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1

Lidar Measurement of Rocket Exhaust Plume Dispersion and Layering in the Stratosphere.  

National Technical Information Service (NTIS)

The Mobile Lidar Trailer (MLT) measures backscattering returns from solid rocket booster exhaust plumes in the stratosphere. A worst-case assessment of the stratospheric ozone depletion, often associated with the use of Solid Rocket Motors such as the TIT...

P. D. Dao A. Dentamaro

1999-01-01

2

Temperature Measurement of Solid Rocket Motor Exhaust Plume by Absorption-Emission SPECTROSCOPY1  

Microsoft Academic Search

A method, which measures the temperature of solid rocket motor exhaust plume, was developed by employing an improved sodium line reversal process. The formula for calculating the temperature was improved and simplified. The temporal temperature-time distributions of the exhaust plume of double base propellant rocket motors were given by the established method. The maximum time resolution and accuracy for the

Dong Yang; Houqian Xu; Junde Wang; Baochang Zhao

2001-01-01

3

Measurement and analysis of laser transmission through solid-propellant rocket motor exhaust plumes  

Microsoft Academic Search

The size distribution of aluminum oxide droplets and particles in rocket exhausts is required for the prediction of two-phase motor performance losses and plume radiative heating. Current estimates of size may be biased due to aerodynamic effects. Rocket exhaust particle size was determined by nonintrusive laser diagnostics. Measurements were performed near the nozzle exit plane of several solid-propellant rocket motors

P. J. Murphy; R. A. Reed; D. B. Cox; G. A. Wilcher; W. A. Watkins; R. Truesdale; M. A. Simmons; D. W. Roberds

1993-01-01

4

Particle Size Measurements in Solid Propellant Rocket Exhaust Plumes.  

National Technical Information Service (NTIS)

Particle sizing interferometer measurement of particle size distributions, velocity and number density in samples of rocket propellant exhaust is described. Signal visibility and scattered intensity for individual particles was measured for a nominal size...

K. E. Harwell W. M. Farmer

1978-01-01

5

Measurement and analysis of laser transmission through solid-propellant rocket motor exhaust plumes  

NASA Astrophysics Data System (ADS)

The size distribution of aluminum oxide droplets and particles in rocket exhausts is required for the prediction of two-phase motor performance losses and plume radiative heating. Current estimates of size may be biased due to aerodynamic effects. Rocket exhaust particle size was determined by nonintrusive laser diagnostics. Measurements were performed near the nozzle exit plane of several solid-propellant rocket motors with a range of thrusts. Mean particle size estimates were obtained using a simple flowfield model. A second method used only the wavelength dependence of the transmission and required no assumptions about the plume flow field. Results agreed well and did not differ greatly from far-field particle collection results. The spatial distribution of aluminum oxide particles within the exhaust plume was investigated with multipath transmission measurements, and a detailed exit plane profile of the exhaust particle opacity was retrieved for one large orbital insertion motor.

Murphy, P. J.; Reed, R. A.; Cox, D. B.; Wilcher, G. A.; Watkins, W. A.; Truesdale, R.; Simmons, M. A.; Roberds, D. W.

1993-07-01

6

Rocket engine exhaust plume diagnostics and health monitoring/management during ground testing  

NASA Astrophysics Data System (ADS)

The current status of a rocket exhaust plume diagnostics program sponsored by NASA is reviewed. The near-term objective of the program is to enhance test operation efficiency and to provide for safe cutoff of rocket engines prior to incipient failure, thereby avoiding the destruction of the engine and the test complex and preventing delays in the national space program. NASA programs that will benefit from the nonintrusive remote sensed rocket plume diagnostics and related vehicle health management and nonintrusive measurement program are Space Shuttle Main Engine, National Launch System, National Aero-Space Plane, Space Exploration Initiative, Advanced Solid Rocket Motor, and Space Station Freedom. The role of emission spectrometry and other types of remote sensing in rocket plume diagnostics is discussed.

Chenevert, D. J.; Meeks, G. R.; Woods, E. G.; Huseonica, H. F.

1992-08-01

7

Evaluation of a Mass Spectrometer Probe for Density and Velocity Distribution Measurements in a Rocket Exhaust Plume.  

National Technical Information Service (NTIS)

The evaluation of a mass spectrometer probe in a highly expanded exhaust plume of a small rocket is described in this report. This probe, which utilizes a quadrupole mass spectrometer, is used for species identification and concentration measurements and ...

D. L. Whitfield D. W. Hill H. M. Powell

1971-01-01

8

Feasibility of moiré deflectometry for measuring temperature and electron number density of rocket exhaust plume  

NASA Astrophysics Data System (ADS)

In this research, the feasibility of moirƩ deflectometry for diagnosing the temperature and the electron number density of rocket exhaust plume is studied. The dependence of the refractive index on the temperature, the pressure, the composition and the probe wavelength is established firstly. Based on which, the theoretical analysis and discussion indicate that it is impossible to achieve the measurement of the electron number density by both one- and two-wavelength moirƩ deflectometry in the given temperature, pressure and probe wavelength regions. Yet, it may be feasible to measure the temperature distribution of rocket exhaust plume by moirƩ deflectometry, if the imprecision of the temperature reconstruction is permitted by the practical measuring requirement.

Chen, Yun-Yun; Song, Yang; Li, Zhen-Hua; He, An-Zhi

2010-11-01

9

An experimental and computational study of moderately underexpanded rocket exhaust plumes in a co-flowing hypersonic free stream  

Microsoft Academic Search

Rocket plume exhaust structures are aerodynamically and thermochemically very complex and the prediction of plume properties such as temperature, velocity, pressure, chemical species concentrations and turbulence properties is a formidable task as there are no definitive models for viscous and chemical effects. Contemporary computational techniques are still in their infancy and cannot yet reliably predict plume properties. Only through validation

N. Morris; D. Buttsworth; T. Jones; C. Brescianini

1995-01-01

10

Lidar measurement of TITAN IV rocket exhaust plumes at stratospheric heights  

NASA Astrophysics Data System (ADS)

Concern exists over the impact of the emissions of large rockets powered by solid motors upon the ozone layer. A scanning lidar, operating at 532, 355 and 308 nm, has been developed to address this issue. We report the first lidar observations of the rocket exhaust plume in the stratosphere. Over 500 sets of lidar profiles were collected in three campaigns covering Titan IV K-21 (Nov 6, '95), Space Shuttle STS-76 (Mar 22, '96) and Titan IV K-16 (Apr 24, '96). Thin particle layers were observed in the 18 - 43 km altitude region for up to three hours after launch. Plume dimensions and dispersion rate were inferred from the observation. The plume thickness was measured to be less than 250 meters. Backscattering signals dependence on wavelengths were analyzed showing a weakening trend with time.

Dao, Phan D.; Gelbwachs, Jerry A.; Farley, Robert; Garner, Richard; Soletski, Philip; Davidson, Gilbert

1996-11-01

11

An experimental and computational study of moderately underexpanded rocket exhaust plumes in a co-flowing hypersonic free stream  

NASA Astrophysics Data System (ADS)

Rocket plume exhaust structures are aerodynamically and thermochemically very complex and the prediction of plume properties such as temperature, velocity, pressure, chemical species concentrations and turbulence properties is a formidable task as there are no definitive models for viscous and chemical effects. Contemporary computational techniques are still in their infancy and cannot yet reliably predict plume properties. Only through validation of computer codes using experimental data, can computational models be developed to the point where they can be confidently used as design and predictive tools. The motivation for this study was to acquire well defined data for rocket plumes at low altitude hypersonic flight conditions so that the above issues could be investigated.

Morris, N.; Buttsworth, D.; Jones, T.; Brescianini, C.

12

Measurements of stratospheric plume dispersion by imagery of solid rocket motor exhaust  

NASA Astrophysics Data System (ADS)

Plume expansion from nine space shuttle and Titan IV vehicles was measured at altitudes of 18, 24, and 30 km in the stratosphere. The plume diameters, inferred from electronic images of polarized, near-infrared solar radiation scattered from the exhaust particles, increased linearly with time. The expansion rate was measured for as long as 50 min. Observations made simultaneously at multiple altitudes showed that the expansion rate increased with increasing altitude for six measurements made at Cape Canaveral but decreased between 24 and 30 km for the one measurement made at Vandenberg Air Force Base. The average expansion rates for all measurements are 4.3±1.0 m s-1 at 18 km, 6.8±1.9 m s-1 at 24 km, and 8.7±2.4 m s-1 at 30 km. Expansion rates varied from launch to launch by as much as a factor of 1.6 at 18 km, 2.2 at 24 km, and 2.6 at 30 km. No correlation between the expansion rate and wind speed or wind shear was evident. These data are compared with several models for diffusivity and are used to update a comprehensive particle model of solid rocket motor exhaust in the stratosphere. The expansion rates are required by models to calculate the spatial extent and temporal persistence of the local stratospheric ozone depletion cause by solid rocket exhaust.

Beiting, Edward J.

2000-03-01

13

Stratospheric plume dispersion: Measurements from STS and Titan solid rocket motor exhaust. Technical report  

SciTech Connect

Plume expansion was measured from nine Space Shuttle and Titan IV vehicles at altitudes of 18, 24, and 30 km in the stratosphere. The plume diameters were inferred from electronic images of polarized, near-infrared solar radiation scattered from the exhaust particles, and these diameters were found to increase linearly with time. The expansion rate was measured for as long as 50 min after the vehicle reached altitude. Measurements made simultaneously at multiple altitudes showed that the expansion rate increased with increasing altitude for six measurements made at Cape Canaveral but decreased between 24 and 30 km for the one measurement made at Vandenberg AFB. The average expansion rates for all measurements are 4.3 {+-} 1.0 m/s at 18 km, 6.8 {+-} 1.9 m/s at 24 km, and 8.7 {+-} 2.5 m/s at 30 km. Expansion rates varied from launch to launch by as much as a factor of 1.6 at 18 km, 2.2 at 24 km, and 2.7 at 30 km. No correlation between the expansion rate and wind speed or shear was evident. These data are compared to several models for diffusivity and are used to update a comprehensive particle model of solid rocket motor exhaust in the stratosphere. The expansion rates are required by models to calculate the spatial extent and temporal persistence of the local stratospheric ozone depletion cause by solid rocket exhaust.

Beiting, E.J.

1999-04-20

14

In situ measurement of the aerosol size distribution in stratospheric solid rocket motor exhaust plumes  

NASA Astrophysics Data System (ADS)

The concentration and size distribution of aerosol in the stratospheric exhaust plumes of two Space Shuttle rockets and one Titan IV rocket were measured using a two component aerosol sampling system carried aboard a WB-57F aircraft. Aerosol size distribution in the 0.01 µm to 4 µm diameter size range was measured using a two component sampling system. The measured distributions display a trimodal form with modes near 0.005 µm, 0.09 µm, and 2.03 µm and are used to infer the relative mass fractionation among the three modes. While the smallest mode has been estimated to contain as much as 10% of the total mass of SRM exhaust alumina, we find show that the smallest mode contains less than 0.05% of the alumina mass. This fraction is so small so as to significantly reduce the likelihood that heterogeneous reactions on the SRM alumina surfaces could produce a significant global impact on stratospheric chemistry.

Ross, M. N.; Whitefield, P. D.; Hagen, D. E.; Hopkins, A. R.

15

In-situ measurement of Cl2 and O3 in a stratospheric solid rocket motor exhaust plume  

NASA Astrophysics Data System (ADS)

The concentration of Cl2 in the stratospheric exhaust plume of a Titan IV launch vehicle was measured with a neutral mass spectrometer carried on a WB-57F aircraft at 18.9 km altitude. Twenty nine minutes after a twilight Titan IV launch, the mean Cl2 concentration across an 8 km wide plume was 126 ± 44 ppbv, consistent with model predictions that a large fraction of the HCl in solid rocket motor exhaust is converted into Cl2 by afterburning reactions in the hot plume. Co-incident measurements with ultraviolet absorption photometers also carried on the aircraft show that ozone concentration in the plume was not different from ambient levels. This is consistent with model predictions that nighttime SRM launches will not cause transient ozone loss in the lower stratosphere. The measured Cl2 concentration equals 15% of the ambient ozone concentration suggesting that transient ozone reduction in SRM plume wakes can be expected after daytime launches when solar ultraviolet radiation will photolyze the exhaust plume Cl2.

Ross, M. N.; Ballenthin, J. O.; Gosselin, R. B.; Meads, R. F.; Zittel, P. F.; Benbrook, J. R.; Sheldon, W. R.

16

Rocket motor exhaust scrubber  

US Patent & Trademark Office Database

A wet scrubber having a series of chambers for capturing and cooling exhaust gases generated during static test firing of rocket motors. Exhaust gas enters an inlet to a first chamber and is cooled and slowed by a spray solution. HCL gas is condensed and absorbed by the spray solution and precipitates to a liquid slurry at the bottom of the device. The remaining exhaust products enter a demister chamber where nozzles continue to spray the gasses as they pass upward and through a mesh-style demister at the top of the vessel. The demister filters liquid and solid waste particles from the gas stream, and the clean, dry gases are accelerated through a centrifugal fan into the atmosphere. A deflector is positioned within the inlet to the first chamber for containing parts in the event of a motor mal-function.

Carns; Richard H. (Byantown, MD); Armstrong; Gerald (Hughesville, MD); Rast; Robert H. (Nanjemoy, MD); Mitchell; Dennis R. (Brooking, OR)

2005-11-15

17

Particle behavior in solid propellant rocket motors and plumes  

Microsoft Academic Search

The particle size distribution inside the combustion chamber and the changes that occurred across the exhaust nozzle were measured in a subscale solid propellant rocket motor with a 2 percent aluminized end-burning propellant grain and a highly underexpanded nozzle. A combination of diagnostic techniques were used. Size distributions in the exhaust plume were determined by a Single Particle Counter, a

John D. McCrorie II

1992-01-01

18

Radiation from advanced solid rocket motor plumes  

Microsoft Academic Search

The overall objective of this study was to develop an understanding of solid rocket motor (SRM) plumes in sufficient detail to accurately explain the majority of plume radiation test data. Improved flowfield and radiation analysis codes were developed to accurately and efficiently account for all the factors which effect radiation heating from rocket plumes. These codes were verified by comparing

Richard C. Farmer; Sheldon D. Smith; Brian L. Myruski

1994-01-01

19

Rocket plume temperature measurement by wire welded thermocouples  

NASA Astrophysics Data System (ADS)

The plume of solid rocket motor is a high velocity flow with high temperature. Temperature distribution in the plume is of great interest for analyzing the compatibility of rocket weapon system. The high temperature exhausted flow field would cause damage on certain equipment and loading vehicles. An instantaneous temperature field with sharp step is established by the exhausted flow field of rocket motor. The increasing rate of the step depends on the flow velocity at cross section of nozzle exit. To perform an accurate measurement of temperature inside the flow field, a thermocouple must be sturdy enough to endure the flow impingement. In the meantime, the thermocouple must have a short time constant to trace the temperature fluctuation in flow field and a small size to avoid disturbing the flow field severely. The dynamic performance of the thermocouples used in exhausted flow temperature measurement must be evaluated before the experiment. The thermocouple which can be used in measuring the temperature distribution in rocket plume was presented in this paper. A NAMNAC(R) self-renew-erode thermocouples with a nominal time constant of 10 microseconds was used as a reference in a dynamic calibration test for this kind of thermocouple. The thermocouple could trace the temperature increase in the exhausted flow perfectly. This kind of thermocouples was used in several real tests of rocket motors, such as the temperature in free exhausted flow field of a stationary rocket motor test, the stagnate temperature in a shock flow field during the launching of a rocket, and the temperature in a launch tube.

Xu, Qiang

2006-06-01

20

Optical studies of rocket exhaust trails and artificial noctilucent clouds produced by Soyuz rocket launches  

NASA Astrophysics Data System (ADS)

Detailed tracing of an exhaust plume from a rocket's initial trajectory is a scientifically and diagnostically useful technique. It can provide detailed information on the atmosphere's mean winds, wind shears, turbulent regime, and physical state over a wide altitude range from 50 to 200 km. We analyze Soyuz rocket exhaust plumes from Plesetsk on 21 May 2009 and 27 June 2011, which uncovered significantly different atmospheric states and underlying dynamics. The first case showed highly dynamical conditions in the mesosphere, characterized by vortex structures, wind shears, and small-scale turbulent eddies. The estimated turbulent energy dissipation rates ranged 330-460 mW kg-1. A characteristic balloon-shaped trail was observed at altitudes between 105 and 160 km, having rapid expansion rates of 500-800 m s-1 over the time period of 2 min which can be explained by complex gas dynamic processes in the rocket wake involving the collision of shock waves. In the second case, we show evidence that the rocket exhaust trail persisted without any changes during its motion from Plesetsk via Denmark to the UK for 9 h, indicating extremely stable atmospheric conditions. This case introduces a new state of the summer mesosphere—remarkably quiet conditions, probably never observed before. The rocket plumes studied, related to the initial rocket trajectory, are essentially twilight phenomena as seen from the ground using wideband spectrum cameras, that is, the Sun should be below the horizon by 6°. For the first time, we analyze the dynamics of rocket exhaust products at the initial trajectory in the mesosphere and lower thermosphere using detailed photographic imaging taken from the ground.

Dalin, P.; Perminov, V.; Pertsev, N.; Dubietis, A.; Zadorozhny, A.; Smirnov, A.; Mezentsev, A.; Frandsen, S.; Grųnne, J.; Hansen, O.; Andersen, H.; McEachran, I.; McEwan, T.; Rowlands, J.; Meyerdierks, H.; Zalcik, M.; Connors, M.; Schofield, I.; Veselovsky, I.

2013-07-01

21

Radiation from advanced solid rocket motor plumes  

NASA Astrophysics Data System (ADS)

The overall objective of this study was to develop an understanding of solid rocket motor (SRM) plumes in sufficient detail to accurately explain the majority of plume radiation test data. Improved flowfield and radiation analysis codes were developed to accurately and efficiently account for all the factors which effect radiation heating from rocket plumes. These codes were verified by comparing predicted plume behavior with measured NASA/MSFC ASRM test data. Upon conducting a thorough review of the current state-of-the-art of SRM plume flowfield and radiation prediction methodology and the pertinent data base, the following analyses were developed for future design use. The NOZZRAD code was developed for preliminary base heating design and Al2O3 particle optical property data evaluation using a generalized two-flux solution to the radiative transfer equation. The IDARAD code was developed for rapid evaluation of plume radiation effects using the spherical harmonics method of differential approximation to the radiative transfer equation. The FDNS CFD code with fully coupled Euler-Lagrange particle tracking was validated by comparison to predictions made with the industry standard RAMP code for SRM nozzle flowfield analysis. The FDNS code provides the ability to analyze not only rocket nozzle flow, but also axisymmetric and three-dimensional plume flowfields with state-of-the-art CFD methodology. Procedures for conducting meaningful thermo-vision camera studies were developed.

