) Efficiently transfer conditioned cryogenic propellant to an engine or tank situated in a microgravity environment. 3) Accurately monitor and gauge cryogenic propellants situated in a microgravity environment.

  14. Ammonium nitrate: a promising rocket propellant oxidizer

    Science.gov (United States)

    Oommen; Jain

    1999-06-30

    Ammonium nitrate (AN) is extensively used in the area of fertilizers and explosives. It is present as the major component in most industrial explosives. Its use as an oxidizer in the area of propellants, however, is not as extensive as in explosive compositions or gas generators. With the growing demand for environmental friendly chlorine free propellants, many attempts have been made of late to investigate oxidizers producing innocuous combustion products. AN, unlike the widely used ammonium perchlorate, produces completely ecofriendly smokeless products. Besides, it is one of the cheapest and easily available compounds. However, its use in large rocket motors is restricted due to some of its adverse characteristics like hygroscopicity, near room temperature phase transformation involving a volume change, and low burning rate (BR) and energetics. The review is an attempt to consolidate the information available on the various issues pertaining to its use as a solid propellant oxidizer. Detailed discussions on the aspects relating to phase modifications, decomposition chemistry, and BR and energetics of AN-based propellants, are presented. To make the review more comprehensive brief descriptions of the history, manufacture, safety, physical and chemical properties and various other applications of the salt are also included. Copyright 1999 Elsevier Science B.V.

  15. Cryogenic Propellant Boil-Off Reduction System

    Science.gov (United States)

    Plachta, D. W.; Christie, R. J.; Carlberg, E.; Feller, J. R.

    2008-03-01

    Lunar missions under consideration would benefit from incorporation of high specific impulse propellants such as LH2 and LO2, even with their accompanying boil-off losses necessary to maintain a steady tank pressure. This paper addresses a cryogenic propellant boil-off reduction system to minimize or eliminate boil-off. Concepts to do so were considered under the In-Space Cryogenic Propellant Depot Project. Specific to that was an investigation of cryocooler integration concepts for relatively large depot sized propellant tanks. One concept proved promising—it served to efficiently move heat to the cryocooler even over long distances via a compressed helium loop. The analyses and designs for this were incorporated into NASA Glenn Research Center's Cryogenic Analysis Tool. That design approach is explained and shown herein. Analysis shows that, when compared to passive only cryogenic storage, the boil-off reduction system begins to reduce system mass if durations are as low as 40 days for LH2, and 14 days for LO2. In addition, a method of cooling LH2 tanks is presented that precludes development issues associated with LH2 temperature cryocoolers.

  16. 14 CFR 23.925 - Propeller clearance.

    Science.gov (United States)

    2010-01-01

    ... seven inches (for each airplane with nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with the landing gear statically.... Positive clearance for airplanes using leaf spring struts is shown with a deflection corresponding to...

  17. Noise Control in Propeller-Driven Aircraft

    Science.gov (United States)

    Rennison, D. C.; Wilby, J. F.

    1983-01-01

    Analytical model predicts noise levels inside propeller-driven aircraft during cruise at mach 0.8. Double wall sidewalls minimize interior noise and weight. Model applied to three aircraft with fuselages of different size (wide-body, narrow-body, and small-diameter) to determine noise reductions required to achieve A-weighted sound level not to exceed 80 dB.

  18. Method of making counterrotating aircraft propeller blades

    Science.gov (United States)

    Nelson, Joey L. (Inventor); Elston, III, Sidney B. (Inventor); Tseng, Wu-Yang (Inventor); Hemsworth, Martin C. (Inventor)

    1990-01-01

    An aircraft propeller blade is constructed by forming two shells of composite material laminates and bonding the two shells to a metallic spar with foam filler pieces interposed between the shells at desired locations. The blade is then balanced radially and chordwise.

  19. Waste reduction at a propellant manufacturing site

    Energy Technology Data Exchange (ETDEWEB)

    Beer, L.A. [Science Applications International Corp., Hackensack, NJ (United States)

    1994-12-31

    It is the US Army policy to reduce the volume and toxicity of hazardous waste generated by its operations and activities. The Army established a goal to reduce 1985 waste generation levels by 50% by the year 1992, with additional reductions proposed through 1999 per Army guidance. To assist in accomplishing this goal, the Production Base Modernization Activity under a program sponsored by the US Army Materiel Command contracted Science Applications International Corporation to conduct a waste minimization audit at Radford Army Ammunition Plant. This study addressed hazardous wastes as well as non-hazardous oily wastes. The investigation was conducted in three phases to document how hazardous and oily wastes are produced and to recommend waste reduction alternatives. Radford Army Ammunition Plant (RAAP) produces in-process materials such as nitric and sulfuric acids, and propellant components including nitrocellulose and nitroglycerin. In addition, to propellants, the explosives trinitrotoluene and diethylene glycol dinitrate can be produced. The manufacture of military propellants generates the majority of waste at the facility. This paper will present the results of the RAAP Hazmin study, focusing on the major waste generating processes involved with propellant manufacture, Hazmin options suggested to minimize waste generation, and lessons learned.

  20. Optimal shapes for self-propelled swimmers

    Science.gov (United States)

    Koumoutsakos, Petros; van Rees, Wim; Gazzola, Mattia

    2011-11-01

    We optimize swimming shapes of three-dimensional self-propelled swimmers by combining the CMA- Evolution Strategy with a remeshed vortex method. We analyze the robustness of optimal shapes and discuss the near wake vortex dynamics for optimal speed and efficiency at Re=550. We also report preliminary results of optimal shapes and arrangements for multiple coordinated swimmers.

  1. Specific Impulses Losses in Solid Propellant Rockets

    Science.gov (United States)

    1974-12-17

    to use the collision function form proposed by Golovin to simplify this production term: 4C><=) <P- .: Accordingly: m hence, by integration: Now, we...November 21, 1940 in Paris, Seine. VFirst Thesis. "Contribution to the Study of Specific i Impulse Loss in Solid Propellant Rockets." Second Thesis

  2. Mars Propellant Production with Ionic Liquids Project

    Science.gov (United States)

    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.

  3. Satellite And Propeller Migration In Saturn's Rings

    Science.gov (United States)

    Crida, Aurelien; Charnoz, S.; Papaloizou, J.; Salmon, J.

    2009-09-01

    Saturn's rings host satellites like Pan and Daphnis, and smaller bodies like the recently discovered propellers (Tiscareno et al. 2006). These bodies interact gravitationally with the rings. Actually, the resulting perturbations on the ring system have revealed the presence of embedded objects (the Encke and Keeler gaps associated with Pan and Daphnis respectively, the little two-folded structures called propellers tracing the scattering of ring particles by some embedded small objects). Reciprocally, the rings must act on the embedded bodies, leading to their migration. Here, we study how the standard theory of planetary migration applies in Saturn's ring, where the pressure is negligible in contrast with standard protoplanetary disks. Pan and Daphnis should be in standard type II migration, governed by the global disk evolution. Therefore, their presence and position provide constraints on the history of the A-ring, which can be studied using numerical simulations of disk-satellite interactions. The propellers are fully embedded in the disc, and therefore should be subject to type I migration. The simple impulse approximation used by Lin and Papaloi zou (1979) to derive the one-sided torque is particularly suited to this case. Refining their calculation, taking density variations into account, and discussing the possibility for these bodies to enter the type III, runaway regime of migration, we aim at estimating a possible migration rate for these propellers, to be compared to the system life time.

  4. The design of propeller and propeller boss cap fins (PBCF) by an integrative method

    Institute of Scientific and Technical Information of China (English)

    MA Cheng; CAI Hao-peng; QIAN Zheng-fang; CHEN Ke

    2014-01-01

    Generally, after a marine propeller design, the propeller boss cap fins (PBCF) design concerns with an optimal selection of model test results, without a due consideration of the interaction between the PBCF and the propeller. In this paper, the PBCF and the propeller are considered as a whole system with their design as an integrative process, in which the concept of the increased loading in the blade root is incorporated. The load distribution on the blade becomes well-proportioned due to the increased loading in the blade root, and it is advantageous to the reduction of the vibratory force and the blade tip vortex. The blade root area is stronger in withstanding forces, and is not easy to be vibrated, therefore, the increased loading there is beneficial to the noise reduction. The disadvantage of the increased loading in the blade root is the generation of the hub vortex behind the boss cap, but the hub vortex can be broken up by the energy saving hydrodynamic mechanism of the PBCF. The integrative design method introduced in this paper can provide a higher efficiency for propellers under the same design conditions. In this paper, an integrative propeller and PBCF design method including the theoretical design and the numerical optimization design is proposed, based on the potential flow theory, the CFD tools, the improved particle swarm optimization algorithm, and the model tests. A propeller with the PBCF is designed based on the method of integrated increased loading in the blade root for a cargo vessel in this paper. The cavitation tunnel model test results show that the propeller and the PBCF thus designed enjoys a higher efficiency, and the design method is effective, reliable and practical.

  5. Space Transportation Infrastructure Supported By Propellant Depots

    Science.gov (United States)

    Smitherman, David; Woodcock, Gordon

    2012-01-01

    A space transportation infrastructure is described that utilizes propellant depot servicing platforms to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicle (ELV) systems 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 Low-Earth-Orbit (LEO) Depot and an Earth-Moon Lagrange Point 1 (L1) Depot to support a 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. New vehicle design concepts are presented that can be launched on current 5 meter diameter ELV systems. These new reusable vehicle concepts include a Crew Transfer Vehicle (CTV) for crew transportation between the LEO Depot, L1 Depot and missions beyond L1; a new reusable lunar lander for crew transportation between the L1 Depot and the lunar surface; and Mars orbital Depot are based on International Space Station (ISS) heritage hardware. Data provided includes the number of launches required for each mission utilizing current ELV systems (Delta IV Heavy or equivalent) and the approximate vehicle masses and propellant requirements. Also included is a discussion on affordability with ideas on technologies that could reduce the number of launches required and thoughts on how this infrastructure include competitive bidding for ELV flights and propellant services, developments of new reusable in-space vehicles and development of a multiuse infrastructure that can support many government and commercial missions simultaneously.

  6. Rheology of composite solid propellants during motor casting

    Science.gov (United States)

    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.

  7. Performance of a capillary propellant management device with hydrazine

    Science.gov (United States)

    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.

  8. Computation of Blast Pressures foam Propellant for Compaction of Soil

    Directory of Open Access Journals (Sweden)

    K. B. Agarwal

    1974-01-01

    Full Text Available The knowledge of blast pressure characteristics is a pre-requisite for a suitable application of foam propellant to emergency military construction such as compacting of the soil from an aircraft using the foam propellant. The foam propellant considered here is a combination of hydrazine and ammonium perchlorate. The blast pressure is found to be a function of the quantity of foam propellant used and the distance of the observation point. This paper attempts to compute the blast pressure versus time characteristics of a foam propellant strip.

  9. Combustion Behaviour of Advanced Solid Propellants.

    Directory of Open Access Journals (Sweden)

    S. N. Asthana

    1993-07-01

    Full Text Available The study reports the effect of incorporation of Al and ammonium perchlorate (AP individually and in combination with each other on combustion pattern and specific impulse (Isp of minimum signature propellants. Incorporation of Al obviates the combustion instability problems; however, it has marginal effect on burning rates. The composition containing AP and zirconium silicate combination gives superior performance; however, its Isp is considerably lower than the composition incorporating 9 per cent AP. A combination of 6 per cent Al gave 20 per cent enhancement in burning rate and 12 s increase in Isp as compared to purely nitramine-based composition, cal-val results also reveal increase in energy output on incorporating AP and Al. Hot stage microscopic and propellant combustion studies indicate occurrence of intense decomposition reaction in case of AP-based compositions.

  10. Integrated model of a composite propellant rocket

    Science.gov (United States)

    Miccio, Francesco

    2016-12-01

    The combustion of composite solid propellants was investigated and an available numerical model was improved for taking into account the change of pressure, when the process occurs in a confined environment, as inside a rocket. The pressure increase upon ignition is correctly described by the improved model for both sandwich and dispersed particles propellants. In the latter case, self-induced fluctuations in the pressure and in all other computed variables occur, as consequence of the periodic rise and depletion of oxidizer particles from the binder matrix. The comparison with the results of the constant pressure model shows a different fluctuating profile of gas velocity, with a possible second order effect induced by the pressure fluctuations.

  11. On shear rheology of gel propellants

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Shai; Peretz, Arie [RAFAEL, MANOR Propulsion and Explosive Systems Division, Haifa (Israel); Natan, Benveniste [Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

    2007-04-15

    Selected fuel, oxidizer and simulant gels were prepared and rheologically characterized using a rotational rheometer. For fuel gelation both organic and inorganic gellants were utilized, whereas oxidizers and simulants were gelled with addition of silica and polysaccharides, respectively. The generalized Herschel-Bulkley constitutive model was found to most adequately represent the gels studied. Hydrazine-based fuels, gelled with polysaccharides, were characterized as shear-thinning pseudoplastic fluids with low shear yield stress, whereas inhibited red-fuming nitric acid (IRFNA) and hydrogen peroxide oxidizers, gelled with silica, were characterized as yield thixotropic fluids with significant shear yield stress. Creep tests were conducted on two rheological types of gels with different gellant content and the results were fitted by Burgers-Kelvin viscoelastic constitutive model. The effect of temperature on the rheological properties of gel propellant simulants was also investigated. A general rheological classification of gel propellants and simulants is proposed. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  12. High Impetus Cool Burning Gun Propellants

    Directory of Open Access Journals (Sweden)

    R.S. Dames

    2000-07-01

    Full Text Available This study explores the possibility of reducing the flame temperature (Tf without decrease in impetus of RDX-NC matrix-based high energy gun propellants by partial replacement of RDX with triaminoguanidine nitrate (TAGN. Compositions containing TAGN as an energetic oxidiser with varying percentage of RDX have been formulated. Glycidyl azide polymer was incorporated as an energetic plasticiser to achieve the higher level of impetus. Performance in terms of ballistic parameters (theoretical/experimental sensitivity, thermal characteristics, stability and mechanical properties was evaluated and compared with the basic composition containing RDX as a single oxidiser. Experimental data indicates that the partial replacement of RDX by TAGN in gun propellant compositions decreases Tf significantly with only marginal decrease in impetus. "

  13. Parametric Erosion Investigation: Propellant Adiabatic Flame Temperature

    Directory of Open Access Journals (Sweden)

    P. J. Conroy

    2002-01-01

    Full Text Available The influence of quasi-independent parameters and their potential influence on erosion in guns have been investigated. Specifically, the effects of flame temperature and the effect of assuming that the Lewis number (ratio of mass-to-heat transport to the surface, Le = 1, has been examined. The adiabatic flame temperature for a propellant was reduced by the addition of a diluent from a high temperature of 3843 K (similar to that of M9 down to 3004 K, which is near the value for M30A1 propellant. Mass fractions of critical species at the surface with and without the assumption of Le = 1 are presented, demonstrating that certain species preferentially reach the surface providing varied conditions for the surface reactions. The results for gun tube bore surface regression qualitatively agree with previous studies and with current experimental data.

  14. Aircraft propeller induced structure-borne noise

    Science.gov (United States)

    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.

  15. Large-eddy simulation of propeller noise

    Science.gov (United States)

    Keller, Jacob; Mahesh, Krishnan

    2016-11-01

    We will discuss our ongoing work towards developing the capability to predict far field sound from the large-eddy simulation of propellers. A porous surface Ffowcs-Williams and Hawkings (FW-H) acoustic analogy, with a dynamic endcapping method (Nitzkorski and Mahesh, 2014) is developed for unstructured grids in a rotating frame of reference. The FW-H surface is generated automatically using Delaunay triangulation and is representative of the underlying volume mesh. The approach is validated for tonal trailing edge sound from a NACA 0012 airfoil. LES of flow around a propeller at design advance ratio is compared to experiment and good agreement is obtained. Results for the emitted far field sound will be discussed. This work is supported by ONR.

  16. Atomic hydrogen as a launch vehicle propellant

    Energy Technology Data Exchange (ETDEWEB)

    Palaszewski, B.A.

    1990-01-01

    An analysis of several atomic hydrogen launch vehicles was conducted. A discussion of the facilities and the technologies that would be needed for these vehicles is also presented. The Gross Liftoff Weights (GLOW) for two systems were estimated; their specific impulses (I{sub sp}) were 750 and 1500 lb{sub f}/s/lb{sub m}. The atomic hydrogen launch vehicles were also compared to the currently planned Advanced Launch System design concepts. Very significant GLOW reductions of 52 to 58 percent are possible over the Advanced Launch System designs. Applying atomic hydrogen propellants to upper stages was also considered. Very high I{sub sp} (greater than 750 lb{sub f}/s/lb{sub m}) is needed to enable a mass savings over advanced oxygen/hydrogen propulsion. Associated with the potential benefits of high I(sub sp) atomic hydrogen are several challenging problems. Very high magnetic fields are required to maintain the atomic hydrogen in a solid hydrogen matrix. The magnetic field strength was estimated to be 30 kilogauss (3 Tesla). Also the storage temperature of the propellant is 4 K. This very low temperature will require a large refrigeration facility for the launch vehicle. The design considerations for a very high recombination rate for the propellant are also discussed. A recombination rate of 210 cm/s is predicted for atomic hydrogen. This high recombination rate can produce very high acceleration for the launch vehicle. Unique insulation or segmentation to inhibit the propellant may be needed to reduce its recombination rate.

  17. Self-propelled chemotactic ionic liquid droplets

    OpenAIRE

    Francis, Wayne; Fay, Cormac; Florea, Larisa; Diamond, Dermot

    2015-01-01

    Herein we report the chemotactic behaviour of self-propelled droplets composed solely of the ionic liquid trihexyl(tetradecyl)phosphonium chloride ([P6,6,6,14][Cl]). These droplets spontaneously move along an aqueous-air boundary in the direction of chloride gradients to specific destinations due to asymmetric release of [P6,6,6,14]+ cationic surfactant from the droplet into the aqueous phase.

  18. Spray and Combustion of Gelled Hypergolic Propellants

    Science.gov (United States)

    2014-10-20

    side of the orifice lip leads to mass flow pulsations at high Reynolds number injection conditions. The main technical achievement in this work has...C. Yoon, S. Heister, G. Xia, C. Merkle. Numerical Modeling of Injection of Shear-Thinning Gel Propellants Through Plain- Orifice Atomizer, Journal...Xia, C. Merkle. Numerical Modeling of Cross-Fed Orifice Flows for Shear-Thinning Fluids, . , . : , S. Snyder, P. Sojka. Secondary Atomization of

  19. Wave propelled ratchets and drifting rafts

    OpenAIRE

    2008-01-01

    Several droplets, bouncing on a vertically vibrated liquid bath, can form various types of bound states, their interaction being due to the waves emitted by their bouncing. Though they associate droplets which are individually motionless, we show that these bound states are self- propelled when the droplets are of uneven size. The driving force is linked to the assymetry of the emitted surface waves. The direction of this ratchet-like displacement can be reversed, by varying the amplitude of ...

  20. Self-propelled film-boiling liquids

    OpenAIRE

    Linke, H.; Aleman, B. J.; Melling, L. D.; Taormina, M. J.; Francis, M J; Dow-Hygelund, C. C.; Narayanan, V.; Taylor, R. P.; Stout, A.

    2005-01-01

    We report that liquids perform self-propelled motion when they are placed in contact with hot surfaces with asymmetric (ratchet-like) topology. The pumping effect is observed when the liquid is in the film-boiling regime, for many liquids and over a wide temperature range. We propose that liquid motion is driven by a viscous force exerted by vapor flow between the solid and the liquid.

  1. Bistable (latching) solenoid actuated propellant isolation valve

    Science.gov (United States)

    Wichmann, H.; Deboi, H. H.

    1979-01-01

    The design, fabrication, assembly and test of a development configuration bistable (latching) solenoid actuated propellant isolation valve suitable for the control hydrazine and liquid fluorine to an 800 pound thrust rocket engine is described. The valve features a balanced poppet, utilizing metal bellows, a hard poppet/seat interface and a flexure support system for the internal moving components. This support system eliminates sliding surfaces, thereby rendering the valve free of self generated particles.

  2. Coaxial Propellant Injectors With Faceplate Annulus Control

    Science.gov (United States)

    Horn, Mark D.; Miyata, Shinjiro; Farhangi, Shahram

    2010-01-01

    An improved design concept for coaxial propellant injectors for a rocket engine (or perhaps for a non-rocket combustion chamber) offers advantages of greater robustness, less complexity, fewer parts, lower cost, and less bulk, relative to prior injectors of equivalent functionality. This design concept is particularly well suited to small, tight-tolerance injectors, for which prior designs are not suitable because the practical implementation of those designs entails very high costs and difficulty in adhering to the tolerances.

  3. Unsteady Processes in Solid Propellant Combustion,

    Science.gov (United States)

    1977-05-01

    0—AflO ~5a INSTITUTO NACIONAL DE TECNICA AEROESPACIAL MADRID (SPAIN) F/S 21/9.2UNSTEADY PROCESSES IN SOLID PROPELLANT COMBUSTION . (U) MAY...PRO C E SS E S IN SOLID P R O P E L L A N T C O M B U S T I O N H A. Crespo and M. Kindelán Instituto Nacional de Técnica Aeroespacial Madrid , Spain j

  4. Cryogenic Propellant Feed System Analytical Tool Development

    Science.gov (United States)

    Lusby, Brian S.; Miranda, Bruno M.; Collins, Jacob A.

    2011-01-01

    The Propulsion Systems Branch at NASA s Lyndon B. Johnson Space Center (JSC) has developed a parametric analytical tool to address the need to rapidly predict heat leak into propellant distribution lines based on insulation type, installation technique, line supports, penetrations, and instrumentation. The Propellant Feed System Analytical Tool (PFSAT) will also determine the optimum orifice diameter for an optional thermodynamic vent system (TVS) to counteract heat leak into the feed line and ensure temperature constraints at the end of the feed line are met. PFSAT was developed primarily using Fortran 90 code because of its number crunching power and the capability to directly access real fluid property subroutines in the Reference Fluid Thermodynamic and Transport Properties (REFPROP) Database developed by NIST. A Microsoft Excel front end user interface was implemented to provide convenient portability of PFSAT among a wide variety of potential users and its ability to utilize a user-friendly graphical user interface (GUI) developed in Visual Basic for Applications (VBA). The focus of PFSAT is on-orbit reaction control systems and orbital maneuvering systems, but it may be used to predict heat leak into ground-based transfer lines as well. PFSAT is expected to be used for rapid initial design of cryogenic propellant distribution lines and thermodynamic vent systems. Once validated, PFSAT will support concept trades for a variety of cryogenic fluid transfer systems on spacecraft, including planetary landers, transfer vehicles, and propellant depots, as well as surface-based transfer systems. The details of the development of PFSAT, its user interface, and the program structure will be presented.

  5. CFD modelling of solid propellant ignition

    OpenAIRE

    Lowe, C

    1996-01-01

    Solid propellant is the highly energetic fuel burnt in the combustion chamber of ballistic weapons. It is manufactured, for this purpose, in either granular or stick form. Internal ballistics describes the behavior within the combustion chamber throughout the ballistic cycle upto projectile exit from the muzzle of the gun barrel. Over the last twenty years this has been achieved by modelling the process using two-phase flow equations. The solid granules or sticks constitute ...

  6. Simulating the Composite Propellant Manufacturing Process

    Science.gov (United States)

    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.

  7. Small transport aircraft technology propeller study

    Science.gov (United States)

    Black, B. M.; Magliozzi, B.; Rohrbach, C.

    1983-01-01

    A study to define potential benefits of advanced technology propeller for 1985-1990 STAT commuter airplanes was completed. Two baselines, a Convair, 30 passenger, 0.47 Mach number airplane and a Lockheed, 50 passenger, 0.70 Mach number airplane, were selected from NASA-Ames sponsored airframe contracts. Parametric performance, noise level, weight and cost trends for propellers with varying number of blades, activity factor, camber and diameter incorporating blade sweep, tip proplets, advanced composite materials, advanced airfoils, advanced prevision synchrophasing and counter-rotation are presented. The resulting DOC, fuel burned, empty weight and acquisition cost benefits are presented for resizings of the two baseline airplanes. Six-bladed propeller having advanced composite blades, advanced airfoils, tip proplets and advanced prevision synchrophasers provided the maximum DOC improvements for both airplanes. DOC and fuel burned were reduced by 8.3% and 17.0% respectively for the Convair airplane and by 24.9% and 41.2% respectively for the Lockheed airplane. The larger reductions arose from a baseline definition with very heavy fuselage acoustic treatment. An alternate baseline, with a cabin noise 13dB in excess of the objective, was also studied.

  8. Process and quality verification controls for solid propellant manufacturing

    Science.gov (United States)

    Rogers, C. J.

    1983-01-01

    It is pointed out that in-process tests to verify quality and detect discrepant propellant which could compromise motor performance are essential elements of the solid composite propellant manufacturing process. The successful performance of the 260SL-1 and 260SL-2 motors aptly verified the controls used for manufacturing the propellant. The present investigation is concerned with the selected control parameters, and their relationships to composition and final propellant properties. Control performance is evaluated by comparison with processing data experienced in the manufacture of the propellant for the 260SL-1 motor. It is found that the in-process quality verification controls utilized in the propellant manufacturing process for the 260-in. diameter motor contributed significantly to the confidence of successful and predictable motor performance.

  9. STRESS ANALYSIS OF COMPOSITE PROPELLER BY USING FINITE ELEMENT ANALYSIS

    Directory of Open Access Journals (Sweden)

    B.SRIDHAR REDDY

    2012-08-01

    Full Text Available Present work proposes a methodology to design a propeller with a metal and composite material to analyze its strength and deformation using Ansys software. In order to evaluate the effectiveness of composite over metals, stress analysis is performed on both composite and metal propeller using Ansys. Proposed methodology showed substantial improvements in metal propellers. The mean deflection, normal stress and shear stress were found for both metallic and composite propeller by using Ansys. From the results, stressanalysis composite propeller is safe resonance phenomenon. In this work effort is made to reduce stress levels so that advantage of weight reduction along with stresses can be obtained. The comparison analysis of metallic and composite propeller was made for the maximum deformation and normal stresses.

  10. Ballistic evaluationof LOVA propellant in high calibre gun

    Directory of Open Access Journals (Sweden)

    A.G.S. Pillai

    2001-04-01

    Full Text Available 'This paper presents the data obrained on dynamic firing of a cellulose acetate binder-based low vulnerability ammunition (LOV A propellant using 120 mm fin-stabilised armour piercing discarding sabot (FSAPDS kinetic energyammunition. An optimised propellant composition formulated ~sing fine RDX as an energetic ingredient and a mixture of cellulose acetate and nitrocellulose as binder was qualified fit for firing in a high calibre gun by its successful static evaluation for absolute ballistics using high pressure closed vessel technique. Dynamic firing of the propellant processed in heptatubular geometry was undertaken to assess the propellant charge mass. This propellant achieved higher muzzle velocity as compared to the standard NQ/M119 triple-base propellant while meeting the non-vulnerability characteristics convincingly.

  11. Simulation of the Propeller Disk Inside the Symmetrical Channel

    OpenAIRE

    Kyncl Martin; Pelant Jaroslav

    2014-01-01

    We work with the system of equations describing non-stationary compressible turbulent fluid flow, and we focus on the numerical solution of these equations, and on the boundary conditions. The computational simulation of the propeller disk is a demanding and time-consuming task. Here the propeller disk is represented by the distribution of the vector of velocities along its radius. The main purpose is to describe the special compatible conditions used to simulate the propeller disk on the bot...

  12. Study on the Detonation Danger of Solid Propellants

    Institute of Scientific and Technical Information of China (English)

    黄风雷; 张宝(金平)

    2004-01-01

    A measurement system to study shock initiation behavior of solid propellants was established experimentally. By using this system, the study on shock initiation to the recovered solid propellants with micro damage was performed, especially on the deflagration to denonation transition (DDT) process of solid propellants under both the strong and weak conditions of restriction. The experimental results show that there is a fully compression region in DDT process.

  13. Burning Rate Studies of Energetic Double Base Propellants

    Directory of Open Access Journals (Sweden)

    V. K. Bhat

    1986-01-01

    Full Text Available A systematic study was carried out on the combustion characteristics of CMDB propellants containing ammonium nitrate, ammonium perchlorate, potassium nitrate, potassium perchlorate, RDX and PETN. While ammonium and potassium perchlorates increased burning rates, other additives maintained either the same burning rate or reduced burning rates marginally. Propellants containing these additives showed marginally higher peak temperatures, indicating interaction among the species of double base propellant decomposition and those of additives.

  14. Simplified Burn-Rate Model for CMDB Propellants

    OpenAIRE

    Kulkarni, A. R.; Bhat, V.K.; S. P. Phadke; R.G.K. Nair

    1990-01-01

    A single model has been proposed to predict the burning rates of bimodal AP,RDX and aluminum containing CMDB propellants. This is done in terms of the respective physical constants on the basis of a recently developed model of combustion of CMDB propellants. The study has been carried out to examine the effects of changes in propellants composition, AP particle size and pressures on burning rate. Computer programs were developed for this purpose and the results obtained for typical set...

  15. AN AIRPLANE WITH UNCONVENTIONALLY PLACED PROPELLER POWER UNIT

    OpenAIRE

    Jan Červinka; Robert Kulhánek; Zdeněk Pátek

    2017-01-01

    The significance of the influence of operating propellers on the aircraft aerodynamic characteristics is well-known. Wind tunnel testing of an airplane model with operating propellers is a complex task regarding the required similarity of the full-scale and the model case. Matching sufficient similarity in axial and rotational velocities in the propeller slipstream is the primordial condition for the global aerodynamic similarity of the windtunnel testing. An example of the model power units ...

  16. A whole life assessment of extruded double base propellants

    OpenAIRE

    Tucker, J.

    2013-01-01

    The manufacturing process for solventless extruded double base propellants involves a number of rolling and reworking stages. Throughout these processes a decrease in weight average molecular weight was observed, this was attributed to denitration. Differential scanning calorimetery data indicated that the reworking stages of extruded double base propellant manufacture were crucial to the homogenisation of the propellant mixture. To determine the homogeneity of the final extruded product, a s...

  17. High Impulse Nanoparticulate-Based Gel Propellants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed Small Business Innovative Research (SBIR) Phase I addresses the development of advanced gel propellants and determination of their suitability for...

  18. Laser-induced fluorescence in high pressure solid propellant flames.

    Science.gov (United States)

    Edwards, T; Weaver, D P; Campbell, D H

    1987-09-01

    The application of laser-induced fluorescence (LIF) to the study of high pressure solid propellant flames is described. The distribution of the OH and CN radicals was determined in several solid propellant flames at pressures up to 3.5 MPa. The greatest difficulty in these measurements was the separation of the desired LIF signals from the large scattering at the laser wavelength from the very optically thick propellant flames. Raman experiments using 308-nm excitation were also attempted in the propellant flames but were unsuccessful due to LIF interferences from OH and NH.

  19. Solid propellant processing factor in rocket motor design

    Science.gov (United States)

    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.

  20. Advances in the research on the solid propellant properties abroad

    Science.gov (United States)

    Du, Lei; Jiang, Zhirong

    1994-06-01

    The recent research on the mechanical properties, burning behavior and processing technology of solid propellants abroad was reviewed. There are some available results in predicting theoretically the mechanical and rheological properties of solid propellants. In order to reduce the cost and increase the reliability in propellants processing, there is great demand on the design and manufacture of continuous mixer of high efficiency and safety. The research on the thermoplastic elastomers used as a kind of future binder of solid propellants has attracted more and more attention of many relevant experts.

  1. CFD and FEM Model of an Underwater Vehicle Propeller

    Directory of Open Access Journals (Sweden)

    Chruściel Tadeusz

    2014-10-01

    Full Text Available Within the framework of the project for design and optimization of the Remotely Operated Vehicle (ROV, research on its propulsion has been carried out. Te entire project was supported by CFD and FEM calculations taking into account the characteristics of the underwater vehicle. One of the tasks was to optimize the semi-open duct for horizontal propellers, which provided propulsion and controllability in horizontal plane. In order to create a measurable model of this task it was necessary to analyze numerical methodology of propeller design, along with the structure of a propellers with nozzles and contra-rotating propellers. It was confronted with theoretical solutions which included running of the analyzed propeller near an underwater vehicle. Also preliminary qualitative analyses of a simplified system with contra-rotating propellers and a semi-open duct were carried out. Te obtained results enabled to make a decision about the ROVs duct form. Te rapid prototyping SLS (Selective Laser Sintering method was used to fabricate a physical model of the propeller. As a consequence of this, it was necessary to verify the FEM model of the propeller, which based on the load obtained from the CFD model. Te article contains characteristics of the examined ROV, a theoretical basis of propeller design for the analyzed cases, and the results of CFD and FEM simulations.