Farmer, Richard C.; Smith, Sheldon D.; Myruski, Brian L.

1994-12-01

22

Design Criteria for Rocket Exhaust Scrubbers.  

National Technical Information Service (NTIS)

The report gives results of an engineering study and design of methods for scrubbing the exhaust of static-tested solid rockets. Pollutants of major concern were hydrogen chloride and hydrogen fluoride gases. The best process for removing these gases was ...

H. F. Barbarika S. Calvert

1978-01-01

23

Prediction of Minuteman Exhaust Plume Electrical Properties.  

National Technical Information Service (NTIS)

Results of a comprehensive investigation of Minuteman exhaust plume electrical properties are presented. Electron density and electron-neutral collision frequency profiles are given for the Stage 1 plume at 100 kft and the Stage 2 plume at 118,200 and 300...

H. S. Pergament R. R. Mikatarian

1973-01-01

24

PARTICLE IMAGE VELOCIMETRY IN THE EXHAUST OF SMALL SOLID ROCKET MOTORS  

Microsoft Academic Search

Combusting environments where high velocities are encountered present a very challenging environment for the application of the Particle image Velocimetry (PIV) method. The physical features of the flow - background irradiance from burning gases, dense smoke, compressibility effects, inability to control seeding densities and inherent CCD limitations - make the measurement process difficult in the exhaust plume of solid rocket

B. J. BALAKUMAR; R. J. ADRIAN

25

Theory of plume radiance from the bow shock ultraviolet 2 rocket flight  

NASA Astrophysics Data System (ADS)

A computational fluid dynamics algorithm is used to simulate the flowfield and solid rocket motor plume about the bow shock ultraviolet 2 flight vehicle. A new computationally efficient algorithm to model two-phase gas and particulate flow is developed. The flow over the complete rocket geometry and its interaction with the particle-laden plume is simulated. The computed plume radiance is compared with radiometric and spectroscopic data and good agreement with radiance magnitudes and spectral characteristics is obtained for the intrinsic core rocket exhaust data. The computation underpredicts the observed signal from the far-field photometers by many orders of magnitude. Based on the particulate flow simulations developed here and new experimental data, we hypothesize that the far-field radiation is due to molecular emission. Use of the CO Cameron band spectra obtained on this flight provides an estimate of the governing temperature of such radiation.

Candler, Graham V.; Levin, Deborah A.; Collins, Robert J.; Erdman, Peter W.; Zipf, Edward; Howlett, Carl

1993-10-01

26

Quantitative image analysis of UV rocket plumes and laboratory images  

Microsoft Academic Search

Rocket plume images photographed with the AFGL UV imager on video system have been analyzed with a video digitizer and an MS-DOS computer. The analysis consists of distortion-free rotation of the images to align the plume axis with the horizontal pixel direction, smoothing the images with appropriate image filters, plotting contours and brightness slices of the images, measuring the size

Donald F. Collins

1988-01-01

27

In-Situ Microphysical Measurements In Rocket Plumes With The Cloud And Aerosol Spectrometer (CAS)  

NASA Astrophysics Data System (ADS)

High resolution, single particle measurements have been made in rocket plumes using an optical particle spectrometer that measures diameters from 0.5 to 44 um. The Cloud and Aerosol Spectrometer (CAS) measures the light scattered in two directions from individual particles that pass through a focused, 680 nm laser beam and we derive the diameter, shape and composition from this information. The CAS was mounted on the NASA WB57-F aircraft as part of the Plume Ultrafast Measurements Acquisition (PUMA) project, an experiment funded by NSF and NASA to study the chemistry and microphysics of rocket plumes. Measurements were first made in a plume generated by an Atlas IIAS rocket in May, 2004 and again in July, 2005 in the plume formed from the exhaust of the solid state boosters used to launch the space shuttle Discovery into orbit. The microstructure of the two plumes and the characteristics of their particles were distinctly different. The two cases had similar maximum concentrations of 300 cm-3, but the space shuttle particles were on average larger and a greater percentage of them were irregular in shape. An analysis of the distance between particles suggests clustering because of the non-Poisson shape of the frequency distribution of inter-arrival times.

Kok, G.; Baumgardner, D.; Avallone, L.; Kalnajs, L.; Herman, R.; Ross, M.; Thompson, T.; Toohey, D.

2005-12-01

28

Rocket plume radiation base heating by reverse Monte Carlo simulation  

NASA Astrophysics Data System (ADS)

A reverse Monte Carlo radiative transfer code is developed to predict rocket plume base heating. It is more computationally efficient than the forward Monte Carlo method, because only the radiation that strikes the receiving point is considered. The method easily handles both gas and particle emission and particle scattering. Band models are used for the molecular emission spectra, and the Henyey-Greenstein phase function is used for the scattering. Reverse Monte Carlo predictions are presented for (1) a gas-only model of the Space Shuttle main engine plume; (2) a purescattering plume with the radiation emitted by a hot disk at the nozzle exit; (3) a nonuniform temperature, scattering, emitting and absorbing plume; and (4) a typical solid rocket motor plume. The reverse Monte Carlo method is shown to give good agreement with previous predictions. Typical solid rocket plume results show that (1) CO2 radiation is emitted from near the edge of the plume; (2) H2O gas and Al2O3 particles emit radiation mainly from the center of the plume; and (3) Al2O3 particles emit considerably more radiation than the gases over the 400-17,000 cm(exp -1) spectral interval.

Everson, John; Nelson, H. F.

1993-10-01

29

Evaluation of the Effect of Exhausts from Liquid and Solid Rockets on Ozone Layer  

Microsoft Academic Search

This paper reports the analytical results of the influences of solid rocket and liquid rocket exhausts on ozone layer. It is worried about that the exhausts from solid propellant rockets cause the ozone depletion in the ozone layer. Some researchers try to develop the analytical model of ozone depletion by rocket exhausts to understand its physical phenomena and to find

Yoshiki Yamagiwa; Tetsuya Ishimaki

2009-01-01

30

Stratospheric aircraft exhaust plume and wake chemistry  

NASA Astrophysics Data System (ADS)

Progress to date in an ongoing study to analyze and model emissions leaving a proposed High Speed Civil Transport (HSCT) from when the exhaust gases leave the engine until they are deposited at atmospheric scales in the stratosphere is documented. A kinetic condensation model was implemented to predict heterogeneous condensation in the plume regime behind an HSCT flying in the lower stratosphere. Simulations were performed to illustrate the parametric dependence of contrail droplet growth on the exhaust condensation nuclei number density and size distribution. Model results indicate that the condensation of water vapor is strongly dependent on the number density of activated CN. Incorporation of estimates for dilution factors into a Lagrangian box model of the far-wake regime with scale-dependent diffusion indicates negligible decrease in ozone and enhancement of water concentrations of 6-13 times background, which decrease rapidly over 1-3 days. Radiative calculations indicate a net differential cooling rate of the plume about 3K/day at the beginning of the wake regime, with a total subsidence ranging between 0.4 and 1 km. Results from the Lagrangian plume model were used to estimate the effect of repeated superposition of aircraft plumes on the concentrations of water and NO(y) along a flight corridor. Results of laboratory studies of heterogeneous chemistry are also described. Kinetics of HCl, N2O5 and ClONO2 uptake on liquid sulfuric acid were measured as a function of composition and temperature. Refined measurements of the thermodynamics of nitric acid hydrates indicate that metastable dihydrate may play a role in the nucleation of more stable trihydrates PSC's.

Miake-Lye, R. C.; Martinez-Sanchez, M.; Brown, R. C.; Kolb, C. E.; Worsnop, D. R.; Zahniser, M. S.; Robinson, G. N.; Rodriguez, J. M.; Ko, M. K. W.; Shia, R.-L.

1993-07-01

31

Nuclear thermal rocket plume interactions with spacecraft. Final report  

Microsoft Academic Search

This is the first study that has treated the Nuclear Thermal Rocket (NTR) effluent problem in its entirety, beginning with the reactor core, through the nozzle flow, to the plume backflow. The summary of major accomplishments is given below: (1) Determined the NTR effluents that include neutral, ionized and radioactive species, under typical NTR chamber conditions. Applied an NTR chamber

B. H. Mauk; N. A. Gatsonis; J. Buzby; X. Yin

1997-01-01

32

Hot rocket plume experiment - Survey and conceptual design  

NASA Astrophysics Data System (ADS)

Attention is given to a space-borne engine plume experiment study to fly an experiment which will both verify and quantify the reduced contamination from advanced rhenium-iridium earth-storable bipropellant rockets (hot rockets) and provide a correlation between high-fidelity, in-space measurements and theoretical plume and surface contamination models. The experiment conceptual design is based on survey results from plume and contamination technologists throughout the U.S. With respect to shuttle use, cursory investigations validate Hitchhiker availability and adaptability, adequate remote manipulator system (RMS) articulation and dynamic capability, acceptable RMS attachment capability, adequate power and telemetry capability, and adequate flight altitude and attitude/orbital capability.

Millard, Jerry M.; Luan, Taylor W.; Dowdy, Mack W.

1992-12-01

33

Method for Suppressing Rocket Motor Exhaust Flame.  

National Technical Information Service (NTIS)

The jet-actuated device includes, in combination, a rocket motor having at least one exit nozzle, a propellant grain within the motor and a flame-suppressing disk bonded to the nozzle end of the grain. The disk consists essentially of potassium sulfate, p...

R. A. Breitengross W. E. Donaldson

1965-01-01

34

Photographic Spectroscopic Measurement of Ultraviolet Solid Rocket Motor Plumes.  

National Technical Information Service (NTIS)

Photographic spectra having a nominal bandpass of 0.4nm were obtained from the radiation from several solid rocket motor exhausts in the spectral region 250nm to 430 nm. The spectra consisted primarily of a continuum with some molecular band structure whi...

D. R. Keefer K. E. Harwell W. J. Phillips

1980-01-01

35

Design Study for Toxic Rocket Exhaust Gas Cleaning.  

National Technical Information Service (NTIS)

A literature and equipment survey resulted in the selection of a high gas velocity chemical spray scrubber as the method for cleaning toxic products from rocket exhaust gases. The study included application of this type of system to 1,000-, 5,000-, 50,000...

J. W. Garrett

1972-01-01

36

Dilution of aircraft exhaust plumes at cruise altitudes  

Microsoft Academic Search

The dilution of jet engine exhaust in the plume behind cruising aircraft is determined from measured plume properties. The data set includes in situ measurements of CO2, NO, NOy, SO2, H2O, temperature, and contrail diameters behind subsonic and supersonic aircraft in the upper troposphere and lower stratosphere, for plume ages of seconds to hours. The set of data is extended

U. Schumann; H. Schlager; F. Arnold; R. Baumann; P. Haschberger; O. Klemm

1998-01-01

37

Insights into Stratospheric Chemistry and Transport from Ultra-fast Measurements in Rocket Plumes  

NASA Astrophysics Data System (ADS)

Fast-response measurements of reactive chlorine (Cl+ClO), carbon dioxide (CO2), ozone (O3) and methane (CH4) were obtained on a number of flights of the WB-57 aircraft into the plumes of rockets. These measurements occurred during the RISO and ACCENT missions in the plumes of the following rockets: Delta (May 1998 and April 1999), Atlas (June 1998 and April 1999), Athena (September 1999) and Space Shuttle (September 2000). These observations have provided a solid foundation for assessing the immediate post-launch impact of rocket exhaust on atmospheric ozone abundances. In addition, the time evolution of these species traces out the complex photochemistry of inorganic chlorine in the lower stratosphere in a way that allows us to examine the rates of key reactions that are important in the background stratosphere. The highly non-linear behavior of Cl and ClO at near-zero abundances of O3 as the plume ages and mixes with ambient air provides a unique window on small-scale (tens of meters) dynamical processes. In this talk we highlight the key observations that provide insight into important stratospheric photochemical and dynamical processes.

Toohey, D.; Avallone, L.; Gates, A.; Thornton, B.; Richard, E.; Kelly, K.

2001-12-01

38

The measurement of electron density in a rocket motor plume  

NASA Astrophysics Data System (ADS)

This paper discusses the development of a diagnostic technique to measure the electron density in a rocket motor plume in order to characterize and rank solid rocket propellants based on their propensity to attenuate the communication signal to a missile. Three techniques were originally investigated as possible low-cost approaches that could be used for plume comparisons as a function of propellant. These approaches consisted of Langmuir probes, electromagnetic coils, and focused microwave probes. The focused microwave probe concept was considered the most appropriate technique to implement for the research to be conducted. The complete design and analysis of a focused microwave probe system operating at 17 GHz was conducted and the selection to determine this operating frequency discussed. Initial estimates of general uncertainty analysis suggest very good results are obtainable using a F-4 lens system and horn diameter of 17 in. for the 17 GHz frequency.

Cooper, David A.; Frederick, Robert A.

1993-06-01

39

Numerical study on the influence of aluminum on infrared radiation signature of exhaust plume  

NASA Astrophysics Data System (ADS)

The infrared radiation signature of exhaust plume from solid propellant rockets has been widely mentioned for its important realistic meaning. The content of aluminum powder in the propellants is a key factor that affects the infrared radiation signature of the plume. The related studies are mostly on the conical nozzles. In this paper, the influence of aluminum on the flow field of plume, temperature distribution, and the infrared radiation characteristics were numerically studied with an object of 3D quadrate nozzle. Firstly, the gas phase flow field and gas-solid multi phase flow filed of the exhaust plume were calculated using CFD method. The result indicates that the Al203 particles have significant effect on the flow field of plume. Secondly, the radiation transfer equation was solved by using a discrete coordinate method. The spectral radiation intensity from 1000-2400 cm-1 was obtained. To study the infrared radiation characteristics of exhaust plume, an exceptional quadrate nozzle was employed and much attention was paid to the influences of Al203 particles in solid propellants. The results could dedicate the design of the divert control motor in such hypervelocity interceptors or missiles, or be of certain meaning to the improvement of ingredients of solid propellants.

Zhang, Wei; Ye, Qing-qing; Li, Shi-peng; Wang, Ning-fei

2013-09-01

40

FLUENT-based modelling of rocket exhaust signatures  

NASA Astrophysics Data System (ADS)

Commercially available fluid-dynamics solvers, such as FLUENT, are being developed to analyze and design missiles of increasing complexity. These robust solvers can be further adapted to predict spectral radiation directly. While retaining the capability to predict signatures from underexpanded axisymmetric rocket exhaust typical of most rockets, this new capability can be extended to include subsonic missiles, such as sea-skimmers, ballistic missiles operating in near-vacuum conditions and side-discharging rockets for manual and semi-automatic command missile guidance. The preliminary results presented in this study suggest that when combined with available atmospheric models, these comprehensive codes can be used to develop improved threat detection and missile guidance optics.

Rapanotti, John L.

2006-06-01

41

Evaluation of Rocket Motor Exhaust and Liner Combustion By-Products.  

National Technical Information Service (NTIS)

This laboratory conducted an evaluation of rocket motor exhaust and liner combustion by-products after four high speed rocket motor sled tests at the Holloman AFB Test Track. The Zuni, HVAR (High Velocity Air Rocket), and Nike rocket motors were evaluated...

I. Atkins M. Dibben

1989-01-01

42

Lidar for remote measurement of ozone in the exhaust plumes of launch vehicles  

NASA Astrophysics Data System (ADS)

Large quantities of chlorine and alumina particles are injected directly into the stratosphere by the current fleet of launch vehicles. Environmental concerns have been raised over the impact of the rocket exhaust on the ozone layer. Recently, differential absorption lidar (DIAL) was selected for remote sensing of ozone density within the plumes of Titan IV launch vehicles. The application of DIAL to this very challenging problem is described, and an implementation of UV-ozone DIAL is discussed that holds promise for this application.

Gelbwachs, Jerry A.

1996-05-01

43

Sublimation of ice particles from rocket exhausts in the upper atmosphere  

NASA Astrophysics Data System (ADS)

The process of sublimation of ice particles from a rocket exhaust in the upper atmosphere is examined. Heating by solar radiation and losses of energy by means thermal radiation and sublimation are taken into account in the thermal balance of the ice particles. The time dependences of size and temperature of the ice particles are obtained. An estimation of water vapor concentration around the rocket trajectory is made. The process of sublimation of the rocket exhaust ice particles may be important for the interpretation of optical phenomena in the upper atmosphere connected with rocket launches and for propagation of disturbances at a large distance from the rocket.

Platov, Y. V.; Kosch, M. J.

2003-12-01

44

Interaction of the Cassini rocket plume with the magnetosphere of Saturn during Saturn orbit injection  

NASA Astrophysics Data System (ADS)

The Cassini spacecraft will be injected into Saturn orbit on July 1, 2004 by a 97 minutes burn of its main rocket engine north of the rings of the planet. The exhaust plume generated at a rate of about 150 g/s produces a comet-like structure ahead of the spacecraft interacting with the extremely thin plasma of the Kronian magneto sphere. We have investigated the interaction of this cloud with the magnetosphere in the framework of the subalfvenic Alfven wing picture to assess the magnitude of the magnetic perturbation signal relative to the accuracy needed for the determina tion of Saturns multipole magnetic field. Although the results are (fortunately!) undra matic from the latter point of view ,the physics involved is quite interesting and exci ting. We shall estimate the magnetic field perturbation, its changing geometry and possible dynamic phenomena.

Neubauer, F.

2003-04-01

45

Nuclear thermal rocket plume interactions with spacecraft. Final report  

SciTech Connect

This is the first study that has treated the Nuclear Thermal Rocket (NTR) effluent problem in its entirety, beginning with the reactor core, through the nozzle flow, to the plume backflow. The summary of major accomplishments is given below: (1) Determined the NTR effluents that include neutral, ionized and radioactive species, under typical NTR chamber conditions. Applied an NTR chamber chemistry model that includes conditions and used nozzle geometries and chamber conditions typical of NTR configurations. (2) Performed NTR nozzle flow simulations using a Navier-Stokes solver. We assumed frozen chemistry at the chamber conditions and used nozzle geometries and chamber conditions typical of NTR configurations. (3) Performed plume simulations using a Direct Simulation Monte Carlo (DSMC) code with chemistry. In order to account for radioactive trace species that may be important for contamination purposes we developed a multi-weighted DSMC methodology. The domain in our simulations included large regions downstream and upstream of the exit. Inputs were taken from the Navier-Stokes solutions.

Mauk, B.H. [Johns Hopkins Univ., Laurel, MD (United States); Gatsonis, N.A.; Buzby, J.; Yin, X. [Worcester Polytechnic Inst., MA (United States). Mechanical Engineering Department

1997-05-01

46

Response of Selected Plant and Insect Species to Simulated Solid Rocket Exhaust Mixtures and to Exhaust Components from Solid Rocket Fuels.  

National Technical Information Service (NTIS)

The effects of solid rocket fuel (SRF) exhaust on selected plant and and insect species in the Merritt Island, Florida area was investigated in order to determine if the exhaust clouds generated by shuttle launches would adversely affect the native, plant...

E. P. Stahel J. N. Mccrimmon J. T. Ambrose W. M. Knott W. W. Heck

1980-01-01

47

Effects of rocket exhaust products in the thermosphere and ionsphere  

SciTech Connect

This paper reviews the current state of understanding of the problem of ionospheric F-layer depletions produced by chemical effects of the exhaust gases from large rockets, with particular emphasis on the Heavy Lift Launch Vehicles (HLLV) proposed for use in the construction of solar power satellites. The currently planned HLLV flight profile calls for main second-stage propulsion confined to altitudes below 124 km, and a brief orbit circularization maneuver at apogee. The second stage engines deposit 9 x 10/sup 31/ H/sub 2/O and H/sub 2/ molecules between 74 and 124 km. Model computations show that they diffuse gradually into the ionospheric F region, where they lead to weak but widespread and persistent depletions of ionization and continuous production of H atoms. The orbit circularization burn deposits 9 x 10/sup 29/ exhaust molecules at about 480-km altitude. These react rapidly with the F2 region 0/sup +/ ions, leading to a substantial (factor-of-three) reduction in plasma density, which extends over a 1000- by 2000-km region and persists for four to five hours. For purposes of computer model verification, a computation is included representing the Skylab I launch, for which observational data exist. The computations and data are compared, and the computer model is described.

Zinn, J.; Sutherland, C.D.

1980-02-01

48

Analytic Model for Washout of HCl(G) from Dispersing Rocket Exhaust Clouds.  

National Technical Information Service (NTIS)

The potential is investigated that precipitation scavenging of HCl from large solid rocket exhaust clouds may result in unacceptably acidic rain in the Cape Canaveral, Florida, area before atmospheric dispersion reduces HCl concentrations to safe limits. ...

G. L. Pellett

1981-01-01

49

Thermochemical ablation of materials from normal impingement of solid propellant rocket motor exhaust  

Microsoft Academic Search

The thermochemical response of three ablative materials was evaluated for protecting a plenum exhaust system from the environments due to the firings of two different solid propellant motors. The response of silica phenolic and two asbestos phenolic materials was studied for the cases of a single step (booster only) rocket motor and a two step (booster and sustainer) rocket motor

G. R. Moore; L. P. Anderson Jr.; C. H. Lewis; A. L. Murray

1978-01-01

50

On the Role of Contrail Ice in the Chemistry of Aircraft Exhaust Plumes  

Microsoft Academic Search

The formation of contrail ice particles has the potential to alter the chemistry occurring in aircraft exhaust plumes. A Gaussian plume model has been used to calculate the impact of contrail ice on plume chemistry as the exhaust emissions mix with the ambient atmosphere. Large Eddy Simulations (LES) were used to determine contrail ice surface areas for temperatures and relative

P. F. Vohralik; D. C. Lewellen; T. F. Rahmes; S. L. Baughcum

2009-01-01

51

Erosion resistance of needled carbon\\/carbon composites exposed to solid rocket motor plumes  

Microsoft Academic Search

The erosion resistance of the needled carbon\\/carbon composite leading edge was investigated by exposure to the solid rocket motor (SRM) plume. The erosion morphology and microstructure were examined and associated erosion mechanisms discussed. The composite leading edge was severely damaged with large recession and erosion rate after exposure. The results suggest that the erosion behavior was determined by the weak

Bo Chen; Li-Tong Zhang; Lai-Fei Cheng; Xin-Gang Luan

2009-01-01

52

Remote measurement of the plume shape of aircraft exhausts at airports by passive FTIR spectrometry  

Microsoft Academic Search

Information about the interaction between the exhaust plume of an aircraft jet engine and ambient air is required for the application of small-scale chemistry-transport models to investigate airport air quality. This interaction is not well understood. In order to study the interaction, spatial information about the plume is required. FTIR emission spectroscopy may be applied to analyze the aircraft exhausts.

Klaus Schäfer; Carsten Jahn; Selina Utzig; Edgar Flores-Jardines; Roland Harig; Peter Rusch

2004-01-01

53

An analysis of aircraft exhaust plumes form accidental encounters  

NASA Astrophysics Data System (ADS)

An analysis of data obtained during the second Airborne Arctic Stratospheric Expedition (AASE-II) was made with emphasis on aircraft exhaust plumes accidentally encountered during the mission. Twenty spikes were found with peak NO(y) increments greater than or equal to 1 ppbv. The examination of CO and CO2 indicated that there was only one NO(y) spike having clearly corresponding spikes of both CO and CO2 and another four with unambigious CO2 spikes. No significant increases were found for CH4 and N2O for these 5 spikes. The ratio of the excess CO2 and NO(y) compares well with the ratio of published subsonic aircraft emission indices. The study of the selected spikes from the DC-8 and another two spikes observed during other missions shows that the odd nitrogen other than NO(x) accounts for a very small percentage of the NO(y) increase associated with the observed spikes.

Zheng, J.; Weinheimer, A. J.; Ridley, B. A.; Liu, S. C.; Sachse, G. W.; Anderson, B. E.; Collins, J. E., Jr.

1994-11-01

54

HCI in Rocket Exhaust Clouds: Atmospheric Dispersion, Acid Aerosol Characteristics, and Acid Rain Deposition  

Microsoft Academic Search

NASA is examining Space Shuttle launch impacts. Solid rocket exhaust includes ˜60 tons HCL and ˜87 tons alumina particles emitted below 2.5 km, of which 50-80% forms an altitude stabilized exhaust cloud (EC). Several 60% smaller Titan-Ill EC were sampled by aircraft for this study. Three distinct features are presented: (a) An analysis of HCL (gaseous plus aqueous) data traces.

G. L. Pellett; D. I. Sebacher; R. J. Bendura; D. E. Wornom

1983-01-01

55

Effect of water to ablative performance under solid rocket exhaust environment  

Microsoft Academic Search

The local environment during a missile firing is particularly hostile. Thermal protection of the missile launcher structure is often achieved with ablatives. Ablatives erode when subjected to high-temperature rocket exhaust, but the backside temperature of the protected structure remains relatively cool due to the insulative nature of ablatives. Multiple missile firings can completely erode the ablative, exposing the launching system

M. J. Miller; J. H. Koo; F. M. Sickler; F. Lecureux; S. M. Dash

1993-01-01

56

Computational investigation of electron production in solid rocket plumes  

NASA Astrophysics Data System (ADS)

The CHEMQ chemical equilibrium code is used to predict electron density at the nozzle exit plane of a solid rocket motor. The presence of alkali metal contaminants is found to dominate electron production. A parametric study of the effects of these contaminants shows that the magnitude of the electron density at the nozzle exit plane is bounded by the assumptions of frozen versus equilibrium flow during nozzle expansion.

Hughes, R. C.; Landrum, D. B.

1993-06-01

57

Analyzing rocket plume spectral data with neural networks  

NASA Astrophysics Data System (ADS)

The Optical Plume Anomaly Detection (OPAD) system is under development to provide early-warning failure detection in support of ground-level testing of the Space Shuttle Main Engine (SSME). Failure detection is to be achieved through the acquisition of spectrally resolved plume emissions and subsequent identification of abnormal levels indicative of engine corrosion or component failure. Two computer codes (one linear and the other non-linear) are used by the OPAD system to iteratively determine specific element concentrations in the SSME plume, given emission intensity and wavelength information. Since this analysis is extremely labor intensive, a study was initiated to develop neural networks that would model the 'inverse' of these computer codes. Optimally connected feed-forward networks with imperceptible prediction error have been developed for each element modeled by the linear code, SPECTRA4. Radial basis function networks were developed for the non-linear code, SPECTRA5, and predict combustion temperature in addition to element concentrations.

Whitaker, Kevin W.; Krishnakumar, K. S.; Benzing, Daniel A.

58

Recommended launch-hold criteria for protecting public health from hydrogen chloride (HC1) gas produced by rocket exhaust  

Microsoft Academic Search

Solid-fuel rocket motors used by the United States Air Force (USAF) to launch missiles and spacecraft can produce ambient-air concentrations of hydrogen chloride (HCI) gas. The HCI gas is a reaction product exhausted from the rocket motor during normal launch or emitted as a result of a catastrophic abort destroying the launch vehicle. Depending on the concentration in ambient air,

J. I. Daniels; R. L. Baskett

1995-01-01

59

Molecular Back Flow from the Exhaust Plume of a Space-Based Laser.  

National Technical Information Service (NTIS)

Back flow from the exhaust of a chemical laser in low earth orbit may be detrimental to the integrity and operation of the selfsame system. Difficulties arise in the calculation of exhaust plume properties and molecular flux as the gas expands from contin...

S. E. McCarty

1985-01-01

60

An assessment of the total ozone mapping spectrometer for measuring ozone levels in a solid rocket plume  

NASA Astrophysics Data System (ADS)

The question whether the total ozone mapping spectrometer (TOMS) is capable of measuring ozone levels in a solid rocket motor plume is examined. Simulated measurements were computed for a chemical kinetics and dispersion model of a Titan IV plume. The principal disadvantage of TOMS for measuring local plume ozone levels is that the detection field-of-view is typically much larger than the column area for ozone loss. A secondary problem is attenuation of backscattered light by plume species and particles that can distort the ozone measurement.

Syage, Jack A.; Ross, Marty N.

61

Characterization of rocket propellant combustion products: Description of sampling and analysis methods for rocket exhaust characterization studies  

SciTech Connect

A systematic approach has been developed and experimentally validated for the sampling and chemical characterization of the rocket motor exhaust generated from the firing of scaled down test motors at the US Army's Signature Characterization Facility (ASCF) at Redstone Arsenal in Huntsville, Alabama. The overall strategy was to sample and analyze major exhaust constituents in near real time, while performing off-site analyses of samples collected for the determination of trace constituents of the particulate and vapor phases. Initial interference studies were performed using atmospheric pressure burns of 1 g quantities of propellants in small chambers at Oak Ridge National Laboratory. Carbon monoxide and carbon dioxide were determined using non-dispersive infrared instrumentation. Hydrogen cyanide, hydrogen chloride, and ammonia determinations were made using ion selective electrode technology. Oxides of nitrogen were determined using chemiluminescence instrumentation. Airborne particulate mass concentration was determined using infrared forward scattering measurements and a tapered element oscillating microbalance, as well as conventional gravimetry. Particulate phase metals were determined by collection on Teflon membrane filters, followed by inductively coupled plasma and atomic absorption analysis. Particulate phase polynuclear aromatic hydrocarbons (PAH) and nitro-PAH were collected using high volume sampling on a two stage filter. Target species were extracted, and quantified by gas chromatography/mass spectrometry (GC/MS). Vapor phase species were collected on multi-sorbent resin traps, and subjected to thermal desorption GC/MS for analysis. 11 refs., 1 fig., 1 tab.

Jenkins, R.A.

1990-06-07

62

Three-dimensional pollutant concentration dispersion of a vehicular exhaust plume in the real atmosphere  

NASA Astrophysics Data System (ADS)

The pollutant dispersion process from the vehicular exhaust plume has a direct impact on human health, particularly on vehicle drivers and passengers, bicyclists, motorcyclists, pedestrians and people working nearby. A three-dimensional vehicular pollutant dispersion numerical model was developed based on the Reynolds-averaged Navier-Stokes equations coupled with a k-? turbulence model to simulate the initial pollutant dispersion process of carbon monoxide, CO, from a vehicular exhaust plume in the real atmospheric environment. Since the ambient wind direction and velocity are stochastic and uncontrollable in the real atmospheric environment, a wind-direction-frequency-weighted (WDFW) approach was used to obtain the real pollutant concentration dispersion along with the development of the vehicular exhaust plume. Within the specified sampling period, the ambient windflow conditions are transformed into the corresponding frequencies of wind directions and averaged magnitudes of wind velocities from directions N, E, S or W. Good agreement between the calculated and measured data for two diesel-fuelled vehicles indicates that with the WDFW approach the initial dispersion of pollutant concentration from a vehicular exhaust plume in the real atmospheric environment can be truly reflected. The present study shows that the dispersion process in the near region for the relative concentration of CO, from R=0.1 (or 10%) to 1 (or 100%), is less influenced by the ambient wind velocity than by the vehicular exhaust velocity, but it is vice versa in the far region from R=0 (or 0%) to 0.1 (or 10%). It implies that the effect of vehicular exhaust exit velocity on the dispersion process is more pronounced than that of ambient wind velocity at the vicinity of the exhaust tailpipe exit, while the effect of ambient wind velocity gradually shows a significant role for the dispersion process along with the development of a vehicular exhaust plume.

Wang, J. S.; Chan, T. L.; Cheung, C. S.; Leung, C. W.; Hung, W. T.

63

On the prediction of concentration variations in a dispersing heavy-duty truck exhaust plume using k– ? turbulent closure  

Microsoft Academic Search

This work presents the computational fluid dynamic modeling of an exhaust plume dispersed from the exhaust pipe of a class-8 tractor truck powered by 330hp Cummins M11 electronically controlled diesel engine. This effort utilizes an advanced CFD technique to accurately predict the variation of carbon dioxide concentration inside a turbulent plume using a k–? eddy dissipation model. The simulation includes

Dong-Hee Kim; Mridul Gautam; Dinesh Gera

2001-01-01

64

Airship Measurements of Ship's Exhaust Plumes and Their Effect on Marine Boundary Layer Clouds  

Microsoft Academic Search

High-resolution aerosol, trace gas, and cloud microphysical measurements were made from an airship during transects across ships exhaust plumes advecting downwind of ships in the marine boundary layer (MBL). This study was part of the Office of Naval Research Monterey Area Ship Track experiment designed to understand the mechanisms by which ships produce cloud tracks visible in satellite imagery. Measurements

G. M. Frick; W. A. Hoppel

2000-01-01

65

Chemical modelling of an aeroplane exhaust plume in the free troposphere.  

National Technical Information Service (NTIS)

The following pilot study has simulated the chemical reactions occurring in an aeroplane exhaust plume using a photochemical atmospheric model. The investigated cases covered altitudes from 4 up to 10 km, i.e. the free troposphere, over a region in France...

K. Pleijel J. Moldanova Y. Andersson-Skoeld

1993-01-01

66

Nozzle installation effects on the noise from supersonic exhaust plumes  

NASA Astrophysics Data System (ADS)

The sensitivity of screech coupling in supersonic jets to nozzle installation geometry is explored as a function of nozzle shape, spacing, and orientation. The coupling phenomenon is shown to be a function of geometry for a variety of twin axisymmetric and rectangular nozzle configurations as well as for a single jet in proximity to a solid surface. Rapid plume merging or close proximity to a wall are shown to minimize the noise increment due to coupling. Twin impinging supersonic plumes experience more complex aeroacoustic interactions. The acoustic near field is dominated by screech and impingement tones, but the fuselage undersurface dynamic loads are primarily due to impingement of the unsteady upwash fountain flow on the fuselage undersurface.

Wlezien, R. W.

1992-04-01

67

Ultrafine particle size distributions measured in aircraft exhaust plumes  

Microsoft Academic Search

Fast-response measurements of particle size distributions were made for the first time in the near-field plume of a Boeing 737-300 aircraft burning fuel with fuel sulfur (S) contents (FSCs) of 56 and 2.6 ppmm, as well as in fresh and dissipating contrails from the same aircraft, using nine particle counters operating in parallel. Nonsoot particles were present in high concentrations,

Charles A. Brock; Franz Schröder; Bernd Kärcher; Andreas Petzold; Reinhold Busen; Markus Fiebig

2000-01-01

68

Remote measurement of the plume shape of aircraft exhausts at airports by passive FTIR spectrometry  

NASA Astrophysics Data System (ADS)

Information about the interaction between the exhaust plume of an aircraft jet engine and ambient air is required for the application of small-scale chemistry-transport models to investigate airport air quality. This interaction is not well understood. In order to study the interaction, spatial information about the plume is required. FTIR emission spectroscopy may be applied to analyze the aircraft exhausts. In order to characterize the plumes spatially, a scanning imaging FTIR system (SIGIS) has been improved. SIGIS is comprised of an interferometer (Bruker OPAG), an azimuth-elevation-scanning mirror, a data acquisition and control system with digital signal processors (DSP), an infrared camera and a personal computer. With this instrumentation it is possible to visualise the plume and to obtain information about the temperature distribution within the plume. Measurements are performed at low spectral resolution, because the dynamic environment of these measurements limits the measurement time to about 2 minutes. Measurements of the plume shapes of an APU and of main engines were performed.

Schäfer, Klaus; Jahn, Carsten; Utzig, Selina; Flores-Jardines, Edgar; Harig, Roland; Rusch, Peter

2004-11-01

69

Possible effect of the chlorine oxide dimer on transient ozone loss in rocket plumes. Technical report  

SciTech Connect

Understanding transient, local ozone holes that may be produced by solid rocket boosters in the stratosphere puts special demands on models. One must consider the time scales as well as the rates for all of the pertinent chemical reactions involved in the destruction of ozone. In this report, we show that consideration of the existence of the chlorine oxide dimer, Cl2O2, and consideration of the necessary time scale for ozone loss are essential for prediction of a transient ozone hole. We argue that photolysis of this species is the major source of atomic chlorine in the plume at 20 km, and the ClO + 0 reaction is the major source at 30 km, although both processes play a role at the higher altitude. Inclusion of the chlorine oxide dimer ozone destruction cycle, which has not been considered in any of the full-scale models to date, predicts substantial ozone destruction on a scale of about 12-km diameter at 20-km altitude and the ClO cycle produces a 49-km-diameter hole at 30-km altitude. This analysis also suggests that the size of the hole at 20 km may be highly variable since it is sensitive to the variable ozone-to-methane ratio at that altitude. Ozone, Rocket launch, Stratospheric, Chlorine.