  2. Propeller Test Facilities  

    Data.gov (United States)

    Federal Laboratory Consortium — Description: Three electrically driven whirl test stands are used to determine propeller (or other rotating device) performance at various rotational speeds. These...

  3. Cryogenic Propellant Storage and Handling Efficiency Improvement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The project determined specific performance metrics and discrete technology development goals with which to gage proposed investments in ground propellant systems...

  4. Beta-carotene

    Science.gov (United States)

    ... patches on the tongue and mouth called oral leukoplakia. Taking beta-carotene by mouth for up to 12 months seems to decrease symptoms of oral leukoplakia. Osteoarthritis. Beta-carotene taken by mouth may prevent ...

  5. Development of controllable pitch propeller mechanism for small high speed boats; Kogata kosokuteiyo kahen pitch propeller kiko no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Y.; Shiba, H.; Inoue, R.; Mori, T. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1995-12-20

    For improving the navigating performance of racing boats, a controllable pitch propeller mechanism has been developed, capable of responding to changes in the propeller load and of making good use of the engine performance. The effort aimed at the optimization of the propeller load to follow changes in surrounding conditions such as weather and the resultant sea roughness, the engine performance, and at the improvement of acceleration features. The blade angle is made smaller for reduced torque absorption at a low engine speed and, as the engine gathers speed, the blade angle is changed to the optimum for rapid acceleration to the maximum boat speed. The blade angle is made smaller upon deceleration. The mechanism has been designed so that it may be added on a boat rigged with a fixed pitch propeller. The design enables a propeller to properly respond to changes in the propeller load without pre-run replacement or shape-changing work. When this propeller`s performance is optimized to match the engine characteristics, there will be a propelling device with its performance further advanced. This design expands the range of engine performance in which usable one may be found. 6 refs., 6 figs., 1 tab.

  6. KAPPEL Propeller. Development of a Marine Propeller with Non-planar Lifting Surfaces

    DEFF Research Database (Denmark)

    Kappel, J.; Andersen, Poul

    2002-01-01

    The principle of non-planar lifting surfaces is applied to the design of modern aircraft wings to obtain better lift to drag ratios. Whereas a pronounced fin or "winglet" at the wingtip has been developed for aircraft, the application of the non-planar principle to marine propellers, dealt...

  7. The inner disc radius in the propeller phase and accretion-propeller transition of neutron stars

    Science.gov (United States)

    Ertan, Ünal

    2017-04-01

    We have investigated the critical conditions required for a steady propeller effect for magnetized neutron stars with optically thick, geometrically thin accretion discs. We have shown through simple analytical calculations that a steady-state propeller mechanism cannot be sustained at an inner disc radius where the viscous and magnetic stresses are balanced. The radius calculated by equating these stresses is usually found to be close to the conventional Alfvén radius for spherical accretion, rA. Our results show that: (1) a steady propeller phase can be established with a maximum inner disc radius that is at least ∼15 times smaller than rA depending on the mass-flow rate of the disc, rotational period and strength of the magnetic dipole field of the star, (2) the critical accretion rate corresponding to the accretion-propeller transition is orders of magnitude lower than the rate estimated by equating rA to the co-rotation radius. Our results are consistent with the properties of the transitional millisecond pulsars that show transitions between the accretion powered X-ray pulsar and the rotational powered radio-pulsar states.

  8. Goldstein's solution of the problem of the aircraft propeller with a finite number of blades

    Science.gov (United States)

    Helmbold, H B

    1931-01-01

    This report examines the Betz theory on frictionless, lightly loaded propellers and Prandtl's addendum extended to moderately loaded propellers. The author then goes on to extend the discussion to Goldstein's solution for propellers with a finite number of blades.

  9. Rotation of microscopic propellers in laser tweezers

    Energy Technology Data Exchange (ETDEWEB)

    Galajda, Peter; Ormos, Pal [Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, PO Box 521, H-6701 (Hungary)

    2002-04-01

    Particles of helical shape trapped in laser tweezers are rotated by light, independently of its polarization state. Light scattering by such propeller-like particles generates the momentum to drive the rotation. The efficiency of the rotation depends on the geometry of the particles. We used photopolymerization of light curing resins to create micrometre-size rotors with different shapes. The rotation of such particles was studied: the effect of shape and size on the rotation, as well as on the stability of the position in the laser tweezers.

  10. PHM Enabled Autonomous Propellant Loading Operations

    Science.gov (United States)

    Walker, Mark; Figueroa, Fernando

    2017-01-01

    The utility of Prognostics and Health Management (PHM) software capability applied to Autonomous Operations (AO) remains an active research area within aerospace applications. The ability to gain insight into which assets and subsystems are functioning properly, along with the derivation of confident predictions concerning future ability, reliability, and availability, are important enablers for making sound mission planning decisions. When coupled with software that fully supports mission planning and execution, an integrated solution can be developed that leverages state assessment and estimation for the purposes of delivering autonomous operations. The authors have been applying this integrated, model-based approach to the autonomous loading of cryogenic spacecraft propellants at Kennedy Space Center.

  11. WOW: light print, light propel, light point

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas

    2012-01-01

    anywhere in a sample at any orientation using real-time 3D optical micromanipulation with six degrees of freedom. One of the key aspects of our demonstrated WOWs is the change in direction of in-coupled light and the marked increase in numerical aperture of the out-coupled light. Hence, each light...... propelled WOW can tap from a relatively broad incident beam and generate a much more tightly confined light at its tip. The presentation contains both numerical simulations related to the propagation of light through a WOW and preliminary experimental demonstrations on our BioPhotonics Workstation...

  12. Green Propellant Loading Demonstration at U.S. Range

    Science.gov (United States)

    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

  13. Green Propellant Landing Demonstration at U.S. Range

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  15. Solid State MEMS Thrusters Using Electrically Controlled Extinguishable Solid Propellant Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ET Materials, LLC developed the first ever electrically controlled extinguishable solid propellant (ECESP). The original propellant developed under Air Force SBIR...

  16. Propellant and Purge System Contamination "2007: A Summer of Fun"

    Science.gov (United States)

    Galloway, Randy

    2010-01-01

    This slide presentation reviews the propellant and purge system contamination that occurred during the summer of 2007 at Stennis Space Center. During this period Multiple propellant/pressurant system contamination events prompted a thorough investigation, the results of which are reviewed.

  17. Burn Rate Modelling of Solid Rocket Propellants (Short Communication

    Directory of Open Access Journals (Sweden)

    A.R. Kulkarni

    1998-01-01

    Full Text Available A generalised model of burning of a solid rocket propellant based on kinetics of propellant hasbeen developed. A complete set of variables has been formed after examining the existing models.Buckingham theorem provides the functional form of the model, such that the existing models are thesubcases of this generalised model. This proposed model has been validated by an experimental data.

  18. Self-propelled oil droplets consuming "fuel" surfactant

    DEFF Research Database (Denmark)

    Toyota, Taro; Maru, Naoto; Hanczyc, Martin M

    2009-01-01

    A micrometer-sized oil droplet of 4-octylaniline containing 5 mol % of an amphiphilic catalyst exhibited a self-propelled motion, producing tiny oil droplets, in an aqueous dispersion of an amphiphilic precursor of 4-octylaniline. The tiny droplets on the surface of the self-propelled droplet wer...

  19. 78 FR 43838 - Airworthiness Directives; Hamilton Sundstrand Corporation Propellers

    Science.gov (United States)

    2013-07-22

    ..., Engine & Propeller Directorate, Aircraft Certification Service. BILLING CODE 4910-13-P ...-48-AD RIN 2120-AA64 Airworthiness Directives; Hamilton Sundstrand Corporation Propellers AGENCY... had applied to certain Hamilton Sundstrand Corporation 14SF-7, 14SF-15, and 14SF-23 series...

  20. Functional Design and Qualification of Surface Tension Propellant Tanks

    Science.gov (United States)

    Figus, C.; Haddad, D.; Ounougha, L.; Autric, J.

    2004-10-01

    During two decades, EADS Astrium has designed and qualified the surface tension device used in the propellant tanks equipping the Eurostar telecommunication satellites platforms. Recent re- orbiting phases of Eurostar E2000 satellites, have allowed to validate those designs and to graveyard the spacecraft with less than 1 kg of propellant left per tank. Moreover, with the emergence of new powerful satellites with full chemical or mixed chemical-plasma propulsion subsystems, EADS Astrium has designed a new larger and improved surface tension propellant tank. Such challenging performances require analyses, and tests in order to assess and confirm the predicted performances. The present article shows the recent development of a new enlarged Eurostar E3000 propellant tanks for Eurostar 3000 satellites and presents the main functional analyses and neutral buoyancy tests results obtained for this new propellant tank These last two years, have contributed to improve this background with the successful graveyard of the first Eurostar spacecraft with less than 1 kg of liquid propellant per tank at the end of the manoeuvre. Moreover, a new enlarged E3000 propellant tank has been designed and qualified in order to cope with the future 12 kW telecom spacecraft applications. This tank designed by EADS-ASTRIUM, is manufactured by EADS-Space transportation. This paper presents the performances and tests results obtained on this new propellant tank.

  1. 14 CFR 33.95 - Engine-propeller systems tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine-propeller systems tests. 33.95 Section 33.95 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.95 Engine-propeller...

  2. Solid Hydrogen Formed for Atomic Propellants

    Science.gov (United States)

    Palaszewski, Bryan A.

    2000-01-01

    Several experiments on the formation of solid hydrogen particles in liquid helium were recently conducted at the NASA Glenn Research Center at Lewis Field. The solid hydrogen experiments are the first step toward seeing these particles and determining their shape and size. The particles will ultimately store atoms of boron, carbon, or hydrogen, forming an atomic propellant. Atomic propellants will allow rocket vehicles to carry payloads many times heavier than possible with existing rockets or allow them to be much smaller and lighter. Solid hydrogen particles are preferred for storing atoms. Hydrogen is generally an excellent fuel with a low molecular weight. Very low temperature hydrogen particles (T < 4 K) can prevent the atoms from recombining, making it possible for their lifetime to be controlled. Also, particles that are less than 1 mm in diameter are preferred because they can flow easily into a pipe when suspended in liquid helium. The particles and atoms must remain at this low temperature until the fuel is introduced into the engine combustion (or recombination) chamber. Experiments were, therefore, planned to look at the particles and observe their formation and any changes while in liquid helium.

  3. Quantitative computer representation of propellant processing

    Science.gov (United States)

    Hicks, M. D.; Nikravesh, P. E.

    1990-01-01

    With the technology currently available for the manufacture of propellants, it is possible to control the variance of the total specific impulse obtained from the rocket boosters to within approximately five percent. Though at first inspection this may appear to be a reasonable amount of control, when it is considered that any uncertainty in the total kinetic energy delivered to the spacecraft translates into a design with less total usable payload, even this degree of uncertainty becomes unacceptable. There is strong motivation to control the variance in the specific impulse of the shuttle's solid boosters. Any small gains in the predictability and reliability of the booster would lead to a very substantial payoff in earth-to-orbit payload. The purpose of this study is to examine one aspect of the manufacture of solid propellants, namely, the mixing process. The traditional approach of computational fluid mechanics is notoriously complex and time consuming. Certain simplifications are made, yet certain fundamental aspects of the mixing process are investigated as a whole. It is possible to consider a mixing process in a mathematical sense as an operator, F, which maps a domain back upon itself. An operator which demonstrates good mixing should be able to spread any subset of the domain completely and evenly throughout the whole domain by successive applications of the mixing operator, F. Two and three dimensional models are developed and graphical visualization two and three dimensional mixing processes are presented.

  4. Nuclear thermal rockets using indigenous extraterrestrial propellants

    Science.gov (United States)

    Zubrin, Robert M.

    1990-01-01

    A preliminary examination of a concept for a Mars and outer solar system exploratory vehicle is presented. Propulsion is provided by utilizing a nuclear thermal reactor to heat a propellant volatile indigenous to the destination world to form a high thrust rocket exhaust. Candidate propellants, whose performance, materials compatibility, and ease of acquisition are examined and include carbon dioxide, water, methane, nitrogen, carbon monoxide, and argon. Ballistics and winged supersonic configurations are discussed. It is shown that the use of this method of propulsion potentially offers high payoff to a manned Mars mission. This is accomplished by sharply reducing the initial mission mass required in low earth orbit, and by providing Mars explorers with greatly enhanced mobility in traveling about the planet through the use of a vehicle that can refuel itself each time it lands. Thus, the nuclear landing craft is utilized in combination with a hydrogen-fueled nuclear-thermal interplanetary launch. By utilizing such a system in the outer solar system, a low level aerial reconnaissance of Titan combined with a multiple sample return from nearly every satellite of Saturn can be accomplished in a single launch of a Titan 4 or the Space Transportation System (STS). Similarly a multiple sample return from Callisto, Ganymede, and Europa can also be accomplished in one launch of a Titan 4 or the STS.

  5. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward......-looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...

  6. Propellant development for the Advanced Solid Rocket Motor

    Science.gov (United States)

    Landers, L. C.; Stanley, C. B.; Ricks, D. W.

    1991-01-01

    The properties of a propellant developed for the NASA Advanced Solid Rocket Motor (ASRM) are described in terms of its composition, performance, and compliance to NASA specifications. The class 1.3 HTPB/AP/A1 propellant employs an ester plasticizer and the content of ballistic solids is set at 88 percent. Ammonia evolution is prevented by the utilization of a neutral bonding agent which allows continuous mixing. The propellant also comprises a bimodal AP blend with one ground fraction, ground AP of at least 20 microns, and ferric oxide to control the burning rate. The propellant's characteristics are discussed in terms of tradeoffs in AP particle size and the types of Al powder, bonding agent, and HTPB polymer. The size and shape of the ballistic solids affect the processability, ballistic properties, and structural properties of the propellant. The revised baseline composition is based on maximizing the robustness of in-process viscosity, structural integrity, and burning-rate tailoring range.

  7. Numerical Modeling of Pressurization of a Propellant Tank

    Science.gov (United States)

    Majumdar, Alok; Steadman, Todd

    1999-01-01

    An unsteady finite volume procedure has been developed to predict the history o pressure, temperature and mass flow rate of the pressurant and propellant during the expulsion of the propellant from a tan. The time dependent mass, momentum and energy conservation equations are solved at the ullage space. The model accounts for the change in the ullage volume due to expulsion of the propellant. It also accounts for the heat transfer from the tank wall and propellant to the ullage gas. The procedure was incorporated in the Generalized Fluid System Simulation Program (GFSSP). The results of several test cases were then compared with a published correlation of pressurant requirements for a given displacement of propellant. The agreement between the predictions and the correlation was found to be satisfactory.

  8. Experimental Simulation for Fracture of Gun Propellant Charge Bed

    Institute of Scientific and Technical Information of China (English)

    RUI Xiao-ting; YUN Lai-feng; WANG Hao; HUANG Ming; CHEN Jian-zhong; CHEN Tao; LIU Jun

    2005-01-01

    The simulation of compression and fracture of charge bed in chamber is one of the key problems in the study of launch safety of gun propellant charge. A new kind of experimental device that can be used for simulation is given. Its structure and operational principle are introduced. Using a semi-closed vessel as a source of compression force, the device can simulate any kind of dynamic environment in a gun propellant charge. Using the low temperature inert gas (N2) as the compression medium, the device can not only ensure that the simulation is real, but also protect the fragmentized propellant from combustion after experiment. Using the device, many simulation experiments have been accomplished, and dynamic environment of propellant fracture is acquired. With the experiments, fragmentized propellant for the compression and fracture of charge bed is obtained. Results of experiments show that the new device can be used to study the principle of the compression and fracture of charge bed.

  9. Image based measurement techniques for aircraft propeller flow diagnostics: Propeller slipstream investigations at high-lift conditions and thrust reverse

    NARCIS (Netherlands)

    Roosenboom, E.W.M.

    2011-01-01

    The aim of the thesis is to measure the propeller slipstream properties (velocity and vorticity) and to assess the unsteady and instantaneous behavior of the propeller flow field at high disk loadings, zero thrust and thrust reverse using the image based measurement techniques. Along with its implem

  10. A preliminary study of a propeller powered by gas jets issuing from the blade tips

    Science.gov (United States)

    Sanders, J C; Sanders, N D

    1946-01-01

    Computations are made of the performance of a propeller designed to develop 56 thrust horsepower at 100 miles per hour. The fuel consumption of the jet-operated propeller would be considerably higher than that of a reciprocating engine and a propeller. The lighter weight of the jet-operated propeller will result in a lighter weight of engine plus fuel for short-range flights. A theoretical analysis is made of a propeller powered by gas jets issuing from the blade tips. In the propeller considered, the air is drawn through the hub and passes through the hollow propeller blades to the tips, where propellers heat the air and expel it through the nozzles in the blade tips. The reaction of the tips rotates the propeller. For long range flights, the weight of the jet-operated propeller with its fuel would be greater than the weight of a reciprocating engine with its propeller and fuel.

  11. Solid Propellant Test Article (SPTA) Test Stand

    Science.gov (United States)

    1991-01-01

    This photograph shows the Solid Propellant Test Article (SPTA) test stand with the Modified Nasa Motor (M-NASA) test article at the Marshall Space Flight Center (MSFC). The SPTA test stand, 12-feet wide by 12-feet long by 24-feet high, was built in 1989 to provide comparative performance data on nozzle and case insulation material and to verify thermostructural analysis models. A modified NASA 48-inch solid motor (M-NASA motor) with a 12-foot blast tube and 10-inch throat makes up the SPTA. The M-NASA motor is being used to evaluate solid rocket motor internal non-asbestos insulation materials, nozzle designs, materials, and new inspection techniques. New internal motor case instrumentation techniques are also being evaluated.

  12. Solid Propellant Test Article (SPTA) Test Firing

    Science.gov (United States)

    1989-01-01

    The Marshall Space Flight Center (MSFC) engineers test fired a 26-foot long, 100,000-pound-thrust solid rocket motor for 30 seconds at the MSFC east test area, the first test firing of the Modified NASA Motor (M-NASA Motor). The M-NASA Motor was fired in a newly constructed stand. The motor is 48-inches in diameter and was loaded with two propellant cartridges weighing a total of approximately 12,000 pounds. The purpose of the test was to learn more about solid rocket motor insulation and nozzle materials and to provide young engineers additional hands-on expertise in solid rocket motor technology. The test is a part of NASA's Solid Propulsion Integrity Program, that is to provide NASA engineers with the techniques, engineering tools, and computer programs to be able to better design, build, and verify solid rocket motors.

  13. Solid Hydrogen Experiments for Atomic Propellants

    Science.gov (United States)

    Palaszewski, Bryan

    2001-01-01

    This paper illustrates experiments that were conducted on the formation of solid hydrogen particles in liquid helium. Solid particles of hydrogen were frozen in liquid helium, and observed with a video camera. The solid hydrogen particle sizes, their molecular structure transitions, and their agglomeration times were estimated. article sizes of 1.8 to 4.6 mm (0.07 to 0. 18 in.) were measured. The particle agglomeration times were 0.5 to 11 min, depending on the loading of particles in the dewar. These experiments are the first step toward visually characterizing these particles, and allow designers to understand what issues must be addressed in atomic propellant feed system designs for future aerospace vehicles.

  14. Nature of packs used in propellant modeling.

    Science.gov (United States)

    Maggi, F; Stafford, S; Jackson, T L; Buckmaster, J

    2008-04-01

    In recent years we have constructed closely packed spheres using the Lubachevsky-Stillinger algorithm to generate morphological models of heterogeneous solid propellants. Improvements to the algorithm now allow us to create large polydisperse packs on a laptop computer, and to create monodisperse packs with packing fractions greater than 70% which display significant crystal order. The use of these models in the physical context motivates efforts to examine in some detail the nature of the packs, including certain statistical properties. We compare packing fractions for binary packs with long-known experimental data. Also, we discuss the near-neighbor number and the radial distribution function (RDF) for monodisperse packs and make comparisons with experimental data. We also briefly discuss the RDF for bidisperse packs. We also consider bounded monodisperse packs, and pay particular attention to the near-wall structure where we identify significant order.

  15. Ariane-5 solid-propellant stage development

    Science.gov (United States)

    Gigou, Jacques

    1992-03-01

    The development status of the solid propellant engine (P230) of the Ariane-5 launcher is described. Large new industrial plants were built in Europe and Guiana for the development and manufacture of the solid-booster stage and are now operational. A product assurance policy, specific and common to the companies that are involved in the engine's development, was defined and will be implemented. The paper describes the production cycles for the charged segments, the igniter, and the nozzle for P230 engine, as well as the process of engine integration and testing. Consideration is also given to the engine thrust capability, the launcher flight control, and the interfaces. The the major engine development tests are described.

  16. Wave propelled ratchets and drifting rafts

    Science.gov (United States)

    Eddi, A.; Terwagne, D.; Fort, E.; Couder, Y.

    2008-05-01

    Several droplets, bouncing on a vertically vibrated liquid bath, can form various types of bound states, their interaction being due to the waves emitted by their bouncing. Though they associate droplets which are individually motionless, we show that these bound states are self-propelled when the droplets are of uneven size. The driving force is linked to the assymetry of the emitted surface waves. The direction of this ratchet-like displacement can be reversed, by varying the amplitude of forcing. This direction reversal occurs when the bouncing of one of the drops becomes sub-harmonic. As a generalization, a larger number of bouncing droplets form crystalline rafts which are also shown to drift or rotate when assymetrical.

  17. Effect of Propellant Combustion on Sapphire

    Directory of Open Access Journals (Sweden)

    Mark L. Bundy

    2000-10-01

    Full Text Available Sapphire (Al2O3 is the window material of choice for laser beam transmission into the combustion chamber of laser-ignited guns. To evaluate the long-term effects of propellant combustion on an Al/sub 2/O/sub 3/ laser window, it is important to know the window temperature during firing. This paper presents temperature data on an Al/sub 2/O/sub 3/ sample located in the breech face of the gun where the laser window would be in a laser-ignited 155 mm(M199 cannon. Al/sub 2/O/sub 3/ sample is a substrate material of a commercially sold thin-film thermocouple, and is therefore thermally, if not optically, representative of an actual Al/sub 2/O/sub 3/ laser window.

  18. Primary helium heater for propellant pressurization systems

    Science.gov (United States)

    Reichmuth, D. M.; Nguyen, T. V.; Pieper, J. L.

    1991-01-01

    The primary helium heater is a unique design that provides direct heating of pressurant gas for large pressure fed propulsion systems. It has been conceptually designed to supply a heated (800-1000 R) pressurization gas to both a liquid oxygen and an RP-1 propellant tank. This pressurization gas is generated within the heater by mixing super critical helium (40-300 R and 3000-1600 psi) with an appropriate amount of combustion products from a 4:1 throttling stoichiometric LO2/LH2 combustor. This simple, low cost and reliable mixer utilizes the large quantity of helium to provide stoichiometric combustor cooling, extend the throttling limits and enhance the combustion stability margin. Preliminary combustion, thermal, and CFD analyses confirm that this low-pressure-drop direct helium heater can provide the constant-temperature pressurant suitable for tank pressurization of both fuel and oxidizer tanks of large pressure fed vehicles.

  19. Rheological Characterization of Ethanolamine Gel Propellants

    Science.gov (United States)

    V. S Jyoti, Botchu; Baek, Seung Wook

    2016-07-01

    Ethanolamine is considered to be an environmentally friendly propellant system because it has low toxicity and is noncarcinogenic in nature. In this article, efforts are made to formulate and prepare ethanolamine gel systems, using pure agarose and hybrids of paired gelling agents (agarose + polyvinylpyrrolidine (PVP), agarose + SiO2, and PVP + SiO2), that exhibit a measurable yield stress, thixotropic behavior under shear rate ranges of 1-1,000 s-1 and a viscoelastic nature. To achieve these goals, multiple rheological experiments (including flow and dynamic studies) are performed. In this article, results are presented from experiments measuring the apparent viscosity, yield stress, thixotropy, dynamic strain, frequency sweep, and tan δ behaviors, as well as the effects of the test temperature, in the gel systems. The results show that the formulated ethanolamine gels are thixotropic in nature with yield stress between 30 and 60 Pa. The apparent viscosity of the gel decreases as the test temperature increases, and the apparent activation energy is the lowest for the ethanolamine-(PVP + SiO2) gel system. The dynamic rheology study shows that the type of gellant, choice of hybrid gelling materials and their concentration, applied frequencies, and strain all vitally affect the viscoelastic properties of the ethanolamine gel systems. In the frequency sweep experiment, the ethanolamine gels to which agarose, agarose + PVP, and agarose + SiO2 were added behave like linear frequency-dependent viscoelastic liquids, whereas the ethanolamine gel to which PVP + SiO2 was added behaves like a nearly frequency-independent viscoelastic solid. The variation in the tan δ of these gelled propellants as a function of frequency is also discussed.

  20. Electrochemically powered self-propelled electrophoretic nanosubmarines

    Science.gov (United States)

    Pumera, Martin

    2010-09-01

    In the past few years, we have witnessed rapid developments in the realization of the old nanotechnology dream, autonomous nanosubmarines. These nanomachines are self-powered, taking energy from their environment by electrocatalytic conversion of chemicals present in the solution, self-propelled by flux of the electrons within the submarine and the hydronium ions on the surface of the nanosub, powering it in the direction opposite to that of the flux of the hydronium. These nanosubmarines are responsive to external fields, able to follow complex magnetic patterns, navigate themselves in complex microfluidic channels, follow chemical gradients, carry cargo, and communicate with each other. This minireview focuses on a discussion of the fundamentals of the electrophoretic mechanism underlying the propulsion of this sort of nanosub, as well as a demonstration of the proof-of-concept capabilities of nanosubmarines.In the past few years, we have witnessed rapid developments in the realization of the old nanotechnology dream, autonomous nanosubmarines. These nanomachines are self-powered, taking energy from their environment by electrocatalytic conversion of chemicals present in the solution, self-propelled by flux of the electrons within the submarine and the hydronium ions on the surface of the nanosub, powering it in the direction opposite to that of the flux of the hydronium. These nanosubmarines are responsive to external fields, able to follow complex magnetic patterns, navigate themselves in complex microfluidic channels, follow chemical gradients, carry cargo, and communicate with each other. This minireview focuses on a discussion of the fundamentals of the electrophoretic mechanism underlying the propulsion of this sort of nanosub, as well as a demonstration of the proof-of-concept capabilities of nanosubmarines. In memory of Karel Zeman, Czech animator, who encouraged thousands of young people into science and technology, on the occasion of the 100th

  1. Crusader solid propellant best technical approach

    Energy Technology Data Exchange (ETDEWEB)

    Graves, V. [Oak Ridge National Lab., TN (United States); Bader, G. [Fire Support Armament Center, Picatinny Arsenal, NJ (United States); Dolecki, M. [Tank-Automotive Research, Development, and Engineering Center, Picatinny, NJ (United States); Krupski, S. [Benet Weapons Lab., Watervliet Arsenal, NY (United States); Zangrando, R. [Close Combat Armament Center, Picatinny Arsenal, NJ (United States)

    1995-12-01

    The goal of the Solid Propellant Resupply Team is to develop Crusader system concepts capable of automatically handling 155mm projectiles and Modular Artillery Charges (MACs) based on system requirements. The system encompasses all aspects of handling from initial input into a resupply vehicle (RSV) to the final loading into the breech of the self-propelled howitzer (SPH). The team, comprised of persons from military and other government organizations, developed concepts for the overall vehicles as well as their interior handling components. An intermediate review was conducted on those components, and revised concepts were completed in May 1995. A concept evaluation was conducted on the finalized concepts, from both a systems level and a component level. The team`s Best Technical Approach (BTA) concept was selected from that evaluation. Both vehicles in the BTA have a front-engine configuration with the crew situated behind the engine-low in the vehicles. The SPH concept utilizes an automated reload port at the rear of the vehicle, centered high. The RSV transfer boom will dock with this port to allow automated ammunition transfer. The SPH rearm system utilizes fully redundant dual loaders. Active magazines are used for both projectiles and MACs. The SPH also uses a nonconventional tilted ring turret configuration to maximize the available interior volume in the vehicle. This configuration can be rearmed at any elevation angle but only at 0{degree} azimuth. The RSV configuration is similar to that of the SPH. The RSV utilizes passive storage racks with a pick-and-place manipulator for handling the projectiles and active magazines for the MACs. A telescoping transfer boom extends out the front of the vehicle over the crew and engine.

  2. Velocity field measurements in the wake of a propeller model

    Science.gov (United States)

    Mukund, R.; Kumar, A. Chandan

    2016-10-01

    Turboprop configurations are being revisited for the modern-day regional transport aircrafts for their fuel efficiency. The use of laminar flow wings is an effort in this direction. One way to further improve their efficiency is by optimizing the flow over the wing in the propeller wake. Previous studies have focused on improving the gross aerodynamic characteristics of the wing. It is known that the propeller slipstream causes early transition of the boundary layer on the wing. However, an optimized design of the propeller and wing combination could delay this transition and decrease the skin friction drag. Such a wing design would require the detailed knowledge of the development of the slipstream in isolated conditions. There are very few studies in the literature addressing the requirements of transport aircraft having six-bladed propeller and cruising at a high propeller advance ratio. Low-speed wind tunnel experiments have been conducted on a powered propeller model in isolated conditions, measuring the velocity field in the vertical plane behind the propeller using two-component hot-wire anemometry. The data obtained clearly resolved the mean velocity, the turbulence, the ensemble phase averages and the structure and development of the tip vortex. The turbulence in the slipstream showed that transition could be close to the leading edge of the wing, making it a fine case for optimization. The development of the wake with distance shows some interesting flow features, and the data are valuable for flow computation and optimization.

  3. Propellants: the feasibility of their manufacture in India

    Directory of Open Access Journals (Sweden)

    R. K. Srivastava

    1963-07-01

    Full Text Available In the light of the recent Chinese aggression, the modernization of our defence forces has become a vital necessity. In this paper, one aspect of this problem has been considered in detail viz. the development of an indigenous rocket and missile force. While it is true that many factors e.g. rocket motors, propellants, guidance systems etc. are involved, it is also true that a start in one area will act as an impetus to developments in the other fields. Solid/liquid propellant and oxidizer systems have been considered, the properties of solid and liquid propellants evaluated and on the basis of such comparison, it has been concluded that effort concentrated on the development of liquid propellants will be well expended. Liquid propellant/oxidizer systems have been compared amongst themselves and it has been concluded that the hydrazine fuels oxidized by RFNA/WFNA/IRFNA would represent systems fulfilling the country's immediate military needs best. The availability of raw materials for the manufacture of hydrazine fuels (and also of some solid propellants has been considered and it is shown that the necessary raw materials are available in sufficient quantities to support an indigenous propellants industry.

  4. Propeller aircraft interior noise model: User's manual for computer program

    Science.gov (United States)

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

    1985-01-01

    A computer program entitled PAIN (Propeller Aircraft Interior Noise) has been developed to permit calculation of the sound levels in the cabin of a propeller-driven airplane. The fuselage is modeled as a cylinder with a structurally integral floor, the cabin sidewall and floor being stiffened by ring frames, stringers and floor beams of arbitrary configurations. The cabin interior is covered with acoustic treatment and trim. The propeller noise consists of a series of tones at harmonics of the blade passage frequency. Input data required by the program include the mechanical and acoustical properties of the fuselage structure and sidewall trim. Also, the precise propeller noise signature must be defined on a grid that lies in the fuselage skin. The propeller data are generated with a propeller noise prediction program such as the NASA Langley ANOPP program. The program PAIN permits the calculation of the space-average interior sound levels for the first ten harmonics of a propeller rotating alongside the fuselage. User instructions for PAIN are given in the report. Development of the analytical model is presented in NASA CR 3813.

  5. A review of research in low earth orbit propellant collection

    Science.gov (United States)

    Singh, Lake A.; Walker, Mitchell L. R.