Martin, L.R.

1994-03-15

70

High-fidelity phenomenology modeling of infrared emissions from missile and aircraft exhaust plumes  

NASA Astrophysics Data System (ADS)

The generation of high-fidelity imagery of infrared radiation from missile and aircraft exhaust plumes is a CPU intensive task. These calculations must include details associated with the generation of the plume flowfield and transport of emitted, scattered, and absorbed radiation. Additionally, spatial and temporal features such as mach discs, intrinsic cores, and shear layers must be consistently resolved regardless of plume orientation to eliminate nonphysical artifacts. This paper presents computational techniques to compute plume infrared radiation imagery for high frame rate applications at the Kinetic Kill Vehicle Hardware-in-the-loop Simulator facility located at Eglin AFB. Details concerning the underlying phenomenologies are also presented to provide an understanding of the computational rationale. Finally, several example calculations are presented to illustrate the level of fidelity that can be achieved using these methods.

Crow, Dennis R.; Coker, Charles F.

1996-05-01

71

Particle-Sizing System for Scanning Electron Microscope Images of Solid-Propellant Combustion Exhaust.  

National Technical Information Service (NTIS)

Accurate measurement of particle size distribution of rocket motor exhausts is essential for predicting the combustion efficiency and infrared plume signature. This thesis presents an automated method for extracting particle size distribution from scannin...

Y. L. Lee

1991-01-01

72

Real Time Diagnostics of Jet Engine Exhaust Plumes Using a Chirped QC Laser Spectrometer  

NASA Astrophysics Data System (ADS)

Quantitative measurements of real-time variations of the chemical composition of a jet engine exhaust plume is demonstrated using a 4.86 ?mn intra-pulse quantum cascade laser spectrometer. The measurements of the gas turbine exhaust were carried out in collaboration with John Black and Mark Johnson at Rolls Royce. The recording of five sets of averaged spectra a second has allowed us to follow the build up of the combustion products within the exhaust, and to demonstrate the large variation of the integrated absorption of these absorption lines with temperature. The absorption cross sections of the lines of both carbon monoxide and water increase with temperature, whereas those of the three main absorption lines of carbon dioxide decrease. At the steady state limit the absorption lines of carbon dioxide are barely visible, and the spectrum is dominated by absorption lines of carbon monoxide and water.

Hay, K. G.; Duxbury, G.; Langford, N.

2010-06-01

73

Theoretical and Experimental Investigation of Lunar and Martian Regolith Simulant Dynamic Response to Rocket Plume Impingement  

NASA Astrophysics Data System (ADS)

An investigation of rocket plume impingement on the regolith of the Moon and Mars is being conducted both theoretically and experimentally. Experimental results (1)and data from the Apollo landings inspired a theoretical model at ORBITEC : the ABL (Ablating Boundary Layer) model that assumes that regolith erosion and entrainment occurs in the thin boundary layer. The resulting crater streamlines itself with curve formed by extremization of the Lagrangian : L = (Z')^2+ Z^2 where Z(r) and Z(r)' are a depth variable and its radial derivative respectively. The actual depth profile z (r) in this model is derived from the formula z=Log ( 1+ Z/Zo) where Zo is a constant. For light soils the model reduces to z˜ Z/Zo and cantenary profiles result, exponential density profiles (2) give conoidal craters. (1) Experimental tests of the ABL model performed at Duke have shown good agreement. Further theoretical modeling and experimental data will be presented. (1) Metzger P., Lane, J., Immer C. and Clements, S. '6^th International Conference on Case Histories in Geotechnicla Engineeering , Arlinton VA August 11-16, 2008. (2) Bresson L. M., Moran C. J., and Assoline, S. Soil Sci. Soc. of Am. Jou, 2004, vol. 68, 4, pp. 1169-1176.

Brandenburg, John; Behringer, Robert; Clarke, Abraham

2009-11-01

74

Rockets  

NSDL National Science Digital Library

This unit teaches students how and why engineers design satellites to benefit life on Earth as well as allows students an opportunity to explore motion, rockets and rocket motion. Students discover that the motion of all objects including the flight of a rocket and even the movement of a canoe is governed by Newton's three laws of motion. Space exploration is a huge consideration for aerospace engineers, and this unit introduces students to the challenges of getting into space for the purpose of exploration. The ideas of thrust, weight and control are covered, allowing students to fully understand how and why rockets are designed with these concepts in mind. Also, students learn about the engineering design process and re-engineering as they design and build their own rockets after learning how and why the experts make specific engineering choices. Lastly, students explore the concept of triangulation that is used in navigation satellites and global positioning systems designed by engineers. And, by investigating these technologies, they learn how people can determine their position or the location of someone else.

Integrated Teaching And Learning Program

75

Numerical analysis of unsteady multiple jet plume interactions  

Microsoft Academic Search

The prediction of the transient behavior of multiple jet plume systems is important in engineering problems such as those encountered in solid rocket motor (SRM) design. Many SRMs employ a pyrogen-type ignition system, which consists of one or more hot exhaust plumes that induce burning in the motor propellant grain through impingement and subsequent heat transfer. Experimental cold-flow studies have

Rhonald M. Jenkins; Winfred A. Foster; Lora S. Wirth

1996-01-01

76

In situ observations in aircraft exhaust plumes in the lower stratosphere at midlatitudes  

SciTech Connect

Instrumentation on the NASA ER-2 high-altitude aircraft has been used to observe engine exhaust from the same aircraft while operating in the lower stratosphere. Encounters with the exhaust plume occurred approximately 10 min after emission with spatial scales near 2 km and durations of up to 10 s. Measurements include total reactive nitrogen, NO(y), the component species NO and NO2, CO2, H2O, CO, N2O, condensation nuclei, and meteorological parameters. The integrated amounts of CO2 and H2O during the encounters are consistent with the stoichiometry of fuel combustion (1:1 molar). Emission indices (EI) for NO(x) (= NO + NO2), CO, and N2O are calculated using simultaneous measurements of CO2. EI values for NO(x) near 4 g/(kg fuel) are in good agreement with values scaled from limited ground-based tests of the ER-2 engine. Non-NO(x) species comprise less than about 20% of emitted reactive nitrogen, consistent with model evaluations. In addition to demonstrating the feasibility of aircraft plume detection, these results increase confidence in the projection of emissions from current and proposed supersonic aircraft fleets and hence in the assessment of potential long-term changes in the atmosphere.

Fahey, D.W.; Keim, E.R.; Woodbridge, E.L.; Gao, R.S.; Boering, K.A.; Daube, B.C.; Wofsy, S.C.; Lohmann, R.P.; Hintsa, E.J.; Dessler, A.E. [National Oceanic and Atmospheric Administration, Boulder, CO (United States)]|[Harvard Univ., Cambridge, MA (United States)]|[Pratt & Whitney, East Harford, CT (United States)

1995-02-01

77

Airship Measurements of Ship's Exhaust Plumes and Their Effect on Marine Boundary Layer Clouds.  

NASA Astrophysics Data System (ADS)

High-resolution aerosol, trace gas, and cloud microphysical measurements were made from an airship during transects across ships exhaust plumes advecting downwind of ships in the marine boundary layer (MBL). This study was part of the Office of Naval Research Monterey Area Ship Track experiment designed to understand the mechanisms by which ships produce cloud tracks visible in satellite imagery. Measurements made below clouds and close to the ships are used to define the concentrations and source strength of effluents, and the size distribution of ship-generated aerosols. Measurements made during crossings inside the cloud indicate that ship-generated aerosol increases the number and decreases the radii of cloud droplets. Case studies of four ships are presented, two of which produced cloud tracks and two that did not. Of the two that did not produce cloud tracks, one did not produce a cloud track because of unfavorable background aerosol loading; the other, because the ship-produced particles were too small relative to the background aerosol. A simple cloud microphysical model that assumes the MBL dynamics remains the same inside and outside the plume is used to study differences in background and plume cloud formation and reveals the intricate relationship among the size and number of background aerosols; MBL dynamics (as it effects cloud supersaturation); and the concentration, size, and composition of ship-generated particles.

Frick, G. M.; Hoppel, W. A.

2000-08-01

78

Reactive Shear Layer Mixing and Growth Rate Effects on Afterburning Properties for Axisymetric Rocket Engine Plumes.  

National Technical Information Service (NTIS)

A semi-empirical model was developed for predicting the afterburning ignition location of film cooled rocket engines. The model is based on two characteristic distances, the distance required for turbulent mixing to generate a combustible mixture with the...

C. R. Hartsfield

2006-01-01

79

Dilution and aerosol dynamics within a diesel car exhaust plume—CFD simulations of on-road measurement conditions  

Microsoft Academic Search

Vehicle particle emissions are studied extensively because of their health effects, contribution to ambient PM levels and possible impact on climate. The aim of this work was to obtain a better understanding of secondary particle formation and growth in a diluting vehicle exhaust plume using 3-d information of simulations together with measurements. Detailed coupled computational fluid dynamics (CFD) and aerosol

U. Uhrner; S. von Löwis; H. Vehkamäki; B. Wehner; S. Bräsel; M. Hermann; F. Stratmann; M. Kulmala; A. Wiedensohler

2007-01-01

80

Coupled turbulence and aerosol dynamics modeling of vehicle exhaust plumes using the CTAG model  

NASA Astrophysics Data System (ADS)

This paper presents the development and evaluation of an environmental turbulent reacting flow model, the Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model. CTAG is designed to simulate transport and transformation of multiple air pollutants, e.g., from emission sources to ambient background. For the on-road and near-road applications, CTAG explicitly couples the major turbulent mixing processes, i.e., vehicle-induced turbulence (VIT), road-induced turbulence (RIT) and atmospheric boundary layer turbulence with gas-phase chemistry and aerosol dynamics. CTAG's transport model is referred to as CFD-VIT-RIT. This paper presents the evaluation of the CTAG model in simulating the dynamics of individual plumes in the "tailpipe-to-road" stage, i.e., VIT behind a moving van and aerosol dynamics in the wake of a diesel car by comparing the modeling results against the respective field measurements. Combined with sensitivity studies, we analyze the relative roles of VIT, sulfuric acid induced nucleation, condensation of organic compounds and presence of soot-mode particles in capturing the dynamics of exhaust plumes as well as their implications in vehicle emission controls.

Wang, Yan Jason; Zhang, K. Max

2012-11-01

81

Estimate of diffusion parameters of aircraft exhaust plumes near the tropopause from nitric oxide and turbulence measurements  

NASA Astrophysics Data System (ADS)

Horizontal and vertical plume scales and respective diffusivities for dispersion of exhaust plumes from airliners at cruising altitudes are determined from nitric oxide (NO) and turbulence data measured with the DLR Falcon research aircraft flying through the plumes. Ten plumes of known source aircraft were encountered about 5 to 100 min after emission at about 9.4 to 11.3 km altitude near the tropopause in the North Atlantic flight corridor at 8°W on three days in October 1993. The ambient atmosphere was stably stratified with bulk Richardson numbers greater than 10. The measured NO peaks had half widths of 500 to 2000 m with maximum concentrations up to 2.4 parts per billion by volume (ppbv), clearly exceeding the background values between 0.13 and 0.5 ppbv. For analysis the measured plumes are approximated by an analytical Gaussian plume model which accounts for anisotropic diffusion in the stably stratified atmosphere and for shear. Two methods are given to obtain diffusivity parameters from either the individual plume data or the set of all plume measurements. Using estimates of the emitted mass of NO per unit length, the vertical plume width is found to be 140 m on average. This width is related to mixing in the initial trailing vortex pair of the aircraft. The range of the plume data suggests vertical diffusivity values between 0 and 0.6 m2 s-1. The turbulence data exhibit strong anisotropic air motions with practically zero turbulent dissipation and weak vertical velocity fluctuations. This implies very small vertical diffusivities. The horizontal diffusivity is estimated as between 5 and 20 m2 s-1 from the increase of horizontal plume scales with time. For constant diffusivities, shear dominates the lateral dispersion after a time of about 1 hour even for the cases with only a weak mean shear of 0.002 s-1.

Schumann, U.; Konopka, P.; Baumann, R.; Busen, R.; Gerz, T.; Schlager, H.; Schulte, P.; Volkert, H.

1995-07-01

82

Investigation of the effects of solid rocket motor propellant composition on plume signature  

Microsoft Academic Search

Three propellants with aluminum\\/silicon weight percentages of 18\\/0%, 13.5\\/4.5%, and 12\\/6% were fired in a subscale motor to determine if the plume infrared signature could be reduced without a significant loss in specific impulse. Spectral measurements from 2.5 to 5.5 micrometers and thermal measurements from 3.5 to 5.0 micrometers were made. Plume particle size measurements showed that only particles with

Clay J. Snaza

1994-01-01

83

Prediction of the Size of Aluminum-Oxide Particles in Exhaust Plumes of Solid Rocket Motors  

Microsoft Academic Search

The processes of coagulation and aerodynamic fragmentation of liquid particles of aluminum oxide in an accelerating gas flow in the Laval nozzle are analyzed. A formula obtained by an approximate analytical solution of equations of a two-phase flow is proposed to calculate the characteristic particle diameter at the nozzle exit. The limiting particle diameter in the nozzle throat calculated theoretically

O. B. Kovalev

2002-01-01

84

Correlative Observations with Space-Borne Direct Doppler Wind Instruments of the Rapid Transport of Shuttle Exhaust Plumes (Invited)  

NASA Astrophysics Data System (ADS)

The Upper Atmosphere Research Satellite (UARS) was launched by Space Shuttle STS-48 on 12 September 1991 and included a direct Doppler experiment, the High Resolution Doppler Imager, HRDI. Ten years later, the TIMED Doppler Interferometer, TIDI, joined HRDI in direct neutral wind observations of the mesosphere and lower thermosphere (MLT). The removal of instrumental artifacts from the raw spectra, complicated by the loss of good attitude knowledge for HRDI and unexpected signal contamination for TIDI has matured to a level where excellent agreement exists for common volume measurements between them. The two experiments were able to perform overlapping measurements of tidal and planetary wave fields for three years permitting unprecedented clarity in the description of the cyclical behaviour of the MLT. The exhaust plume left in the wake of the launch of STS-107 (16 January 2003) provided a stringent test between TIDI, HRDI, and independent imagery, the latter of which showed rapid transport across the equator to the Antarctic. Though TIDI and HRDI observed the atmosphere at the plume’s location at different local solar times, all correlative observations supported the hypothesis indicated by once-a-day images of the plume - rapid southern transport over thousands of kilometers. A simple spectral analysis of simultaneous observations of the neutral winds by HRDI and TIDI indicates that a classical two-day wave (longitudinal wavenumber = 3) exists in the southern hemisphere during the ~80-hour transit time coinciding with the transport of the plume exhaust from launch to the Antarctic. A least-squares fit of the wave in the meridional wind indicates maximum amplitude in the MLT of ~80 m/s southwards. Other shuttle launches have also been accompanied by evidence that implies rapid transport of exhaust plumes to Arctic latitudes. This paper will summarize correlative HRDI and/or TIDI wind observations of these events and associated spectral analysis of the meridional wind in the MLT. There is no question that TIDI and HRDI confirm the rapid implied motion suggested by space-borne imagery of shuttle exhaust plumes. Empirical and first-principle physical models of MLT dynamics fall short in describing the amplitude and long life of strong meridional flow. The consistency between TIDI, HRDI, and independent observations of rapid plume transport indicate that our understanding of MLT dynamics is far from complete.

Niciejewski, R.; Meier, R. R.; Stevens, M. H.; Skinner, W. R.; Cooper, M.; Marshall, A.; Ortland, D. A.; Wu, Q.

2010-12-01

85

Box and Gaussian plume models of the exhaust composition evolution of subsonic transport aircraft in- and out of the flight corridor  

NASA Astrophysics Data System (ADS)

A box and a Gaussian plume model including gas-phase photochemistry and with plume dispersion parameters estimated from the few available plume observations are proposed and used for evaluation of photochemical transformations of exhausts from a single subsonic transport aircraft. The effects of concentration inhomogeneities in the plume cross section on the photochemical sources and sinks in the plume are analyzed for various groups of compounds. The influence of these inhomogeneities on the rate and on the mass of ambient air entrainment into the plume are studied also by comparing the box and the Gaussian plume model simulations during the first hours of their life''. Due to the enterance of HOx and NOx from ambient air into the plume with rates varying from the wind shear and turbulence conditions, the rate of emitted NOx oxidation in the plume is dependent on these and also on the background concentration levels of HOx and NOx.

Karol, I. L.; Ozolin, Y. E.; Rozanov, E. V.

1997-01-01

86

Influence of fuel sulfur on the composition of aircraft exhaust plumes: The experiments SULFUR 1-7  

Microsoft Academic Search

The series of SULFUR experiments was performed to determine the aerosol particle and contrail formation properties of aircraft exhaust plumes for different fuel sulfur contents (FSC, from 2 to 5500 mug\\/g), flight conditions, and aircraft (ATTAS, A310, A340, B707, B747, B737, DC8, DC10). This paper describes the experiments and summarizes the results obtained, including new results from SULFUR 7. The

U. Schumann; F. Arnold; R. Busen; J. Curtius; B. Kärcher; A. Kiendler; A. Petzold; H. Schlager; F. Schröder; K.-H. Wohlfrom

2002-01-01

87

PLUMES  

EPA Science Inventory

PLUMES INCLUDES TWO INITIAL DILUTION PLUME MODELS (RSB AND UM) AND A MODEL INTERFACE MANAGER FOR PREPARING COMMON INPUT AND RUNNING THE MODELS. TWO FARFIELD ALGORITHMS ARE AUTOMATICALLY INITIATED BEYOND THE ZONE OF INITIAL DILUTION. PLUMES ALSO INCORPORATES THE FLOW CLASSIFICAT...

88

Modeling Macro- and Micro-Scale Turbulent Mixing and Chemistry in Engine Exhaust Plumes.  

National Technical Information Service (NTIS)

Simulation of turbulent mixing and chemical processes in the near-field plume and plume-vortex regimes has been successfully carried out recently using a reduced gas phase kinetics mechanism which substantially decreased the computational cost. A detailed...

S. Menon

1998-01-01

89

Mixing and reaction processes in rocket based combined cycle and conventional rocket engines  

Microsoft Academic Search

Raman spectroscopy was used to make species measurements in two rocket engines. An airbreathing rocket, the rocket based combined cycle (RBCC) engine, and a conventional rocket were investigated. A supersonic rocket plume mixing with subsonic coflowing air characterizes the ejector mode of the RBCC engine. The mixing length required for the air and plume to become homogenous is a critical

Matthew Kurt Lehman

2000-01-01

90

Prediction of engine and near-field plume reacting flows in low-thrust chemical rockets  

Microsoft Academic Search

A computational model is employed to study the reacting flow within the engine and near-field plumes of several small gaseous hydrogen-oxygen thrusters. The model solves the full Navier-Stokes equations coupled with species diffusion equations for a hydrogen-oxygen reaction kinetics system and includes a two-equation q-omega model for turbulence. Predictions of global performance parameters and localized flowfield variables are compared with

Jonathan M. Weiss; Charles L. Merkle

1993-01-01

91

Recommended launch-hold criteria for protecting public health from hydrogen chloride (HC1) gas produced by rocket exhaust  

SciTech Connect

Solid-fuel rocket motors used by the United States Air Force (USAF) to launch missiles and spacecraft can produce ambient-air concentrations of hydrogen chloride (HCI) gas. The HCI gas is a reaction product exhausted from the rocket motor during normal launch or emitted as a result of a catastrophic abort destroying the launch vehicle. Depending on the concentration in ambient air, the HCI gas can be irritating or toxic to humans. The diagnostic and complex-terrain wind field and particle dispersion model used by the Lawrence Livermore National Laboratory`s (LLNL`s) Atmospheric Release Advisory Capability (ARAC) Program was applied to the launch of a Peacekeeper missile from Vandenberg Air Force Base (VAFB) in California. Results from this deterministic model revealed that under specific meteorological conditions, cloud passage from normal-launch and catastropic-abort situations can yield measureable ground-level air concentrations of HCI where the general public is located. To protect public health in the event of such cloud passage, scientifically defensible, emergency ambient-air concentration limits for HCI were developed and recommended to the USAF for use as launch-hold criteria. Such launch-hold criteria are used to postpone a launch unless the forecasted meteorological conditions favor the prediction of safe ground-level concentrations of HCl for the general public. The recommended concentration limits are a 2 ppM 1-h time-weighted average (TWA) concentration constrained by a 1-min 10-ppM average concentration. This recommended criteria is supported by human dose-response information, including data for sensitive humans (e.g., asthmatics), and the dose response exhibited experimentally by animal models with respiratory physiology or responses considered similar to humans.

Daniels, J.I.; Baskett, R.L.

1995-11-01

92

Size distribution of unburned aluminum particles in solid propellant rocket motor exhaust  

SciTech Connect

The size distribution of particles of unburned aluminum exiting a solid propellant rocket chamber is calculated by extending a previously developed theoretical model. Both one-dimensional and two-dimensional approximations to the chamber flow field are considered, but particle velocity lags are neglected. Results of the one-dimensional analysis differ from the more realistic two-dimensional results in that they predict a lower overall combustion efficiency and a most probable particle size which is always greater than zero. It is argued that these observations can be explained by the fact that the one-dimensional flow field allows many particles to pass through the chamber with a very short residence time.

Larson, R.S.

1986-06-01

93

Analysis of reacting flowfields in low-thrust rocket engines and plumes  

NASA Astrophysics Data System (ADS)

The mixing and combustion processes in small gaseous hydrogen-oxygen thrusters and plumes are studied by means of a computational model developed as a general purpose analytic procedure for solving low speed, reacting, internal flowfields. The model includes the full Navier-Stokes equations coupled with species diffusion equations for a hydrogen-oxygen reaction kinetics system as well as the option to use either the k-Epsilon or q-Omega low Reynolds number, two-equation turbulence models. Solution of the governing equations is accomplished by a finite-volume formulation with central-difference spatial discretizations and an explicit, four-stage, Runge Kutta time-integration procedure. The Runge-Kutta scheme appears to provide efficient convergence when applied to the calculation of turbulent, reacting flowfields in these small thrusters. Appropriate boundary conditions are developed to properly model propellant mass flowrates and regenerative wall cooling. The computational method is validated against measured engine performance parameters on a global level, as well as experimentally obtained exit plane and plume flowfield properties on a local level. The model does an excellent job of predicting the measured performance trends of an auxiliary thruster as a function of O/F ratio, although the performance levels are consistently underpredicted by approximately 4 percent. These differences arise because the extent to which the wall coolant layer and combustion gases mix and react is underpredicted. Predictions of velocity components, temperature and species number densities in the near-field plume regions of several low-thrust engines show reasonable agreement with experimental data obtained by two separate laser diagnostic techniques. Discrepancies between the predictions and measurements are primarily due to three-dimensional mixing processes which are not accounted for in the analysis. Both comparisons with experiment and the evident reason for errors in absolute levels of predicted quantities suggest the method should prove valuable for predicting parametric trends for design studies. In addition, issues such as numerical stability, robustness and computational efficiency are addressed. These include the evaluation of a numerically compatible two-equation turbulence model and the implementation of a time-derivative preconditioning method for convergence enhancement of low Mach number, chemically reacting flows.

Weiss, Jonathan Mitchell

94

On the fast zonal transport of the STS-121 space shuttle exhaust plume in the lower thermosphere  

NASA Astrophysics Data System (ADS)

Meier et al. (2011) reported rapid eastward transport of the STS-121 space shuttle (launch: July 4, 2006) main engine plume in the lower thermosphere, observed in hydrogen Lyman ? images by the GUVI instrument onboard the TIMED satellite. In order to study the mechanism of the rapid zonal transport, diagnostic tracer calculations are performed using winds from the Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model (TIME-GCM) simulation of July, 2006. It is found that the strong eastward jet at heights of 100-110 km, where the exhaust plume was deposited, results in a persistent eastward tracer motion with an average velocity of 45 m/s. This is generally consistent with, though faster than, the prevailing eastward shuttle plume movement with daily mean velocity of 30 m/s deduced from the STS-121 GUVI observation. The quasi-two-day wave (QTDW) was not included in the numerical simulation because it was found not to be large. Its absence, however, might be partially responsible for insufficient meridional transport to move the tracers away from the fast jet in the simulation. The current study and our model results from Yue and Liu (2010) explain two very different shuttle plume transport scenarios (STS-121 and STS-107 (launch: January 16, 2003), respectively): we conclude that lower thermospheric dynamics is sufficient to account for both very fast zonal motion (zonal jet in the case of STS-121) and very fast meridional motion to polar regions (large QTDW in the case of STS-107).

Yue, Jia; Liu, Han-Li; Meier, R. R.; Chang, Loren; Gu, Sheng-Yang; Russell, James, III

2013-03-01

95

First gaseous ion composition measurements in the exhaust plume of a jet aircraft in flight: Implications for gaseous sulfuric acid, aerosols, and chemiions  

NASA Astrophysics Data System (ADS)

Mass spectrometric composition measurements of gaseous negative ions have been made in the exhaust plume of a commercial jet aircraft (Airbus A310) in flight at altitudes around 10.4 km and at two plume ages around 3.0 and 3.6 s. Negative ions observed inside the exhaust plume are mostly NO3-(HNO3)m and HSO4-(HNO3)m with m ?2. Outside the plume in the “background” atmosphere the same negative ion species with the same R = (HSO4-(HNO3)m)/(NO3-(HNO3)m) were observed. This indicates that the ions observed in the plume were entrained ambient atmospheric ions. By contrast no indications for negative chemiions (with masses ?1100 amu) produced by the airbus engines were found in the plume. Furthermore our measurements indicate a modest decrease of the total concentration of entrained negative ions in the plume compared to the ambient atmosphere outside the plume. This decrease may be due to ion-removal by ion-attachment to aerosol-particles and/or ion-recombination with positive chemiions. We propose that the observed entrained ions can serve as probes for important plume components including gaseous sulfuric acid, aerosol particles and chemiions. Making use of this analytical potential we infer upper limits for the gaseous sulfuric acid concentration, total aerosol surface area density, and positive chemiion concentration. We conclude that initially formed gaseous sulfuric acid must have experienced rapid gas-to-particle conversion already in the very early plume at plume ages < 1.6 s.

Arnold, F.; Wohlfrom, K.-H.; Klemm, M. W.; Schneider, J.; Gollinger, K.; Schumann, U.; Busen, R.

96

Another Look at Rocket Thrust  

ERIC Educational Resources Information Center

|Rocket propulsion is often introduced as an example of Newton's third law. The rocket exerts a force on the exhaust gas being ejected; the gas exerts an equal and opposite force--the thrust--on the rocket. Equivalently, in the absence of a net external force, the total momentum of the system, rocket plus ejected gas, remains constant. The law of…

Hester, Brooke; Burris, Jennifer

2012-01-01

97

Influence of ejector technique on infrared radiation of the exhaust plume outside rectangular nozzle  

NASA Astrophysics Data System (ADS)

For accurate knowledge of the impact of ejector technique on infrared radiation of the plume, the physical model of the rectangular nozzle is established. The 3-D flow field outside the rectangular nozzle is simulated by numerical method with software Fluent6.3 pre and post the application of ejector technique, then the data of the flow fields, such as temperature, pressure and density and so on, are obtained, and according to the characteristic of the rectangular nozzle plume the computational domain of infrared radiation was established. This paper uses Lorentz linear statistical narrow-band model to calculate the mean absorption coefficient of the plume in the narrow band. Then it uses Finite Volume Method(FVM) to solve the radiation transmission equations in gas medium, and it obtains the total intensity distribution in 3~5?m of the plume radiation pre and post the application of ejector technique. The results shows that the infrared radiant of the rectangular nozzle decreases significantly by 80% after the application of ejector technique.

Feng, Yunsong; Lu, Yuan; Qiao, Ya

2013-09-01

98

Apollo 12 Lunar Module exhaust plume impingement on Lunar Surveyor III  

Microsoft Academic Search

Understanding plume impingement by retrorockets on the surface of the Moon is paramount for safe lunar outpost design in NASA’s planned return to the Moon for the Constellation Program. Visual inspection, Scanning Electron Microscopy, and surface scanned topology have been used to investigate the damage to the Lunar Surveyor III spacecraft that was caused by the Apollo 12 Lunar Module’s

Christopher Immer; Philip Metzger; Paul E. Hintze; Andrew Nick; Ryan Horan

2011-01-01

99

One-Dimensional Rocket Launch  

NSDL National Science Digital Library

A simulation of a 1-d rocket launch from the Earth's surface with graph of position versus time. Rocket parameters may be varied by typing new values for the initial mass of the fuel and the exhaust velocity.

Christian, Wolfgang; Belloni, Mario

2006-01-12

100

Measurements of Cl, ClO, and CO2 in the Exhaust Plume of the Space Shuttle  

NASA Astrophysics Data System (ADS)

Measurements of chlorine atoms (Cl), chlorine oxide (ClO), and carbon dioxide (CO2) were carried out in the exhaust plume of the Space Shuttle on September 8, 2000 (STS-106). Cl and ClO were detected at abundances exceeding 20 parts per billion (ppb) and 50 ppb, respectively at a sampling rate of 25 Hz by the technique of resonance fluorescence on the NASA WB-57 aircraft. These results provide a horizontal resolution of about 10 meters, and extreme variability is observed over these scales for over an hour. CO2 was measured by non-dispersive infrared with a sampling frequency of 1 second, with enhancements of tens of parts per million (ppm) on most passes. We examine the evolution of the ratio of Cl to ClO, referenced to CO2 as a conservative tracer of mixing, examine the correlations with ozone and methane, and discuss the implications for ozone loss.

Toohey, D. W.; Thornton, B. F.; Avallone, L. M.; Ross, M. N.; Richard, E.; Kelly, K.

2001-05-01

101

Comparison of the particle size distribution of heavy-duty diesel exhaust using a dilution tailpipe sampler and an in-plume sampler during on-road operation.  

PubMed

Originally constructed to develop gaseous emission factors for heavy-duty diesel trucks, the U.S. Environmental Protection Agency's (EPA) On-Road Diesel Emissions Characterization Facility has been modified to incorporate particle measurement instrumentation. An electrical low-pressure impactor designed to continuously measure and record size distribution data was used to monitor the particle size distribution of heavy-duty diesel truck exhaust. For this study, which involved a high-mileage (900,000 mi) truck running at full load, samples were collected by two different methods. One sample was obtained directly from the exhaust stack using an adaptation of the University of Minnesota's air-ejector-based mini-dilution sampler. The second sample was pulled from the plume just above the enclosed trailer, at a point approximately 11 m from the exhaust discharge. Typical dilution ratios of about 300:1 were obtained for both the dilution and plume sampling systems. Hundreds of particle size distributions were obtained at each sampling location. These were compared both selectively and cumulatively to evaluate the performance of the dilution system in simulating real-world exhaust plumes. The data show that, in its current residence-time configuration, the dilution system imposes a statistically significant bias toward smaller particles, with substantially more nanoparticles being collected than from the plume sample. PMID:11002602

Brown, J E; Clayton, M J; Harris, D B; King, F G

2000-08-01

102

Measurement of plasma parameters in the exhaust of a magnetoplasma rocket by gridded energy analyzer and emissive Langmuir probe  

NASA Astrophysics Data System (ADS)

The 10 kilowatt prototype of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine, abbreviated as VX-10, is designed to eject plasma at exhaust velocities of tens of kilometers per second. In this device, energy is imparted to the plasma ions by two mechanisms: ion cyclotron resonant heating (ICRH), and acceleration in an ambipolar electric field. Measurements from two different electrostatic probes are combined to determine how much each mechanism contributes to the total ion energy. The first probe is a gridded retarding potential analyzer (RPA) that incorporates a multi-channel collimator to obtain precise measurement of the ion and electron parallel energy distributions. The second is an emissive Langmuir probe that measures the DC and RF components of the plasma potential. The plasma potential obtained from the emitting probe allows calculation of the parallel velocity distribution once the parallel energy distribution is obtained from the energy analyzer data. Biasing the RPA housing is shown to minimize the plasma perturbation, as monitored by an auxiliary probe. When this minimization is done, the RPA measurements become compatible with the emissive probe's measurement of plasma potential. The collimated RPA and emissive probe have been used to examine the effects of a double dual half-turn (DDHT) antenna encircling the plasma. When power at the ion cyclotron frequency is applied, changes are seen in the saturation current and mean ion energy of the collimated RPA characteristic. The evolution of these changes as the RPA is moved downstream from the antenna is interpreted as firm evidence of ion cyclotron heating, albeit at absorbed energies of less than 1 electronvolt per ion. The emissive probe shows that, within experimental error, all of the increased ion energy is accounted for by an increase in the plasma potential that occurs when the ICRF power is applied. The combined RPA and emissive probe data also show that there is a jet of flowing plasma in the VX-10 when operated with the helicon source alone but that the signal from this jet is overwhelmed by a rapidly growing stationary plasma within the first second of the discharge.

Glover, Timothy Ward

2002-01-01

103

Characterization of rocket propellant combustion products. Chemical characterization and computer modeling of the exhaust products from four propellant formulations: Final report, September 23, 1987--April 1, 1990  

SciTech Connect

The overall objective of the work described in this report is four-fold: to (a) develop a standardized and experimentally validated approach to the sampling and chemical and physical characterization of the exhaust products of scaled-down rocket launch motors fired under experimentally controlled conditions at the Army`s Signature Characterization Facility (ASCF) at Redstone Arsenal in Huntsville, Alabama; (b) determine the composition of the exhaust produces; (c) assess the accuracy of a selected existing computer model for predicting the composition of major and minor chemical species; (d) recommended alternations to both the sampling and analysis strategy and the computer model in order to achieve greater congruence between chemical measurements and computer prediction. 34 refs., 2 figs., 35 tabs.

Jenkins, R.A.; Nestor, C.W.; Thompson, C.V.; Gayle, T.M.; Ma, C.Y.; Tomkins, B.A.; Moody, R.L.

1991-12-09

104

Modelling exhaust plume mixing in the near field of an aircraft  

Microsoft Academic Search

A simplified approach has been applied to analyse the mixing and entrainment processes of the engine exhaust through their interaction with the vortex wake of an aircraft. Our investigation is focused on the near field, extending from the exit nozzle until about 30 s after the wake is generated, in the vortex phase. This study was performed by using an

F. Garnier; S. Brunet; L. Jacquin

1997-01-01

105

Modelling exhaust plume mixing in the near field of an aircraft  

Microsoft Academic Search

A simplified approach has been applied to analyse the mixing and entrainment processes of the engine exhaust through their interaction with the vortex wake of an aircraft. Our investigation is focused on the near field, extending from the exit nozzle until about 30s after the wake is generated, in the vortex phase. This study was performed by using an integral

F. Garnier; S. Brunet; L. Jacquin

1997-01-01

106

Large-eddy simulation of aircraft exhaust plumes in the free atmosphere: Effective diffusivities and cross-sections  

NASA Astrophysics Data System (ADS)

The effective diffusion of aircraft emissions in the free stably stratified atmosphere is investigated by means of large-eddy simulation in a domain of size 4.3 × 1.1 × 1.1 km³. On that scale, the atmosphere is represented by a weakly turbulent flow under uniformly stratified and shearless conditions. It is assumed that aircraft induced turbulence has ceased. The exhaust plumes of aircraft are represented by line sources with Gaussian cross-sections. The stratification has been varied between 0.006 s-1 and 0.03 s-1. The computed effective horizontal diffusion coefficient lies between 11±2 m²s-1 and 21±4 m²s-1, depending on the level of stratification. Likewise the vertical diffusivity ranges from 2.3±0.6 m²s-1 to 0.37±0.04 m²s-1 in the beginning of the diffusion process, and amounts almost independently of the stratification to about 0.15±0.01 m²s-1 later on. The plume cross-sections increase with time and stratification. The scattering of the results for a given stratification reflects the action of decaying, anisotropic, and homogeneous turbulence. The results confirm very well data from recent in-situ flight measurements in the North-Atlantic flight corridor in the tropopause region.