    2015-05-01

    This comprehensive review examines the efforts of previous researchers to develop concepts for propellant-collecting spacecraft, estimate the performance of these systems, and understand the physics involved. Rocket propulsion requires the spacecraft to expend two fundamental quantities: energy and propellant mass. A growing number of spacecraft collect the energy they need to execute propulsive maneuvers in-situ with solar panels. In contrast, every spacecraft using rocket propulsion has carried all of the propellant mass needed for the mission from the ground, which limits the range and mission capabilities. Numerous researchers have explored the concept of collecting propellant mass while in space. These concepts have varied in scale and complexity from chemical ramjets to fusion-driven interstellar vessels. Research into propellant-collecting concepts occurred in distinct eras. During the Cold War, concepts tended to be large, complex, and nuclear powered. After the Cold War, concepts transitioned to solar power sources and more effort has been devoted to detailed analysis of specific components of the propellant-collecting architecture. By detailing the major contributions and limitations of previous work, this review concisely presents the state-of-the-art and outlines five areas for continued research. These areas include air-compatible cathode technology, techniques to improve propellant utilization on atmospheric species, in-space compressor and liquefaction technology, improved hypersonic and hyperthermal free molecular flow inlet designs, and improved understanding of how design parameters affect system performance.

  6. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for......, the return of the BAB factor is low. (4) Increased funding liquidity risk compresses betas toward one. (5) More constrained investors hold riskier assets....... for US equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures. (2) A betting against beta (BAB) factor, which is long leveraged low-beta assets and short high-beta assets, produces significant positive risk-adjusted returns. (3) When funding constraints tighten...

  7. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets........S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...

  8. Imperfect World of $\\beta\\beta$-decay Nuclear Data Sets

    CERN Document Server

    Pritychenko, B

    2015-01-01

    The precision of double-beta ($\\beta\\beta$) decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for $\\beta\\beta$-decay T$_{1/2}^{2\

  9. Numerical Study of the Hull-Propeller-Rudder Interaction

    Science.gov (United States)

    Lungu, Adrian; Pacuraru, Florin

    2009-09-01

    The paper describes the solution of a RANS solver coupled with a body force method as an attempt in investigating the flow features around a maneuvering containership equipped with a rotating propeller and rudder. A special focus is made on the propeller non-symmetrical inflow field, aimed at obtaining the necessary data for the propulsive performances evaluation as well as for the propeller final design. The reported work allows not only the performance evaluation for the overall performances of a hull, but also leads to the development, implementation and validation of new concepts in modeling the turbulent vortical flows, with direct connection to the ship propulsion problem.

  10. The Damage Law of HTPB Propellant under Thermomechanical Loading

    Science.gov (United States)

    Liu, Cheng-wu; Yang, Jian-hong; Wang, Xian-meng; Ma, Yong-kang

    2016-01-01

    By way of measuring the acoustic emission (AE) signals of Hydroxyl-terminated polybutadiene (HTPB) propellant in condition of uniform speed, and combined with the scanning electron microscopy (SEM) fracture surface observation, the damage law of HTPB composite solid propellant under thermomechanical loading was studied. The results show that the effects of thermomechanical loading on HTPB propellant are related to the time and can be divided into three different stages. In the first stage, thermal air aging dominates; in the second stage, interface damage is dominant; and in the third stage, thermal air aging is once again dominant.

  11. Analytical model of the combustion of multicomponent solid propellants

    Science.gov (United States)

    Cohen, N. S.; Price, C. F.; Strand, L. D.

    1977-01-01

    Multiple flame models derived for simple composite propellants are extended to describe the combustion of propellants containing multimodal particle sizes, mixed oxidizers and monopropellant binders. Models combining the component contributions to propellant surface structure, flame structure and energy distribution are based in part upon experimental observations and in part upon hypotheses constrained to provide reasonable agreement with measured burning rate characteristics. The methods employed consist of superposition, interaction and iteration. The computerized model is applied to explain the effects of multiple ingredients and to discuss burning rate tailoring problems of current interest.

  12. Simplified Burn-Rate Model for CMDB Propellants

    Directory of Open Access Journals (Sweden)

    A. R. Kulkarni

    1990-07-01

    Full Text Available A single model has been proposed to predict the burning rates of bimodal AP,RDX and aluminum containing CMDB propellants. This is done in terms of the respective physical constants on the basis of a recently developed model of combustion of CMDB propellants. The study has been carried out to examine the effects of changes in propellants composition, AP particle size and pressures on burning rate. Computer programs were developed for this purpose and the results obtained for typical sets of input data have been presented and compared with the actual results.

  13. Gaussian memory in kinematic matrix theory for self-propellers.

    Science.gov (United States)

    Nourhani, Amir; Crespi, Vincent H; Lammert, Paul E

    2014-12-01

    We extend the kinematic matrix ("kinematrix") formalism [Phys. Rev. E 89, 062304 (2014)], which via simple matrix algebra accesses ensemble properties of self-propellers influenced by uncorrelated noise, to treat Gaussian correlated noises. This extension brings into reach many real-world biological and biomimetic self-propellers for which inertia is significant. Applying the formalism, we analyze in detail ensemble behaviors of a 2D self-propeller with velocity fluctuations and orientation evolution driven by an Ornstein-Uhlenbeck process. On the basis of exact results, a variety of dynamical regimes determined by the inertial, speed-fluctuation, orientational diffusion, and emergent disorientation time scales are delineated and discussed.

  14. Air propellers and their environmental problems on ACV's

    Science.gov (United States)

    Soley, D. H.

    The development of ACV blade protection against erosion, both on the propeller blade faces and leading edge, is considered. Polyurethane spray coating is now the standard protection applied to all Dowty Rotol propellers, with thicknesses from 0.015-0.020 on aircraft, and up to 0.080 on the ACV. The bolt-on guard reduced leading edge replacement time by 50 percent, and makes possible replacement in all weather conditions. Typical damage and repairs to ACV blades are discussed, and the propeller installation on the LCAC craft being built for the U.S. Navy is addressed.

  15. 14 CFR 35.3 - Instructions for propeller installation and operation.

    Science.gov (United States)

    2010-01-01

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

  16. Effects of Nano-Aluminium on The Combustion of A PolyNIMMO-Based Propellant

    Institute of Scientific and Technical Information of China (English)

    Clive Woodley; Peter Henning

    2014-01-01

    Propellants containing micro-aluminium particles have been shown to produce faster burn rates than conventional gun propellants.However,they are also more abrasive than conventional propellants.Nano-material propellants have been reported to give similar benefits to micron-material propellants but without the disadvantage of increased abrasion.Tests were conducted to compare the burn rates,ignitability and wear rates of a propellant loaded with 0% aluminium,15% micro-aluminium and 15%nano-aluminium.Closed vessel tests showed a burn rate increase of 39% in the range 30-250 MPa,and 70% at low pressure (50-100 MPa)for the nano-aluminium propellant compared with the baseline propellant.The micro-aluminium propellant showed only a 10% increase in the burn rate compared with the standard propellant.The ignition delay for the nano-aluminium propellant was slightly shorter than that of the baseline propellant.Substantially increased wear rates were measured for the micro-aluminium propellant.The nano-aluminium propellant showed reduced wear rates compared with the micro-aluminium propellant but these were still substantially greater than those for the baseline propellant.

  17. 30 CFR 75.1403-6 - Criteria-Self-propelled personnel carriers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Criteria-Self-propelled personnel carriers. 75... § 75.1403-6 Criteria—Self-propelled personnel carriers. (a) Each self-propelled personnel carrier..., each track-mounted self-propelled personnel carrier should: (1) Be provided with a suitable...

  18. FANS Simulation of Propeller Wash at Navy Harbors (ESTEP Project ER-201031)

    Science.gov (United States)

    2016-08-01

    with two ducted propellers. This model enables us to evaluate the effect of water depth, ship speed, propeller rotating speed, and pier wall ...propeller blowing to open water , (2) propeller blowing toward a pier wall , and (3) propeller blowing parallel to a pier wall . Since the detailed geometries...9.144 (30 ft) Distance from ship bow to pier wall at waterline (m) 1.8288 (6 ft) Open water 1.8288 (6 ft) Distance from ship stern to pier wall

  19. Measurement of noise and its correlation to performance and geometry of small aircraft propellers

    OpenAIRE

    Štorch Vít; Nožička Jiří; Brada Martin; Gemperle Jiří; Suchý Jakub

    2016-01-01

    A set of small model and UAV propellers is measured both in terms of aerodynamic performance and acoustic noise under static conditions. Apart from obvious correlation of noise to tip speed and propeller diameter the influence of blade pitch, blade pitch distribution, efficiency and shape of the blade is sought. Using the measured performance data a computational model for calculation of aerodynamic noise of propellers will be validated. The range of selected propellers include both propeller...

  20. Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

    OpenAIRE

    Zheng-gang Xiao; San-jiu Ying; Fu-ming Xu

    2014-01-01

    Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN) (TEGDN propellants) to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances...

  1. 78 FR 9001 - Airworthiness Directives; Hamilton Sundstrand Corporation Propellers

    Science.gov (United States)

    2013-02-07

    ... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation... armature, preventing the pump from feathering the propeller. This condition, if not corrected, could...

  2. Propellant and Terrestrial Fuel Production from Atmospheric Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Build and test in a relevant environment a Mars propellant production plant of an appropriate scale for an initial demonstration on Mars. It will produce sufficient...

  3. Self-Propelled Hovercraft Based on Cold Leidenfrost Phenomenon

    Science.gov (United States)

    Shi, Meng; Ji, Xing; Feng, Shangsheng; Yang, Qingzhen; Lu, Tian Jian; Xu, Feng

    2016-06-01

    The Leidenfrost phenomenon of liquid droplets levitating and dancing when placed upon a hot plate due to propulsion of evaporative vapor has been extended to many self-propelled circumstances. However, such self-propelled Leidenfrost devices commonly need a high temperature for evaporation and a structured solid substrate for directional movements. Here we observed a “cold Leidenfrost phenomenon” when placing a dry ice device on the surface of room temperature water, based on which we developed a controllable self-propelled dry ice hovercraft. Due to the sublimated vapor, the hovercraft could float on water and move in a programmable manner through designed structures. As demonstrations, we showed that the hovercraft could be used as a cargo ship or a petroleum contamination collector without consuming external power. This phenomenon enables a novel way to utilize programmable self-propelled devices on top of room temperature water, holding great potential for applications in energy, chemical engineering and biology.

  4. Viscoelastic Behaviour of Solid Propellants based on Various Polymeric Binders

    Directory of Open Access Journals (Sweden)

    N. Prabhakaran

    1995-01-01

    Full Text Available The dynamic mechanical properties of different binders and corresponding propellants are studied in terms of storage modulus and loss tangent. The binders investigated are HTPB, CTPB, PBAN, HEF-20 and ISRO polyol. The viscoelastic behaviour is investigated using Rheovibron viscoelastometer at 35 Hz covering a wide temperature range (-100 degree centigrade to 100 degree centigrade. The properties of the binder and corresponding propellant are compared in terms of parameters, tan delta/sub max/, T/sub g/ and the trend of their master relaxation modulus curves. It is found that polybutadiene binders exhibit lowest T/sub g/ (around -60 degree centigrade and ISRO polyol the highest (near -20 degree centigrade. The propellants have higher moduli than the binders at any temperature. The master relaxation modulus curve is influenced by the type of propellant.

  5. Propellant Preparation Laboratory Complex (Area1-21)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: Area 1-21 is an explosion resistant complex of nine cells built into the side of a granite ridge. Three solid propellant cutting cells are housed in the...

  6. Optimum Disposition of Metal Particles in the Propellant Grain

    Directory of Open Access Journals (Sweden)

    Leonid L. Minkov

    2014-01-01

    Full Text Available Using the dispersed metal in solid propellants to increase the temperature of combustion products leads to such a problem as the specific impulse loss due to the incomplete combustion of metal particles in the exhaust products. A redistribution of metal loaded into the propellant grain is one of the methods to decrease the specific impulse loss. This paper reports on the ways to obtain the optimum metal particle disposition for the case-bounded propellant grain of tube cross-sectional type. Three different approaches to analyze the metal combustion efficiency are discussed. The influence of the dynamic nonequilibrium of two-phase flow on the optimum metal particles disposition in the propellant grain of tube cross-sectional type is investigated.

  7. Some Observations on the Ignition of Composite Solid Propellants

    Directory of Open Access Journals (Sweden)

    K. Kishore

    1995-07-01

    Full Text Available Heat-up times derived from studies on the ignition characteristics of a few model composite solid propellants, containing polystyrene, carboxy-terminated polybutadiene, plasticised polyvinyl chloride and polyphenol formaldehyde as binders, show that they are directly proportional to the mass of the sample and inversely proportional to the heat flux. Propellant weight-loss prior to ignition and high pressure ignition temperature data on the propellants, ammonium per chlorate, and binders show that the ignition is governed by the gasification of the binder pyrolysis products. The activation energy for the gasification of the pyrolysed polymer products corresponds to their ignition behaviour suggesting that propellant ignition is controlled by the binder.

  8. Dynamic characterization and analysis of space shuttle SRM solid propellant

    Science.gov (United States)

    Hufferd, W. L.

    1979-01-01

    The dynamic response properties of the space shuttle solid rocket moter (TP-H1148) propellant were characterized and the expected limits of propellant variability were established. Dynamic shear modulus tests conducted on six production batches of TP-H1148 at various static and dynamic strain levels over the temperature range from 40 F to 90 F. A heat conduction analysis and dynamic response analysis of the space shuttle solid rocket motor (SRM) were also conducted. The dynamic test results show significant dependence on static and dynamic strain levels and considerable batch-to-batch and within-batch variability. However, the results of the SRM dynamic response analyses clearly demonstrate that the stiffness of the propellant has no consequential on the overall SRM dynamic response. Only the mass of the propellant needs to be considered in the dynamic analysis of the space shuttle SRM.

  9. Advanced Insulation Materials for Cryogenic Propellant Storage Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Materials Technology, Inc responds to the NASA solicitation Topic X9 entitled "Propulsion and Propellant Storage" under subtopic X9-01, "Long Term Cryogenic...

  10. Propellant Flow Actuated Piezoelectric Rocket Engine Igniter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Under a Phase 1 effort, IES successfully developed and demonstrated a spark ignition concept where propellant flow drives a very simple fluid mechanical oscillator...

  11. AN AIRPLANE WITH UNCONVENTIONALLY PLACED PROPELLER POWER UNIT

    Directory of Open Access Journals (Sweden)

    Jan Červinka

    2017-02-01

    Full Text Available The significance of the influence of operating propellers on the aircraft aerodynamic characteristics is well-known. Wind tunnel testing of an airplane model with operating propellers is a complex task regarding the required similarity of the full-scale and the model case. Matching sufficient similarity in axial and rotational velocities in the propeller slipstream is the primordial condition for the global aerodynamic similarity of the windtunnel testing. An example of the model power units with related devices is presented. Examples of the wind tunnel testing results illustrate the extent of the propeller influence on aerodynamic characteristics of an aircraft of unconventional configuration with power units positioned at the fuselage afterbody.

  12. Model-based Diagnostics for Propellant Loading Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The loading of spacecraft propellants is a complex, risky operation. Therefore, diagnostic solutions are neces- sary to quickly identify when a fault occurs, so that...

  13. Propellant Flow Actuated Piezoelectric Rocket Engine Igniter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spark ignition of a bi-propellant rocket engine is a classic, proven, and generally reliable process. However, timing can be critical, and the control logic,...

  14. Gun barrel erosion - Comparison of conventional and LOVA gun propellants

    NARCIS (Netherlands)

    Hordijk, A.C.; Leurs, O.

    2006-01-01

    The research department Energetic Materials within TNO Defence, Security and Safety is involved in the development and (safety and insensitive munitions) testing of conventional (nitro cellulose based) and thermoplastic elastomer (TPE) based gun propellants. Recently our testing capabilities have be

  15. Modified Collins Cryocooler for Cryo-Propellant Thermal Management Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future lunar and planetary explorations will require the storage of cryogenic propellants, particularly liquid oxygen (LOX) and liquid hydrogen (LH2), in low earth...

  16. Dynamical Model of Rocket Propellant Loading with Liquid Hydrogen

    Data.gov (United States)

    National Aeronautics and Space Administration — A dynamical model describing the multi-stage process of rocket propellant loading has been developed. It accounts for both the nominal and faulty regimes of...

  17. Negative Beta Encoder

    CERN Document Server

    Kohda, Tohru; Aihara, Kazuyuki

    2008-01-01

    A new class of analog-digital (A/D), digital-analog (D/A) converters as an alternative to conventional ones, called $\\beta$-encoder, has been shown to have exponential accuracy in the bit rates while possessing self-correction property for fluctuations of amplifier factor $\\beta$ and quantizer threshold $\

  18. Double beta decay experiments

    CERN Document Server

    Barabash, A S

    2011-01-01

    The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.

  19. Prediction of propeller-induced hull-pressure fluctuations

    OpenAIRE

    Van Wijngaarden, H.C.J.

    2011-01-01

    The cavitating propeller often forms the primary source of noise and vibration on board ships. The propeller induces hydroacoustic pressure fluctuations due to the passing blades and, more importantly, the dynamic activity of cavities in the propeller’s immediate vicinity. The accurate prediction of the resulting vibratory hull-excitation forces is indispensible in the ship design process, but is not always warranted. From this follows the main objective of the thesis, which is the developmen...

  20. Ballistic evaluationof LOVA propellant in high calibre gun

    OpenAIRE

    A.G.S. Pillai; R. R. Sanghavi; C. R. Dayanandan; M. M. Joshi; J. S. Karir

    2001-01-01

    'This paper presents the data obrained on dynamic firing of a cellulose acetate binder-based low vulnerability ammunition (LOV A) propellant using 120 mm fin-stabilised armour piercing discarding sabot (FSAPDS) kinetic energyammunition. An optimised propellant composition formulated ~sing fine RDX as an energetic ingredient and a mixture of cellulose acetate and nitrocellulose as binder was qualified fit for firing in a high calibre gun by its successful static evaluation for absolute...

  1. The Thermodynamics of Interior Ballistics and Propellant Performance

    Science.gov (United States)

    2013-11-01

    modified version of a JANNAF paper presented at the 29 th JANNAF Combustion Subcommittee Meeting, NASA Langley Research Center , Hampton, VA, 19–21... called the chemical energy [CE = I/(γ − 1)] is also usually calculated, since it is sometimes viewed as one of the traditional measures of propellant...before burnout , Lagrange gradient, no losses—the processes delineating propellant performance (and the conditions at muzzle) are calculated via BLAKE

  2. Prevention of propeller foreign object damage - Theory and practice

    Science.gov (United States)

    Payne, C.; Vitale, D. J.

    Foreign object damage hazards to which ACV propellers are exposed, and the phenomena causing the damage, are discussed. Comparison of the effects of energy absorption in systems of hard, soft, smooth and rough particles impacting upon soft and hard propeller materials is made. Molded urethane strips were found to increase the life of the blades from 20 minutes between maintenance actions to nine hours between maintenance actions. Molded urethanes and sprayed or brushed urethanes are compared.

  3. A Semi-Automatic Thickness Inspection Technique for Marine Propellers

    Institute of Scientific and Technical Information of China (English)

    M; K; Lam; S; F; Lee; C; S; Lam; W; S; Chow; P; Iovenitti; S; H; Masood

    2002-01-01

    This paper describes the design and development of a Semi-Automatic Precision Caliper System to measure the thickness of an outboard marine engine propeller blade. Several commonly used methods for measuring the thickness of a propeller blade are reviewed in this paper. These include the P rops Scan, 3D Vision System and Black Dog. However, the operating practices and availability of different facilities in industry necessitate a more cost-effect ive approach. An alternative method using a Semi-Auto...

  4. Atmospheric Processing Module for Mars Propellant Production

    Science.gov (United States)

    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.

  5. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... Understand Genetics Home Health Conditions beta thalassemia beta thalassemia Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Beta thalassemia is a blood disorder that reduces the production ...

  6. Analysis of Metallised Propellant Ignition Process under Conductive Heating

    Directory of Open Access Journals (Sweden)

    K. A. Bhaskaran

    1998-07-01

    Full Text Available Ignition of a composite aluminised propellant (AP-HTPB-Al in stagnant hot air is analysed theoretically, based on solid phase and gas phase theories. According to solid phase theory, ignition is due to reaction of the propellant in the solid phase at elevated temperatures. One-dimensional transient solid phase energy equation is solved to obtain the surface temperature profile of the propellant. By gas phase theory, an exothermic gas phase reaction, adjacent to the propellant surface, is considered responsible for the ignition. The changes in temperature and concentrations in the gas phase and the temperature profile below the propellant surface during the pre-ignition induction period are considered. Equations of energy and concentrations of reactants have been solved to obtain the species concentration and temperature profiles in the gas phase. An experimental investigation of the ignition of AP-HTPB-Al propellant is also carried out in a shock tube under end-mount conditions. Pressure and temperature ranges were 6-16 bar and 1500-3000 K, respectively. A comparison of the experimental data with predicted results shows that the ignition in an oxidizing atmosphere is by gas phase reaction, whereas in an inert atmosphere, solid phase reaction may be predominant.

  7. Development of a solid propellant viscoelastic dynamic model

    Science.gov (United States)

    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.

  8. An assessment of propeller aircraft noise reduction technology

    Science.gov (United States)

    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.

  9. The NASA aircraft noise prediction program improved propeller analysis system

    Science.gov (United States)

    Nguyen, L. Cathy

    1991-01-01

    The improvements and the modifications of the NASA Aircraft Noise Prediction Program (ANOPP) and the Propeller Analysis System (PAS) are described. Comparisons of the predictions and the test data are included in the case studies for the flat plate model in the Boundary Layer Module, for the effects of applying compressibility corrections to the lift and pressure coefficients, for the use of different weight factors in the Propeller Performance Module, for the use of the improved retarded time equation solution, and for the effect of the number grids in the Transonic Propeller Noise Module. The DNW tunnel test data of a propeller at different angles of attack and the Dowty Rotol data are compared with ANOPP predictions. The effect of the number of grids on the Transonic Propeller Noise Module predictions and the comparison of ANOPP TPN and DFP-ATP codes are studied. In addition to the above impact studies, the transonic propeller noise predictions for the SR-7, the UDF front rotor, and the support of the enroute noise test program are included.

  10. Performance Evaluation and Experimental Studies on Metallised Gel Propellants

    Directory of Open Access Journals (Sweden)

    T. L. Varghese

    1999-01-01

    Full Text Available Metallised gel propellants offer higher specific impulse and volumetric loading, reduced vaporisation loss, spillage and slosh problems and easy storage in comparison to the conventional liquid propellants. Theoretical performance analysis of gel propellant containing Al in unsymmetrical dimethyl hydrazine-dinitrogen tetroxide (UDMH-N/sub 2/O/sub 4} system shows peak Isp (vacuum condition of 316.7 s and 318.3 s at oxidiser/fuel (O/f ratios of 1.5 and 1.0, respectively for 30 per cent and 40 per cent UDMH-Al gel propellants, under standard conditions. The effect of other parameters like area ratio and chamber pressure on performance has been brought out in view of mission oriented applications. Aluminium has been found to be a better choice over magnesium in metallised gel propellants. Experimental studies on UDMH gellation using propellant grade (15 micrometerand pyrotechnic grade (1.5 micrometerAl in 500g batch level show that gellant(methyl cellulose concentration could be reduced by 50 percent using pyrotechnic grade Al. The pseudoplastic-thixotropic behaviour, flow rate through die holes, burst pressure tests and bulk density are studied. UDMH -25 to 30 per cent Al gels with both grades of Al are found to be stable, pseudoplastic (shear thinning and thixotropic (time-dependent shear thinning, but their flow pattern through die holes differ in nature.

  11. Glycidyl Azide Polymer-based Enhanced Energy LOVA Gun Propellant

    Directory of Open Access Journals (Sweden)

    R. R. Sanghavi

    2006-07-01

    Full Text Available In this study, cyclotrimethylene trinitramine propellants with triacetin (TA-plasticisedcellulose acetate (CA and nitrocellulose (NC combination as binders were evaluated for lowvulnerable ammunition (LOVA. Triacetin was replaced by energetic plasticiser; glycidyl azidepolymer (GAP in increments to enhance the performance in terms of force constant . In additionto ballistics, parameters like vulnerability, mechanical and thermal properties of GAP-basedpropellants in comparison to those of TA-based propellants, were also determined. The studybrings out that the incorporation of 2-6 per cent GAP in place of TA resulted in the enhancementof force constant by 22-70 J/g and improved overall combustion characteristics. DSC revealedthat thermal decomposition of GAP-LOVA propellants evolved more energy than TA-LOVApropellants. GAP-based LOVA propellant similar to TA-plasticised LOVA propellant, was foundsuperior to NQ propellant in vulnerability tests as well as in hot fragment conductive ignition(HFCI studies. As regards mechanical properties, incorporation of GAP resulted in improvedcompression strength.

  12. Prediction of span loading of straight-wing/propeller combinations up to stall. [propeller slipstreams and wing loading

    Science.gov (United States)

    Mcveigh, M. A.; Gray, L.; Kisielowski, E.

    1975-01-01

    A method is presented for calculating the spanwise lift distribution on straight-wing/propeller combinations. The method combines a modified form of the Prandtl wing theory with a realistic representation of the propeller slipstream distribution. The slipstream analysis permits calculations of the nonuniform axial and rotational slipstream velocity field of propeller/nacelle combinations. This nonuniform field was then used to calculate the wing lift distribution by means of the modified Prandtl wing theory. The theory was developed for any number of nonoverlapping propellers, on a wing with partial or full-span flaps, and is applicable throughout an aspect ratio range from 2.0 and higher. A computer program was used to calculate slipstream characteristics and wing span load distributions for a number of configurations for which experimental data are available, and favorable comparisons are demonstrated between the theoretical predictions and the existing data.

  13. Rapid synthesis of beta zeolites

    Science.gov (United States)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  14. Investigation of Ignition of Liquid Propellant in Reservoir in Regenerative Liquid Propellant Gun Trials

    Directory of Open Access Journals (Sweden)

    D. K. Kharat

    1997-04-01

    Full Text Available It is important to understand the internal ballistic processes for the development of regenerative liquid propellant guns (RLPGs. A 30 mm RLPG test fixture was developed and firing trials were conducted to study the performance of the gun. During the trials, sometimes, combustion ignition in the reservoir took place resulting in substantial damage to the injection piston. This paper highlights the possible causes of this combustion and offers suggestions. regarding improvement in the design. An elaborate instrumentation set-up which could pinpoint the specific conditions leading to failures is suggested.

  15. Performance and slipstream characteristics of small-scale propellers at low Reynolds numbers

    Science.gov (United States)

    Deters, Robert W.

    The low Reynolds number effects of small-scale propellers were investigated. At the Reynolds numbers of interest (below 100,000), a decrease in lift and an increase in drag is common making it difficult to predict propeller performance characteristics. A propeller testing apparatus was built to test small scale propellers in static conditions and in an advancing flow. Twenty-seven off-the-shelf propellers, with diameters ranging from 2.25 in to 9 in, were tested in order to determine the general effects of low Reynolds numbers on small propellers. From these tests, increasing the Reynolds number for a propeller increases its efficiency by either increasing the thrust produced or decreasing the power. By doubling the Reynolds number of a propeller, it is not uncommon to increase the efficiency by more the 10%. Using off-the-shelf propellers limits the geometry available and finding propellers of the same geometry but of different scale is very difficult. To solve this problem, four propellers were design and built using a 3D printer. Two of the propellers were simple rectangular twisted blades of different chords. Another propeller was modeled after a full-scale propeller. The fourth propeller was created using inverse design to minimize power loss. Each propeller was built in a 5-in and 9-in diameter version in order to test a larger range of Reynolds numbers. A separate propeller blade and hub system was created to allow each propeller to be tested with different pitch angles and to test each propeller in a 2-, 3-, and 4-blade version. From the performance results of the 3D printed propellers, it was shown that propellers of different scale, but tested at the same Reynolds number, had about the same performance results. Finally, the slipstreams of different propellers were measured using a 7-hole probe. Propeller slipstreams can have a large effect on the aerodynamics of lifting surfaces downstream of the propeller. Small UAVs and MAVs flying in close proximity

  16. Combustion response modeling for composite solid propellants

    Science.gov (United States)

    1977-01-01

    A computerized mathematical model of the combustion response function of composite solid propellants was developed with particular attention to the contributions of the solid phase heterogeneity. The one-dimensional model treats the solid phase as alternating layers of ammonium perchlorate and binder, with an exothermic melt layer at the surface. Solution of the Fourier heat equation in the solid provides temperature and heat flux distributions with space and time. The problem is solved by conserving the heat flux at the surface from that produced by a suitable model of the gas phase. An approximation of the BDP flame model is utilized to represent the gas phase. By the use of several reasonable assumptions, it is found that a significant portion of the problem can be solved in closed form. A method is presented by which the model can be applied to tetramodal particle size distributions. A computerized steady-state version of the model was completed, which served to validate the various approximations and lay a foundation for the combustion response modeling. The combustion response modeling was completed in a form which does not require an iterative solution, and some preliminary results were acquired.

  17. A Liquefier for Mars Surface Propellant Production

    Science.gov (United States)

    Salerno, Lou J.; Helvensteijn, B. P. M.; Kittel, P.; Arnold, James O. (Technical Monitor)

    1999-01-01

    NASA's planned Mars exploration missions will require that cryogenic propellants be manufactured on the surface. The present scenario calls for oxygen and methane gases to he produced using the carbon dioxide atmosphere plus seed hydrogen brought from Earth. Gases will require liquefaction for both storage on the Martian surface and for use in the ascent vehicle. The planned liquefaction rates range from 12.6 g/hr of oxygen for the 2003 robotic mission to 2500 g/hr for the later human missions. This paper presents the results of a nitrogen liquefaction demonstration using a commercially available cryocooler. The experiment was set up to liquefy nitrogen gas instead of oxygen to limit laboratory safety concerns. A nitrogen gas condensor, attached to the cooler's cold tip, was sized to liquefy up to 42 gN2/hr at the intended storage pressure (0.2 MPa). The experiment was conducted inside an atmospheric, air-filled, refrigerated chamber simulating the average Martian daytime temperature (240 K). In this demonstration a liquefaction rate of 9.1 gN2/hr was realized, which is equivalent to 13 gO2/hr.

  18. Energy production with a tubular propeller turbine

    Science.gov (United States)

    Samora, I.; Hasmatuchi, V.; Münch-Alligné, C.; Franca, M. J.; Schleiss, A. J.; Ramos, H. M.

    2016-11-01

    Micro-hydropower is a way of improving the energetic efficiency of existent water systems. In the particular case of drinking water systems, several studies have showed that pressure reducing valves can be by-passed with turbines in order to recover the dissipated hydraulic energy to produce electricity. As conventional turbines are not always cost-effective for power under 20 kW, a new energy converter is studied. A five blade tubular propeller (5BTP), assessed through laboratorial tests on a reduced model with a diameter of 85 mm diameter and a maximal output power of 300 W, is addressed in this work. Having showed promising potential for further development, since global efficiencies of around 60% were observed, the turbine has been further used to estimate the potential for energy production in a real case study. A sub-grid of the drinking water system of the city of Lausanne, Switzerland, has been used to obtain an annual energy production through hourly simulations with several turbines.

  19. TNT equivalency of M10 propellant

    Science.gov (United States)

    Mcintyre, F. L.; Price, P.

    1978-01-01

    Peak, side-on blast overpressure and scaled, positive impulse have been measured for M10 single-perforated propellant, web size 0.018 inches, using configurations that simulate the handling of bulk material during processing and shipment. Quantities of 11.34, 22.7, 45.4, and 65.8 kg were tested in orthorhombic shipping containers and fiberboard boxes. High explosive equivalency values for each test series were obtained as a function of scaled distance by comparison to known pressure, arrival time and impulse characteristics for hemispherical TNT surface bursts. The equivalencies were found to depend significantly on scaled distance, with higher values of 150-100 percent (pressure) and 350-125 percent (positive impulse) for the extremes within the range from 1.19 to 3.57 m/cube root of kg. Equivalencies as low as 60-140 percent (pressure) and 30-75 percent (positive impulse) were obtained in the range of 7.14 to 15.8 m/cube root of kg. Within experimental error, both peak pressure and positive impulse scaled as a function of charge weight for all quantities tested in the orthorhombic configuration.

  20. LNG systems for natural gas propelled ships

    Science.gov (United States)

    Chorowski, M.; Duda, P.; Polinski, J.; Skrzypacz, J.