Dürbeck, Tilman; Gerz, Thomas

107

Three-dimensional reconstruction method on the PDE exhaust plume flow flame temperature field  

NASA Astrophysics Data System (ADS)

Pulse detonation engine (referred to as PDE) has many advantage about simple structure, high efficiency thermal [1] cycling etc. In the future, it can be widely used in unmanned aircraft, target drone, luring the plane, the imaginary target, target missiles, long-range missiles and other military targets. However, because the exhaust flame of PDE is complicated [2], non-uniform temperature distribution and mutation in real time, its 3-D temperature distribution is difficult to be measured by normal way. As a result, PDE is used in the military project need to face many difficulties and challenges. In order to analyze and improve the working performance of PDE, deep research on the detonation combustion process is necessary. However, its performance characteristic which is in non-steady-state, as well as high temperature, high pressure, transient combustion characteristics put forward high demands about the flow field parameters measurement. In this paper, the PDE exhaust flames temperature field is reconstructed based on the theory of radiation thermometry [3] and Emission Spectral Tomography (referred to as EST) [4~6] which is one branch of Optical CT. It can monitor the detonation wave temperature distribution out of the exhaust flames at different moments, it also provides authentication for the numerical simulation which directs towards PDE work performance, and then it provides the basis for improving the structure of PDE.

Zhang, Zhimin; Wan, Xiong; Luo, Ningning; Li, Shujing

2010-05-01

108

Simulation of the evolution of aircraft exhaust plumes including detailed chemistry and segregation  

NASA Astrophysics Data System (ADS)

The Field Monte Carlo or Stochastic Fields (SF) method for turbulent reacting flows has been applied to the chemical evolution of the early part of a hot jet with bypass flow producing 7kN of thrust, using a 23 species chemical mechanism. This is done to broadly approximate a turbofan engine at idle thrust setting. Much of the chemistry was found to take place inside the core of the jet before mixing occurs, as there is no reactant gradient there, considering segregation makes little difference. Radical concentrations, however, were found to be changed. The reaction between NO and ambient O3, which is slow compared to the fast mixing timescale of the turbulent jet, is unaffected by segregation. The local Damköhler number was calculated based on an estimate of the chemical timescale and the local large-eddy timescale. It was found that only those species which had local Da greater than five were affected by segregation. In this work we have applied the SF method the early part of the plume, however the method developed here could equally be employed to study the plume over a longer distance.

Garmory, A.; Britter, R. E.; Mastorakos, E.

2008-04-01

109

Characteristics of aerosol particles and trace gases in ship exhaust plumes  

NASA Astrophysics Data System (ADS)

Gaseous and particulate matter from marine vessels gain increasing attention due to their significant contribution to the anthropogenic burden of the atmosphere, implying the change of the atmospheric composition and the impact on local and regional air quality and climate (Eyring et al., 2010). As ship emissions significantly affect air quality of onshore regions, this study deals with various aspects of gas and particulate plumes from marine traffic measured near the Elbe river mouth in northern Germany. In addition to a detailed investigation of the chemical and physical particle properties from different types of commercial marine vessels, we will focus on the chemistry of ship plumes and their changes while undergoing atmospheric processing. Measurements of the ambient aerosol, various trace gases and meteorological parameters using a mobile laboratory (MoLa) were performed on the banks of the Lower Elbe which is passed on average, daily by 30 ocean-going vessels reaching the port of Hamburg, the second largest freight port of Europe. During 5 days of sampling from April 25-30, 2011 170 commercial marine vessels were probed at a distance of about 1.5-2 km with high temporal resolution. Mass concentrations in PM1, PM2.5 and PM10 and number as well as PAH and black carbon (BC) concentrations in PM1 were measured; size distribution instruments covered the size range from 6 nm up to 32 ?m. The chemical composition of the non-refractory aerosol in the submicron range was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase species analyzers monitored various trace gas concentrations in the air and a weather station provided meteorological parameters. Additionally, a wide spectrum of ship information for each vessel including speed, size, vessel type, fuel type, gross tonnage and engine power was recorded via Automatic Identification System (AIS) broadcasts. Although commercial marine vessels powered by diesel engines consume high-sulfur fuel, the chemical submicron aerosol fraction is mainly composed of hydrocarbon-like organic aerosol (HOA) species. These include PAHs that are adsorbed onto the high number of ultrafine particles. Nevertheless, the chemical composition, typical particle sizes as well as emitted gaseous components vary substantially dependent on the engine or ship type, engine operation condition and fuel mixture. This results in cargo vessels compared to tankers, passenger ships and river boats being the largest polluters influencing the Elbe shipping lane areas by high amounts of NOx, SO2, CO2, PAH, BC and ultrafine particulate matter. The tropospheric ozone chemistry in this area is also substantially affected particularly due to the increasing number of Elbe-passing ships. As onshore regions can be influenced by aged shipping plumes, trajectory pathways and transportation times were examined. As a consequence of the plumes' aging, variations of the organic fraction of the mass spectral fingerprints were found. Eyring, V. et al. (2010), Atmospheric Environment, 44, 4735-4771.

Drewnick, F.; Diesch, J.; Borrmann, S.

2011-12-01

110

MOL Fluid Dynamics Preliminary Data Report: Thrustor Plume Tests. Sequence Number B319. Item Data Number UT-132.  

National Technical Information Service (NTIS)

An experimental test program was conducted to assess the effects of rocket exhaust plume impingement on MOL vehicle surfaces and equipment. Testing was performed in a vacuum chamber by use of flat panels to represent vehicle surfaces and a subscale thrust...

M. L. Lofland

1969-01-01

111

Observation of stratospheric ozone depletion associated with Delta II rocket emissions  

NASA Astrophysics Data System (ADS)

Ozone, chlorine monoxide, methane, and submicron particulate concentrations were measured in the stratospheric plume wake of a Delta II rocket powered by a combination of solid (NH4ClO4/Al) and liquid (LOX/kerosene) propulsion systems. We apply a simple kinetics model describing the main features of gas-phase chlorine reactions in solid propellant exhaust plumes to derive the abundance of total reactive chlorine in the plume and estimate the associated cumulative ozone loss. Measured ozone loss during two plume encounters (12 and 39 minutes after launch) exceeded the estimate by about a factor of about two. Insofar as only the most significant gas-phase chlorine reactions are included in the calculation, these results suggest that additional plume wake chemical processes or emissions other than reactive chlorine from the Delta II propulsion system affect ozone levels in the plume.

Ross, M. N.; Toohey, D. W.; Rawlins, W. T.; Richard, E. C.; Kelly, K. K.; Tuck, A. F.; Proffitt, M. H.; Hagen, D. E.; Hopkins, A. R.; Whitefield, P. D.; Benbrook, J. R.; Sheldon, W. R.

112

Recycled Plastic: A Clean and Low Cost Rocket Fuel.  

National Technical Information Service (NTIS)

Recycled polyethylene plastic as a hybrid rocket fuel takes advantage of a low cost and readily available resource and eliminates toxic exhaust emissions for a cleaner combustion fuel. Solid rocket motors produce extremely harmful exhaust compounds of hyd...

K. W. Schulze

1994-01-01

113

Direct active measurements of movements of lunar dust: Rocket exhausts and natural effects contaminating and cleansing Apollo hardware on the Moon in 1969  

NASA Astrophysics Data System (ADS)

Dust is the Number 1 environmental hazard on the Moon, yet its movements and adhesive properties are little understood. Matchbox-sized, 270-gram Dust Detector Experiments (DDEs) measured contrasting effects triggered by rocket exhausts of Lunar Modules (LM) after deployment 17 m and 130 m from Apollo 11 and 12 LMs. Apollo 11 Lunar Seismometer was contaminated, overheated and terminated after 21 days operation. Apollo 12 hardware was splashed with collateral lunar dust during deployment. DDE horizontal solar cell was cleansed of nominally 0.3 mg cm-2 dust by 80% promptly at LM ascent and totally within 7 minutes. A vertical cell facing East was half-cleaned promptly then totally over hundreds of hours. Each cell cooled slightly. For the first time lunar electrostatic adhesive forces on smooth silicon were directly measured by comparison with lunar gravity. Analyses imply this adhesive force weakens as solar angle of incidence decreases. If valid, future lunar astronauts may have greater problems with dust adhesion in the middle half of the day than faced by Apollo missions in early morning. A sunproof shed may provide dust-free working environments on the Moon. Low-cost laboratory tests with DDEs and simulated lunar dust can use DDE benchmark lunar data quickly, optimising theoretical modelling and planning of future lunar expeditions, human and robotic.

O'Brien, Brian

2009-05-01

114

Plasma Diagnostics Development for Advanced Rocket Engines  

Microsoft Academic Search

The VASIMR (Variable Specific Impulse Magnetoplasma Rocket) engine is a next-generation rocket engine under development at the Johnson Space Center's Advanced Space Propulsion Laboratory. With an exhaust velocity up to 50 times that of chemical rocket engines such as the Space Shuttle Main Engine, the VASIMR concept promises fast, efficient interplanetary flight. Rice University has participated in VASIMR research since

Timothy Glover; Carter Kittrell; Anthony Chan; Franklin Chang-Diaz

2000-01-01

115

Composition of individual particles in the wakes of an Athena II rocket and the space shuttle  

NASA Astrophysics Data System (ADS)

The Particle Analysis by Laser Mass Spectrometry (PALMS) instrument was used to obtain the first in situ measurements of the composition of particles in the wakes of solid rocket motor (SRMs) launch vehicles. PALMS acquired mass spectra of over 2300 exhaust particles within the plumes of an Athena II rocket and the Space Shuttle. The majority of positive spectra indicated the presence of primary and trace components of the aluminum fuel and the combustion catalyst. Negative spectra showed chlorine from the oxidizer. Nitrate and phosphate fragments and water were common features of spectra acquired during the Space Shuttle encounters. Elemental carbon (EC) was a significant particle type observed in the Athena II plume. The data show that particles emitted by SRMs are more diverse and probably more reactive than previously considered.

Cziczo, D. J.; Murphy, D. M.; Thomson, D. S.; Ross, M. N.

2002-11-01

116

COMPARISON OF THE PARTICLE SIZE DISTRIBUTION OF HEAVY-DUTY DIESEL EXHAUST USING A DILUTION TAIL-PIPE SAMPLER AND IN-PLUME SAMPLER DURING ON-ROAD OPERATION  

EPA Science Inventory

The paper compares the particle size distribution of heavy-duty diesel exhaust using a dilution tail-pipe sampler and an in-plume sampler during on-road operation. EPA's On-road Diesel Emissions Characterization Facility, modified to incorporate particle measurement instrumentat...

117

Rocket engine nozzle attenuator  

Microsoft Academic Search

The function of a rocket engine nozzle is to expand the hot engine exhaust gases down to ambient pressure, transforming thermal energy to directed kinetic energy in order to produce thrust. Considering nozzle design, there is an optimum nozzle shape and length, the bell-shaped or contour nozzle. The reason for this specific contour is that the nozzle must be designed

David A. Lewis

1993-01-01

118

Measured particulate behavior in a subscale solid propellant rocket motor  

NASA Astrophysics Data System (ADS)

Particulate matter are sized in the exhaust nozzle and plume of small rocket motors of varying geometry to assess the effects of the expansion process on particle size. Both converging and converging-diverging nozzles are considered, and particle sizing is accomplished at pressures of up to 4.36 MPa with aluminum loadings of 2.0 and 4.7 percent. An instrument based on Fraunhofer diffraction is used to measure the particle-size distributions showing that: (1) high burning rates reduce particle agglomeration and increase C* efficiency; (2) high pressures lead to small and monomodal D32 entering the nozzle; and (3) D32 sizes increase appreciably at the tailoff. Some variations in plume signature are theorized to be caused by the tailoff phenomenon, and particle collisions and/or surface effects in the nozzle convergence are suggested by the reduced number of larger particles at the nozzle convergence.

Brennan, W. D.; Hovland, D. L.; Netzer, D. W.

1992-10-01

119

Chemical rocket propulsion and the environment  

SciTech Connect

Results are presented from the examination by the Chemical Rocket Propulsion and the Environment Workshop conducted by AIAA in June 1991 of the impact of rocket launches and ground testing on the earth's environment. The major conclusions of this workshop were: (1) at projected rocket launch rates, neither the liquid- nor the solid-rocket motors will significantly impact stratospheric ozone; (2) there is no global acid rain problem associated with rocket exhaust; and (3) the local launch site and static test site acidification is a minor problem and can be managed.

Mcdonald, A.J. (Thiokol Corp., Brigham City, UT (United States))

1992-03-01

120

Rocket Flight.  

ERIC Educational Resources Information Center

|Describes an activity for designing, building, and launching rockets that provides students with an intrinsically motivating and real-life application of what could have been classroom-only concepts. Includes rocket design guidelines and a sample grading rubric. (KHR)|

Van Evera, Bill; Sterling, Donna R.

2002-01-01

121

The Ultraviolet Plume Instrument (UVPI)  

Microsoft Academic Search

The Ultraviolet Plume Instrument (UVPI) was launched aboard the Low-power Atmospheric Compensation Experiment (LACE) satellite on 14 Feb. 1990. Both the spacecraft and the UVPI were sponsored by the Directed Energy Office of the Strategic Defense Initiative Organization. The mission of the UVPI was to obtain radiometrically calibrated images of rocket plumes at high altitude and background image data of

D. M. Horan

1993-01-01

122

Particle Rotation Effects in Rarefied Two-Phase Plume Flows  

NASA Astrophysics Data System (ADS)

We evaluate the effects of solid particle rotation in high-altitude solid rocket exhaust plume flows, through the development and application of methods for the simulation of two phase flows involving small rotating particles and a nonequilibrium gas. Green's functions are derived for the force, moment, and heat transfer rate to a rotating solid sphere within a locally free-molecular gas, and integration over a Maxwellian gas velocity distribution is used to determine the influence of particle rotation on the heat transfer rate at the equilibrium limit. The use of these Green's functions for the determination of particle phase properties through the Direct Simulation Monte Carlo method is discussed, and a procedure is outlined for the stochastic modeling of interphase collisions. As a test case, we consider the nearfield plume flow for a Star-27 solid rocket motor exhausting into a vacuum, and vary particle angular velocities at the nozzle exit plane in order to evaluate the influence of particle rotation on various flow properties. Simulation results show that rotation may lead to slightly higher particle temperatures near the central axis, but for the case considered the effects of particle rotation are generally found to be negligible.

Burt, Jonathan M.; Boyd, Iain D.

2005-05-01

123

Rocket Engine Jet Blast Attenuation in Water.  

National Technical Information Service (NTIS)

The investigation was conducted to determine the feasibility of launching missiles and superboosters from overwater sites. Information is needed to predict the depth of liquid-propellant rocket engine exhaust gas penetration into water. Methods will be re...

G. W. Leese

1967-01-01

124

Some problems in communications with relativistic interstellar rockets  

Microsoft Academic Search

The feasibility of interstellar travel with relativistic rockets is discussed and some communications problems that will occur with such rockets are analyzed. For interstellar travel at relativistic velocities, rockets with exhaust velocities exceeding 0.01 times the speed of light are required. The principle effect on communications due to interstellar distances is the time delay between the transmission and reception of

G. M. Anderson

1975-01-01

125

Smoke Plume Method of Measuring Upper Winds.  

National Technical Information Service (NTIS)

Contents: Development of a dependable 'Smoke producing' rocket to a height limit of 3000 to 4000 ft; Development of photographic techniques for sequentically recording the smoke plumes in three-dimensions, and, the techniques employed in the determination...

G. C. Gill A. W. Stohrer T. L. Sweeny

1968-01-01

126

Rocket engine nozzle attenuator  

NASA Astrophysics Data System (ADS)

The function of a rocket engine nozzle is to expand the hot engine exhaust gases down to ambient pressure, transforming thermal energy to directed kinetic energy in order to produce thrust. Considering nozzle design, there is an optimum nozzle shape and length, the bell-shaped or contour nozzle. The reason for this specific contour is that the nozzle must be designed in such a manner that the expansion shock waves emanating from the nozzle throat region coincide, and thus diminish the compression effects accompanying the reorientation of flow in the center region of the expansion section. A rocket nozzle must absorb a variety of loads caused by such shocks due to thermal expansion and contraction, as well as shocks from sudden pressurization at startup, and flight accelerations. A rocket engine nozzle is provided which is capable of attenuating nozzle vibrations generated therein during use. The nozzle includes an annular closed chamber surrounding the nozzle adjacent to its gas exhaust end. Within the chamber is a dense but unrestricted particulate mass capable of undergoing frictional movement within the chamber.

Lewis, David A.

1993-01-01

127

Method and Apparatus for Reducing Smoke at Launch of High Performance Rockets.  

National Technical Information Service (NTIS)

The patent application relates to a method whereby the exhaust signature of high performance rockets is reduced by including in a solid propellant rocket motor a substantially smokeless, double-base propellant and a smoky, high-energy, composite propellan...

B. E. Barsell F. J. Worcester

1975-01-01

128

Evaluation of Systems for Control of Emissions from Rocket Motors. Phase I.  

National Technical Information Service (NTIS)

The report gives results of design studies related to the control of emissions from solid rocket test firings. It summarizes literature in the subject area and contact with those installations treating rocket exhausts. It gives results of an examination o...

S. Calvert S. Stalberg

1975-01-01

129

Two-dimensional motions of rockets  

NASA Astrophysics Data System (ADS)

We analyse the two-dimensional motions of the rockets for various types of rocket thrusts, the air friction and the gravitation by using a suitable representation of the rocket equation and the numerical calculation. The slope shapes of the rocket trajectories are discussed for the three types of rocket engines. Unlike the projectile motions, the descending parts of the trajectories tend to be gentler and straighter slopes than the ascending parts for relatively large launching angles due to the non-vanishing thrusts. We discuss the ranges, the maximum altitudes and the engine performances of the rockets. It seems that the exponential fuel exhaustion can be the most potent engine for the longest and highest flights.

Kang, Yoonhwan; Bae, Saebyok

2007-01-01

130

Rockets Away!  

ERIC Educational Resources Information Center

|Describes a project that involved a rocket-design competition where students played the roles of McDonnell Douglas employees competing for NASA contracts. Provides a real world experience involving deadlines, design and performance specifications, and budgets. (JRH)|

Kaahaaina, Nancy

1997-01-01

131

Rocket Engines  

NSDL National Science Digital Library

This video from SpaceTEC National Aerospace Technical Education Center explains the theory of rocket engines using Newton's third law of motion. This five minute video is one of the aerospace certification readiness courses.

2011-07-27

132

Rocket Launchers  

NSDL National Science Digital Library

In this activity, learners work with an adult to build a rocket and launcher out of a plastic 2-liter bottle, flexible plastic hose, plastic tubing, toilet paper tube, and duct tape. Use this stomp rocket activity to demonstrate that air is something, comprised of molecules that, when acted upon, have the power to move things. This activity guide includes an extension activity and related activity for younger learners.