    2015-12-01

    In order to reduce the atmospheric pollution generated by ships, the International Marine Organization has established Emission Controlled Areas. In these areas, nitrogen oxides, sulphur oxides and particulates emission is strongly controlled. From the beginning of 2015, the ECA covers waters 200 nautical miles from the coast of the US and Canada, the US Caribbean Sea area, the Baltic Sea, the North Sea and the English Channel. From the beginning of 2020, strong emission restrictions will also be in force outside the ECA. This requires newly constructed ships to be either equipped with exhaust gas cleaning devices or propelled with emission free fuels. In comparison to low sulphur Marine Diesel and Marine Gas Oil, LNG is a competitive fuel, both from a technical and economical point of view. LNG can be stored in vacuum insulated tanks fulfilling the difficult requirements of marine regulations. LNG must be vaporized and pressurized to the pressure which is compatible with the engine requirements (usually a few bar). The boil-off must be controlled to avoid the occasional gas release to the atmosphere. This paper presents an LNG system designed and commissioned for a Baltic Sea ferry. The specific technical features and exploitation parameters of the system will be presented. The impact of strict marine regulations on the system's thermo-mechanical construction and its performance will be discussed. The review of possible flow-schemes of LNG marine systems will be presented with respect to the system's cost, maintenance, and reliability.

  1. Burning rate characteristics of energetic CMDB propellants (III). Effect of initial propellant temperature; Ko energy CMDB suishinyaku no nensho sokudo tokusei (III). Suishinyaku shoki ondo no koka

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, I. [Nissan Motor Co. Ltd., Tokyo (Japan)

    1998-01-01

    In case of double-base properants, the temperature sensitivity of burning rate for this type of propellants having higher energy becomes smaller than that of propellants having lower energy. When the energy contained in propellants increases, or initial propellant temperatures increase, the burning surface temperature of propellant increases, therefore, the reaction in fizz zone is accelerated, the dark zone temperature increases, and the temperature gradient in fizz zone increases. This increase of temperature gradient increases the burning rate of propellant. In case of HMX-CMDB propellants, when the energy contained in propellants increases, or initial propellant temperatures decrease, the burning surface temperature of propellant decreases, therefore, the reaction in fizz zone is decelerated, the dark zone temperature decreases, and the temperature gradient in fizz zone decreases. This decrease of temperature gradient decreases the burning rate of propellant. As a result, it was clarified that the temperatures as common physical properties which had an effect of initial propellant temperatures on the burning rates were the burning surface temperature and the dark zone temperature. 22 refs., 12 figs., 2 tabs.

  2. 76 FR 27281 - Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller...

    Science.gov (United States)

    2011-05-11

    ..., Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New... Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park..., Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. BILLING CODE 4910-13-P...

  3. Unsteady Aerodynamic Investigation of the Propeller-Wing Interaction for a Rocket Launched Unmanned Air Vehicle

    Directory of Open Access Journals (Sweden)

    G. Q. Zhang

    2013-01-01

    Full Text Available The aerodynamic characteristics of propeller-wing interaction for the rocket launched UAV have been investigated numerically by means of sliding mesh technology. The corresponding forces and moments have been collected for axial wing placements ranging from 0.056 to 0.5D and varied rotating speeds. The slipstream generated by the rotating propeller has little effects on the lift characteristics of the whole UAV. The drag can be seen to remain unchanged as the wing's location moves progressively closer to the propeller until 0.056D away from the propeller, where a nearly 20% increase occurred sharply. The propeller position has a negligible effect on the overall thrust and torque of the propeller. The efficiency affected by the installation angle of the propeller blade has also been analyzed. Based on the pressure cloud and streamlines, the vortices generated by propeller, propeller-wing interaction, and wing tip have also been captured and analyzed.

  4. Compact and Integrated Liquid Bismuth Propellant Feed System

    Science.gov (United States)

    Polzin, Kurt A.; Stanojev, Boris; Korman, Valentin; Gross, Jeffrey T.

    2007-01-01

    Operation of Hall thrusters with bismuth propellant has been shown to be a promising path toward high-power, high-performance, long-lifetime electric propulsion for spaceflight missions [1]. There has been considerable effort in the past three years aimed at resuscitating this promising technology and validating earlier experimental results indicating the advantages of a bismuth-fed Hall thruster. A critical element of the present effort is the precise metering of propellant to the thruster, since performance cannot be accurately assessed without an accurate accounting of mass flow rate. Earlier work used a pre./post-test propellant weighing scheme that did not provide any real-time measurement of mass flow rate while the thruster was firing, and makes subsequent performance calculations difficult. The motivation of the present work is to develop a precision liquid bismuth Propellant Management System (PMS) that provides hot, molten bismuth to the thruster while simultaneously monitoring in real-time the propellant mass flow rate. The system is a derivative of our previous propellant feed system [2], but the present system represents a more compact design. In addition, all control electronics are integrated into a single unit and designed to reside on a thrust stand and operate in the relevant vacuum environment where the thruster is operating, significantly increasing the present technology readiness level of liquid metal propellant feed systems. The design of various critical components in a bismuth PMS are described. These include the bismuth reservoir and pressurization system, 'hotspot' flow sensor, power system and integrated control system. Particular emphasis is given to selection of the electronics employed in this system and the methods that were used to isolate the power and control systems from the high-temperature portions of the feed system and thruster. Open loop calibration test results from the 'hotspot' flow sensor are reported, and results of

  5. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  6. Flagellated ectosymbiotic bacteria propel a eucaryotic cell.

    Science.gov (United States)

    Tamm, S L

    1982-09-01

    A devescovinid flagellate from termites exhibits rapid gliding movements only when in close contact with other cells or with a substrate. Locomotion is powered not by the cell's own flagella nor by its remarkable rotary axostyle, but by the flagella of thousands of rod bacteria which live on its surface. That the ectosymbiotic bacteria actually propel the protozoan was shown by the following: (a) the bacteria, which lie in specialized pockets of the host membrane, bear typical procaryotic flagella on their exposed surface; (b) gliding continues when the devescovinid's own flagella and rotary axostyle are inactivated; (c) agents which inhibit bacterial flagellar motility, but not the protozoan's motile systems, stop gliding movements; (d) isolated vesicles derived from the surface of the devescovinid rotate at speeds dependent on the number of rod bacteria still attached; (e) individual rod bacteria can move independently over the surface of compressed cells; and (f) wave propagation by the flagellar bundles of the ectosymbiotic bacteria is visualized directly by video-enhanced polarization microscopy. Proximity to solid boundaries may be required to align the flagellar bundles of adjacent bacteria in the same direction, and/or to increase their propulsive efficiency (wall effect). This motility-linked symbiosis resembles the association of locomotory spirochetes with the Australian termite flagellate Mixotricha (Cleveland, L. R., and A. V. Grimstone, 1964, Proc. R. Soc. Lond. B Biol. Sci., 159:668-686), except that in our case propulsion is provided by bacterial flagella themselves. Since bacterial flagella rotate, an additional novelty of this system is that the surface bearing the procaryotic rotary motors is turned by the eucaryotic rotary motor within.

  7. Stability of laser-propelled wafer satellites

    Science.gov (United States)

    Srinivasan, Prashant; Hughes, Gary B.; Lubin, Philip; Zhang, Qicheng; Madajian, Jonathan; Brashears, Travis; Kulkarni, Neeraj; Cohen, Alexander; Griswold, Janelle

    2016-09-01

    For interstellar missions, directed energy is envisioned to drive wafer-scale spacecraft to relativistic speeds. Spacecraft propulsion is provided by a large array of phase-locked lasers, either in Earth orbit or stationed on the ground. The directed-energy beam is focused on the spacecraft, which includes a reflective sail that propels the craft by reflecting the beam. Fluctuations and asymmetry in the beam will create rotational forces on the sail, so the sail geometry must possess an inherent, passive stabilizing effect. A hyperboloid shape is proposed, since changes in the incident beam angle due to yaw will passively counteract rotational forces. This paper explores passive stability properties of a hyperboloid reflector being bombarded by directed-energy beam. A 2D cross-section is analyzed for stability under simulated asymmetric loads. Passive stabilization is confirmed over a range of asymmetries. Realistic values of radiation pressure magnitude are drawn from the physics of light-mirror interaction. Estimates of beam asymmetry are drawn from optical modeling of a laser array far-field intensity using fixed and stochastic phase perturbations. A 3D multi-physics model is presented, using boundary conditions and forcing terms derived from beam simulations and lightmirror interaction models. The question of optimal sail geometry can be pursued, using concepts developed for the baseline hyperboloid. For example, higher curvature of the hyperboloid increases stability, but reduces effective thrust. A hyperboloid sail could be optimized by seeking the minimum curvature that is stable over the expected range of beam asymmetries.

  8. Alpha and Beta Determinations

    CERN Document Server

    Dunietz, Isard

    1999-01-01

    Because the Bd -> J/psi Ks asymmetry determines only sin(2 beta), a discrete ambiguity in the true value of beta remains. This note reviews how the ambiguity can be removed. Extractions of the CKM angle alpha are discussed next. Some of the methods require very large data samples and will not be feasible in the near future. In the near future, semi-inclusive CP-violating searches could be undertaken, which are reviewed last.

  9. Quantitative Assessment of the Condensed Phase Heats of Reaction in a Double Base Propellant

    Directory of Open Access Journals (Sweden)

    K. Kishore

    1985-01-01

    Full Text Available Heat of decomposition of the double base propellant has been calculated from the knowledge of the composition and decomposition enthalpy of the ingredients. This was compared with the experimentally observed value of the propellant decomposition which suggested that condensed phase contribution is very marginal (one twentieth of the total calorimetric value in double base propellants unlike composite solid propellants where condensed phase contribution is as high as one third. The condensed-phase in double base propellant was attributed to the nitration of the 2n-diphenylamine stabilizer in the propellant matrix.

  10. Measurement of noise and its correlation to performance and geometry of small aircraft propellers

    Science.gov (United States)

    Štorch, Vít; Nožička, Jiří; Brada, Martin; Gemperle, Jiří; Suchý, Jakub

    2016-03-01

    A set of small model and UAV propellers is measured both in terms of aerodynamic performance and acoustic noise under static conditions. Apart from obvious correlation of noise to tip speed and propeller diameter the influence of blade pitch, blade pitch distribution, efficiency and shape of the blade is sought. Using the measured performance data a computational model for calculation of aerodynamic noise of propellers will be validated. The range of selected propellers include both propellers designed for nearly static conditions and propellers that are running at highly offdesign conditions, which allows to investigate i.e. the effect of blade stall on both noise level and performance results.

  11. Measurement of noise and its correlation to performance and geometry of small aircraft propellers

    Directory of Open Access Journals (Sweden)

    Štorch Vít

    2016-01-01

    Full Text Available A set of small model and UAV propellers is measured both in terms of aerodynamic performance and acoustic noise under static conditions. Apart from obvious correlation of noise to tip speed and propeller diameter the influence of blade pitch, blade pitch distribution, efficiency and shape of the blade is sought. Using the measured performance data a computational model for calculation of aerodynamic noise of propellers will be validated. The range of selected propellers include both propellers designed for nearly static conditions and propellers that are running at highly offdesign conditions, which allows to investigate i.e. the effect of blade stall on both noise level and performance results.

  12. Discussion on Mechanism of Breech-Blow Caused by Propellant Charge

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    From the view point of launch safety caused by fracture of propellant charge, this paper points out that the safety criterion of pressure wave is inadequate to evaluate the launch safety of propellant charge based on the initial negative differential pressure and sensitivity tests. Generally, the maximum barrel pressure does not depend upon the intensity of pressure wave correspondingly. The pressure wave intensity can not describe the fracture degree of propellant charge in chamber and reflect the mechanical environment of propellant charge fracturing exactly and wholly. The evaluation criterion for launch safety of propellant charge should be built on the basis of depicting the fracture degree of propellant bed.

  13. {beta} - amyloid imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

  14. Beta cell dynamics: beta cell replenishment, beta cell compensation and diabetes.

    Science.gov (United States)

    Cerf, Marlon E

    2013-10-01

    Type 2 diabetes, characterized by persistent hyperglycemia, arises mostly from beta cell dysfunction and insulin resistance and remains a highly complex metabolic disease due to various stages in its pathogenesis. Glucose homeostasis is primarily regulated by insulin secretion from the beta cells in response to prevailing glycemia. Beta cell populations are dynamic as they respond to fluctuating insulin demand. Beta cell replenishment and death primarily regulate beta cell populations. Beta cells, pancreatic cells, and extra-pancreatic cells represent the three tiers for replenishing beta cells. In rodents, beta cell self-replenishment appears to be the dominant source for new beta cells supported by pancreatic cells (non-beta islet cells, acinar cells, and duct cells) and extra-pancreatic cells (liver, neural, and stem/progenitor cells). In humans, beta cell neogenesis from non-beta cells appears to be the dominant source of beta cell replenishment as limited beta cell self-replenishment occurs particularly in adulthood. Metabolic states of increased insulin demand trigger increased insulin synthesis and secretion from beta cells. Beta cells, therefore, adapt to support their physiology. Maintaining physiological beta cell populations is a strategy for targeting metabolic states of persistently increased insulin demand as in diabetes.

  15. Producing propellants from water in lunar soil using solar lasers

    Science.gov (United States)

    de Morais Mendonca Teles, Antonio

    The exploration of the Solar System is directly related to the efficiency of engines designed to explore it, and consequently, to the propulsion techniques, materials and propellants for those engines. With the present day propulsion techniques it is necessary great quantities of propellants to impulse a manned spacecraft to Mars and beyond in the Solar System, which makes these operations financially very expensive because of the costs involved in launching it from planet Earth, due to its high gravity field strength. To solve this problem, it is needed a planetary place with smaller gravity field strength, near to the Earth and with great quantities of substances at the surface necessary for the in-situ production of propellants for spacecrafts. The only place available is Earth's natural satellite the Moon. So, here in this paper, I propose the creation of a Lunar Propellant Manufacturer. It is a robot-spacecraft which can be launched from Earth using an Energia Rocket, and to land on the Moon in an area (principally near to the north pole where it was discovered water molecules ice recently) with great quantities of oxygen and hydrogen (propellants) in the silicate soil, previously observed and mapped by spacecrafts in lunar orbit, for the extraction of those molecules from the soil and the in-situ production of the necessary propellants. The Lunar Propellant Manufacturer (LPM) spacecraft consists of: 1) a landing system with four legs (extendable) and rovers -when the spacecraft touches down, the legs retract in order that two apparatuses, analogue to tractor's wheeled belts parallel sided and below the spacecraft, can touch firmly the ground -it will be necessary for the displacement of the spacecraft to new areas with richer propellants content, when the early place has already exhausted in propellants; 2) a digging machine -a long, resistant extendable arm with an excavator hand, in the outer part of the spacecraft -it will extend itself to the ground

  16. Procedure for Application-Oriented Optimisation of Marine Propellers

    Directory of Open Access Journals (Sweden)

    Florian Vesting

    2016-11-01

    Full Text Available The use of automated optimisation in engineering applications is emerging. In particular, nature inspired algorithms are frequently used because of their variability and robust application in constraints and multi-objective optimisation problems. The purpose of this paper is the comparison of four different algorithms and several optimisation strategies on a set of seven test propellers in realistic industrial design setting. The propellers are picked from real commercial projects and the manual final designs were delivered to customers. The different approaches are evaluated and final results of the automated optimisation toolbox are compared with designs generated in a manual design process. We identify a two-stage optimisation for marine propellers, where the geometry is first modified by parametrised geometry distribution curves to gather knowledge of the test case. Here we vary the optimisation strategy in terms of applied algorithms, constraints and objectives. A second supporting optimisation aims to improve the design by locally changing the geometry, based on the results of the first optimisation. The optimisation algorithms and strategies yield propeller designs that are comparable to the manually designed propeller blade geometries, thus being suitable as robust and advanced design support tools. The supporting optimisation, with local modification of the blade geometry and the proposed cavity shape constraints, features particular good performance in modifying cavitation on the blade and is, with the AS NSGA-II (adaptive surrogate-assisted NSGA-II, superior in lead time.

  17. Evaluation of Energetic Plasticisers for Solid Gun Propellant

    Directory of Open Access Journals (Sweden)

    R.S. Damse

    2008-01-01

    Full Text Available This paper reports the evaluation of four different energetic plasticisers, viz., glycidyl azidepolymer (GAP, MW = 390, 1,5-diazido-3-nitrazapentane (DANPE, ethylene-glycol-bis-azido-acetate (EGBAA and N-n-butyl-N-(2 nitroxyethyl nitramine (n-Bu-NENA separately into highenergy gun propellant containing 28 per cent NC (13.1 N %, 65 per cent RDX, 6 per cent di-octyl-phthahate (DOP and 1 per cent carbamite.  Four different propellant compositions based on theenergetic plasticiser have been formulated separately with the replacement of non-energeticplasticiser, DOP. The propellants were processed by standard solvent method and evaluatedexperimentally along with the control composition to determine the ballistic parameters, cal-val,sensitivity, thermal characterisation, thermal stability and mechanical properties. The performanceof the propellants containing the energetic plasticiser has  been compared with that of thecontrol composition containing the non-energetic plasticiser, DOP so as to assess the suitabilityof the energetic plasticiser for the futuristic gun propellant formulations. It has been found outthat n-Bu-NENA is the superior plasticiser among the four energetic plasticisers evaluated inthis study.Defence Science Journal, 2008, 58(1, pp.86-93, DOI:http://dx.doi.org/10.14429/dsj.58.1627

  18. Rheokinetic Analysis of Hydroxy Terminated Polybutadiene Based Solid Propellant Slurry

    Directory of Open Access Journals (Sweden)

    Abhay K Mahanta

    2010-01-01

    Full Text Available The cure kinetics of propellant slurry based on hydroxy-terminated polybutadiene (HTPB and toluene diisocyanate (TDI polyurethane reaction has been studied by viscosity build up method. The viscosity (ɳ–time (t plots conform to the exponential function ɳ = aebt, where a & b are empirical constants. The rate constants (k for viscosity build up at various shear rate (rpm, evaluated from the slope of dɳ/dt versus ɳ plots at different temperatures, were found to vary from 0.0032 to 0.0052 min-1. It was observed that the increasing shear rate did not have significant effect on the reaction rate constants for viscosity build up of the propellant slurry. The activation energy (Eɳ, calculated from the Arrhenius plots, was found to be 13.17±1.78 kJ mole-1, whereas the activation enthalpy (∆Hɳ* and entropy (∆Sɳ* of the propellant slurry, calculated from Eyring relationship, were found to be 10.48±1.78 kJ mole-1 and –258.51± 5.38 J mole-1K-1, respectively. The reaction quenching temperature of the propellant slurry was found to be -9 ° C, based upon the experimental data. This opens up an avenue for a “freeze-and-store”, then “warm-up and cast”, mode of manufacturing of very large solid rocket propellant grains.

  19. Biodegradation of nitroglycerin from propellant residues on military training ranges.

    Science.gov (United States)

    Bordeleau, Geneviève; Martel, Richard; Drouin, Mathieu; Ampleman, Guy; Thiboutot, Sonia

    2014-03-01

    Nitroglycerin (NG) is often present in soils and sometimes in pore water at antitank firing positions due to incomplete combustion of propellants. Various degradation processes can contribute to the natural attenuation of NG in soils and pore water, thus reducing the risks of groundwater contamination. However, until now these processes have been sparsely documented. This study aimed at evaluating the ability of microorganisms from a legacy firing position to degrade dissolved NG, as well as NG trapped within propellant particles. Results from the shake-flask experiments showed that the isolated culture is capable of degrading dissolved NG but not the nitrocellulose matrix of propellant particles, so that the deeply embedded NG molecules cannot be degraded. Furthermore, the results from column experiments showed that in a nutrient-poor sand, degradation of dissolved NG may not be sufficiently rapid to prevent groundwater contamination. Therefore, the results from this study indicate that, under favorable soil conditions, biodegradation can be an important natural attenuation process for NG dissolving out of fresh propellant residues. In contrast, biodegradation does not contribute to the long-term attenuation of NG within old, weathered propellant residues. Although NG in these old residues no longer poses a threat to groundwater quality, if soil clean-up of a legacy site is required, active remediation approaches should be sought.

  20. Combustion characteristics of SMX and SMX based propellants

    Science.gov (United States)

    Reese, David A.

    This work investigates the combustion of the new solid nitrate ester 2,3-hydroxymethyl-2,3-dinitro-1,4-butanediol tetranitrate (SMX, C6H 8N6O16). SMX was synthesized for the first time in 2008. It has a melting point of 85 °C and oxygen balance of 0% to CO 2, allowing it to be used as an energetic additive or oxidizer in solid propellants. In addition to its neat combustion characteristics, this work also explores the use of SMX as a potential replacement for nitroglycerin (NG) in double base gun propellants and as a replacement for ammonium perchlorate in composite rocket propellants. The physical properties, sensitivity characteristics, and combustion behaviors of neat SMX were investigated. Its combustion is stable at pressures of up to at least 27.5 MPa (n = 0.81). The observed flame structure is nearly identical to that of other double base propellant ingredients, with a primary flame attached at the surface, a thick isothermal dark zone, and a luminous secondary flame wherein final recombination reactions occur. As a result, the burning rate and primary flame structure can be modeled using existing one-dimensional steady state techniques. A zero gas-phase activation energy approximation results in a good fit between modeled and observed behavior. Additionally, SMX was considered as a replacement for nitroglycerin in a double base propellant. Thermochemical calculations indicate improved performance when compared with the common double base propellant JA2 at SMX loadings above 40 wt-%. Also, since SMX is a room temperature solid, migration may be avoided. Like other nitrate esters, SMX is susceptible to decomposition over long-term storage due to the presence of excess acid in the crystals; the addition of stabilizers (e.g., derivatives of urea) during synthesis should be sufficient to prevent this. the addition of Both unplasticized and plasticized propellants were formulated. Thermal analysis of unplasticized propellant showed a distinct melt

  1. The Application of Erosive Burning to Propellant Charge Interior Ballistics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-lin

    2009-01-01

    Erosive burning is a common burning phenomenon of the gunpowder with inner holes. The actual combustion law of the gunpowder with inner holes can be changed by erosive burning. Pressure difference between the inner and the outer of hole caused by loading density variation of the propellant charge makes erosive burning occur at inner holes during in-bore burning. The effect of erosive burning on burning speed of the propellant is studied by using the effects of flow rate, heat transfer and erosion of the combustion gas in inner holes on burning rate. The mathematic model of erosive burning of the propellant is established. The effects of the factors such as loading density, inner hole size and grain length on erosive burning and interior ballistic performance are analyzed .The method to improve the bore pressure for small charge mass and small firing range by erosive burning is proposed.

  2. Shear Thickening Behaviour of Composite Propellant Suspension under Oscillatory Shear

    Directory of Open Access Journals (Sweden)

    D. Singh

    2016-04-01

    Full Text Available Composite propellant suspensions consist of highly filled polymeric system wherein solid particles of different sizes and shapes are dispersed in a polymeric matrix. The rheological behaviour of a propellant suspension is characterised by viscoplasticity and shear rate and time dependant viscosity. The behaviour of composite propellant suspension has been studied under amplitude sweep test where tests were performed by continuously varying strain amplitude (strain in %, γ by keeping the frequency and temperature constant and results are plotted in terms of log γ (strain amplitude vs logGʹ and logGʺ (Storage modulus and loss modulus, respectively. It is clear from amplitude sweep test that dynamic moduli and complex viscosity show marked increase at critical strain amplitude after a plateau region, infering a shear thickening behaviour.

  3. Studies of solid propellant combustion with pulsed radiography

    Science.gov (United States)

    Godai, T.; Tanemura, T.; Fujiwara, T.; Shimizu, M.

    1987-01-01

    Pulsed radiography was applied to observe solid propellant surface regression during rocket motor operation. Using a 150 KV flash X-ray system manufactured by the Field Emission Corporation and two kinds of film suppliers, images of the propellant surface of a 5 cm diameter end burning rocket motor were recorded on film. The repetition frame rate of 8 pulses per second and the pulse train length of 10 pulses are limited by the capability of the power supply and the heat build up within the X-ray tube, respectively. The experiment demonstrated the effectiveness of pulsed radiography for observing solid propellant surface regression. Measuring the position of burning surface images on film with a microdensitometer, quasi-instantaneous burning rate as a function of pressure and the variation of characteristic velocity with pressure and gas stay time were obtained. Other research items to which pulsed radiography can be applied are also suggested.

  4. Laboratory test methods for combustion stability properties of solid propellants

    Science.gov (United States)

    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.

  5. Design and performance verification of a passive propellant management system

    Science.gov (United States)

    Hess, D. A.; Regnier, W. W.

    1978-01-01

    This paper describes the design and verification testing of a reusable passive propellant management system. The system was designed to acquire propellant in low- or zero-g environments and also retain this propellant under high axially directed accelerations that may be experienced during launch and orbit-to-orbit transfer. The system design requirements were established to satisfy generally the requirements for a large number of potential NASA and military applications, such as orbit-to-orbit shuttles and satellite vehicles. The resulting concept was a multicompartmented tank with independent surface tension acquisition channels in each compartment. The tank was designed to provide a minimum expulsion efficiency of 98 percent when subjected to the simultaneous conditions of acceleration, vibration, and outflow. The system design has the unique capability to demonstrate low-g performance in a 1-g test environment, and the test program summarized was structured around this capability.

  6. Rocket Solid Propellant Alternative Based on Ammonium Dinitramide

    Directory of Open Access Journals (Sweden)

    Grigore CICAN

    2017-03-01

    Full Text Available Due to the continuous run for a green environment the current article proposes a new type of solid propellant based on the fairly new synthesized oxidizer, ammonium dinitramide (ADN. Apart of having a higher specific impulse than the worldwide renowned oxidizer, ammonium perchlorate, ADN has the advantage, of leaving behind only nitrogen, oxygen and water after decomposing at high temperatures and therefore totally avoiding the formation of hydrogen chloride fumes. Based on the oxidizer to fuel ratios of the current formulations of the major rocket solid booster (e.g. Space Shuttle’s SRB, Ariane 5’s SRB which comprises mass variations of ammonium perchlorate oxidizer (70-75%, atomized aluminum powder (10-18% and polybutadiene binder (12-20% a new solid propellant was formulated. As previously stated, the new propellant formula and its variations use ADN as oxidizer and erythritol tetranitrate as fuel, keeping the same polybutadiene as binder.

  7. Aeroelastic analysis for propellers - mathematical formulations and program user's manual

    Science.gov (United States)

    Bielawa, R. L.; Johnson, S. A.; Chi, R. M.; Gangwani, S. T.

    1983-01-01

    Mathematical development is presented for a specialized propeller dedicated version of the G400 rotor aeroelastic analysis. The G400PROP analysis simulates aeroelastic characteristics particular to propellers such as structural sweep, aerodynamic sweep and high subsonic unsteady airloads (both stalled and unstalled). Formulations are presented for these expanded propeller related methodologies. Results of limited application of the analysis to realistic blade configurations and operating conditions which include stable and unstable stall flutter test conditions are given. Sections included for enhanced program user efficiency and expanded utilization include descriptions of: (1) the structuring of the G400PROP FORTRAN coding; (2) the required input data; and (3) the output results. General information to facilitate operation and improve efficiency is also provided.

  8. Combustion of HMX-CMDB propellants. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Y.; Kubota, N.

    1985-12-01

    The combustion wave structure of HMX-CMDB (composite modified double-base) propellants was studied in order to elucidate the gas phase reaction mechanism and to understand the burning rate characteristics. Experiments were conducted to determine the thickness of the reaction zone, gaseous products in the dark zone, and the temperature profile in the combustion waves. The reaction rate in the dark zone is increased by the addition of HMX. This is caused by the equivalence ratio of the oxidizer/fuel in the dark zone shifting towards a stoichiometric ratio when HMX is added. However, the reaction rate in the fizz zone and the heat feedback from the gas phase to the burning surface is decreased by the addition of HMX. Thus, the burning rate of HMX-CMDB propellants decreases when HMX is mixed within double-base propellants.

  9. Propeller aircraft interior noise model utilization study and validation

    Science.gov (United States)

    Pope, L. D.

    1984-01-01

    Utilization and validation of a computer program designed for aircraft interior noise prediction is considered. The program, entitled PAIN (an acronym for Propeller Aircraft Interior Noise), permits (in theory) predictions of sound levels inside propeller driven aircraft arising from sidewall transmission. The objective of the work reported was to determine the practicality of making predictions for various airplanes and the extent of the program's capabilities. The ultimate purpose was to discern the quality of predictions for tonal levels inside an aircraft occurring at the propeller blade passage frequency and its harmonics. The effort involved three tasks: (1) program validation through comparisons of predictions with scale-model test results; (2) development of utilization schemes for large (full scale) fuselages; and (3) validation through comparisons of predictions with measurements taken in flight tests on a turboprop aircraft. Findings should enable future users of the program to efficiently undertake and correctly interpret predictions.

  10. Use of A Shatter Test Vessel to Assess Propellant Safety

    Institute of Scientific and Technical Information of China (English)

    Clive WOODLEY; Peter HENNING

    2015-01-01

    At low temperatures,gun propellant grains may become brittle and this can lead to fracture or shatter of the grains during gun firing.Should this event occur then it will result in an increase in the burning surface of the propellant and will give rise to a change in ballistic performance.Also,if the resultant over pressure is sufficient,a breech failure may result.Understanding the propensity of a grain to fracture or shatter is therefore important in determining its safety in use.This document describes a test that may be used to derive knowledge and to quantify the physical behaviour of a gun propellant grain at the low temperatures at which fracture or shatter is most likely to occur.

  11. On Performance Evaluation of a New Liquid Propellant

    Directory of Open Access Journals (Sweden)

    S. P. Panda

    1986-01-01

    Full Text Available A blend of 3-carene and cardanol in 70:30 weight proportion exhibits synergistic hypergolic ignition with red fuming nitric acid (RFNA as oxidizer. Attempts have been made to evaluate this new propellant by theoretical calculationof performance parameters and verification of the results by static firing of a 10 kg thrust rocket motor around 20 atmosphers of chamber pressure. At an oxidizer-to-fuel weight ratio (O/F of 3.34 (RFNA used had 21% N204 and 5% by weight of concentrated sulphuric acid as catalyst, the propellant produced a reasonably smooth pressure-time curve with an ignition delay of 35 milliseconds. The theoretical characteristic velocity value matched well with the experimental. No carbon residue was left in the rocket motor after firing. Specific impulse (theoretical of the propellant has been found to be 223.8 seconds at chamber pressure, 20 atmos and exist pressure, 1 atmos.

  12. Gaussian memory in kinematic matrix theory for self-propellers

    Science.gov (United States)

    Nourhani, Amir; Crespi, Vincent H.; Lammert, Paul E.

    2014-12-01

    We extend the kinematic matrix ("kinematrix") formalism [Phys. Rev. E 89, 062304 (2014)., 10.1103/PhysRevE.89.062304], which via simple matrix algebra accesses ensemble properties of self-propellers influenced by uncorrelated noise, to treat Gaussian correlated noises. This extension brings into reach many real-world biological and biomimetic self-propellers for which inertia is significant. Applying the formalism, we analyze in detail ensemble behaviors of a 2D self-propeller with velocity fluctuations and orientation evolution driven by an Ornstein-Uhlenbeck process. On the basis of exact results, a variety of dynamical regimes determined by the inertial, speed-fluctuation, orientational diffusion, and emergent disorientation time scales are delineated and discussed.

  13. The Effect of the Propeller Jet on Pile Groups

    Institute of Scientific and Technical Information of China (English)

    Kubilay Cihan

    2014-01-01

    The objective of this study is to determine the effect of jet propeller on the damage of berthing structures combined of armoured slope with pile groups. For this purpose, scour measurements were performed for four types berthing structures, which were armoured slope with tandem arrangements of piles for two and three piles and with side by side arrangements of piles for two and three piles. The effect of gap between piles on damage was investigated. The damage level induced by propeller jet between piles was determined. The gaps were 1, 2, 3, and 4 times the pile diameter. Three different values of Rpm (690, 820, and 950) were chosen for the tests. The diameter of circular piles is 40 mm. The slope ratio was 1/3 and the diameter of propeller was 10 cm.

  14. Characterization of aluminum/RP-1 gel propellant properties

    Science.gov (United States)

    Rapp, Douglas C.; Zurawski, Robert L.

    1988-01-01

    Research efforts are being conducted by the NASA Lewis Research Center to formulate and characterize the properties of Al/RP-1 and RP-1 gelled propellants for rocket propulsion systems. Twenty four different compositions of gelled fuels were formualted with 5 and 16 micron, atomized aluminum powder in RP-1. The total solids concentration in the propellant varied from 5 to 60 wt percent. Tests were conducted to evaluate the stability and rheological characteristics of the fuels. Physical separation of the solids occurred in fuels with less than 50 wt percent solids concentration. The rheological characteristics of the Al/RP-1 fuels varied with solids concentration. Both thixotropic and rheopectic gel behavior were observed. The unmetallized RP-1 gels, which were formulated by a different technique than the Al/RP-1 gels, were highly viscoelastic. A history of research efforts which were conducted to formulate and characterize the properties of metallized propellants for various applications is also given.

  15. Composite propellant tank study for very low cost space transportation

    Science.gov (United States)

    Moser, D. J.; Keith, E. L.

    1992-01-01

    A study of life-cycle cost is conducted to determine acceptable options for composite propellant tanks at low cost and weight and for use at moderate pressures. The review examines all cost issues relevant to the production, mass, applications, and reliability of the tanks for pressure-fed rockets. Specific attention is given to the manufacturing and life-cycle issues relevant to the use of composite materials in this application since composites are effective materials for liquid propellant tanks. Specific costs and parametric considerations are given for several tank candidates with 62,303-lb capacities. The mass sensitivity of the fourth stage for the concept vehicle is shown to be high, and the use of a 325-psi fourth-stage tank is shown to yield the minimum cost/lb for the stage. Wound S-glass/epoxy composites can be employed as cost-effective replacements for steel in the design of liquid-propellant tanks.

  16. Analyzing Bleriot's propeller gaps in Cassini NAC images

    Science.gov (United States)

    Hoffmann, Holger; Chen, Cheng; Seiß, Martin; Albers, Nicole; Spahn, Frank; Nic

    2016-10-01

    Among the great discoveries of the Cassini mission are the propeller-shaped structures created by small moonlets embedded in Saturn's dense rings. These moonlets are not massive enough to counteract the viscous ring diffusion to open and maintain circumferential gaps, distinguishing them from ring-moons like Pan and Daphnis.Although one of the defining features of propeller structures, well-formed partial gaps have been resolved by the Imaging Science Subsystem Narrow Angle Camera onboard the Cassini spacecraft only for the largest known propeller named Bleriot. We analyze images of the sunlit side of Saturn's outer A ring showing the propeller Bleriot with clearly visible gaps. By fitting a Gaussian to radial brightness profiles at different azimuthal locations, we obtain the evolution of gap minimum and gap width downstream of the moonlet.We report two findings:1) Numerical simulations indicate that the radial separation of the partial propeller gaps is expected to be 4 Hill radii (Spahn and Sremcevic, 2000, A&A). We infer Bleriot's Hill radius to be a few hundred meters, consistent with values given by Sremcevic et al. (2014, DPS) and Hoffmann et al. (2015, Icarus).2) In order to estimate the ring viscosity in the region of Saturn's outer A ring, where Bleriot orbits, we fit several model functions (one example being the analytic solution derived by Sremcevic, Spahn and Duschl, 2002, MNRAS) describing the azimuthal evolution of the surface density in the propeller gap region to the data obtained from the image analysis. We find viscosity values consistent with the parameterization of ring viscosity by Daisaka et al. (2001, Icarus), but significantly lower than the upper limit given by Esposito et al. (1983, Icarus)

  17. Flexible Screen Propellant Management Device for Near Term In-Space Demonstration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — While evaluating lunar ascent and descent stage propellant acquisition options in 2008 and 2009 for NASA GRC, IES conceived a novel, flexible screen propellant...

  18. Boosted beta regression.

    Directory of Open Access Journals (Sweden)

    Matthias Schmid

    Full Text Available Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1. Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures.

  19. Study of Solid Propellant Combustion under External Radiation

    Directory of Open Access Journals (Sweden)

    V.E. Zarko

    1992-07-01

    Full Text Available The influence of constant and transient radiant flux on the burning rate of solid propellants is considered. The validity of the equivalence principle for the radiant flux and increase in initial temperature and also the problem of possible photochemical effect of thermal radiation are discussed. Experimental data on burning rate response to periodical perturbations of radiant flux for different types of solid propellants are reported. The problem of correlation between burning rate response to perturbations of pressure and external radiation is considered. Formulation of the problem on transient combustion in terms of the Zeldovich- Novozhilov phenomenological approach is described and the results of numerical integration are presented.

  20. Assessment of analytical techniques for predicting solid propellant exhaust plumes

    Science.gov (United States)

    Tevepaugh, J. A.; Smith, S. D.; Penny, M. M.

    1977-01-01

    The calculation of solid propellant exhaust plume flow fields is addressed. Two major areas covered are: (1) the applicability of empirical data currently available to define particle drag coefficients, heat transfer coefficients, mean particle size and particle size distributions, and (2) thermochemical modeling of the gaseous phase of the flow field. Comparisons of experimentally measured and analytically predicted data are made. The experimental data were obtained for subscale solid propellant motors with aluminum loadings of 2, 10 and 15%. Analytical predictions were made using a fully coupled two-phase numerical solution. Data comparisons will be presented for radial distributions at plume axial stations of 5, 12, 16 and 20 diameters.

  1. Self-propelled sweeping removal of dropwise condensate

    Science.gov (United States)

    Qu, Xiaopeng; Boreyko, Jonathan B.; Liu, Fangjie; Agapov, Rebecca L.; Lavrik, Nickolay V.; Retterer, Scott T.; Feng, James J.; Collier, C. Patrick; Chen, Chuan-Hua

    2015-06-01

    Dropwise condensation can be enhanced by superhydrophobic surfaces on which the condensate drops spontaneously jump upon coalescence. However, the self-propelled jumping in prior reports is mostly perpendicular to the substrate. Here, we propose a substrate design with regularly spaced micropillars. Coalescence on the sidewalls of the micropillars leads to self-propelled jumping in a direction nearly orthogonal to the pillars and therefore parallel to the substrate. This in-plane motion in turn produces sweeping removal of multiple neighboring drops. The spontaneous sweeping mechanism may greatly enhance dropwise condensation in a self-sustained manner.

  2. An investigation on thermal decomposition of DNTF-CMDB propellants

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Wei; Wang, Jiangning; Ren, Xiaoning; Zhang, Laying; Zhou, Yanshui [Xi' an Modern Chemistry Research Institute, Xi' an 710065 (China)

    2007-12-15

    The thermal decomposition of DNTF-CMDB propellants was investigated by pressure differential scanning calorimetry (PDSC) and thermogravimetry (TG). The results show that there is only one decomposition peak on DSC curves, because the decomposition peak of DNTF cannot be separated from that of the NC/NG binder. The decomposition of DNTF can be obviously accelerated by the decomposition products of the NC/NG binder. The kinetic parameters of thermal decompositions for four DNTF-CMDB propellants at 6 MPa were obtained by the Kissinger method. It is found that the reaction rate decreases with increasing content of DNTF. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  3. A model for the burning rates of composite propellants

    Science.gov (United States)

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

    1980-01-01

    An analytical model of the steady-state burning of composite solid propellants is presented. An improved burning rate model is achieved by incorporating an improved AP monopropellant model, a separate energy balance for the binder in which a portion of the diffusion flame is used to heat the binder, proper use of the binder regression rate in the model, and a model for the combustion of the energetic binder component of CMDB propellants. Also, an improved correlation and model of aluminum agglomeration is developed which properly describes compositional trends.

  4. Review of recent research of interior noise of propeller aircraft

    Science.gov (United States)

    Mixson, J. S.; Powell, C. A.

    1984-01-01

    Publications on the topics of propeller source noise, airborne noise transmission, and passenger comfort response to noise and vibration are reviewed. Of the 187 publications referenced, 140 have appeared since 1978. Examples of research accomplishments are presented to illustrate the state of the art. Emphasis is on comparisons of theoretical and measured results, but the description of the theories is left to the references. This review shows that substantial progress has been made in understanding the characteristics of propeller noise, airborne noise, and passenger response, and in the development of prediction methods. Application of the technology to cabin noise control and possible future research directions are discussed.

  5. Dynamic Model for Thrust Generation of Marine Propellers

    DEFF Research Database (Denmark)

    Blanke, Mogens; Lindegaard, Karl-Petter; Fossen, Thor I.

    2000-01-01

    Mathematical models of propeller thrust and torque are traditionally based on steady state thrust and torque characteristics obtained in model basin or cavitation tunnel tests. Experimental results showed that these quasi steady state models do not accurately describe the transient phenomena...... in a thruster. A recently published dynamic model was based on the experimental observations. Describing zero advance speed conditions accurately, this model, however, does not work for a vessel at non- zero relative water speed. This paper derives a large signal dynamic model of propeller that includes...

  6. Spectrophotometric determination of channel black in small arms propellants.

    Science.gov (United States)

    Galan, M; Norwitz, G

    1967-05-01

    A spectrophotometric method is proposed for the determination of Channel Black in small arms propellants. The Channel Black is separated from the nitrocellulose and other organic compounds by dissolution of the propellant in morpholine and filtration through a sintered porcelain crucible containing an asbestos mat. The Channel Black is then dissolved by treating the mat and crucible with boiling nitric acid for 3 hr, the solution is filtered, and the yellow colour is measured. The colour is due to polycarboxylic acids with cyclic nuclei. The range of the method is from 0 to 0.5% of Channel Black.

  7. Natural Rubber Based Fuel Rich Propellant for Ramjet Rocket

    OpenAIRE

    Solomon Thomas; T. L. Varghese; Gupta, S. K.; T. S. Ram; V. N. Krishnamurthy

    1992-01-01

    Development of fuel rich propellants for air-breathing propulsion is one of the frontier areas of research. This carries less oxidiser than the normal propellants, uses ram air for complete combustion and is heavily metallised. Studies were conducted at VSSC for the development of hydroxyl-terminated natural rubber (HTNR)-based Mg and Mg-Al alloy-filled polyurethane systems. The HTNR prepolymer was modified to make it free of acid functionality so as to avoid reaction with the metals a...

  8. Diagnosis of the jet-propelled engine by vibration analysis

    Directory of Open Access Journals (Sweden)

    Mariusz ŻOKOWSKI

    2009-01-01

    Full Text Available In this paper presented works connected with the preparation of the active experiment with the jet-propelled engine. The experiment was prepared and done at the Air Force Institute of Technology. The main aim of this preparation was the explanation of the causes of the damages of military aerial ships after air incidents, notified damages in the process of exploitation and obtainment of the vibration answer on simulated damages.The exit test of the jet-propelled engine was the point of the reference after the repair in the Military Aviation Depot.

  9. Prediction of Non-Cavitation Propeller Noise in Time Domain

    Institute of Scientific and Technical Information of China (English)

    YE Jin-ming; XIONG Ying; XIAO Chang-run; BI Yi

    2011-01-01

    The blade frequency noise of non-cavitation propeller in a uniform flow is analyzed in time domain.The unsteady loading (dipole source) on the blade surface is calculated by a potential-based surface panel method.Then the timedependent pressure data is used as the input for Ffowcs Williams-Hawkings formulation to predict the acoustics pressure.The integration of noise source is performed over the true blade surface rather than the nothickness blade surface,and the effect of hub can be considered.The noise characteristics of the non-cavitation propeller and the numerical discretization forms are discussed.

  10. Diagnosis of the jet-propelled engine by vibration analysis

    OpenAIRE

    Mariusz ŻOKOWSKI; Marek SZCZEKALA; Jarosław SPYCHAŁA

    2009-01-01

    In this paper presented works connected with the preparation of the active experiment with the jet-propelled engine. The experiment was prepared and done at the Air Force Institute of Technology. The main aim of this preparation was the explanation of the causes of the damages of military aerial ships after air incidents, notified damages in the process of exploitation and obtainment of the vibration answer on simulated damages.The exit test of the jet-propelled engine was the point of the re...

  11. Interactive Schematic Integration Within the Propellant System Modeling Environment

    Science.gov (United States)

    Coote, David; Ryan, Harry; Burton, Kenneth; McKinney, Lee; Woodman, Don

    2012-01-01

    Task requirements for rocket propulsion test preparations of the test stand facilities drive the need to model the test facility propellant systems prior to constructing physical modifications. The Propellant System Modeling Environment (PSME) is an initiative designed to enable increased efficiency and expanded capabilities to a broader base of NASA engineers in the use of modeling and simulation (M&S) technologies for rocket propulsion test and launch mission requirements. PSME will enable a wider scope of users to utilize M&S of propulsion test and launch facilities for predictive and post-analysis functionality by offering a clean, easy-to-use, high-performance application environment.

  12. Cryogenic propellant management system requirements for Space Station Freedom

    Science.gov (United States)

    Saucillo, R. J.; Stevenson, S. M.; Corban, R. R.

    1991-01-01

    Specific propellant management system requirements have been identified for each facility category of SSF. Distributed systems have been analyzed to indentify momentum management, guidance, and traffic management requirements associated with the guidance, navigation, and control system; space-to-space communications and enhanced tracking requirements associated with the communications and tracking system; and propellant management system utility requirements associated with the electrical power system. Flight element analyses determined attach structure, utility distribution, and structural integrity requirements for the pre-integrated truss and high mass manipulation and translation requirements for the mobile base system.

  13. Cryogenic propellant management: Integration of design, performance and operational requirements

    Science.gov (United States)

    Worlund, A. L.; Jamieson, J. R., Jr.; Cole, T. W.; Lak, T. I.

    1985-01-01

    The integration of the design features of the Shuttle elements into a cryogenic propellant management system is described. The implementation and verification of the design/operational changes resulting from design deficiencies and/or element incompatibilities encountered subsequent to the critical design reviews are emphasized. Major topics include: subsystem designs to provide liquid oxygen (LO2) tank pressure stabilization, LO2 facility vent for ice prevention, liquid hydrogen (LH2) feedline high point bleed, pogo suppression on the Space Shuttle Main Engine (SSME), LO2 low level cutoff, Orbiter/engine propellant dump, and LO2 main feedline helium injection for geyser prevention.

  14. Impact of Advanced Propeller Technology on Aircraft/Mission Characteristics of Several General Aviation Aircraft

    Science.gov (United States)

    Keiter, I. D.

    1982-01-01

    Studies of several General Aviation aircraft indicated that the application of advanced technologies to General Aviation propellers can reduce fuel consumption in future aircraft by a significant amount. Propeller blade weight reductions achieved through the use of composites, propeller efficiency and noise improvements achieved through the use of advanced concepts and improved propeller analytical design methods result in aircraft with lower operating cost, acquisition cost and gross weight.

  15. A Review on Decomposition Deflagration of Oxidizer and Binders in Composite Solid Propellants

    Directory of Open Access Journals (Sweden)

    K. Kishore

    1979-01-01

    Full Text Available Binder and oxidizer decomposition play very significant role during the combustion of composite solid propellants. Ammonium perchlorate (AP is the practical oxidizer in composite propellant formulations. Available information on binder decomposition in general and AP decomposition in particular have been collected and reviewed from the viewpoint of their application in propellants. This review may be useful in understanding the mechanism of propellant combustion.

  16. JANNAF 30th Propellant Development and Characterization Subcommittee Meeting. Volume I

    Science.gov (United States)

    Moore, T. L. (Editor); Becker, D. L. (Editor)

    2002-01-01

    This volume, the first of three volumes, is a compilation of 22 unclassified/unlimited technical papers presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 30th Propellant Development & Characterization Subcommittee Meeting, held on 18-21 March 2002 at the Sheraton Colorado Springs Hotel, Colorado Springs, Colorado. The papers presented herein reflect work performed in the areas of green energetic materials (GEM) development; liquid and gel propellant development; propellant surveillance and aging; and propellant chemistry test methods.

  17. Summary of Air Force Research Laboratory Support for the NASA Green Propellant Infusion Mission

    Science.gov (United States)

    2015-07-01

    launch pressurized propellant tanks on a spacecraft or satellite, a fracture mechanics analysis is required to verify the safe design life of the...propellant tanks on a spacecraft or satellite, a fracture mechanics analysis is required to verify the safe design life of the pressure vessel in... pressurant flow. FIGURE 4: SERVICE VALVE MANIFOLD PROPELLANT TANK COUPON FRACTURE ANALYSIS In order to enable qualification of the propellant

  18. Green propellant propulsion concepts for space transportation and technology development needs

    NARCIS (Netherlands)

    Haeseler, D.; Bombelli, V.; Vuillermoz, P.; Lo, R.; Maree, A.G.M.; Caramelli, F.

    2004-01-01

    A study has been performed under contract from ESA/ESTEC identifying the development needs in Europe in the field of new green propellant utilization. Criteria for green propellants are defined and discussed. Promising propellants are identified together with their rating w.r.t. those criteria, in p

  19. The scaling of the threshold conditions for solid propellant erosive burning

    Science.gov (United States)

    Strand, L. D.; Nguyen, M. H.; Cohen, N. S.

    1988-01-01

    Rocket test firings were performed to measure the transition length threshold conditions while systematically varying various rocket motor parameters. These include the crossflow velocity, the chamber pressure, the propellant nonerosive burning rate, the propellant surface roughness, and the motor port diameter. The erosive burning trends with varying propellant burning rate, motor chamber pressure, and mass flow rate are consistent with published results.

  20. Characterization of Energetic Porous Silicon for a Microelectromechanical System (MEMS)-Based Solid Propellant Microthruster

    Science.gov (United States)

    2014-09-01

    Characterization of Energetic Porous Silicon for a Microelectromechanical System (MEMS)-Based Solid Propellant Microthruster by Raghav...Energetic Porous Silicon for a Microelectromechanical System (MEMS)-Based Solid Propellant Microthruster Raghav Ramachandran, Wayne Churaman, David...Microelectromechanical System (MEMS)-Based Solid Propellant Microthruster 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  1. 14 CFR 420.69 - Solid and liquid propellants located together.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Solid and liquid propellants located... Licensee § 420.69 Solid and liquid propellants located together. (a) A launch site operator proposing an explosive hazard facility where solid and liquid propellants are to be located together shall determine...

  2. An Overview of Combustion Mechanisms and Flame Structures for Advanced Solid Propellants

    Science.gov (United States)

    Beckstead, M. W.

    2000-01-01

    Ammonium perchlorate (AP) and cyclotretamethylenetetranitramine (HMX) are two solid ingredients often used in modern solid propellants. Although these two ingredients have very similar burning rates as monopropellants, they lead to significantly different characteristics when combined with binders to form propellants. Part of the purpose of this paper is to relate the observed combustion characteristics to the postulated flame structures and mechanisms for AP and HMX propellants that apparently lead to these similarities and differences. For AP composite, the primary diffusion flame is more energetic than the monopropellant flame, leading to an increase in burning rate over the monopropellant rate. In contrast the HMX primary diffusion flame is less energetic than the HMX monopropellant flame and ultimately leads to a propellant rate significantly less than the monopropellant rate in composite propellants. During the past decade the search for more energetic propellants and more environmentally acceptable propellants is leading to the development of propellants based on ingredients other than AP and HMX. The objective of this paper is to utilize the more familiar combustion characteristics of AP and HMX containing propellants to project the combustion characteristics of propellants made up of more advanced ingredients. The principal conclusion reached is that most advanced ingredients appear to burn by combustion mechanisms similar to HMX containing propellants rather than AP propellants.

  3. CFD Study on Effective Wake of Conventional and Tip-modified Propellers

    DEFF Research Database (Denmark)

    Shin, K. W.; Andersen, Poul

    2016-01-01

    by integrating velocity fields at a section 40% of the propeller radius upstream from the propeller plane in self-propulsion simulations. The difference of effective wake fraction from integrating velocity fields between tip-modified and conventional propellers is less than 1%. Based on the open-water simulation...

  4. 14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

    Science.gov (United States)

    2010-01-01

    ..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided...

  5. 14 CFR 35.42 - Components of the propeller control system.

    Science.gov (United States)

    2010-01-01

    ... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Tests and Inspections § 35.42 Components of the propeller control system. The applicant must demonstrate by tests, analysis based on tests, or service... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Components of the propeller control...

  6. 76 FR 9495 - Feathering Propeller Systems for Light-Sport Aircraft Powered Gliders

    Science.gov (United States)

    2011-02-18

    ... Administration 14 CFR Part 1 RIN 2120-AJ81 Feathering Propeller Systems for Light-Sport Aircraft Powered Gliders... propeller operation for powered gliders that qualify as light-sport aircraft. DATES: The effective date for... aircraft (LSA) had a fixed or autofeathering propeller system. The restriction to ``autofeathering''...

  7. 76 FR 5 - Feathering Propeller Systems for Light-Sport Aircraft Powered Gliders

    Science.gov (United States)

    2011-01-03

    ... aircraft, if powered, would be limited to a fixed or ground adjustable propeller.'' We determined that ``a... found in multi-engine aircraft, automatically feather a propeller in the event of a power loss during... manual feathering propeller on an LSA powered glider could impose a hazard to the aircraft...

  8. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Science.gov (United States)

    2010-01-01

    ... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on... provisions of §§ 21.183(c), 21.184(b), or 21.185(c); and (2) New aircraft engines or propellers...

  9. Hydrodynamic analysis of propellers under steady state operation; Analise hidrodinamica de propulsores em regime permanente

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Carlos Antonio Levi da; Troyman, Antonio Carlos Ramos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Programa de Engenharia Oceanica

    1995-07-01

    Surface panel method has been applied to the propeller analysis. For the propeller modeling, the boss and blades surfaces have been discretized in quadrilateral panels with dipoles and sources constant distributions. The surface of the blade wakes have been represented by panels with dipole constant distributions. This discussion focused only the propeller under steady state operation.

  10. Production of Dioxins and Furans from the Burning of Excess Gun Propellant

    Science.gov (United States)

    2011-01-01

    Chemical composition of M1 gun propellant Constituents Proportions (weight/weight %) Nitrocellulose 85 ± 2 2,4-dinitrotoluene 10 ± 2...Production of dioxins and furans from the burning of excess gun propellant Isabelle Poulin Sonia Thiboutot Sylvie Brochu DRDC Valcartier Defence...excess gun propellant Isabelle Poulin Sonia Thiboutot Sylvie Brochu DRDC Valcartier Defence R&D Canada – Valcartier

  11. Kinetic evaluation of propellants decomposition via Kissinger and Flynn-Wall-Ozawa method (Poster)

    NARCIS (Netherlands)

    Guns, S.; Krabbendam-La Haye, E.L.M.; Klerk, W.P.C. de

    2014-01-01

    Nitrocellulose (NC) based propellants are intrinsically unstable due to degradation of NC as a function of time and temperature. A propellant that decomposes, dissipates heat to the surrounding. Self-heating of the propellants starts when this heat production becomes larger than its dissipation to t

  12. Cryogenic Propellant Storage and Transfer (CPST) Technology Demonstration For Long Duration In-Space Missions

    Science.gov (United States)

    Meyer, Michael L.; Motil, Susan M.; Kortes, Trudy F.; Taylor, William J.; McRight, Patrick S.

    2012-01-01

    (1) Store cryogenic propellants in a manner that maximizes their availability for use regardless of mission duration; (2) Efficiently transfer conditioned cryogenic propellant to an engine or tank situated in a microgravity environment; and (3) Accurately monitor and gauge cryogenic propellants situated in a microgravity environment

  13. 46 CFR 30.10-62 - Self-propelled tank vessel-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Self-propelled tank vessel-TB/ALL. 30.10-62 Section 30.10-62 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-62 Self-propelled tank vessel—TB/ALL. Self-propelled tank vessel means a...

  14. 46 CFR 160.035-3 - Construction of steel oar-propelled lifeboats.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Construction of steel oar-propelled lifeboats. 160.035-3... § 160.035-3 Construction of steel oar-propelled lifeboats. (a) Type. Lifeboats shall have rigid sides... when fully loaded with persons and equipment. The capacity of an oar-propelled lifeboat is limited to...

  15. 77 FR 44258 - Agency Information Collection Activities: Exportation of Used Self-Propelled Vehicles

    Science.gov (United States)

    2012-07-27

    ... Self-Propelled Vehicles AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland... the Exportation of Used Self-Propelled Vehicles. This request for comment is being made pursuant to...-Propelled Vehicles. OMB Number: 1651-0054. Form Number: None. Abstract: CBP regulations require...

  16. 30 CFR 75.523-2 - Deenergization of self-propelled electric face equipment; performance requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Deenergization of self-propelled electric face... Electrical Equipment-General § 75.523-2 Deenergization of self-propelled electric face equipment; performance requirements. (a) Deenergization of the tramming motors of self-propelled electric face equipment, required...

  17. 46 CFR 160.035-6 - Construction of aluminum oar-, hand-, and motor-propelled lifeboats.

    Science.gov (United States)

    2010-10-01

    ...-propelled lifeboats. 160.035-6 Section 160.035-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Lifeboats for Merchant Vessels § 160.035-6 Construction of aluminum oar-, hand-, and motor-propelled... employed such as, the installation of the mechanical disengaging gear, hand propelling gear, or...

  18. Design and numerical investigation of swirl recovery vanes for the Fokker 29 propeller

    NARCIS (Netherlands)

    Wang, Y.; Li, Q.; Eitelberg, G.; Veldhuis, L.L.M.; Kotsonis, M.

    2014-01-01

    Swirl recovery vanes (SRVs) are a set of stationary vanes located downstream from a propeller, which may recover some of the residual swirl from the propeller, hoping for an improvement in both thrust and efficiency. The SRV concept design for a scaled version representing the Fokker 29 propeller is

  19. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.;

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...

  20. Enantioselective synthesis of aziridines using asymmetric transfer hydrogenation as a precursor for chiral derivatives used as bonding agent for rocket solid propellants

    Directory of Open Access Journals (Sweden)

    Aparecida M. Kawamoto

    2002-11-01

    Full Text Available A rapid, expedient and enantioselective method for the synthesis of beta-hydroxy amines and monosubstituted aziridines in up to 99% e.e., via asymmetric transfer hydrogenation of a-amino ketones and cyclisation through treatment with tosyl chloride and base, is described. (1R,2R-N-(para-toluenesulfonyl-1,2-ethylenediamine with formic acid has been utilised as a ligand for the Ruthenium (II catalysed enantioselective transfer hydrogenation of the ketones.The chiral 2-methyl aziridine, which is a potentially more efficient bonding agent for Rocket Solid Propellant has been successfully achieved.

  1. Development of a Marine Propeller With Nonplanar Lifting Surfaces

    DEFF Research Database (Denmark)

    Andersen, Poul; Friesch, Jürgen; Kappel, Jens J.

    2005-01-01

    The principle of non-planar lifting surfaces is applied to the design of modern aircraft wings to obtain better lift to drag ratios. Whereas a pronounced fin or winglet at the wingtip has been developed for aircraft, the application of the nonplanar principle to marine propellers, dealt...

  2. Developments on HNF based high performance and green solid propellants

    NARCIS (Netherlands)

    Keizers, H.L.J.; Heijden, A.E.D.M. van der; Vliet, L.D. van; Welland-Veltmans, W.H.M.; Ciucci, A.

    2001-01-01

    Worldwide developments are ongoing to develop new and more energetic composite solid propellant formulations for space transportation and military applications. Since the 90's, the use of HNF as a new high performance oxidiser is being reinvestigated. Within European development programmes, signific

  3. Dynamic mechanical analysis of double base rocket propellants

    Directory of Open Access Journals (Sweden)

    Marcin Cegła

    2016-03-01

    Full Text Available The article presents dynamic mechanical analysis (DMA for solid rocket propellants testing. Principles of operation and measured values are briefly described. The authors refer to the previous research of PTFE material and literature data providing information about proper experimental conditions and influence of measurement frequency, load amplitude, and heating rate on the results of DMA tests. The experimental results of solid double-base rocket propellant testing obtained on the N Netzsch DMA 242 device are presented. Mechanical properties such as the dynamic storage modulus E´, the dynamic loss modulus E˝ and tan(δ were measured within temperature range from (–120°C to (+90°C at the heating rate of 1 K/min. The test sample was subjected to a dual cantilever multi-frequency test. Special attention was paid to determination of the glass transition temperature of the tested propellant in reference to the NATO standardization agreement 4540 as well as influence of the measurement frequency on the glass transition.[b]Keywords[/b]: Dynamic mechanical analysis, solid rocket propellants, glass transition temperature

  4. Radiographic Sensitivity of Flaw Detection in Solid Rocket Propellants

    Directory of Open Access Journals (Sweden)

    G.G Puranik

    1977-10-01

    Full Text Available The sensitivity of flaw detection with x-ray radiographic methods is investigated here qualitatively in case of cast double base and cast composite propellants and for air pockets it is found to be 1.5 and 0.9 percent of the web respectively. General guidelines for the inspection of sustainer charges have also been laid down.

  5. Monitor for physical property changes in solid propellants

    Science.gov (United States)

    Black, R. E., Jr.

    1973-01-01

    Specially designed sensor is attached to or imbedded in propellant. When sensor is driven into vibration, it moves with a phase lag directly proportional to internal friction or loss coefficent. Resonance frequency of the system is related to Young's modulus. Modulus or internal friction can be monitored over long period of time.

  6. Advanced technologies available for future solid propellant grains

    Science.gov (United States)

    Thépénier, Jean; Fonblanc, Gilles

    2001-03-01

    Significant advances have been made during the last decade in several fields of solid propulsion: the advances have enabled new savings in the motor development phase and recurring costs, because they help limit the number of prototypes and tests. The purpose of the paper is to describe the improvements achieved by SNPE in solid grain technologies, making these technologies available for new developments in more efficient and reliable future SRMs: new energetic molecules, new solid propellants, new processes for grain manufacturing, quick response grain design tools associated with advanced models for grain performance predictions. Using its expertise in chemical synthesis, SNPE develops new molecules to fit new energetic material requirements. Tests based on new propellant formulations have produced good results in the propellant performance/safety behavior ratio. New processes have been developed simultaneously to reduce the manufacturing costs of the new propellants. In addition, the grain design has been optimized by using the latest generation of predictive theoretical tools supported by a large data bank of experimental parameters resulting from over 30 years' experience in solid propulsion: Computer-aided method for the preliminary grain design Advanced models for SRM operating and performance predictions

  7. LANTR-based Mars missions: Go to phobos for propellant?

    Science.gov (United States)

    Stancati, Michael L.; Jacobs, Mark K.; Rauwolf, Gerald A.

    1999-01-01

    Two of the high-leverage propulsion technologies that have been proposed for human Mars missions-the Nuclear Thermal Rocket (NTR) engine and In Situ Propellant Production (ISPP)-show even greater potential when combined. Many previous studies have demonstrated the efficacy of manufacturing return propellant in situ to reduce the delivered mass requirement for the Earth launch and outbound transportation elements for any round trip mission. For human Mars exploration, this advantage may well be enabling, given current launch vehicle capability projections and reasonable expectations for a constrained program budget. NASA has proposed that the same LOX-Augmented NTR (LANTR) engine concept designed for use on lunar stages could also be used for Mars vehicle configurations, and that the tanks could be filled with propellants from Phobos for the return trip. This approach preserves the strategy of using a few common design elements for both lunar and Mars missions, while also making a significant mass performance improvement for the Mars return stage. We characterize the likely impact on performance of ``steady-state'' Earth-Mars transportation, as compared to Mars-only ISPP alternatives, and offer a preview of potential cost savings (work still in progress) for steady-state operation with Phobos propellants.

  8. Combustion Characteristics of Coated Nano Aluminum in Composite Propellants

    Directory of Open Access Journals (Sweden)

    Yunlan Sun

    2006-10-01

    Full Text Available The effects of coated nano-sized aluminum (Al powder (n-Al and micron-sized Al powder(g-Al in propellants on the burning rate and pressure exponent have been investigated. Theresults show that the burning rates of propellants increase as the n-Al content increases, butthe burning rate pressure exponents tend to decrease. Compared with propellant containing-Al, the increments of burning rates of propellants containing n-Al powder reduce graduallywith increase in the pressure because of the differences of the combustion characteristics andignition performances of n-Al powder and g-Al powder. Single short distance photograph, scanningelectron microscopy, x-ray fluorescence analysis were used to characterise the flame image,combustion phenomena, the quenched surface image, and surface elements. A substantialdifference in combustion characteristics of n-Al powder has been found in comparison with-Al powder. In addition, oxygen-bomb combustion heat, ignition temperature, and recoveryratio of residues were measured.

  9. A review of propeller modelling techniques based on Euler methods

    NARCIS (Netherlands)

    Zondervan, G.J.D.

    1998-01-01

    Future generation civil aircraft will be powered by new, highly efficient propeller propulsion systems. New, advanced design tools like Euler methods will be needed in the design process of these aircraft. This report describes the application of Euler methods to the modelling of flowfields generate

  10. PIV-based load determination in aircraft propellers

    NARCIS (Netherlands)

    Ragni, D.