Museum, Chicago C.

2010-01-01

133

Air-Powered Rockets.  

ERIC Educational Resources Information Center

|This document describes methods for designing and building two types of rockets--rockets from paper and rockets from bottles. Devices used for measuring the heights that the rockets obtain are also discussed. (KHR)|

Rodriguez, Charley; Raynovic, Jim

134

HCL measurements in space vehicle exhaust clouds  

Microsoft Academic Search

The United States Space Program requires the use of large launch vehicles like the space shuttle, Titan 34D, Titan IV, and the proposed heavy-lift vehicle. These large launch systems utilize solid rocket motors to place heavy payloads into orbit. However, most solid rocket motors utilize ammonium perchlorate as an oxidizer and release an exhaust cloud, which is a dynamic mixture

M. D. Smith; T. McRae; R. Kennedy; D. Garvis; T. Kulp; L. S. Berstein; F. Bien; W. Cheng; R. P. Domingue; S. C. Richtmeier

1988-01-01

135

Rocket observations  

NASA Astrophysics Data System (ADS)

The Institute of Space and Astronautical Science (ISAS) sounding rocket experiments were carried out during the periods of August to September, 1982, January to February and August to September, 1983 and January to February, 1984 with sounding rockets. Among 9 rockets, 3 were K-9M, 1 was S-210, 3 were S-310 and 2 were S-520. Two scientific satellites were launched on February 20, 1983 for solar physics and on February 14, 1984 for X-ray astronomy. These satellites were named as TENMA and OHZORA and designated as 1983-011A and 1984-015A, respectively. Their initial orbital elements are also described. A payload recovery was successfully carried out by S-520-6 rocket as a part of MINIX (Microwave Ionosphere Non-linear Interaction Experiment) which is a scientific study of nonlinear plasma phenomena in conjunction with the environmental assessment study for the future SPS project. Near IR observation of the background sky shows a more intense flux than expected possibly coming from some extragalactic origin and this may be related to the evolution of the universe. US-Japan cooperative program of Tether Experiment was done on board US rocket.

1984-05-01

136

Pop Rockets  

NSDL National Science Digital Library

In this activity, learners make film canister rocket ships. A fin pattern is glued onto the outside of the canister, and fuel (water and half an antacid tablet) is mixed inside the canister. When the water and tablet mix, the acid and base in the tablet react to produce carbon dioxide, and the gas accumulates in the closed container until pressure increases enough to push the "rocket" off of the canister cap and into the air. This activity is messy and should probably be done outside (or at least on floors without carpeting).

Society, American C.

2008-01-01

137

Ozone depletion caused by NO and H2O emissions from hydrazine-fueled rockets  

Microsoft Academic Search

Rockets using unsymmetrical dimethyl hydrazine (N(CH3)2NH2) and dinitrogen tetroxide (N2O4) propellants account for about one third of all stratospheric rocket engine emissions, comparable to the solid-fueled rocket emissions. We use plume and global atmosphere models to provide the first estimate of the local and global ozone depletion caused by NO and H2O emissions from the Proton rocket, the largest hydrazine-fueled

M. N. Ross; M. Y. Danilin; D. K. Weisenstein; M. K. W. Ko

2004-01-01

138

A smoke producing rocket motor for atmospheric wind profiling  

SciTech Connect

A composite propellant was developed to produce a dense plume from a rocket motor. The development of this propellant combined the smoke producing capabilities of a smoke generator with a rocket motor, thereby integrating the separate systems into one unit. A rocket motor was designed for use with this propellant to produce a high density particulate plume. This plume could then be used to determine the wind profile in the atmosphere by using a light detection and ranging system. Additionally, this smoke producing propellant could be used for rapid screening or identification. The burn rate characteristics of the propellant were measured and static firings of rocket motors were conducted to determine the performance of the propellant. The results of these tests will be presented as well as theoretical performance predictions of a flight vehicle.

Grubelich, M.C. [Sandia National Labs., Albuquerque, NM (United States); Rowland, J. [Johns Hopkins Univ., Laurel, MD (United States). Applied Physics Lab.

1991-12-31

139

Aerosol number size distributions within the exhaust plume of a diesel and a gasoline passenger car under on-road conditions and determination of emission factors  

Microsoft Academic Search

A new setup has been developed and built to measure number size distributions of exhaust particles and thermodynamic parameters under real traffic conditions. Measurements have been performed using a diesel and a gasoline passenger car driving with different speeds and engine conditions. Significant number of nucleation mode particles was found only during high load conditions, i.e. high car and engine

B. Wehner; U. Uhrner; S. von Löwis; M. Zallinger; A. Wiedensohler

2009-01-01

140

Aerosol number size distributions within the exhaust plume of a diesel and a gasoline passenger car under on-road conditions and determination of emission factors  

NASA Astrophysics Data System (ADS)

A new setup has been developed and built to measure number size distributions of exhaust particles and thermodynamic parameters under real traffic conditions. Measurements have been performed using a diesel and a gasoline passenger car driving with different speeds and engine conditions. Significant number of nucleation mode particles was found only during high load conditions, i.e. high car and engine speeds behind the diesel car. The number concentration of soot mode particles varied within a factor of two for different engine conditions while the concentration of nucleation mode particles varied up to two orders of magnitude. The results show that roadside measurements are still quite different from those behind the tailpipe. Beside dilution transformation processes within the first meter behind the tailpipe also play an important role, such as nucleation and growth. Emission factors were calculated and compared with those obtained by other studies. Emission factors for particles larger than 25 nm (primary emissions) varied within 1.1 × 10 14 km -1 and 2.7 × 10 14 km -1 for the diesel car and between 0.6 × 10 12 km -1 and 3.5 × 10 12 km -1 for the gasoline car. The advantage of these measurements is the exhaust dilution under atmospheric conditions and the size-resolved measurement technique to divide into primary emitted and secondary formed particles.

Wehner, B.; Uhrner, U.; von Löwis, S.; Zallinger, M.; Wiedensohler, A.

141

The Ultraviolet Plume Instrument (UVPI)  

NASA Astrophysics Data System (ADS)

The Ultraviolet Plume Instrument (UVPI) was launched aboard the Low-power Atmospheric Compensation Experiment (LACE) satellite on 14 Feb. 1990. Both the spacecraft and the UVPI were sponsored by the Directed Energy Office of the Strategic Defense Initiative Organization. The mission of the UVPI was to obtain radiometrically calibrated images of rocket plumes at high altitude and background image data of the Earth, Earth's limb, and celestial objects in the near- and middle-UV wave bands. The UVPI was designed for nighttime observations, i.e., to acquire and track relatively bright objects against a dark background.

Horan, D. M.

142

Design and description of the Ultraviolet Plume Instrument (UVPI)  

Microsoft Academic Search

The Ultraviolet Plume Instrument (UVPI) is designed to image and make radiometric measurements of rocket plumes, image and conduct earth background measurements, and gather earth background clutter data in the 200 to 450 nm region. The instrument will be one of several experiments in an earth orbiting satellite to be launched by the Naval Research Laboratory. The optical system uses

Louis H. Reynolds; William D. Ramsey; H. D. Wolpert; Herbert W. Smathers; Donald Horan

1989-01-01

143

Mixing and reaction processes in rocket based combined cycle and conventional rocket engines  

NASA Astrophysics Data System (ADS)

Raman spectroscopy was used to make species measurements in two rocket engines. An airbreathing rocket, the rocket based combined cycle (RBCC) engine, and a conventional rocket were investigated. A supersonic rocket plume mixing with subsonic coflowing air characterizes the ejector mode of the RBCC engine. The mixing length required for the air and plume to become homogenous is a critical dimension. For the conventional rocket experiments, a gaseous oxygen/gaseous hydrogen single-element shear coaxial injector was used. Three chamber Mach number conditions, 0.1, 0.2 and 0.3, were chosen to assess the effect of Mach number on mixing. The flow within the chamber was entirely subsonic. For the RBCC experiments, vertical Raman line measurements were made at multiple axial locations downstream from the rocket nozzle plane. Species profiles assessed the mixing progress between the supersonic plume and subsonic air. For the conventional rocket, Raman line measurements were made downstream from the injector face. The goal was to evaluate the effect of increased chamber Mach number on injector mixing/reaction. For both engines, quantitative and qualitative information was collected for computational fluid dynamics (CFD development. The RBCC experiments were conducted for three distinct geometries. The primary flow path was a diffuse and afterburner design with a direct-connect air supply. A sea-level static (SLS) version and a thermally choked variant were also tested. The experimental results show that mixing length increases with additional coflow air in the DAB geometry. Operation of variable rocket mixture ratios at identical air flow rates did not significantly affect the mixing length. The thermally choked variant had a longer mixing length compared to the DAB geometry, and the SLS modification had a shorter mixing length due to a reduced air flow. The conventional rocket studies focused on the effect of chamber Mach number on primary injector mixing. Chamber Mach number was set at 0.1, 0.2 and 0.3, and Raman species measurements were made at three axial locations within the chamber. The experimental results clearly showed an increase in mixing with increased chamber Mach number. Data are presented in radial mole fraction profiles and mixture fraction pdf plots for a quantitative assessment of the mixing. Radial dimension plots in time-averaged form are provided for comparison with previous experimental work at a very low chamber Mach number.

Lehman, Matthew Kurt

144

12. Building 202 exhaust scrubber facility, looking southwest from catwalk ...  

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

12. Building 202 exhaust scrubber facility, looking southwest from catwalk located northeast of Building 202 pump house. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

145

13. Building 202 exhaust scrubber water detention tank, looking southeast ...  

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

13. Building 202 exhaust scrubber water detention tank, looking southeast from bed of Abram Creek. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

146

9. Building 202 test stand B and exhaust scrubber stack, ...  

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

9. Building 202 test stand B and exhaust scrubber stack, looking southwest from concrete apron north of Building 202 test cell. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

147

11. Building 202 exhaust scrubber stack, looking northwest from location ...  

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

11. Building 202 exhaust scrubber stack, looking northwest from location west of shop wing of Building 202. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

148

10. Building 202 exhaust scrubber and stack, looking southeast from ...  

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

10. Building 202 exhaust scrubber and stack, looking southeast from bank of branch of Abram Creek. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

149

Investigation of gas\\/particle heat transfer rates in solid rocket motors  

Microsoft Academic Search

The ability of the current Nusselt number prediction technique developed by Kavanau (1955) to accurately predict alumina particle heat transfer rates in solid rocket nozzles and plumes is investigated. For the solid rocket motors SRMS) analyzed, the transitional regime is the dominant regime for the majority of particles in the flowfield. The analytical approach to determine accuracy of the Kavanau

B. Moylan; P. Sulyma

1992-01-01

150

Ozone depletion caused by NO and H2O emissions from hydrazine-fueled rockets  

NASA Astrophysics Data System (ADS)

Rockets using unsymmetrical dimethyl hydrazine (N(CH3)2NH2) and dinitrogen tetroxide (N2O4) propellants account for about one third of all stratospheric rocket engine emissions, comparable to the solid-fueled rocket emissions. We use plume and global atmosphere models to provide the first estimate of the local and global ozone depletion caused by NO and H2O emissions from the Proton rocket, the largest hydrazine-fueled launcher in use. NO and H2O emission indices are assumed to be 20 and 350 g/kg (propellant), respectively. Predicted maximum ozone loss in the plume of the Proton rocket is 21% at 44 km altitude. Plume ozone loss at 20 km equals 8% just after launch and steadily declines to 2% by model sunset. Predicted steady state global ozone loss from ten Proton launches annually is 1.2 × 10-4%, with nearly all of the loss due to the NO component of the emission. Normalized by stratospheric propellant consumption, the global ozone depletion efficiency of the Proton is approximately 66-90 times less than that of solid-fueled rockets. In situ Proton plume measurements are required to validate assumed emission indices and to assess the role of rocket emissions not considered in these calculations. Such future studies would help to establish a formalism to evaluate the relative ozone depletion caused by different rocket engines using different propellants.

Ross, M. N.; Danilin, M. Y.; Weisenstein, D. K.; Ko, M. K. W.

2004-11-01

151

Compression technique for plume hyperspectral images  

Microsoft Academic Search

The authors recently developed a hyperspectral image output option for a standardized government code designed to predict missile exhaust plume infrared signatures. Typical predictions cover the 2- to 5-m wavelength range (2000 to 5000 cm-1) at 5 cm-1 spectral resolution, and as a result the hyperspectral images have several hundred frequency channels. Several hundred hyperspectral plume images are needed to

B. K. Feather; S. A. Fulkerson; J. H. Jones; R. A. Reed; M. A. Simmons; D. G. Swann; W. E. Taylor; L. S. Bernstein

2005-01-01

152

Liquid Booster Module (LBM) Plume Flowfield Model.  

National Technical Information Service (NTIS)

A complete definition of the LBM plume is important for many Shuttle design criteria. The exhaust plume shape has a significant effect on the vehicle base pressure. The LBM definition is also important to the Shuttle base heating, aerodynamics and the inf...

S. D. Smith

1981-01-01

153

Nuclear fuels in space rockets  

Microsoft Academic Search

There are three different types of rocket engines; solid propelled rockets, liquid propelled rockets and nuclear rockets. Nuclear rockets work by routing an appropriate gas through a nuclear rector. The reactor is at high temperature. Gas expands as it leaves the nozzle, producing a high amount of thrust. Nuclear rockets don't need an oxidizer and they require much less fuel

Ahmet Yayli; A. A. Aksit

2003-01-01

154

Soviet Tunneling Rockets.  

National Technical Information Service (NTIS)

An operational tunneling rocket is described which has been developed by a Soviet army officer. The information is mainly from one article in a semipopular journal, and hence is largely descriptive without giving precise performance data on the rocket. Pr...

S. G. Hibben

1973-01-01

155

Rockets for Spin Recovery.  

National Technical Information Service (NTIS)

The potential effectiveness of rockets as an auxiliary means for an aircraft to effect recovery from spins was investigated. The advances in rocket technology produced by the space effort suggested that currently available systems might obviate many of th...

R. D. Whipple

1980-01-01

156

Building Bottle Rockets  

NSDL National Science Digital Library

You will be investigating the physics behind the launching of a bottle rocket that you will design and build. Go to Air resistance definition and answer the following questions: 1. What is air resistance? 2. How will you design your rocket to reduce the effect of the air resistance? Go to Aerodynamic Forces and list the 4 forces that act on a rocket in motion. Which ones propel the rocket upward and which ...

Benenati, Mr.

2008-03-23

157

Subscale solid rocket motor infrared signature and particle behavior  

Microsoft Academic Search

A combined optical and particle collection probe which used an in situ particle size distribution measurement method and an infrared camera were used to obtain data that could be used to validate solid propellant rocket motor plume signature prediction codes. The probe design was optimized and the required rates for window purge and ejector flows were determined which provided proper

John A. Racine

1991-01-01

158

Effects of rocket engines on laser during lunar landing  

NASA Astrophysics Data System (ADS)

In the Chinese moon exploration project "ChangE-3", the laser telemeter and lidar are important equipments on the lunar landing vehicle. A low-thrust vernier rocket engine works during the soft landing, whose plume may influence on the laser equipments. An experiment has first been accomplished to evaluate the influence of the plume on the propagation characteristics of infrared laser under the vacuum condition. Combination with our theoretical analysis has given an appropriate assessment of the plume's effects on the infrared laser hence providing a valuable basis for the design of lunar landing systems.

Wan, Xiong; Shu, Rong; Huang, Genghua

2013-11-01

159

Exhaust recirculation  

Microsoft Academic Search

An exhaust gas recirculation system for the reduction of nitrogen oxides in automobile exhaust is described that provides for the reduction of recirculation during engine idling without the prior-art complexities of moving parts. The system also achieves preheating and improved mixing and carburetion of the fuel-air mixture in the inlet header. Exhaust gases are recycled by means of a swirl

Sarto

1974-01-01

160

Engine Cycle Analysis of Air Breathing Microwave Rocket with Reed Valves  

Microsoft Academic Search

The Microwave Rocket is a candidate for a low cost launcher system. Pulsed plasma generated by a high power millimeter wave beam drives a blast wave, and a vehicle acquires impulsive thrust by exhausting the blast wave. The thrust generation process of the Microwave Rocket is similar to a pulse detonation engine. In order to enhance the performance of its

Masafumi Fukunari; Reiji Komatsu; Toshikazu Yamaguchi; Kimiya Komurasaki; Yoshihiro Arakawa; Hiroshi Katsurayama

2011-01-01

161

Method for Simulating 3-D Aircraft Flow Fields with Jet Plume Effects.  

National Technical Information Service (NTIS)

The objective is to develop, demonstrate, and document a coupled flow analysis procedure for computing 3D aircraft flow fields with deflected subsonic and supersonic jet exhaust plumes. The PNS plume code was transferred to the Ames computer facility for ...

1984-01-01

162

Lazy plumes  

NASA Astrophysics Data System (ADS)

We examine the dynamics of turbulent lazy plumes rising from horizontal area sources and from vertically distributed line sources into a quiescent environment of uniform density. First, we consider plumes with internal buoyancy flux gain and, secondly, plumes from horizontal area sources that have significant momentum flux deficits. We re-cast the conservation equations of Morton et al. (1956) for a constant entrainment coefficient (?) in terms of three dimensionless parameters: the plume radius ?; a parameter ? characterizing the local balance of momentum, buoyancy and volume fluxes; and a parameter ? that characterizes the rate of internal buoyancy flux gain with height. For a plume with a linear internal buoyancy flux gain with height the flow is shown to be a constant-velocity lazy plume. For highly lazy area sources we derive exact solutions for the key plume parameters in terms of ? and an approximate solution for the variation of ? with height. We show that near the source there is a region of zero entrainment.

Hunt, G. R.; Kaye, N. B.

2005-06-01

163

Small Rocket Research and Technology.  

National Technical Information Service (NTIS)

Small chemical rockets are used on nearly all space missions. The small rocket program provides propulsion technology for civil and government space systems. Small rocket concepts are developed for systems which encompass reaction control for launch and o...

S. Schneider J. Biaglow

1993-01-01

164

Liquid rocket propulsion. Theory  

NASA Astrophysics Data System (ADS)

The purpose is to introduce the fundamentals and the basic technology of liquid propellant rockets. Much of the material is derived from other courses on propulsion. The first lecture covers the foundations at the broad brush level. Starting from the functional requirements placed on the device, various types of rocket are examined. The missions for which liquid propellant rockets are the better choice are identified. An ideal gas examination of the essential performance parameters and their variation with basic controllable inputs is presented. The thermodynamics and the fluid mechanics of the reacting flows occurring in rocket combustors and nozzles are considered. The effects of propellant choices and the +/- 5 performance estimates are included.