    2012-01-01

    The thesis describes the application of particle image velocimetry (PIV) to study the aerodynamic loads of airfoils and aircraft propellers. The experimental work focuses on the development of a measurement procedure to infer the pressure of the flow field from the velocity distribution obtained by

  11. Glycidyl Azide Polymer-based Enhanced Energy LOVA Gun Propellant

    OpenAIRE

    R. R. Sanghavi; P. J. Kamale; M.A.R. Shaikh; T. K. Chakraborthy; S. N. Asthana; Amarjit Singh

    2006-01-01

    In this study, cyclotrimethylene trinitramine propellants with triacetin (TA)-plasticisedcellulose acetate (CA) and nitrocellulose (NC) combination as binders were evaluated for lowvulnerable ammunition (LOVA). Triacetin was replaced by energetic plasticiser; glycidyl azidepolymer (GAP) in increments to enhance the performance in terms of force constant . In additionto ballistics, parameters like vulnerability, mechanical and thermal properties of GAP-basedpropellants in comparison to those o...

  12. MEMS-Based Solid Propellant Rocket Array Thruster

    Science.gov (United States)

    Tanaka, Shuji; Hosokawa, Ryuichiro; Tokudome, Shin-Ichiro; Hori, Keiichi; Saito, Hirobumi; Watanabe, Masashi; Esashi, Masayoshi

    The prototype of a solid propellant rocket array thruster for simple attitude control of a 10 kg class micro-spacecraft was completed and tested. The prototype has 10×10 φ0.8 mm solid propellant micro-rockets arrayed at a pitch of 1.2 mm on a 20×22 mm substrate. To realize such a dense array of micro-rockets, each ignition heater is powered from the backside of the thruster through an electrical feedthrough which passes along a propellant cylinder wall. Boron/potassium nitrate propellant (NAB) is used with/without lead rhodanide/potassium chlorate/nitrocellulose ignition aid (RK). Impulse thrust was measured by a pendulum method in air. Ignition required electric power of at least 3 4 W with RK and 4 6 W without RK. Measured impulse thrusts were from 2×10-5 Ns to 3×10-4 Ns after the calculation of compensation for air dumping.

  13. Modeling and Fault Simulation of Propellant Filling System

    Science.gov (United States)

    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.

  14. History force on coated microbubbles propelled by ultrasound

    NARCIS (Netherlands)

    Garbin, Valeria; Dollet, Benjamin; Overvelde, Marlies; Cojoc, Dan; Di Fabrizio, Enzo; Wijngaarden, van Leen; Prosperetti, Andrea; Jong, de Nico; Lohse, Detlef; Versluis, Michel

    2009-01-01

    In this paper the unsteady translation of coated microbubbles propelled by acoustic radiation force is studied experimentally. A system of two pulsating microbubbles of the type used as contrast agent in ultrasound medical imaging is considered, which attract each other as a result of the secondary

  15. In-situ tensile testing of propellant samples within SEM

    NARCIS (Netherlands)

    Benedetto, G.L. di; Ramshorst, M.C.J. van; Duvalois, W.; Hooijmeijer, P.A.; Heijden, A.E.D.M. van der; Klerk, W.P.C. de

    2015-01-01

    A tensile module system placed within a FEI NovaNanoSEM 650 Scanning Electron Microscope (SEM) was utilized in this work to conduct in-situ tensile testing of propellant material samples. This tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mec

  16. Natural Rubber Based Fuel Rich Propellant for Ramjet Rocket

    Directory of Open Access Journals (Sweden)

    Solomon Thomas

    1992-07-01

    Full Text Available Development of fuel rich propellants for air-breathing propulsion is one of the frontier areas of research. This carries less oxidiser than the normal propellants, uses ram air for complete combustion and is heavily metallised. Studies were conducted at VSSC for the development of hydroxyl-terminated natural rubber (HTNR-based Mg and Mg-Al alloy-filled polyurethane systems. The HTNR prepolymer was modified to make it free of acid functionality so as to avoid reaction with the metals and was then reacted with calculated amount of propylene oxide in the presence of tertiary amine catalyst at room temperature. Various levels of Mg and Mg-Al alloy were used in different compositions and the effect on propellant characteristics was studied. TMP and butane diol were used for higher crosslinking, chain extension, etc and their effects were evaluated. Propellant compositions using 30-35 per cent by weight of Mg/Mg-Al alloy with the modified prepolymer have been developed. They exhibit good processibility and mechanical properties. The feasibility of room temperature curing was attempted. Motors weighing 2 kg with 100 mm OD and 200 mm length were successfully static-tested in the primary mode for performance evaluation.

  17. Soybean seedlings tolerate abrasion from air-propelled grit

    Science.gov (United States)

    New tools for controlling weeds would be useful for soybean production in organic systems. Air-propelled abrasive grit is one such tool that performs well for in-row weed control in corn, but crop safety in soybean is unknown. We examined responses to abrasion by corn-cob grit of soybean seedlings a...

  18. Liquid Propellant Blast Yields for Delta IV Heavy Vehicles

    Science.gov (United States)

    2010-07-01

    exterior shells shown in a layered construction. Unfortunately, the 3D model is too computationally intensive to run on a PC, and may even be too large to...Research Triangle Institute, Cocoa Beach, FL, 30 July 2004. LIQUID PROPELLANT BLAST YIELDS FOR DELTA IV HEAVY VEHICLES Ron R. Lambert ACTA Lompoc, CA

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

    Science.gov (United States)

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

    2000-01-01

    In the early 1970's a program was initiated at the Naval Surface Warfare Center/Indian Head Division (NSWC/IHDIV) to address the well-known problems associated with availability and suppliers of critical ingredients. These critical ingredients are necessary for preparation of solid propellants and explosives manufactured by the Navy. The objective of the program was to identify primary and secondary (or back-up) vendor information for these critical ingredients, and to develop suitable alternative materials if an ingredient is unavailable. In 1992 NSWC/IHDIV funded Chemical Propulsion Information Agency (CPIA) under a Technical Area Task (TAT) to expedite the task of creating a database listing critical ingredients used to manufacture Navy propellant and explosives based on known formulation quantities. Under this task CPIA provided employees that were 100 percent dedicated to the task of obtaining critical ingredient suppliers information, selecting the software and designing the interface between the computer program and the database users. TAT objectives included creating the Explosive Ingredients Source Database (EISD) for Propellant, Explosive and Pyrotechnic (PEP) critical elements. The goal was to create a readily accessible database, to provide users a quick-view summary of critical ingredient supplier's information and create a centralized archive that CPIA would update and distribute. EISD funding ended in 1996. At that time, the database entries included 53 formulations and 108 critical used to manufacture Navy propellant and explosives. CPIA turned the database tasking back over to NSWC/IHDIV to maintain and distribute at their discretion. Due to significant interest in propellant/explosives critical ingredients suppliers' status, the Propellant Development and Characterization Subcommittee (PDCS) approached the JANNAF Executive committee (EC) for authorization to continue the critical ingredient database work. In 1999, JANNAF EC approved the PDCS panel

  20. Viscoelastic Modelling of Solid Rocket Propellants using Maxwell Fluid Model

    Directory of Open Access Journals (Sweden)

    Himanshu Shekhar

    2010-07-01

    Full Text Available Maxwell fluid model consisting of a spring and a dashpot in series is applied for viscoelastic characterisation of solid rocket propellants. Suitable values of spring constant and damping coefficient wereemployed by least square variation of errors for generation of complete stress-strain curve in uniaxial tensile mode for case-bonded solid propellant formulations. Propellants from the same lot were tested at different strain rates. It was observed that change in spring constant, representing elastic part was very small with strain rate but damping constant varies significantly with variation in strain rate. For a typical propellant formulation, when strain rate was raised from 0.00037/s to 0.185/s, spring constant K changed from 5.5 MPato 7.9 MPa, but damping coefficient D was reduced from 1400 MPa-s to 4 MPa-s. For all strain rates, stress-strain curve was generated using Maxwell model and close matching with actual test curve was observed.This indicates validity of Maxwell fluid model for uniaxial tensile testing curves of case-bonded solid propellant formulations. It was established that at higher strain rate, damping coefficient becomes negligible as compared to spring constant. It was also observed that variation of spring constant is logarithmic with strain rate and that of damping coefficient follows power law. The correlation coefficients were introduced to ascertain spring constants and damping coefficients at any strain rate from that at a reference strain rate. Correlationfor spring constant needs a coefficient H, which is function of propellant formulation alone and not of test conditions and the equation developeds K2 = K1 + H ´ ln{(de2/dt/(de1/dt}. Similarly for damping coefficient D also another constant S is introduced and prediction formula is given by D2 = D1 ´ {(de2/dt/(de1/dt}S.Evaluating constants H and S at different strain rates validate this mathematical formulation for differentpropellant formulations

  1. Applied Beta Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements.

  2. Beta Thalassemia (For Parents)

    Science.gov (United States)

    ... had their spleens removed. Slower growth rates. The anemia resulting from beta thalassemia can cause children to grow more slowly and also can lead ... boost production of new red blood cells. Some children with moderate anemia may require an occasional blood transfusion , particularly after ...

  3. Trichoderma .beta.-glucosidase

    Science.gov (United States)

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  4. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross-section...

  5. Subcutaneous pedicle propeller flap: An old technique revisited and modified!

    Directory of Open Access Journals (Sweden)

    Durga Karki

    2016-01-01

    Full Text Available Background: Post-burn axillary and elbow scar contracture is a challenging problem to the reconstructive surgeon owing to the wide range of abduction and extension that should be achieved, respectively, while treating either of the joint. The aim of this paper is to highlight the use of subcutaneous pedicle propeller flap for the management of post-burn axillary and elbow contractures. Methodology: This is a prospective case study of axillary and elbow contractures managed at a tertiary care hospital using propeller flap based on subcutaneous pedicle from 2009 to 2014. Surgical treatment comprised of subcutaneous-based pedicle propeller flap from the normal tissue within the contracture based on central axis pedicle. The flap was rotated axially to break the contracture. The technique further encompassed a modification, a Zig-Zag incision of the flap, which was seen to prevent hypertrophy along the incision line. There was a mean period of 12 months of follow-up. Results: Thirty-eight patients consisting of 22 males and 16 females were included in this study among which 23 patients had Type II axillary contractures and 15 had moderate flexion contractures at elbow joint. The post-operative abduction achieved at shoulder joint had a mean of 168° whereas extension achieved at elbow had a mean of 175°. The functional and aesthetic results were satisfactory. Conclusion: The choice of surgical procedure for reconstruction of post-burn upper extremity contractures should be made according to the pattern of scar contracture and the state of surrounding skin. The choice of subcutaneous pedicle propeller flap should be emphasised because of the superior functional results of flap as well as ease to learn it. Moreover, the modification of propeller flap described achieves better results in terms of scar healing. There is an inter-positioning of healthy skin in between the graft, so it prevents scar band formation all around the flap.

  6. Modeling the effects of wind tunnel wall absorption on the acoustic radiation characteristics of propellers

    Science.gov (United States)

    Baumeister, K. J.; Eversman, W.

    1986-01-01

    Finite element theory is used to calculate the acoustic field of a propeller in a soft walled circular wind tunnel and to compare the radiation patterns to the same propeller in free space. Parametric solutions are present for a 'Gutin' propeller for a variety of flow Mach numbers, admittance values at the wall, microphone position locations, and propeller to duct radius ratios. Wind tunnel boundary layer is not included in this analysis. For wall admittance nearly equal to the characteristic value of free space, the free field and ducted propeller models agree in pressure level and directionality. In addition, the need for experimentally mapping the acoustic field is discussed.

  7. TGF-beta and osteoarthritis.

    NARCIS (Netherlands)

    Blaney Davidson, E.N.; Kraan, P.M. van der; Berg, W.B. van den

    2007-01-01

    OBJECTIVE: Cartilage damage is a major problem in osteoarthritis (OA). Growth factors like transforming growth factor-beta (TGF-beta) have great potential in cartilage repair. In this review, we will focus on the potential therapeutic intervention in OA with TGF-beta, application of the growth facto

  8. Investigation on the foaming behaviors of NC-based gun propellants

    Directory of Open Access Journals (Sweden)

    Yu-xiang Li

    2014-09-01

    Full Text Available To prepare the porous NC-based (nitrocellulose-based gun propellants, the batch foaming process of using supercritical CO2 as the physical blowing agent is used. The solubilities of CO2 in the single-base propellants and TEGDN (trimethyleneglycol dinitrate propellants are measured by the gravimetric method, and SEM (scanning electron microscope is used to observe the morphology of foamed propellants. The result shows that a large amount of CO2 could be dissolved in NC-based propellants. The experimental results also reveal that the energetic plasticizer TEGDN exerts an important influence on the pore structure. The triaxial tensile failure mechanism for solid-state nucleation is used to explain the nucleation of NC-based propellants in the solid state. Since some specific foaming behaviors of NC-based propellants can not be explained by the failure mechanism, a solid-state nucleation mechanism which revises the triaxial tensile failure mechanism is proposed and discussed.

  9. High-Lift Propeller System Configuration Selection for NASA's SCEPTOR Distributed Electric Propulsion Flight Demonstrator

    Science.gov (United States)

    Patterson, Michael D.; Derlaga, Joseph M.; Borer, Nicholas K.

    2016-01-01

    Although the primary function of propellers is typically to produce thrust, aircraft equipped with distributed electric propulsion (DEP) may utilize propellers whose main purpose is to act as a form of high-lift device. These \\high-lift propellers" can be placed upstream of wing such that, when the higher-velocity ow in the propellers' slipstreams interacts with the wing, the lift is increased. This technique is a main design feature of a new NASA advanced design project called Scalable Convergent Electric Propulsion Technology Operations Research (SCEPTOR). The goal of the SCEPTOR project is design, build, and y a DEP aircraft to demonstrate that such an aircraft can be much more ecient than conventional designs. This paper provides details into the high-lift propeller system con guration selection for the SCEPTOR ight demonstrator. The methods used in the high-lift propeller system conceptual design and the tradeo s considered in selecting the number of propellers are discussed.

  10. Investigation on the wake evolution of contra-rotating propeller using RANS computation and SPIV measurement

    Directory of Open Access Journals (Sweden)

    Paik Kwang-Jun

    2015-05-01

    Full Text Available The wake characteristics of Contra-Rotating Propeller (CRP were investigated using numerical simulation and flow measurement. The numerical simulation was carried out with a commercial CFD code based on a Reynolds Averaged Navier-Stokes (RANS equations solver, and the flow measurement was performed with Stereoscopic Particle Image Velocimetry (SPIV system. The simulation results were validated through the comparison with the experiment results measured around the leading edge of rudder to investigate the effect of propeller operation under the conditions without propeller, with forward propeller alone, and with both forward and aft propellers. The evolution of CRP wake was analyzed through velocity and vorticity contours on three transverse planes and one longitudinal plane based on CFD results. The trajectories of propeller tip vortex core in the cases with and without aft propeller were also compared, and larger wake contraction with CRP was confirmed.

  11. Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

    DEFF Research Database (Denmark)

    Fossen, T.I.; Blanke, M.

    1999-01-01

    More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback controller...... minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...

  12. Workshop on ESD (Electrostatic Discharge) Ignition of Composite Solid Propellants Held on April 18-19, 1989 in Nashville, Tennessee

    Science.gov (United States)

    1990-01-01

    CMDB propellants decreased 40 percent and CTPB propellants decreased about 3 percent. The AC volume resistivity decreased with increasing frequency for...each sample. CMDB propel- lants are somewhat conductive even at the low frequencies. Both HTPB and CTPB propellants have a relatively high resistivity

  13. 46 CFR 151.12-10 - Operation of oceangoing non-self-propelled ships Carrying Category D NLS.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Operation of oceangoing non-self-propelled ships... of oceangoing non-self-propelled ships Carrying Category D NLS. (a) An oceangoing non-self-propelled... oceangoing non-self-propelled ship that carries a Category D NLS listed under § 151.12-5 shall ensure...

  14. Differential regulation of chemoattractant-stimulated beta 2, beta 3, and beta 7 integrin activity.

    Science.gov (United States)

    Sadhu, C; Masinovsky, B; Staunton, D E

    1998-06-01

    Leukocyte adhesion to endothelium and extravasation are dynamic processes that require activation of integrins. Chemoattractants such as IL-8 and FMLP are potent activators of leukocyte integrins. To compare the chemoattractant-stimulated activation of three integrins, alpha 4 beta 7, alpha L beta 2, and alpha V beta 3, in the same cellular context, we expressed an IL-8 receptor (IL-8RA) and FMLP receptor (FPR) in the lymphoid cell line JY. Chemoattractants induced a rapid increase in alpha L beta 2- and alpha V beta 3-dependent JY adhesion within 5 min, and it was sustained for 30 min. In contrast, stimulation of alpha 4 beta 7-dependent adhesion was transient, returning to basal levels by 30 min. The activation profiles of the integrins were similar regardless of whether IL-8 or FMLP was used for induction. We also demonstrate that alpha 4 beta 7-dependent adhesion was uniquely responsive to the F actin-disrupting agent cytochalasin D and the protein kinase C (PKC) inhibitor chelerythrin. While alpha V beta 3- and alpha L beta 2-mediated cell adhesion was significantly reduced by cytochalasin D, alpha 4 beta 7-mediated adhesion was enhanced. Chelerythrin inhibited both the IL-8 and PMA activation of alpha L beta 2 and alpha V beta 3. In contrast, inducible alpha 4 beta 7 activity was unaffected, and basal activity was increased. These findings demonstrate that the mechanism of alpha 4 beta 7 regulation by chemoattractants is different from that of alpha L beta 2 and alpha V beta 3 and that it appears to involve distinct cytoskeletal and PKC dependencies. In addition, PKC activity may be a positive or negative regulator of integrin-dependent adhesion.

  15. History of solid propellants in the 20. century; Histoire des propergols solides au 20. siecle

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Ph.; Davenas, A.; McDonald, A.J.; Bret, P.; Moreau, J.P.; Boisson, J.; Kuentzmannn, P.; Maire, G.; Pontvianne, G.; Tranchant, J.; Evans, G.; Reydellet, D.; Vallet, G.; Eymard, M.; Pascal, Ph.; Kuentzmann, P.; Bonnevie, E.; Guery, J.F.; Lengelle, G.; Lhuillier, J.N.; Rat, R.; Keromnes, A.; Mathieu, D.; Simonetti, Ph.; Betin, P.; Thevenin, M.; Serra, J.J.; Delbac, P.; Lepeuple, G.; Miermont, H.; Guillot, J.; Vidal, M.; Citon, C.; Tauzia, J.M.; Chounet, G.; Cardin, J.; Longevialle, Y.; Uhrig, G.

    2004-07-01

    This colloquium has been jointly organized by the research center of history of sciences and techniques (CRHST) and the association of the friends of the gunpowder and pyrotechnical patrimony (A3P). It gathers historians of sciences and techniques and specialists of solid propellants and their applications who make a review of the approaches that have led to todays propellants efficiency and mastery. This books contains 2 introductive talks, 24 articles, a round table and some concluding remarks. The articles deal with: 1 - from the black powder rockets to the space shuttle: France, pioneer of solid propulsion, from Vaillant to Damblanc (1821-1938); the development of solid propellants in the 20. century; lessons learnt from the Challenger accident; 2 - the institutions: the laboratory of ballistics of Sevran-Livry (1945-1969); an historical overview of ONERA's researches on solid propellants; the cast propellants at the Direction of Explosives (1945-1955); 3 - the propellants: the manufacturing secrets of the extruded double base propellants; the development of cast double base propellants; the invention of composite propellants; 4 - space applications: the Diamant adventure; the solid propellant engines of Ariane 5, an endless story; P80, a new generation of solid propellant engines for space applications; 6 - physics and models: from ap{sup n} to 3-D simulations: the combustion of solid propellants in the 20. century; the mechanical behaviour of solid propellant loads (1960-70 years); composite propellants and static electricity (SE) or the occurrence of SE in the manufacturing and implementation of composite propellants; a priori calculation of the performances and synthesis of new energy materials for propellants; 6 - defense applications: French solid propellant rockets and missiles up to the 1960's; from PHI 1500 to PHI 1930 or the fabulous history of metallic and roving propulsion systems; the G2P, the propulsion system of the M4, the exploratory

  16. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  17. Beta-thalassemia.

    Science.gov (United States)

    Galanello, Renzo; Origa, Raffaella

    2010-05-21

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  18. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A.; Pascual, P.

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  19. Realized Beta GARCH

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri Radkov

    2014-01-01

    We introduce a multivariate generalized autoregressive conditional heteroskedasticity (GARCH) model that incorporates realized measures of variances and covariances. Realized measures extract information about the current levels of volatilities and correlations from high-frequency data, which...... is particularly useful for modeling financial returns during periods of rapid changes in the underlying covariance structure. When applied to market returns in conjunction with returns on an individual asset, the model yields a dynamic model specification of the conditional regression coefficient that is known...... as the beta. We apply the model to a large set of assets and find the conditional betas to be far more variable than usually found with rolling-window regressions based exclusively on daily returns. In the empirical part of the paper, we examine the cross-sectional as well as the time variation...

  20. Coroutine Sequencing in BETA

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger;

    In object-oriented programming, a program execution is viewed as a physical model of some real or imaginary part of the world. A language supporting object-oriented programming must therefore contain comprehensive facilities for modeling phenomena and concepts form the application domain. Many ap...... applications in the real world consist of objects carrying out sequential processes. Coroutines may be used for modeling objects that alternate between a number of sequential processes. The authors describe coroutines in BETA...

  1. Magic Baseline Beta Beam

    CERN Document Server

    Agarwalla, Sanjib Kumar; Raychaudhuri, Amitava

    2007-01-01

    We study the physics reach of an experiment where neutrinos produced in a beta-beam facility at CERN are observed in a large magnetized iron calorimeter (ICAL) at the India-based Neutrino Observatory (INO). The CERN-INO distance is close to the so-called "magic" baseline which helps evade some of the parameter degeneracies and allows for a better measurement of the neutrino mass hierarchy and $\\theta_{13}$.

  2. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades......, but the mechanisms involved are still not clarified. In this review the information obtained in previous studies is recapitulated together with some of the current attempts to resolve the controversy in the field: identification of the putative progenitor cells, identification of the factors involved...

  3. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  4. A Study of Boat and Boat Propeller-Related Injuries in the United States, 1991-1992

    Science.gov (United States)

    1993-06-01

    propeller 1 gas propeller 2 water (jet) 2 water (jet) 9 don’t know 9 don’t know e.Number of 0 none 0 none propellers 1 one propeller 1 one propeller 2 two...stern drive 3 stern drive 4 jet drive 4 jet drive 5 fan 5 fan 6 other: 6 other: 9 don’t know 9 don’t know d.Power source: 0 none 0 none 1 gas

  5. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  6. Liquid propellant analogy technique in dynamic modeling of launch vehicle

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The coupling effects among lateral mode,longitudinal mode and torsional mode of a launch vehicle cannot be taken into account in traditional dynamic analysis using lateral beam model and longitudinal spring-mass model individually.To deal with the problem,propellant analogy methods based on beam model are proposed and coupled mass-matrix of liquid propellant is constructed through additional mass in the present study.Then an integrated model of launch vehicle for free vibration analysis is established,by which research on the interactions between longitudinal and lateral modes,longitudinal and torsional modes of the launch vehicle can be implemented.Numerical examples for tandem tanks validate the present method and its necessity.

  7. Reactivities of Precision Cleaning Solvents with Hypergolic Propellants

    Science.gov (United States)

    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.

  8. Homogenization Issues in the Combustion of Heterogeneous Solid Propellants

    Science.gov (United States)

    Chen, M.; Buckmaster, J.; Jackson, T. L.; Massa, L.

    2002-01-01

    We examine random packs of discs or spheres, models for ammonium-perchlorate-in-binder propellants, and discuss their average properties. An analytical strategy is described for calculating the mean or effective heat conduction coefficient in terms of the heat conduction coefficients of the individual components, and the results are verified by comparison with those of direct numerical simulations (dns) for both 2-D (disc) and 3-D (sphere) packs across which a temperature difference is applied. Similarly, when the surface regression speed of each component is related to the surface temperature via a simple Arrhenius law, an analytical strategy is developed for calculating an effective Arrhenius law for the combination, and these results are verified using dns in which a uniform heat flux is applied to the pack surface, causing it to regress. These results are needed for homogenization strategies necessary for fully integrated 2-D or 3-D simulations of heterogeneous propellant combustion.

  9. Parametric Studies on Star Port Propellant Grain For Ballistic Evaluation

    Directory of Open Access Journals (Sweden)

    Himanshu Shekhar

    2005-10-01

    Full Text Available Star port propellant grains have been extensively studied for their operating as well as geometrical parameters. It is observed that reduced tail-off and better neutrality cannot be achieved simultaneously in a configuration. Parametric study is conducted to know the effect of various parameters of star-shaped propellant grains for ballistic evaluation motor. For reduced tail-off, higher characteristic velocity, lower outer diameter of the star, and lower value of angular fraction is preferred. Star angle, burning rate, and throat diameter have negligible effects on the tail-off factor. For better neutrality, higher value of angular  fraction, higher star outer diameter, and star angle near to neutrality, is needed. An alternate configuration is suggested using this parametric study to ascertain least tail-off and enhanced neutrality.

  10. [Combustion temperature measurement of solid propellant by remote sensing FTIR].

    Science.gov (United States)

    Li, Yan; Wang, Jun-De; Sun, Xiu-Yun; Zhou, Xue-Tie

    2004-08-01

    The combustion temperature of solid propellant was measured in this paper. Emission spectra of the combustion flame were collected with remote sensing FTIR at the resolution of 4 cm(-1). The combustion temperatures with the burning time were calculated from the maximum spectral line intensity and the molecular rotation-vibration spectra of HF molecule, respectively. Combustion temperatures at each time were all 1 788.8 K from the maximum spectral line intensity method. For comparison, the temperatures calculated from the molecular rotation-vibration spectra were 1 859.7, 1 848. 3, 1 804.0 and 1 782.7 K, respectively. Results show that the two methods are all dependable in measuring combustion temperature of solid propellant. But the maximum spectral line intensity method is more convenient and rapid than the other when the combustion is relatively stable.

  11. Oscillatory burning of solid propellants including gas phase time lag.

    Science.gov (United States)

    T'Ien, J. S.

    1972-01-01

    An analysis has been performed for oscillatory burning of solid propellants including gas phase time lag. The gaseous flame is assumed to be premixed and laminar with a one-step overall chemical reaction. The propellant is assumed to decompose according to the Arrenhius Law, with no condensed phase reaction. With this model, strong gas phase resonance has been found in certain cases at the characteristic gas-phase frequencies, but the peaking of the acoustic admittance is in the direction favoring the damping of pressure waves. At still higher frequencies, moderate wave-amplifying ability was found. The limit of low frequency response obtained previously by Denison and Baum was recovered, and the limitations of the quasi-steady theory were investigated.

  12. A stop-restart solid propellant study with salt quench

    Science.gov (United States)

    Kumar, R. N.

    1976-01-01

    Experiments were conducted to gain insight into the unsatisfactory performance of the salt quench system of solid propellants in earlier studies. Nine open-air salt spray tests were conducted and high-speed cinematographic coverage was obtained of the events. It is shown that the salt spray by the detonator is generally a two-step process yielding two different fractions. The first fraction consists of finely powdered salt and moves practically unidirectionally at a high velocity (thousand of feet per second) while the second fraction consists of coarse particles and moves randomly at a low velocity (a few feet per second). Further investigation is required to verify the speculation that a lower quench charge ratio (weight of salt/propellant burning area) than previously employed may lead to an efficient quench

  13. A molecular propeller effect for chiral separation and analysis

    Science.gov (United States)

    Clemens, Jonathon B.; Kibar, Osman; Chachisvilis, Mirianas

    2015-07-01

    Enantiomers share nearly identical physical properties but have different chiral geometries, making their identification and separation difficult. Here we show that when exposed to a rotating electric field, the left- and right-handed chiral molecules rotate with the field and act as microscopic propellers; moreover, owing to their opposite handedness, they propel along the axis of field rotation in opposite directions. We introduce a new molecular parameter called hydrodynamic chirality to characterize the coupling of rotational motion of a chiral molecule into its translational motion and quantify the direction and velocity of such motion. We demonstrate >80% enrichment level of counterpart enantiomers in solution without using chiral selectors or circularly polarized light. We expect our results to have an impact on multiple applications in drug discovery, analytical and chiral chemistry, including determination of absolute configuration, as well as in influencing the understanding of artificial and natural molecular systems where rotational motion of the molecules is involved.

  14. Thermal Degradation Studies of A Polyurethane Propellant Binder

    Energy Technology Data Exchange (ETDEWEB)

    Assink, R.A.; Celina, M.; Gillen, K.T.; Graham, A.C.; Minier, L.M.

    1999-06-12

    The thermal oxidative aging of a crosslinked hydroxy-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) based polyurethane rubber, used as a polymeric binder in solid propellant grain, was investigated at temperatures from 25 C to 125 C. The changes in tensile elongation, polymer network properties and chain dynamics, mechanical hardening and density were determined with a range of techniques including modulus profiling, solvent swelling, NMR relaxation and O{sub 2} permeability measurements. We critically evaluated the Arrhenius methodology that is commonly used with a linear extrapolation of high temperature aging data using extensive data superposition and highly sensitive oxygen consumption experiments. The effects of other constituents in the propellant formulation on aging were also investigated. We conclude that crosslinking is the dominant process at higher temperatures and that the degradation involves only limited hardening in the bulk of the material. Significant curvature in the Arrhenius diagram of the oxidation rates was observed. This is similar to results for other rubber materials.

  15. Hydrogen/Oxygen Propellant Densifier Thermoacoustic Stirling Heat Engine

    Science.gov (United States)

    Nguyen, C. T.; Yeckley, A. J.; Schieb, D. J.; Haberbusch, M. S.

    2004-06-01

    A unique, patent pending, thermoacoustic propellant densifier for the simultaneous densification of hydrogen and oxygen propellants for aerospace vehicles is introduced. The densifier uses a high-pressure amplitude, low-frequency Thermoacoustic Stirling Heat Engine (TASHE) coupled with a uniquely designed half-wave-length resonator to drive a pulse tube cryocooler using a Gas Helium (GHe) working fluid. The extremely reliable TASHE has no moving parts, is water cooled, and is electrically powered. The helium-filled TASHE is designed to ASME piping codes, which enables the safe inspection of the system while in operation. The resonator is designed to eliminate higher-order harmonics with minimal acoustic losses. A system description will be presented, and experimental data on both the TASHE and the resonator will be compared with analytical results.

  16. Scaling theory for liquid propellant rocket thrust chambers

    Directory of Open Access Journals (Sweden)

    C. M. Sethna

    1960-04-01

    Full Text Available With the advent of the very large liquid propellant rocket, it has become necessary, if possible, to derive a rational scaling theory for combustion chamber design so as to enable relatively simple and economical initial tests to be carried out on small scaled models using scaled parameters of propellant mass flows, pressure etc., and from these to predict operating and design data for the full scale rocket. Owing to the complex and interdependent nature of the aerothermo-chemical processes in the chamber involving evaporation, diffusion and chemical reaction, the similarity criteria must necessarily extend over several, non-dimensional parameters, but it is still possible to evolve relatively simple rules for correlating the design and performance of the model and large scale motors-as shown by Penner-Tsien and Crocco. The paper concludes with a discussion of the accuracy and practical feasibility of such scaling rules.

  17. Aircraft Noise Prediction Program theoretical manual: Propeller aerodynamics and noise

    Science.gov (United States)

    Zorumski, W. E. (Editor); Weir, D. S. (Editor)

    1986-01-01

    The prediction sequence used in the aircraft noise prediction program (ANOPP) 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 first group. Predictions of periodic thickness and loading noise are determined with time-domain methods. Broadband noise is predicted by a semiempirical method. Near-field predictions of fuselage surface pressrues include the effects of boundary layer refraction and scattering. Far-field predictions include atmospheric and ground effects.

  18. Metallised Fuel rich Propellants for Solid Rocket Ramjet: A Review

    Directory of Open Access Journals (Sweden)

    B. K. Athawale

    1994-10-01

    Full Text Available This paper reviews the research work carried out in the field of metallised fuel-rich propellants (FRP. Limitations and merits of various potential metals (Al, Mg, B, Be, or Zr as a component of FRP are discussed. The paper also includes a discussion on the combustion mechanism of metallised propellants, including problem areas and probable remedial measures. Zirconium and Ti appear to have potential to offer FRP with efficient combustion. Ideal performance is not achieved with current systems based on Al and B and further work is needed to develop FRP having all three desirable attributes, viz., ease of ignition, stable combustion and high specific impulse (I/sub sp/ in a single composition.

  19. Optimization of propellant binders - part I: statistical methodology

    Energy Technology Data Exchange (ETDEWEB)

    Niehaus, Michael; Greeb, Olaf [Fraunhofer Institut fuer Chemische Technologie, D-76327 Pfinztal (Germany)

    2004-06-01

    The development of new propellant binder systems requires the thermodynamic calculation of physico-chemical data as well as the adaption of the mechanical properties in order to achieve a reliable innerballistic profile of the resulting propellant. However, in most cases the mechanical data may not be easily predicted due to the complex interactions between the components of the binder like the resin, the curing agent or possibly plasticizers and curing catalysts. Therefore, this study focusses on the capability of the multivariate analysis on the prediction of the E-modulus of a system comprising nitrocellulose as well as GAP, Desmodur N100 and an energetic plasticiser. Using this method, an equation has been derived which, within the regression intervall, may be used for the prediction of the E-modulus as a function of the components mentioned above. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  20. Propellant Feed System for Swirl-Coaxial Injection

    Science.gov (United States)

    Reynolds, David Christopher (Inventor)

    2015-01-01

    A propellant feed system for swirl-coaxial injection of a liquid propellant includes a reservoir having a bottom plate and at least one tube originating in the bottom plate and extending therefrom. The tube has rectangular slits defined in and distributed tangentially and evenly about a portion of the tube that is disposed in the bottom plate. Drain holes are provided in the bottom plate and tunnels are defined in the bottom plate. Each tunnel fluidly couples one of the drain holes to a corresponding one of the rectangular slits. Each tunnel includes (i) a bend of at least 90.degree., and (ii) a straight portion leading to its corresponding rectangular slit wherein the straight portion is at least five times as long as a hydraulic diameter of the corresponding rectangular slit.

  1. Modelling of Heat Loss in Closed Vessels during propellant Burning

    Directory of Open Access Journals (Sweden)

    U.P. KulKarni

    2000-10-01

    Full Text Available Closed vessel technique is essentially used to determine the force constant, vivacity and the burning rate of gun propellants. In fact, it is the only method to find out these three parameters experimentally. It is a well-known fact that however small the propellant burning time may be, there will be heat loss to the walls of the vessel due to conduction, convection, radiation and also due to the expansion of the vessel. This fact necessitates applying correction to the observed maximum pressure in the experiment. An analysis is presented in this paper as to how this heat loss can be modelled along with discussion about other models reported in this field.

  2. Magnetic propeller effect in the spectra of young stars

    Science.gov (United States)

    Grinin, V. P.; Potravnov, I. S.; Ilyin, I. V.; Shulman, S. G.

    2015-08-01

    The origin of the blueshifted narrow absorption components in the resonance sodium doublet lines observed in the spectra of some young stars is discussed. Such components are assumed to be formed by the interaction of the circumstellar gas with the stellar magnetosphere in the magnetic propeller regime. The results of observations for the post UX Ori star RZ Psc are discussed in detail. This star shows distinctive signatures of mass outflow in the absence of any clear accretion signatures. Such a picture is quite possible in the magnetic propeller regime. Estimates show that for this regime to be realized, the star must have a surface magnetic field of ~1 kG at an accretion rate that does not exceed 10-10 M . yr-1.

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

    Science.gov (United States)

    2010-03-19

    ... blades that are constructed of composite material. The blade has a carbon fiber spar, a shell composed of...-SC, for McCauley Propeller Systems for model propeller 3D15C1401/C80MWX-X (71 FR 43674). On...

  4. 76 FR 61558 - Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller...

    Science.gov (United States)

    2011-10-05

    ..., Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine & Propeller Directorate, 12 New..., Manager, Engine & Propeller Directorate, Aircraft Certification Service. BILLING CODE 4910-13-P ...-01-AD; Amendment 39-16807; AD 2011-19-02] RIN 2120-AA64 Airworthiness Directives; Dowty...

  5. On the Effects of an Installed Propeller Slipstream on Wing Aerodynamic Characteristics

    Directory of Open Access Journals (Sweden)

    F. M. Catalano

    2004-01-01

    Full Text Available This work presents an experimental study of the effect of an installed propeller slipstream on a wing boundary layer. The main objective was to analyse through wind tunnel experiments the effect of the propeller slipstream on the wing boundary layer characteristics such as: laminar flow extension and transition, laminar separation bubbles and reattachment and turbulent separation. Two propeller/wing configurations were studied: pusher and tractor. Experimental work was performed using two different models: a two-dimensional wing with a central cylindrical nacelle for the tractor configuration, and a simple two-dimensional wing with a downstream propeller for the pusher tests. The relative position between propeller and wing could be changed in the pusher model, and a total of 7 positions were analysed. For the tractor tests the relative propeller/wing was fixed, but three different propellers: two, three and four bladed were tested. Measurements included pressure distribution, hot wire anemometry and boundary layer characteristics by flow visualisation. The results showed that the pusher propeller inflow affects the wing characteristics by changing the lift, drag, and also delays the boundary layer transition and separation. These effects are highly dependent on the relative position of the wing/propeller. On the other hand, the tractor propeller slipstream induces transition and its effect is dependent on the number of blades.

  6. Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

    Institute of Scientific and Technical Information of China (English)

    Zheng-gang XIAO; San-jiu YING; Fu-ming XU

    2014-01-01

    Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN) (TEGDN propellants) to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

  7. Evaluation of Propellant Erosivity with Vented Erosion Apparatus

    Science.gov (United States)

    1981-03-01

    Controlling Olllca) 10. PROGRAM ELEMENT. PROJECT. TASK AREA & WORK UNIT NUMBERS 12. REPORT DATE MARCH 1981 13. NUMBER OF PAGES 50 15...surface area , etc. Another important factor in determining the relative erosivi- ties of various propellants and p-vs-t programs is the dynamics of...Ellington DRDAR- -LCS- -D, K. Rubin J. Houle DRDAR- -QA, J Rutkowski DRDAR- -SC, D. Gyorog H. Kahn B. Brodman S. Cystron L. Stiefel DRDAR- -TSS (5

  8. Solid propellant combustion response to oscillatory radiant heat flux

    Science.gov (United States)

    Strand, L. D.; Weil, M. T.; Cohen, N. S.

    1989-01-01

    A progress report is given on a research project to use the microwave Doppler velocimeter technique to measure the combustion response to an oscillating thermal radiation source (CO2 laser). The test technique and supporting analyses are described, and the results are presented for an initial test series on the nonmetallized, composite propellant, Naval Weapons Center formulation A-13. It is concluded that in-depth transmission of radiant heat flux is not a factor at the CO2 laser wave length.

  9. Longitudinal Stability Criteria for a Propeller-Driven Aircraft

    OpenAIRE

    Gil Iosilevskii

    2010-01-01

    The Routh criterion is used to assess longitudinal dynamic stability of a propeller-driven aircraft. Under a few plausible assumptions on possible ranges of the pertinent stability derivatives, it reduces to a pair of simple conditions imposing a traditional aft limit (the forward of the maneuver and the neutral-speed-stability points) on the center-of-gravity position and an upper limit on the longitudinal moment of inertia. It is demonstrated that most aircraft have sufficiently small inert...

  10. AFRL Solid Propellant Laboratory Explosive Siting and Renovation Lessons Learned

    Science.gov (United States)

    2010-05-19

    Siting and Renovation Lessons Learned 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Daniel F . Schwartz (AFRL/RZSP) 5d. PROJECT... Daniel F . Schwartz a. REPORT Unclassified b. ABSTRACT Unclassified c. THIS PAGE Unclassified SAR 35 19b. TELEPHONE NUMBER (include...1 AFRL Solid Propellant Laboratory Explosive Siting and Renovation Lessons Learned Daniel F . Schwartz Air Force Research Laboratory

  11. Propellant combustion response to oscillatory radiant heat flux

    Science.gov (United States)

    Strand, L. D.; Schwartz, K.; Burns, S. P.

    1987-01-01

    An introductory progress report is given on a research project to use the microwave Doppler velocimeter technique to measure the combustion response to an oscillating thermal radiation source (laser). The objective is to relate the measured burning rate response to the thermal radiation to an equivalent oscillation in pressure using existing thermal combustion theory. The test system is described, and the results of an initial test series on the composite propellant A-13 are presented.

  12. Nitramine-Based High Energy Propellant Compositions for Tank Guns

    OpenAIRE

    R.S. Damse; Haridwar Singh

    2000-01-01

    Six different RDX-based gun propellant compositions have been formulated and studied to select the most suitable composition for tank gun ammunition in terms of higher force constant at relatively lower flame temperature (T). Ballistic'performance of the compositions was evaluated on the basis of closed vessel test. JIea(energy was determined using a bomb calorimeter. Sensitivity, thermal characteristics, stability and mechanical properties of the compositions were studied for assessing their...

  13. Fuel-Cell Power Source Based on Onboard Rocket Propellants

    Science.gov (United States)

    Ganapathi, Gani; Narayan, Sri

    2010-01-01

    The use of onboard rocket propellants (dense liquids at room temperature) in place of conventional cryogenic fuel-cell reactants (hydrogen and oxygen) eliminates the mass penalties associated with cryocooling and boil-off. The high energy content and density of the rocket propellants will also require no additional chemical processing. For a 30-day mission on the Moon that requires a continuous 100 watts of power, the reactant mass and volume would be reduced by 15 and 50 percent, respectively, even without accounting for boiloff losses. The savings increase further with increasing transit times. A high-temperature, solid oxide, electrolyte-based fuel-cell configuration, that can rapidly combine rocket propellants - both monopropellant system with hydrazine and bi-propellant systems such as monomethyl hydrazine/ unsymmetrical dimethyl hydrazine (MMH/UDMH) and nitrogen tetroxide (NTO) to produce electrical energy - overcomes the severe drawbacks of earlier attempts in 1963-1967 of using fuel reforming and aqueous media. The electrical energy available from such a fuel cell operating at 60-percent efficiency is estimated to be 1,500 Wh/kg of reactants. The proposed use of zirconia-based oxide electrolyte at 800-1,000 C will permit continuous operation, very high power densities, and substantially increased efficiency of conversion over any of the earlier attempts. The solid oxide fuel cell is also tolerant to a wide range of environmental temperatures. Such a system is built for easy refueling for exploration missions and for the ability to turn on after several years of transit. Specific examples of future missions are in-situ landers on Europa and Titan that will face extreme radiation and temperature environments, flyby missions to Saturn, and landed missions on the Moon with 14 day/night cycles.

  14. Analyses of Cryogenic Propellant Tank Pressurization based upon Ground Experiments

    OpenAIRE

    Ludwig, Carina; Dreyer, Michael

    2012-01-01

    The pressurization system of cryogenic propellant rockets requires on-board pressurant gas. The objective of this study was to analyze the influence of the pressurant gas temperature on the required pressurant gas mass in terms of lowering the launcher mass. First, ground experiments were performed in order to investigate the pressurization process with regard to the influence of the pressurant gas inlet temperature. Second, a system study for the cryogenic upper stage of a sma...

  15. A thermodynamic study of the turbine-propeller engine

    Science.gov (United States)

    Pinkel, Benjamin; Karp, Irvin M

    1953-01-01

    Equations and charts are presented for computing the thrust, the power output, the fuel consumption, and other performance parameters of a turbine-propeller engine for any given set of operating conditions and component efficiencies. Included are the effects of the pressure losses in the inlet duct and the combustion chamber, the variation of the physical properties of the gas as it passes through the system, and the change in mass flow of the gas by the addition of fuel.

  16. Transition Metal Carbohydrazide Nitrates: Burn-rate Modifiers for Propellants

    Directory of Open Access Journals (Sweden)

    S. H. Sonawane

    2006-07-01

    Full Text Available This paper discusses the synthesis and characterisation of cobalt (Co, nickel (Ni andcopper (Cu carbohydrazide nitrates. In differential scanning calorimetry (DSC, the complexesexhibited exothermic decomposition indicating their energetic nature. The commencement ofdecomposition was observed at 220 °C for Ni complex, and at 160 °C for Co complex whereasthat of Cu complex occurred at 75 °C. In view of the better thermal stability, Ni and Co complexeswere selected for further study. The activation energy of decomposition of Ni and Co complexeswere found to be 47 kcal/mol and 60 kcal/mol respectively. Impact and friction sensitivity testresults revealed relatively lower vulnerability of carbohydrazide cobalt nitrate. Its incorporationin an ammonium perchlorate (AP-based composite propellant led to 9-19 per cent enhancementwhereas that of carbohydrazide nickel nitrate resulted in 28-74 per cent enhancement in burningrates in the pressure range 1.9 MPa to 8.8 MPa. Exothermic decomposition of the coordinationcomplexes on propellant surface and involvement of metal at molecular level formed ondecomposition of the complexes in combustion environment of composite propellant may beattributed to the catalytic effect of this class of compounds on the lines of reported literature.

  17. The University of Arizona program in solid propellants

    Science.gov (United States)

    Ramohalli, Kumar

    1989-01-01

    The University of Arizona program is aimed at introducing scientific rigor to the predictability and quality assurance of composite solid propellants. Two separate approaches are followed: to use the modern analytical techniques to experimentally study carefully controlled propellant batches to discern trends in mixing, casting, and cure; and to examine a vast bank of data, that has fairly detailed information on the ingredients, processing, and rocket firing results. The experimental and analytical work is described briefly. The principle findings were that: (1) pre- (dry) blending of the coarse and fine ammonium perchlorate can significantly improve the uniformity of mixing; (2) the Fourier transformed IR spectra of the uncured and cured polymer have valuable data on the state of the fuel; (3) there are considerable non-uniformities in the propellant slurry composition near the solid surfaces (blades, walls) compared to the bulk slurry; and (4) in situ measurements of slurry viscosity continuously during mixing can give a good indication of the state of the slurry. Several important observations in the study of the data bank are discussed.

  18. Interpenetrating Polymer Networks as Binders for Solid Composite Propellants

    Directory of Open Access Journals (Sweden)

    S. Parthiban

    1992-07-01

    Full Text Available A new family of polymeric binders for solid composite propellants is proposed, based on two component interpenetrating polymer networks (IPNs. These networks comprise two different polyurethanes based on hydroxy terminated polybutadiene and ISRO polyol interpenetrated with two different vinyl polymers, viz poly methyl methacrylate and polystyrene. the networks synthesized by the simultaneous interpenetrating technique have been characterized for their properties, such as stress-strain, density, viscosity, thermal degradation, and heat of combustion. Phase morphologies have been determined using electron microscopy. Suitable explanations have been adduced to rationalize the properties of IPNs in terms of their structures and chain interactions. A study of the mechanical properties and burning rates of the ammonium perchlorate (AP-based solid propellant using the newly synthesised IPNs as binders, has been carried out. The results show that both mechanical strength and burning rate of solid propellants could be suitably modified by simply changing the nature and/or the ratio of the two interpenetrating polymer components.

  19. Applications for Solid Propellant Cool Gas Generator Technology

    Science.gov (United States)

    van der List, M.; van Vliet, L. D.; Sanders, H. M.; Put, P. A. G.; Elst, J. W. E. C.

    2004-10-01

    In 2002 and 2003, Bradford Engineering B.V. conducted, in corporation with the Dutch research institute TNO Prins Maurits Laboratory (PML) a SME study for ESA-ESTEC for the identification of spaceflight applications and on-ground demonstration of Solid Propellant Cool Gas Generator (SPCGG) technology. This innovative technology has been developed by TNO-PML while Bradford Engineering also brought in its experience in spaceflight hardware development and manufacturing. The Solid Propellant Cool Gas Generator (SPCGG) technology allows for pure gas generation at ambient temperatures, as opposed to conventional solid propellant gas generators. This makes the SPCGG technology interesting for a wide range of terrestrial spaceflight applications. During the first part of the study, a variety of potential applications have been identified and three applications were selected for a more detailed quantitative study. In the third phase a ground demonstration was performed successfully for a cold gas propulsion system application. During the actual demonstration test, 10 cool gas generators were mounted and all operated successfully in sequence, demonstrating good repeatability of the produced amount of gas and pressure.

  20. Large-eddy simulations of a propelled submarine model

    Science.gov (United States)

    Posa, Antonio; Balaras, Elias

    2015-11-01

    The influence of the propeller on the wake as well as the evolution of the turbulent boundary layers over an appended notional submarine geometry (DARPA SUBOFF) is reported. The present approach utilizes a wall-resolved LES, coupled with an immersed boundary formulation, to simulate the flow model scale Reynolds numbers (Re = 1 . 2 e + 06 , based on the free-stream velocity and the length of the body). Cylindrical coordinates are adopted, and the computational grid is composed of 3.5 billion nodes. Our approach has been validated on the appended submarine body in towed conditions (without propeller), by comparisons to wind tunnel experiments in the literature. The comparison with the towed configuration shows profound modifications in the boundary layer over the stern surface, due to flow acceleration, with higher values of turbulent kinetic energy in the inner layer and lower values in the outer layer. This behavior was found tied to a different topology of the coherent structures between propelled and towed cases. The wake is also highly affected, and the momentum deficit displays a non-monotonic evolution downstream. An axial peak of turbulent kinetic energy replaces the bimodal distribution of the stresses in the wake, observed in the towed configuration. Supported by ONR Grant N000141110455, monitored by Dr. Ki-Han Kim.

  1. Regenerative Gas Dryer for In-Situ Propellant Production

    Science.gov (United States)

    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.

  2. Computation of the tip vortex flowfield for advanced aircraft propellers

    Science.gov (United States)

    Tsai, Tommy M.; Dejong, Frederick J.; Levy, Ralph

    1988-01-01

    The tip vortex flowfield plays a significant role in the performance of advanced aircraft propellers. The flowfield in the tip region is complex, three-dimensional and viscous with large secondary velocities. An analysis is presented using an approximate set of equations which contains the physics required by the tip vortex flowfield, but which does not require the resources of the full Navier-Stokes equations. A computer code was developed to predict the tip vortex flowfield of advanced aircraft propellers. A grid generation package was developed to allow specification of a variety of advanced aircraft propeller shapes. Calculations of the tip vortex generation on an SR3 type blade at high Reynolds numbers were made using this code and a parametric study was performed to show the effect of tip thickness on tip vortex intensity. In addition, calculations of the tip vortex generation on a NACA 0012 type blade were made, including the flowfield downstream of the blade trailing edge. Comparison of flowfield calculations with experimental data from an F4 blade was made. A user's manual was also prepared for the computer code (NASA CR-182178).

  3. Predictions of wing and pylon forces caused by propeller installation

    Science.gov (United States)

    Martinez, Rudolph

    1987-05-01

    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.

  4. Self-propelled droplet behavior during condensation on superhydrophobic surfaces

    Science.gov (United States)

    Chu, Fuqiang; Wu, Xiaomin; Zhu, Bei; Zhang, Xuan

    2016-05-01

    Self-propelled droplet motion has applications in various engineering fields such as self-cleaning surfaces, heat transfer enhancement, and anti-icing methods. A superhydrophobic surface was fabricated using two simultaneous chemical reactions with droplet condensation experiments performed on the horizontal superhydrophobic surface to characterize the droplet behavior. The droplet behavior is classified into three types based on their motion features and leftover marks as immobile droplet coalescence, self-propelled droplet jumping, and self-propelled droplet sweeping. This study focuses on the droplet sweeping that occurs due to the ultra-small rolling angle of the superhydrophobic surface, where the resulting droplet sweeps along the surface, merging with all the droplets it meets and leaving a long, narrow, clear track with a large droplet at the end of the track. An easy method is developed to predict the droplet sweeping direction based on the relative positions of the droplets just before coalescence. The droplet sweeping always absorbs dozens of droplets and is not limited by the surface structures; thus, this sweeping has many useful applications. In addition, the relationships between the droplet behavior and the number of participating droplets are also analyzed statistically.

  5. Occupational incidents with self-propelled machinery in Austrian agriculture.

    Science.gov (United States)

    Mayrhofer, Hannes; Quendler, Elisabeth; Boxberger, Josef

    2013-01-01

    Tractors, self-propelled harvesting machinery, and material handling machinery are the most commonly used self-propelled machineries in Austrian agriculture, and they have similarities in main accident scenarios. Statistical data of all occupational incidents with these machines reported between 2008 and 2010 were analyzed to obtain information about the circumstances of the incidents, and about the victims and their work environments. Criteria of recognized occupational incidents provided by the Austrian Social Insurance Institution for Farmers were analyzed according to machinery category by means of cross-tabulation and chi-square tests. The results were discussed and evaluated in the context of the literature. The results of the analysis of the databases show that 786 occupational incidents with tractors, self-propelled harvesting machinery, and material handling machinery occurred in Austrian agriculture between 2008 and 2010. There were 231 occupational incidents in 2008; the number rose to 268 in 2009 and to 286 in 2010. A total of 41 incidents were fatal. For the machinery categories analyzed, the majority of injured victims were male, older than 40 years, Austrian citizens, and managers of a mixed-agricultural farm. A large number of the incidents occurred in all machinery categories by loss of control during operating a vehicle.

  6. Environmental impact evaluation of static tests of solid propellant propellers; Evaluation de l`impact sur l`environnement des essais statiques de propulseurs a propergol solide

    Energy Technology Data Exchange (ETDEWEB)

    Aguesse, T.; Moreau, S. [DGA, Direction des Missiles et de l`Espace, Centre d`Achevement et d`Essais des Propulseurs et Engins, 33 - Saint Medard en Jalles (France)

    1996-12-31

    The CAEPE, the French Centre of Propellers and Engines Completion and Testing is in charge of the static tests of solid propellant fuelled propellers. In order to determine the schedule of firing permissions, predictive means are used to predict the environmental impact of propellers firing. Calculation and simulation codes are used to build maps of acoustic nuisance and acid fallout. These codes, which use in-situ meteorological radio sounding data, were progressively adjusted during testing of engines with different sizes (up to the Ariane 5 P230 auxiliary propeller). In this presentation, the authors focus on a model derived from the G.A. Briggs` model for the ascension of high temperature effluents. The correct simulation of acid rains requires a good description of this phenomenon. Concerning the other aspects of the codes, the main references are given. (J.S.) 15 refs.

  7. Improved method to label beta-2 agonists in metered-dose inhalers with technetium-99m

    Energy Technology Data Exchange (ETDEWEB)

    Ballinger, J.R.; Calcutt, L.E.; Hodder, R.V.; Proulx, A.; Gulenchyn, K.Y. (Ottawa Civic Hospital, Ottawa (Canada). Div. of Nuclear Medicine and Respiratory Unit)

    1993-01-01

    Labelling beta-2 agonists in a metered-dose inhaler (MDI) with technetium-99m allows imaging of the deposition of the aerosol in the respiratory tract. We have developed an improved labeling method in which anhydrous pertechnetate is dissolved in a small volume of ethanol, diluted with a fluorocarbon, and introduced into a commercial MDI. Imaging the MDI demonstrated that the [sup 99m]Tc was associated with the active ingredient, not just the propellant. The method has been used successfully with salbutamol and fenoterol MDIs and should be directly applicable to other MDIs which contain hydrophilic drugs. (Author).

  8. Optimization of energy saving device combined with a propeller using real-coded genetic algorithm

    Directory of Open Access Journals (Sweden)

    Ryu Tomohiro

    2014-06-01

    Full Text Available This paper presents a numerical optimization method to improve the performance of the propeller with Turbo-Ring using real-coded genetic algorithm. In the presented method, Unimodal Normal Distribution Crossover (UNDX and Minimal Generation Gap (MGG model are used as crossover operator and generation-alternation model, respectively. Propeller characteristics are evaluated by a simple surface panel method “SQCM” in the optimization process. Blade sections of the original Turbo-Ring and propeller are replaced by the NACA66 a = 0.8 section. However, original chord, skew, rake and maximum blade thickness distributions in the radial direction are unchanged. Pitch and maximum camber distributions in the radial direction are selected as the design variables. Optimization is conducted to maximize the efficiency of the propeller with Turbo-Ring. The experimental result shows that the efficiency of the optimized propeller with Turbo-Ring is higher than that of the original propeller with Turbo-Ring.

  9. DAMAGE OF A HIGH-ENERGY SOLID PROPELLANT AND ITS EFFECTS ON COMBUSTION

    Institute of Scientific and Technical Information of China (English)

    张泰华; 白以龙; 王世英; 刘培德

    2001-01-01

    In order to improve the safety of high-energy solid propellants, a study is carried out for the effects of damage on the combustion of the NEPE (Nitrate Ester Plasticized Polyether) propellant. The study includes: (1) to introduce damage into the propellants by means of a large-scale drop-weight apparatus; (2) to observe microstructural variations of the propellant with a scanning electron microscope (SEM) and then to characterize the damage with density measurements; (3) to investigate thermal decomposition; (4) to carry out closed-bomb tests. The NEPE propellant can be considered as a viscoelastic material. The matrices of damaged samples are severely degraded, but the particles are not. The results of the thermal decomposition and closed-bomb tests show that the microstructural damage in the propellant affects its decomposition and burn rate.

  10. Studies on Some Nitramine based Low Vulnerability Ammunition Propellants with Cellulose Acetate as a Binder

    Directory of Open Access Journals (Sweden)

    A.G.A. Pillai

    1996-04-01

    Full Text Available Several formulations of propellants based on RDX as an energetic solid ingredients and cellulose acetate (CA as a binder were processed using either dioctyl pthalate(DOP or tracetin(TA as plastisizer and a small amount of nitrocellulose(NC. The Performance of these propellants was evaluated on the basis of closed vessel firing data. The vulnerability aspects of these formulations were compared with those of conventional picrite propellant, NQ on the basis of their ignition temperatures and sensitivity to friction and impact. Triacetin was found to be better plasticizer than DOP for CA binder. Some RDX/CA/TA/NC/-based propellants were found to have energy levels comparable with NQ propellant and had less sensitivity to heat, impact and friction, and therefore have the potential for being used as low-vulnerability ammunition propellants for gun applications.

  11. Studies on Some Aspects of Propellants for Improving the Performance of Tank Guns

    Directory of Open Access Journals (Sweden)

    K. P. Rao

    1987-01-01

    Full Text Available The main criterion, in the design of propellant charge for a tank gun, is to achieve the highest possible muzzle velocity for fin stabilized armour piercing dicarding sabot (FSAPDS projectiles. This ensures penetration through the toughest armour plates by the kinetic energy of the projectile. One of the solutions, is to increase the force constant of the propellant. Higher force constant from conventional double and triple base propellant compositions lead to prohibitive linear rates of burning coefficients. ERDL has developed a high energy propellant based on RDX, with very high force constant and low linear rate of burning coefficient. The objective of the present paper is to discuss various aspects of the interior ballistics of the three types of propellants in question in 105 mm tank gun with FSAPDS ammunition. The study shows that only the solution with RDX base propellant is feasible for an increase of three per cent in muzzle velocity.

  12. The Obligations of Single-Propeller Vessels at the Head-On Situation

    Directory of Open Access Journals (Sweden)

    Bekir Sahin

    2016-04-01

    Full Text Available Manoeuvring characteristics of the vessels at the head-on situation are examined in this study. The meetings between the power-driven vessels are considered based on their propellers. These vessels can either have a single propeller or double propellers. A vessel with a single right-handed propeller alters her course to port side easier than the starboard side. There exists an unnoticed gap, therefore the authors discuss the International Regulations for Preventing Collisions at Sea, 1972 (COLREGs, Rule 14, considering the vessel orientation based on its propeller walk. After presenting all possible cases and their probable consequences, this paper offers authorities to embed the information of propeller characteristics into the Automatic Identification Systems (AIS in order to prevent misunderstandings during the VHF communications, probable collision risks and discussions on liability issues in case of marine accidents.

  13. Performance analysis of mini-propellers based on FlightGear

    Science.gov (United States)

    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.

  14. Numerical Simulation and Experimental Research on Hydrodynamic Performance of Propeller with Varying Shaft Depths

    Institute of Scientific and Technical Information of China (English)

    郭春雨; 赵大刚; 孙瑜

    2014-01-01

    In order to study hydrodynamic performance of a propeller in the free surface, the numerical simulation and open-water experiments are carried out with varying shaft depths of propeller. The influences of shaft depths of a propeller on thrust and torque coefficient in calm water are mainly studied. Meanwhile, this paper also studies the propeller air-ingestion under special working conditions by experiment and theoretical calculation method, and compares the calculation results and experimental results. The results prove that the theoretical calculation model used in this paper can imitate the propeller air-ingestion successfully. The successful phenomenon simulation provides an essential theoretical basis to understand the physical essence of the propeller air-ingestion.

  15. The Calculations of Propeller Induced Velocity by RANS and Momentum Theory

    Institute of Scientific and Technical Information of China (English)

    Qiuxin Gao; Wei Jin; Dracos Vassalos

    2012-01-01

    In order to provide instructions for the calculation of the propeller induced velocity in the study of the hull-propeller interaction using the body force approach,three methods were used to calculate the propeller induced velocity:1) Reynolds-Averaged Navier-Stokes (RANS) simulation of the self-propulsion test,2)RANS simulation of the propeller open water test,and 3) momentum theory of the propeller.The results from the first two methods were validated against experimental data to assess the accuracy of the computed flow field.The thrust identity method was adopted to obtain the advance velocity,which was then used to derive the propeller induced velocity from the total velocity field.The results computed by the first two approaches were close,while those from the momentum theory were significantly overestimated.The presented results could prove to be useful for further calculations of self-propulsion using the body force approach.

  16. Self-propelled carbon nanotube based microrockets for rapid capture and isolation of circulating tumor cells

    Science.gov (United States)

    Banerjee, Shashwat S.; Jalota-Badhwar, Archana; Zope, Khushbu R.; Todkar, Kiran J.; Mascarenhas, Russel R.; Chate, Govind P.; Khutale, Ganesh V.; Bharde, Atul; Calderon, Marcelo; Khandare, Jayant J.

    2015-05-01

    Here, we report a non-invasive strategy for isolating cancer cells by autonomously propelled carbon nanotube (CNT) microrockets. H2O2-driven oxygen (O2) bubble-propelled microrockets were synthesized using CNT and Fe3O4 nanoparticles in the inner surface and covalently conjugating transferrin on the outer surface. Results show that self-propellant microrockets can specifically capture cancer cells.Here, we report a non-invasive strategy for isolating cancer cells by autonomously propelled carbon nanotube (CNT) microrockets. H2O2-driven oxygen (O2) bubble-propelled microrockets were synthesized using CNT and Fe3O4 nanoparticles in the inner surface and covalently conjugating transferrin on the outer surface. Results show that self-propellant microrockets can specifically capture cancer cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr01797a

  17. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  18. Strand Burner Results of AFP-001 Propellant with Inert Coating for Temperature Compensation

    Science.gov (United States)

    2015-10-01

    ARL-MR-0907 ● OCT 2015 US Army Research Laboratory Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature...Laboratory Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature Compensation by John J Ritter and Anthony Canami...COVERED (From - To) February 2015 4. TITLE AND SUBTITLE Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature Compensation

  19. Pressure-coupled combustion response model for solid propellants based on Zeldovich-Novozhilov approach

    Science.gov (United States)

    Harstad, K. G.; Strand, L. D.

    1987-01-01

    An exact analytical solution is given to the problem of long-time propellant thermal response to a specified pressure oscillation. Coupling to the gas phase is made using the quasisteady Zeldovich-Novozhilov approximation. Explicit linear and lowest order (quadratic) nonlinear expressions for propellant response are obtained from the implicit nonlinear solutions. Using these expressions, response curves are presented for an ammonium perchlorate composite propellant and HMX monopropellant.

  20. [Combustion temperature measurement of solid propellant and the effect of organic compound on combustion temperature].

    Science.gov (United States)

    Zhou, Xue-tie; Li, Yan; Chen, Zuo-ru; Wang, Jun-de

    2003-06-01

    The FTIR emission spectra in the spectral range of 4,500-300 cm-1 for the solid propellants were measured by a remote sensing FTIR system. The P-branch of fine structure of HCl fundamental band lying at 3.46 microns was used for precise combustion temperature measurement of the solid propellant. The effect of the organic compound in the solid propellant on the combustion temperature was discussed.

  1. A numerical study of scale effects on performance of a tractor type podded propeller

    Directory of Open Access Journals (Sweden)

    Choi Jung-Kyu

    2014-06-01

    Full Text Available In this study, the scale effect on the performance of the podded propeller of tractor type is investigated. Turbulent flow computations are carried out for Reynolds numbers increasing progressively from model scale to full scale using the CFD analysis. The result of the flow calculation for model scale Reynolds numbers agrees well with that of the experiment of a large cavitation tunnel. The existing numerical analysis indicates that the performance of the podded propeller blades is mainly influenced by the advance coefficient and relatively little by the Reynolds number. However, the drag of pod housing with propeller in operation is different from that of pod housing without propeller due to the acceleration and swirl of propeller slipstream which is altered by propeller loading as well as the pressure recovery and friction according to Reynolds number, which suggests that the pod housing drag under the condition of propeller in operation is the key factor of the scale effect on the performance between model and full scale podded propellers. The so called ‘drag ratio’, which is the ratio of pod housing drag to total thrust of podded propeller, increases as the advance coefficient increases due to accelerated flow in the slipstream of the podded propeller. However, the increasing rate of the drag ratio reduces continuously as the Reynolds number increases from model to full scale progressively. The contribution of hydrodynamic forces, which acts on the parts composed of the pod housing with propeller operating in various loading conditions, to the thrust and the torque of the total propeller unit are presented for a range of Reynolds numbers from model to full scales.

  2. Studies on Some Nitramine based Low Vulnerability Ammunition Propellants with Cellulose Acetate as a Binder

    OpenAIRE

    A.G.A. Pillai; C. R. Dayanandan; B. R. Gandhe; J. S. Karir

    1996-01-01

    Several formulations of propellants based on RDX as an energetic solid ingredients and cellulose acetate (CA) as a binder were processed using either dioctyl pthalate(DOP) or tracetin(TA) as plastisizer and a small amount of nitrocellulose(NC). The Performance of these propellants was evaluated on the basis of closed vessel firing data. The vulnerability aspects of these formulations were compared with those of conventional picrite propellant, NQ on the basis of their ignition temperat...

  3. Self-propelled carbon nanotube based microrockets for rapid capture and isolation of circulating tumor cells.

    Science.gov (United States)

    Banerjee, Shashwat S; Jalota-Badhwar, Archana; Zope, Khushbu R; Todkar, Kiran J; Mascarenhas, Russel R; Chate, Govind P; Khutale, Ganesh V; Bharde, Atul; Calderon, Marcelo; Khandare, Jayant J

    2015-05-21

    Here, we report a non-invasive strategy for isolating cancer cells by autonomously propelled carbon nanotube (CNT) microrockets. H2O2-driven oxygen (O2) bubble-propelled microrockets were synthesized using CNT and Fe3O4 nanoparticles in the inner surface and covalently conjugating transferrin on the outer surface. Results show that self-propellant microrockets can specifically capture cancer cells.

  4. Simulations of the DARPA Suboff Submarine Including Self-Propulsion with the E1619 Propeller

    Science.gov (United States)

    2012-01-01

    measurements for steady inflow. Fuhs (2005) evaluated PUF -2, PUF -14, MPUF-3A, and PROPCAV solvers with DTMB propellers 4119, 4661, 4990, and 5168...the potential flow propeller solver PUF -14, with the goal of realizing substantial time savings over discretized propeller computations, while still...previously described. After validation, CFDShip/ PUF could be used with the Suboff submarine to estimate self-propulsion and compare with the

  5. Differential Draining of Parallel-Fed Propellant Tanks in Morpheus and Apollo Flight

    Science.gov (United States)

    Hurlbert, Eric; Guardado, Hector; Hernandez, Humberto; Desai, Pooja

    2015-01-01

    Parallel-fed propellant tanks are an advantageous configuration for many spacecraft. Parallel-fed tanks allow the center of gravity (cg) to be maintained over the engine(s), as opposed to serial-fed propellant tanks which result in a cg shift as propellants are drained from tank one tank first opposite another. Parallel-fed tanks also allow for tank isolation if that is needed. Parallel tanks and feed systems have been used in several past vehicles including the Apollo Lunar Module. The design of the feedsystem connecting the parallel tank is critical to maintain balance in the propellant tanks. The design must account for and minimize the effect of manufacturing variations that could cause delta-p or mass flowrate differences, which would lead to propellant imbalance. Other sources of differential draining will be discussed. Fortunately, physics provides some self-correcting behaviors that tend to equalize any initial imbalance. The question concerning whether or not active control of propellant in each tank is required or can be avoided or not is also important to answer. In order to provide data on parallel-fed tanks and differential draining in flight for cryogenic propellants (as well as any other fluid), a vertical test bed (flying lander) for terrestrial use was employed. The Morpheus vertical test bed is a parallel-fed propellant tank system that uses passive design to keep the propellant tanks balanced. The system is operated in blow down. The Morpheus vehicle was instrumented with a capacitance level sensor in each propellant tank in order to measure the draining of propellants in over 34 tethered and 12 free flights. Morpheus did experience an approximately 20 lb/m imbalance in one pair of tanks. The cause of this imbalance will be discussed. This paper discusses the analysis, design, flight simulation vehicle dynamic modeling, and flight test of the Morpheus parallel-fed propellant. The Apollo LEM data is also examined in this summary report of the

  6. Effect of Oxidizer Particle Size on Burning Rate and Thermal Decomposition of Composite Solid Propellants

    Directory of Open Access Journals (Sweden)

    K. Kishore

    1982-07-01

    Full Text Available Studies on Thermal decomposition of ammonium perchlorarte(AP- polystyrene(PS propellant and burning rate of PS/AP propellant have been carried out as a function of oxidizer particle size. Thermal decomposition of AP and AP/PS propellant as function of AP particle size shows a maximum rate around 100 micro particle size which has been explained on the basis of Mample's theory. No such maximum is observed in the case of PS/AP propellant burning rate.

  7. Application of Model Based Prognostics to Pneumatic Valves in a Cryogenic Propellant Loading Testbed

    Data.gov (United States)

    National Aeronautics and Space Administration — Pneumatic-actuated valves are critical components in many applications, including cryogenic propellant loading for space operations. For these components, failures...

  8. Role of inorganic additives on the ballistic performance of gun propellant formulations.

    Science.gov (United States)

    Damse, R S; Sikder, A K

    2008-06-15

    This paper explores the possibility of increasing the ballistic performance of gun propellant with the addition of inorganic additives viz. aluminium and ammonium perchlorate. Compositions based on propellant NQ containing additional aluminium and ammonium perchlorate in different parts were studied theoretically and experimentally. Performance in respect of ballistic parameters, sensitivity, thermal characteristics, thermal stability and mechanical properties are evaluated and compared with that of the conventional triple base propellant NQ. Experimental data on comparative study indicate that the compositions containing aluminium and ammonium perchlorate are superior to propellant NQ in respect of energy.

  9. Closed vessel technique for assessment of ballistic characteristics in quality control of propellant manufacture

    Directory of Open Access Journals (Sweden)

    G. Siva Ramakrishnan

    1958-07-01

    Full Text Available "In order to assess the ballistic performance of a propellant it is necessary to measure its following characteristics: (aForce constant, (bvivacity, and (cshape. It is possible to determine (aand (bby the closed vessel technique which enables ballistic performance of the propellant in the gun to be estimated. It can be very usefully employed for quality control of propellant manufacture. As more and more experience is gained in the closed vessel technique these tests have several other possible practical applications such as those: (afor inspection of propellants, (bfor assessment of quality, (c to reduce proof in guns, and (dto check ballistics of a lot after long storage."

  10. Research on Propeller Dynamic Load Simulation System of Electric Propulsion Ship

    Institute of Scientific and Technical Information of China (English)

    HUANG Hui; SHEN Ai-di; CHU Jian-xin

    2013-01-01

    A dynamic marine propeller simulation system was developed,which is utilized for meeting the experimental requirement of theory research and engineering design of marine electric propulsion system.By applying an actual ship parameter and its accurate propeller J'~KT' and J'~Kp' curve data,functional experiments based on the simulation system were carried out.The experiment results showed that the system can correctly emulate the propeller characteristics,produce the dynamic and steady performances of the propeller under different navigation modes,and present actual load torque for electric propulsion motor.

  11. Numerical Analysis of the High Skew Propeller of an Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    Hassan Ghasseni; Parviz Ghadimi

    2011-01-01

    A numerical analysis based on the boundary element method (BEM) was presented for the hydrodynamic performance of a high skew propeller (HSP) which is employed by an underwater vehicle (UV).Since UVs operate at two different working conditions (surface and submerged conditions),the design of such a propeller is a cumbersome task.This is primarily due to the fact that the resistance forces as well as the vessel efficiency under these conditions are significantly different.Therefore,some factors are necessary for the design of the optimum propeller to utilize the power at the mentioned conditions.The design objectives of the optimum propeller are to obtain the highest possible thrust,minimum torque,and efficiency.In the current study,a 5-bladed HSP was chosen for running the UV.This propeller operated at the stem of the UV hull where the inflow velocity to the propeller was non-uniform.Some parameters of the propeller were predicted based on the UV geometrical hull and operating conditions.The computed results include the pressure distribution and the hydrodynamic characteristics of the HSP in open water conditions,and comparison of these results with those of the experimental data indicates good agreement.The propeller efficiency for both submerged and surface conditions was found to be 67% and 64%,respectively,which compared to conventional propellers is a significantly higher efficiency.

  12. Triphenylamine - a 'new' stabilizer for nitrocellulose based propellants. Pt. 1: chemical stability studies

    Energy Technology Data Exchange (ETDEWEB)

    Wilker, Stephan; Heeb, Gerhard [WIWEB ASt Heimerzheim, Grosses Cent, 53913 Swisttal (Germany); Vogelsanger, Beat [Nitrochemie Wimmis AG, Niesenstr. 44, 3752 Wimmis (Switzerland); Petrzilek, Jan; Skladal, Jan [Explosia a.s. - Research Institute of Industrial Chemistry (VUPCH), 532 17 Pardubice (Czech Republic)

    2007-04-15

    Triphenylamine (TPA) was used for the first time in France in 1937 as a stabilizer for propellants. The stability of those samples was described as 'good'. Around 1950 an American group produced TPA stabilized propellants and investigated the decomposition mechanism. Apart from one single experiment in the 1970s no further attempts were made to take TPA as a stabilizer for propellants. With the background of an increasingly critical discussion about nitrosamines in propellants and their declaration of being carcinogenic, TPA revealed a renaissance since the year 2000. To achieve the goal of nitrosamine free propellants several TPA stabilized propellants were produced. Their processability, stability and ballistic properties were investigated. This publication summarizes the most important results of stability tests on more than 30 different TPA stabilized propellants including the decomposition mechanism, the synthesis of the consecutive products and their stabilizing properties. In addition, the internal compatibility of TPA with the most important propellant ingredients is discussed and its relative decomposition rate is compared with that of other stabilizers. In summary TPA is a suitable stabilizer for propellants. It has nevertheless two disadvantages. It is relatively rapidly consumed in double base formulations (which makes it difficult to pass the criteria of AOP-48, Ed. 2) and the stabilizing activity of the two major consecutive products 4-NO{sub 2}-TPA and especially 4,4{sup '}-di-NO{sub 2}-TPA is low. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  13. Prediction of a propellant tank pressure history using state space methods

    Science.gov (United States)

    Estey, P. N.; Lewis, D. H., Jr.; Connor, M.

    1983-01-01

    An analysis of the time response of a propellant supply system operating in the blowdown mode is presented. The supply system is part of a pump-fed propulsion system intended for use on interplanetary spacecraft. As such, the supply system must provide the pump with propellant at sufficient pressure to avoid pump cavitation. The system, consisting of the tank, the liquid propellant, the pressurant gas and propellant vapor mixture, and a film layer separating the liquid and vapor phases, is analyzed using the principles of mass and energy conservation. The resulting set of ordinary, coupled, nonlinear differential equations for the thermodynamic state variables is integrated as an initial value problem. The resulting histories of total pressure, propellant vapor pressure, propellant liquid temperature, film layer temperature, propellant vapor/pressurant gas temperature, propellant vapor mass, and propellant liquid mass enable the calculation of the net positive suction head available at the pump which determines the viability of the pump-fed system concept when operated in the blowdown mode.

  14. Effect of Nitrate Ester on the Combustion Characteristics of PET/HMX -based Propellants

    Directory of Open Access Journals (Sweden)

    Yunlan Sun

    2011-04-01

    Full Text Available The effect of nitrate ester NG/TEGDN on the combustion characteristics of PET/HMX-based propellants has been experimentally investigated using of high-speed photography technique and scanning electron microscopy. It is indicated that the increase of NG/TEGDN content has little impact on the propellant burning rates at the same pressure. Furthermore, propellant can not be self-sustaining combustion at low pressure (£1 MPa. The increase of NG/TEGDN content does not affect the flame structure of propellant, but it plays an important role in condensed phase reaction zone. The flame structure of propellant is estimated. The thermal decomposition products in different combustion zones are also discussed. Scanning electron microscopy examination of quenched sample indicates that a liquified layer forms during combustion of these propellants. Numerous gas bubbles are present. Especially, the burning surface of propellant with low NG/TEGDN content shows signs of crystallization. The thickness of condensed phase reaction zone, by cross-section examination of propellant burning surface, has also been investigated. The results show that the thickness of condensed phase reaction zone increases with NG/TEGDN content increasing. These observations suggest that the condensed phase zone plays significant role in propellant combustion.Defence Science Journal, 2011, 61(3, pp.206-213, DOI:http://dx.doi.org/10.14429/dsj.61.567

  15. An Experimental Study on the aerodynamic and aeroacoustic performances of Maple-Seed-Inspired UAV Propellers

    Science.gov (United States)

    Hu, Hui; Ning, Zhe

    2016-11-01

    Due to the auto-rotating trait of maple seeds during falling down process, flow characteristics of rotating maple seeds have been studied by many researchers in recent years. In the present study, an experimental investigation was performed to explore maple-seed-inspired UAV propellers for improved aerodynamic and aeroacoustic performances. Inspired by the auto-rotating trait of maple seeds, the shape of a maple seed is leveraged for the planform design of UAV propellers. The aerodynamic and aeroacoustic performances of the maple-seed-inspired propellers are examined in great details, in comparison with a commercially available UAV propeller purchased on the market (i.e., a baseline propeller). During the experiments, in addition to measuring the aerodynamic forces generated by the maple-seed-inspired propellers and the baseline propeller, a high-resolution Particle Image Velocimetry (PIV) system was used to quantify the unsteady flow structures in the wakes of the propellers. The aeroacoustic characteristics of the propellers are also evaluated by leveraging an anechoic chamber available at the Aerospace Engineering Department of Iowa State University. The research work is supported by National Science Foundation under Award Numbers of OSIE-1064235.

  16. Beta section Beta: biogeographical patterns of variation and taxonomy.

    NARCIS (Netherlands)

    Letschert, J.P.W.

    1993-01-01

    In Chapter 1 an account is given of the historical subdivision of the genus Beta and its sections, and the relations of the sections are discussed. Emphasis is given to the taxonomic treatment of wild section Beta by various authors. The Linnaean names B. vulgaris L. and B. maritima L. are lectotypi

  17. Cyclic modular beta-sheets.

    Science.gov (United States)

    Woods, R Jeremy; Brower, Justin O; Castellanos, Elena; Hashemzadeh, Mehrnoosh; Khakshoor, Omid; Russu, Wade A; Nowick, James S

    2007-03-07

    The development of peptide beta-hairpins is problematic, because folding depends on the amino acid sequence and changes to the sequence can significantly decrease folding. Robust beta-hairpins that can tolerate such changes are attractive tools for studying interactions involving protein beta-sheets and developing inhibitors of these interactions. This paper introduces a new class of peptide models of protein beta-sheets that addresses the problem of separating folding from the sequence. These model beta-sheets are macrocyclic peptides that fold in water to present a pentapeptide beta-strand along one edge; the other edge contains the tripeptide beta-strand mimic Hao [JACS 2000, 122, 7654] and two additional amino acids. The pentapeptide and Hao-containing peptide strands are connected by two delta-linked ornithine (deltaOrn) turns [JACS 2003, 125, 876]. Each deltaOrn turn contains a free alpha-amino group that permits the linking of individual modules to form divalent beta-sheets. These "cyclic modular beta-sheets" are synthesized by standard solid-phase peptide synthesis of a linear precursor followed by solution-phase cyclization. Eight cyclic modular beta-sheets 1a-1h containing sequences based on beta-amyloid and macrophage inflammatory protein 2 were synthesized and characterized by 1H NMR. Linked cyclic modular beta-sheet 2, which contains two modules of 1b, was also synthesized and characterized. 1H NMR studies show downfield alpha-proton chemical shifts, deltaOrn delta-proton magnetic anisotropy, and NOE cross-peaks that establish all compounds but 1c and 1g to be moderately or well folded into a conformation that resembles a beta-sheet. Pulsed-field gradient NMR diffusion experiments show little or no self-association at low (

  18. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some form...

  19. Measurements of sin 2 $\\beta$

    CERN Document Server

    Tricomi, A

    2000-01-01

    A review of the most recent measurements of the CP violating parameter sin 2 beta from LEP and CDF is reported. These yield an average value of sin 2 beta =0.91+or-0.35, giving a confidence level that CP violation in the B system has been observed of almost 99%. (10 refs).

  20. Beta decay of Cu-56

    NARCIS (Netherlands)

    Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M

    2001-01-01

    The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the p

  1. Beta Function and Anomalous Dimensions

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2011-01-01

    We demonstrate that it is possible to determine the coefficients of an all-order beta function linear in the anomalous dimensions using as data the two-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows to determine the anomalou...

  2. First Stage Solid Propellant Multiply Debris Thermal Analysis

    Science.gov (United States)

    Toleman, Benjamin M.

    2011-01-01

    Destruction of a solid rocket stage of a launch vehicle can create a thermal radiation hazard for an aborting crew module. This hazard was assessed for the Constellation Program (Cx) crew and launch vehicle concept. For this concept, if an abort was initiated in first stage flight, the Crew Module (CM) will separate and be pulled away from the malfunctioning launch vehicle via a Launch Abort System (LAS). Having aborted the mission, the launch vehicle will likely be destroyed via a Flight Termination System (FTS) in order to prevent it from errantly traversing back over land and posing a risk to the public. The resulting launch vehicle debris field, composed primarily of first stage solid propellant, poses a threat to the CM. The harsh radiative thermal environment, caused by surrounding burning propellant debris, may lead to CM parachute failure. A methodology, detailed herein, has been developed to address this concern and to quantify the risk of first stage propellant debris leading to the thermal demise of the CM parachutes. Utilizing basic thermal radiation principles, a software program was developed to calculate parachute temperature as a function of time for a given abort trajectory and debris piece trajectory set. Two test cases, considered worst case aborts with regard to launch vehicle debris environments, were analyzed using the simulation: an abort declared at Mach 1 and an abort declared at maximum dynamic pressure (Max Q). For both cases, the resulting temperature profiles indicated that thermal limits for the parachutes were not exceeded. However, short duration close encounters by single debris pieces did have a significant effect on parachute temperature. Therefore while these two test cases did not indicate exceedance of thermal limits, in order to quantify the risk of parachute failure due to radiative effects from the abort environment, a more thorough probability-based analysis using the methodology demonstrated herein must be performed.

  3. First Stage Solid Propellant Multi Debris Thermal Analysis

    Science.gov (United States)

    Toleman, Benjamin M.

    2011-01-01

    The crew launch vehicle considered for the Constellation (Cx) Program utilizes a first stage solid rocket motor. If an abort is initiated in first stage flight the Crew Module (CM) will separate and be pulled away from the launch vehicle via a Launch Abort System (LAS) in order to safely and quickly carry the crew away from the malfunction launch vehicle. Having aborted the mission, the launch vehicle will likely be destroyed via a Flight Termination System (FTS) in order to prevent it from errantly traversing back over land and posing a risk to the public. The resulting launch vehicle debris field, composed primarily of first stage solid propellant, poses a threat to the CM. The harsh radiative thermal environment induced by surrounding burning propellant debris may lead to CM parachute failure. A methodology, detailed herein, has been developed to address this concern and quantify the risk of first stage propellant debris leading to radiative thermal demise of the CM parachutes. Utilizing basic thermal radiation principles, a software program was developed to calculate parachute temperature as a function of time for a given abort trajectory and debris piece trajectory set. Two test cases, considered worst-case aborts with regard to launch vehicle debris environments, were analyzed using the simulation: an abort declared at Mach 1 and an abort declared at maximum dynamic pressure (Max Q). For both cases, the resulting temperature profiles indicated that thermal limits for the parachutes were not exceeded. However, short duration close encounters by single debris pieces did have a significant effect on parachute temperature, with magnitudes on the order of 10 s of degrees Fahrenheit. Therefore while these two test cases did not indicate exceedance of thermal limits, in order to quantify the risk of parachute failure due to radiative effects from the abort environment, a more thorough probability-based analysis using the methodology demonstrated herein must be

  4. Formulation & Storage Studies on Hydrazine-Based Gelled Propellants.

    Directory of Open Access Journals (Sweden)

    Mohan Verma

    1996-12-01

    Full Text Available The current trend in the area of high energy storable liquid rocket propellant research is to develop gelled/metallized systems and to explore the feasibility of their application in rocket motors. The idea stems from the fact that the conversion of a conventional liquid propellant to a gelled state and its subsequent metallization has the potential to significantly enhance the performance and density specific impulse. However, it is mandatory that the gelation of the liquid propellant be brought about with a minimum concentration of gellant and the gel formed should show a shear-thinning behaviour and good storage life. Keeping this in view, an experimental program to prepare thixotropic gels of hydrazine and its methyl substitutedderivatives like monomethyl hydrazineand unsymmetrical dimethyl hydrazinewas conducted under ambient conditions. The gellants investigated included particulate, chemical and synthetic materials. The gelation of the liquid fuels ..ould be brought about with gellant concentration as low as I wt per cent in some cases. Metallized gels using up to 40 wt per cent of AlIMg metal powders could be formulated. These heterogeneous systems showed a reduction in critical gellant concentration with degree of metallization. Further, less gelation time is observed if the gellant concentration is kept fixed and metal content is increased. The storage studies on gelled systems conducted over a period of three months showed good stability. The metallized systems, however, showed the settling of metal powders in meagre concentration which does not pose a major problem as these gels could be re-homogenized with stirring.

  5. RAVEN Beta Release

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Congjian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Maljovec, Daniel Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, Paul William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  6. Self-propelled Janus particles in a ratchet: Numerical simulations

    CERN Document Server

    Ghosh, Pulak Kumar; Marchesoni, Fabio; Nori, Franco

    2013-01-01

    Brownian transport of self-propelled overdamped microswimmers (like Janus particles) in a two-dimensional periodically compartmentalized channel is numerically investigated for different compartment geometries, boundary collisional dynamics, and particle rotational diffusion. The resulting time-correlated active Brownian motion is subject to rectification in the presence of spatial asymmetry. We prove that ratcheting of Janus particles can be orders of magnitude stronger than for ordinary thermal potential ratchets and thus experimentally accessible. In particular, autonomous pumping of a large mixture of passive particles can be induced by just adding a small fraction of Janus particles.

  7. Limited Toxicity and Mutagenicity Testing of Five Unicharge Propellant Compounds.

    Science.gov (United States)

    1992-01-31

    Conjunctivae 1,0 0,0 0,0 0,0 Cornea = degree of opacity Iris = degree of iritis Conjunctivae = redness, chemosis 14 TABLE II (continued) Summary of Ocular...degree of opacity Iris = degree of iritis Conjunctivae = redness, chemosis 15 TABLE III Summary of Positive Scores of Two Unicharge Propellants in the...6 Iritis 0/6 0/6 0/6 0/6 Coniuntivae Redness 4/6 0/6 0/6 0/6 Chemosis 0/6 0/6 0/6 0/6 Bis-(2,2-Dinitropropyl) Formal without Diphenyl Amine Stablizer

  8. The superconducting MHD-propelled ship YAMATO-1

    Science.gov (United States)

    Sasakawa, Yohei; Takezawa, Setsuo; Sugawara, Yoshinori; Kyotani, Yoshihiro

    1995-04-01

    In 1985 the Ship & Ocean Foundation (SOF) created a committee under the chairmanship of Mr. Yohei Sasakawa, Former President of the Ship & Ocean Foundation, and began researches into superconducting magnetohydrodynamic (MHD) ship propulsion. In 1989 SOF set to construction of a experimental ship on the basis of theoretical and experimental researches pursued until then. The experimental ship named YAMATO-1 became the world's first superconducting MHD-propelled ship on her trial runs in June 1992. This paper describes the outline of the YAMATO-1 and sea trial test results.

  9. Aluminum flame temperature measurements in solid propellant combustion.

    Science.gov (United States)

    Parigger, Christian G; Woods, Alexander C; Surmick, David M; Donaldson, A B; Height, Jonathan L

    2014-01-01

    The temperature in an aluminized propellant is determined as a function of height and plume depth from diatomic AlO and thermal emission spectra. Higher in the plume, 305 and 508 mm from the burning surface, measured AlO emission spectra show an average temperature with 1σ errors of 2980 ± 80 K. Lower in the plume, 152 mm from the burning surface, an average AlO emission temperature of 2450 ± 100 K is inferred. The thermal emission analysis yields higher temperatures when using constant emissivity. Particle size effects along the plume are investigated using wavelength-dependent emissivity models.

  10. SRM (Solid Rocket Motor) propellant and polymer materials structural modeling

    Science.gov (United States)

    Moore, Carleton J.

    1988-01-01

    The following investigation reviews and evaluates the use of stress relaxation test data for the structural analysis of Solid Rocket Motor (SRM) propellants and other polymer materials used for liners, insulators, inhibitors, and seals. The stress relaxation data is examined and a new mathematical structural model is proposed. This model has potentially wide application to structural analysis of polymer materials and other materials generally characterized as being made of viscoelastic materials. A dynamic modulus is derived from the new model for stress relaxation modulus and is compared to the old viscoelastic model and experimental data.

  11. Flame spectra of solid propellants during unstable combustion.

    Science.gov (United States)

    Eisel, J. L.; Ryan, N. W.; Baer, A. D.

    1972-01-01

    The spectral and temporal details of the flames of a series of ammonium perchlorate-polyurethane propellants during both unstable and stable combustion were observed experimentally. A 400-scan per second optical spectrometer operating in the middle infrared region was used. During unstable combustion at low ratios of chamber free volume to nozzle throat area, three different frequencies were observed simultaneously. These were attributable to at least two mechanisms. During stable combustion periodic fluctuations in flame temperature and composition were also observed. Some aspects of theory of bulk mode instability were confirmed, but the assumptions of constant flame temperature and constant composition were found to be inaccurate.

  12. Experimental study on a magnetofluid sealing liquid for propeller shaft

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chang-fa; SUN Rong-hua; ZHENG Jin-xing

    2003-01-01

    The selecting and preparing method of the basic material of magnetic fluid was introduced. By using a chemical method, the magnetic micropowder Fe3O4 was successfully yielded, and an oil-base as a working carrier and dispersing agent was determined. The preparation process of the magnetic fluid and prescription of the oil-base magnetic fluid were discussed. The simulation experimental rig of magnetic fluid sealing for propeller shaft was designed. The sealing ability experiment was conducted and results were analyzed. The pressure of sealing is up to 2 Mpa.

  13. Parametric study of propeller boss cap fins for container ships

    Directory of Open Access Journals (Sweden)

    Lim Sang-Seop

    2014-06-01

    Full Text Available The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD analysis with a propeller open water (POW test was performed to check the validity of CFD analysis. The design of experiment (DOE case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test

  14. Development of Laser Propelled ``Semi-Perpetual'' Rotary Machine

    Science.gov (United States)

    Gualini, M. M.; Khan, S. A.; Zulfiqar, K.

    2006-05-01

    This paper covers the initial work oriented to develop a semi-perpetual rotary machine propelled by laser ablation propulsion. The laser is equipped with a pulse repetition frequency tuned to the rotational frequency of the flying wheel. Purpose of this work is to establish the potentiality of a self-sustained closed system capable of generating kinetic rotary energy which can be exploited for traction of vehicles and production of electrical energy at very low cost. The work presented is in process of being patented.

  15. Evacuation areas for transportation accidents involving propellant tank pressure bursts

    Science.gov (United States)

    Siewert, R. D.

    1972-01-01

    Evacuation areas are defined for those transportation accidents where volatile chemical propellant tanks are exposed to fire in the wreckage and eventually explode with consequent risks from fragments in surrounding populated areas. An evacuation area with a minimum radius of 600 m is recommended to limit the statistical probability of fatality to one in 100 such accidents. The result of this study was made possible by the derivation of a distribution function of distances reached by fragments from bursting chemical car tanks. Data concerning fragments were obtained from reports of tank car pressure bursts between 1958 and 1971.

  16. Aerodynamics for Loads and Performance of Wind Turbines and Propellers

    Energy Technology Data Exchange (ETDEWEB)

    Montgomerie, Bjoern [FOI - Swedish Defence Research Agency, Stockholm (Sweden). FFA Aeronautics

    2003-03-01

    This documentation summarizes a method for converting two dimensional wing profile data to usable three dimensional data to be applied to performance and load generation for horizontal axis wind turbines and propellers. The methods described are to be seen as preliminary in a larger context where several activities cooperate to yield reliable prediction of foremost stall controlled wind turbine loading. Complementary future activities, not included in this document, are further development of the methods presented here, computer programming, exercising the program against measured data and consequential model parameter adjustment and method modification.

  17. On the hydrodynamics of rocket propellant engine inducers and turbopumps

    Science.gov (United States)

    d'Agostino, L.

    2013-12-01

    The lecture presents an overview of some recent results of the work carried out at Alta on the hydrodynamic design and rotordynamic fluid forces of cavitating turbopumps for liquid propellant feed systems of modern rocket engines. The reduced order models recently developed for preliminary geometric definition and noncavitating performance prediction of tapered-hub axial inducers and centrifugal turbopumps are illustrated. The experimental characterization of the rotordynamic forces acting on a whirling four-bladed, tapered-hub, variable-pitch high-head inducer, under different load and cavitation conditions is presented. Future perspectives of the work to be carried out at Alta in this area of research are briefly illustrated.

  18. [Serum beta 2 microglobulin (beta 2M) following renal transplantation].

    Science.gov (United States)

    Pacheco-Silva, A; Nishida, S K; Silva, M S; Ramos, O L; Azjen, H; Pereira, A B

    1994-01-01

    Although there was an important improvement in graft and patient survival the last 10 years, graft rejection continues to be a major barrier to the success of renal transplantation. Identification of a laboratory test that could help to diagnose graft rejection would facilitate the management of renal transplanted patients. PURPOSE--To evaluate the utility of monitoring serum beta 2M in recently transplanted patients. METHODS--We daily determined serum beta 2M levels in 20 receptors of renal grafts (10 from living related and 10 from cadaveric donors) and compared them to their clinical and laboratory evolution. RESULTS--Eight patients who presented immediate good renal function following grafting and did not have rejection had a mean serum beta 2M of 3.7 mg/L on the 4th day post transplant. The sensitivity of the test for the diagnosis of acute rejection was 87.5%, but the specificity was only 46%. Patients who presented acute tubular necrosis (ATN) without rejection had a progressive decrease in their serum levels of beta 2M, while their serum creatinine changed as they were dialyzed. In contrast, patients with ATN and concomitance of acute rejection or CSA nephrotoxicity presented elevated beta 2M and creatinine serum levels. CONCLUSION--Daily monitoring of serum beta 2M does not improve the ability to diagnose acute rejection in patients with good renal function. However, serum beta 2M levels seemed to be useful in diagnosing acute rejection or CSA nephrotoxicity in patients with ATN.

  19. High Performance Liquid Chromatography of Propellants. Part 1. Analysis of M1, M6, and M10 Propellants

    Science.gov (United States)

    1986-05-01

    High performance liquid chromatography permits the differentation among the stabilizers and their degradation products together with accurate quantitation. This progress report describes work carried out in the analysis of single base propellants containing diphenylamine (DPA) as the stabilizer. Several degradation products have been identified and the routine determination of these compounds is feasible. The degradation of DPA seems to follow a pattern that is unique for M1 and M6’s as compared to the pattern for M10’s. It is postulated

  20. High Energy, Low Temperature Gelled Bi-Propellant Formulation for Long-Duration In-Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The use of gelled propellants for deep space planetary missions may enable adoption of high performance (Isp-vac>360 sec) propellant combinations that do not...