Martinez-Sanchez, M.

165

Rocket astronomy - an overview  

NASA Astrophysics Data System (ADS)

The history of rocket astronomy is retold, with emphasis on solar investigations. The use of captured V-2 rockets after World War II was followed by the Aerobee, which exceeded the V-2's altitude and was more reliable. The V-2 has made first-generation investigations in X-ray and UV photometry, which was followed by studies of the solar cycle X-ray variablity, the X-ray corona, and solar flares. Nike rockets played an important role in these investigations. The role of rockets in galactic X-ray astronomy is briefly described.

Friedman, H.

166

Rockets -- Part II.  

ERIC Educational Resources Information Center

|If two rockets are identical except that one engine burns in one-tenth the time of the other (total impulse and initial fuel mass of the two engines being the same), which rocket will rise higher? Why? The answer to this question (part 1 response in v20 n6, p410, Sep 1982) is provided. (Author/JN)|

Leitner, Alfred

1982-01-01

167

Tea Bag Rocket  

NSDL National Science Digital Library

In this activity, create a mini rocket out of a tea bag. Use this activity to explore convection and heat. Compare different brands of tea bags to see which bags work best as rockets. This activity guide includes a step-by-step instructional video. Safety note: this activity requires an open flame; adult supervision required.

Center, Saint L.

2013-01-30

168

Model Rockets and Microchips.  

ERIC Educational Resources Information Center

|Points out the instructional applications and program possibilities of a unit on model rocketry. Describes the ways that microcomputers can assist in model rocket design and in problem calculations. Provides a descriptive listing of model rocket software for the Apple II microcomputer. (ML)|

Fitzsimmons, Charles P.

1986-01-01

169

Missile EMP Interaction: Dielectric and Plume-Connection Effects  

Microsoft Academic Search

Electromagnetic pulse (EMP) interaction with missiles composed largely of dielectric materials is considered. Effects of a dielectric missile body and the missile exhaust plume electrical connection on missile EMP response are evaluated.

James F. Prewitt

1978-01-01

170

Ground and Space-Based Measurement of Rocket Engine Burns in the Ionosphere  

Microsoft Academic Search

On-orbit firings of both liquid and solid rocket motors provide localized disturbances to the plasma in the upper atmosphere. Large amounts of energy are deposited to ionosphere in the form of expanding exhaust vapors which change the composition and flow velocity. Charge exchange between the neutral exhaust molecules and the background ions (mainly $\\\\hbox{O}^{+}$) yields energetic ion beams. The rapidly

P. A. Bernhardt; J. O. Ballenthin; J. L. Baumgardner; A. Bhatt; I. D. Boyd; J. M. Burt; R. G. Caton; A. Coster; P. J. Erickson; J. D. Huba; G. D. Earle; C. R. Kaplan; J. C. Foster; K. M. Groves; R. A. Haaser; R. A. Heelis; D. E. Hunton; D. L. Hysell; J. H. Klenzing; M. F. Larsen; F. D. Lind; T. R. Pedersen; R. F. Pfaff; R. A. Stoneback; P. A. Roddy; S. P. Rodriquez; G. S. San Antonio; P. W. Schuck; C. L. Siefring; C. A. Selcher; S. M. Smith; E. R. Talaat; J. F. Thomason; R. T. Tsunoda; R. H. Varney

2012-01-01

171

Andoya Rocket Range  

NSDL National Science Digital Library

The National Aeronautic and Space Administration (NASA) has sponsored the Cleft Accelerated Plasma Experimental Rocket, CAPER, campaign. The objective of this mission is to "probe a fountain of ions that is always blowing into space." Scientists have launched this project just after a solar storm tore apart a part of the Earth's upper atmosphere. The CAPER Rocket launch will take place at the Andoya Rocket Range in January, 1999. This Website offers more information about the CAPER project as well as the launch site.

172

ASTRID rocket flight test  

SciTech Connect

On February 4, 1994, we successfully flight tested the ASTRID rocket from Vandenberg Air Force Base. The technology for this rocket originated in the Brilliant Pebbles program and represents a five-year development effort. This rocket demonstrated how our new pumped-propulsion technology-which reduced the total effective engine mass by more than one half and cut the tank mass to one fifth previous requirements-would perform in atmospheric flight. This demonstration paves the way for potential cost-effective uses of the new propulsion system in commercial aerospace vehicles, exploration of the planets, and defense applications.

Whitehead, J.C.; Pittenger, L.C.; Colella, N.J.

1994-07-01

173

Computer model predictions of the local effects of large, solid-fuel rocket motors on stratospheric ozone. Technical report  

Microsoft Academic Search

The solid-fuel rocket motors of large space launch vehicles release gases and particles that may significantly affect stratospheric ozone densities along the vehicle's path. In this study, standard rocket nozzle and flowfield computer codes have been used to characterize the exhaust gases and particles through the afterburning region of the solid-fuel motors of the Titan IV launch vehicle. The models

Zittel

1994-01-01

174

Space Shuttle Plume Simulation Application. Results and Math Model.  

National Technical Information Service (NTIS)

Pressure and gauge wind tunnel data from a transonic test of a 0.02 scale model of the space shuttle launch vehicle was analyzed to define the aerodynamic influence of the main propulsion system and solid rocket booster plumes during the transonic portion...

W. Boyle B. Conine

1978-01-01

175

Rocketing into Adaptive Inquiry.  

ERIC Educational Resources Information Center

|Defines adaptive inquiry and argues for employing this method which allows lessons to be shaped in response to student needs. Illustrates this idea by detailing an activity in which teams of students build rockets. (DDR)|

Farenga, Stephen J.; Joyce, Beverly A.; Dowling, Thomas W.

2002-01-01

176

Rocket engine numerical simulator  

NASA Astrophysics Data System (ADS)

The topics are presented in viewgraph form and include the following: a rocket engine numerical simulator (RENS) definition; objectives; justification; approach; potential applications; potential users; RENS work flowchart; RENS prototype; and conclusion.

Davidian, Ken

177

Rocket engine numerical simulation  

NASA Astrophysics Data System (ADS)

The topics are presented in view graph form and include the following: a definition of the rocket engine numerical simulator (RENS); objectives; justification; approach; potential applications; potential users; RENS work flowchart; RENS prototype; and conclusions.

Davidian, Ken

1993-12-01

178

Rocket astronomy - an overview  

Microsoft Academic Search

The history of rocket astronomy is retold, with emphasis on solar investigations. The use of captured V-2 rockets after World War II was followed by the Aerobee, which exceeded the V-2's altitude and was more reliable. The V-2 has made first-generation investigations in X-ray and UV photometry, which was followed by studies of the solar cycle X-ray variablity, the X-ray

H. Friedman

1981-01-01

179

Action-Reaction Rocket!  

NSDL National Science Digital Library

Learners construct a rocket from a balloon propelled along a guide string. They use this model to learn about Newton's three laws of motion, examining the effect of different forces on the motion of the rocket. This activity can be combined with other activities to create a larger lesson. Resource contains vocabulary definitions and suggestions for assessment, extensions, and scaling for different levels of learners.

Duren, Sabre; Heavner, Ben; Zarske, Malinda S.; Carlson, Denise

2004-01-01

180

Characterization of rocket propellant combustion products  

SciTech Connect

The overall objective of the work described in this report is four-fold: to (a) develop a standardized and experimentally validated approach to the sampling and chemical and physical characterization of the exhaust products of scaled-down rocket launch motors fired under experimentally controlled conditions at the Army's Signature Characterization Facility (ASCF) at Redstone Arsenal in Huntsville, Alabama; (b) determine the composition of the exhaust produces; (c) assess the accuracy of a selected existing computer model for predicting the composition of major and minor chemical species; (d) recommended alternations to both the sampling and analysis strategy and the computer model in order to achieve greater congruence between chemical measurements and computer prediction. 34 refs., 2 figs., 35 tabs.

Jenkins, R.A.; Nestor, C.W.; Thompson, C.V.; Gayle, T.M.; Ma, C.Y.; Tomkins, B.A.; Moody, R.L.

1991-12-09

181

PHYSICAL AND NUMERICAL MODELING OF ASD EXHAUST DISPERSION AROUND HOUSES  

EPA Science Inventory

The report discusses the use of a wind tunnel to physically model the dispersion of exhaust plumes from active soil depressurization (ASD) radon mitigation systems in houses. he testing studied the effects of exhaust location (grade level vs. above the eave), as house height, roo...

182

Magnetic Detachment and Plume Control in Escaping Magnetized Plasma  

SciTech Connect

The model of two-fluid, axisymmetric, ambipolar magnetized plasma detachment from thruster guide fields is extended to include plasmas with non-zero injection angular velocity profiles. Certain plasma injection angular velocity profiles are shown to narrow the plasma plume, thereby increasing exhaust efficiency. As an example, we consider a magnetic guide field arising from a simple current ring and demonstrate plasma injection schemes that more than double the fraction of useful exhaust aperture area, more than halve the exhaust plume angle, and enhance magnetized plasma detachment.

P. F. Schmit and N. J. Fisch

2008-11-05

183

Mechanical analysis on rocket propellants  

Microsoft Academic Search

The mechanical properties of solid rocket propellants are very important for good functioning of rocket motors. During use\\u000a and storage the mechanical properties of rocket propellants are changing, due to chemical and mechanical influences such as\\u000a thermal reactions, oxidation reactions or vibrations. These influences can result in malfunctioning, leading to an unwanted\\u000a explosion of the rocket motor. Most of modern

G. Herder; F. P. Weterings; W. P. C. de Klerk

2003-01-01

184

Baking Soda and Vinegar Rockets  

ERIC Educational Resources Information Center

|Rocket experiments demonstrating conservation of momentum will never fail to generate enthusiasm in undergraduate physics laboratories. In this paper, we describe tests on rockets from two vendors that combine baking soda and vinegar for propulsion. The experiment compared two analytical approximations for the maximum rocket height to the…

Claycomb, James R.; Zachary, Christopher; Tran, Quoc

2009-01-01

185

THE ENVIRONMENT CREATED BY AN OPEN-AIR SOLID ROCKET PROPELLANT FIRE  

Microsoft Academic Search

A 91 kg (200 lbm) block of aluminized solid rocket propellant was burned in open air to simulate an accidental propellant fire. A suite of remote optical instruments measured the temperature and radiative properties of the plume. Solid molybdenum calorimeters provided data for heat flux estimates. Various refractory oxide and metallic witness samples placed in the fire provided temperature benchmarks and insight

L. W. HUNTER; Y. CHANG; H. N. OGUZ; J. T. WILKERSON; A. M. LENNON; R. P. CAIN; B. G. CARKHUFF; M. E. THOMAS; S. C. WALTS; C. A. MITCHELL; D. W. BLODGETT; D. H. TERRY

2007-01-01

186

ROCKET REFRACTORIES, A BIBLIOGRAPHY  

Microsoft Academic Search

This bibliography on rocket refractories contains 615 items. Literature ; on the application of these materials as protective coatings, combustion-chamber ; liners, and nozzles is emphasized. Some references on the composition of ; refractories and on their capabilities and modes of fabrication are included. ; (auth)

1957-01-01

187

Solid rocket motors  

NASA Astrophysics Data System (ADS)

Structural requirements, materials and, especially, processing are critical issues that will pace the introduction of new types of solid rocket motors. Designers must recognize and understand the drivers associated with each of the following considerations: (1) cost; (2) energy density; (3) long term storage with use on demand; (4) reliability; (5) safety of processing and handling; (6) operability; and (7) environmental acceptance.

Carpenter, Ronn L.

1993-02-01

188

Gaseous Nuclear Rocket.  

National Technical Information Service (NTIS)

The nuclear rocket for extraterrestrial flight is in the form of a gaseous nuclear reactor. One or more streams of a working fluid are introduced concentrically adjacent to a gaseous fissile material in a heating chamber or cell. Introduction of a working...

F. E. Rom

1965-01-01

189

This Is Rocket Science!  

NASA Astrophysics Data System (ADS)

Using model rockets to teach physics can be an effective way to engage students in learning. In this paper, we present a curriculum developed in response to an expressed need for helping high school students review physics equations in preparation for a state-mandated exam. This required a mode of teaching that was more advanced and analytical than that offered by Estes Industries,1 but more basic than the analysis of Nelson et al.2,3 In particular, drag is neglected until the very end of the exercise, which allows the concept of conservation of energy to be shown when predicting the rocket's flight. Also, the variable mass of the rocket motor is assumed to decrease linearly during the flight (while the propulsion charge and recovery delay charge are burning) and handled simplistically by using an average mass value. These changes greatly simplify the equations needed to predict the times and heights at various stages of flight, making it more useful as a review of basic physics. Details about model rocket motors, range safety, and other supplemental information may be found online at Apogee Components4 and the National Association of Rocketry.5

Keith, Wayne; Martin, Cynthia; Veltkamp, Pamela

2013-09-01

190

Water Rocket Launch  

NSDL National Science Digital Library

In this activity, learners explore rocketry and the principals of space flight. Learners work in teams with adult supervision and construct and launch a rocket from a soda bottle and everyday materials powered by an air pump. Learners observe their own achievements and challenges, as well as those of other teams, complete a reflection sheet, and present their experiences to the class.

Ieee

2013-07-08

191

The Relativistic Rocket  

ERIC Educational Resources Information Center

|We solve the problem of the relativistic rocket by making use of the relation between Lorentzian and Galilean velocities, as well as the laws of superposition of successive collinear Lorentz boosts in the limit of infinitesimal boosts. The solution is conceptually simple, and technically straightforward, and provides an example of a powerful…

Antippa, Adel F.

2009-01-01

192

Introduction to rocket propulsion  

Microsoft Academic Search

The design process for solid propellant rocket motors is presented in an introductory text suitable for professional reference as well as for instruction at the high school senior through college junior level. Beginning with a brief history of rocketry and a short discussion of the basic properties of matter, the text progresses through the development of the governing laws of

J. M. Lyon

1991-01-01

193

Two-Dimensional Motions of Rockets  

ERIC Educational Resources Information Center

|We analyse the two-dimensional motions of the rockets for various types of rocket thrusts, the air friction and the gravitation by using a suitable representation of the rocket equation and the numerical calculation. The slope shapes of the rocket trajectories are discussed for the three types of rocket engines. Unlike the projectile motions, the…

Kang, Yoonhwan; Bae, Saebyok

2007-01-01

194

ASSESSMENT OF PLUME DIVING  

EPA Science Inventory

This presentation presents an assessment of plume diving. Observations included: vertical plume delineation at East Patchogue, NY showed BTEX and MTBE plumes sinking on either side of a gravel pit; Lake Druid TCE plume sank beneath unlined drainage ditch; and aquifer recharge/dis...

195

Numerical assessment of plume heat and mechanical loads and contamination on multi-layer insulation in hard vacuum  

Microsoft Academic Search

The paper presents a numerical analysis of plume exhausted from the 10N bipropellant thruster. The computations have been performed for steady state and pulse mode firing of the thruster. The plume impinges a multi-layer insulation (MLI) that covers a satellite surface, where plume effects have been computed for ideal and bulged shapes of the MLI. The ideal shape is a

Gennady Markelov; Rolf Brand; Georg Ibler; Wolfgang Supper

196

Application of Genetic Algorithms to In Situ Particle Sizing.  

National Technical Information Service (NTIS)

Particulates in the solid rocket exhaust plume cause rocket base heating, motor performance losses, and determine the plume spectral properties. The particle properties that contribute to these effects are the particle size distribution function (PSDF), e...

M. R. McKee

1997-01-01

197

Hybrid rocket performance  

NASA Astrophysics Data System (ADS)

A hybrid rocket is a system consisting of a solid fuel grain and a gaseous or liquid oxidizer. Figure 1 shows three popular hybrid propulsion cycles that are under current consideration. NASA MSFC has teamed with industry to test two hybrid propulsion systems that will allow scaling to motors of potential interest for Titan and Atlas systems, as well as encompassing the range of interest for SEI lunar ascent stages and National Launch System Cargo Transfer Vehicle (NLS CTV) and NLS deorbit systems. Hybrid systems also offer advantages as moderate-cost, environmentally acceptable propulsion system. The objective of this work was to recommend a performance prediction methodology for hybrid rocket motors. The scope included completion of: a literature review, a general methodology, and a simplified performance model.

Frederick, Robert A., Jr.

1992-12-01

198

ISRO's solid rocket motors  

NASA Astrophysics Data System (ADS)

Solid rocket motors have been the mainstay of ISRO's sounding rockets and the first generation satellite launch vehicles. For the new launch vehicle under development also, the solid rocket motors contribute significantly to the vehicle's total propulsive power. The rocket motors in use and under development have been developed for a variety of applications and range in size from 30 mm dia employing 450 g of solid propellant—employed for providing a spin to the apogee motors—to the giant 2.8 m dia motor employing nearly 130 tonnes of solid propellant. The initial development, undertaken in 1967 was of small calibre motor of 75 mm dia using a double base charge. The development was essentially to understand the technological elements. Extruded aluminium tubes were used as a rocket motor casing. The fore and aft closures were machined from aluminium rods. The grain was a seven-pointed star with an enlargement of the port at the aft end and was charged into the chamber using a polyester resin system. The nozzle was a metallic heat sink type with graphite throat insert. The motor was ignited with a black powder charge and fired for 2.0 s. Subsequent to this, further developmental activities were undertaken using PVC plastisol based propellants. A class of sounding rockets ranging from 125 to 560 mm calibre were realized. These rocket motors employed improved designs and had delivered lsp ranging from 2060 to 2256 Ns/kg. Case bonding could not be adopted due to the higher cure temperatures of the plastisol propellants but improvements were made in the grain charging techniques and in the design of the igniters and the nozzle. Ablative nozzles based on asbestos phenolic and silica phenolic with graphite inserts were used. For the larger calibre rocket motors, the lsp could be improved by metallic additives. In the early 1970s designs were evolved for larger and more efficient motors. A series of 4 motors for the country's first satellite launch vehicle SLV-3 were developed. The first and second stages of 1 and 0.8 m dia respectively used low carbon steel casing and PBAN propellant. The first stage used segmented construction with a total propellant weight of 8600 kg. The second stage employed about 3 tonnes of the same propellant. The third and fourth stages were of GFRP construction and employed respectively 1100 and 275 kg of CTPB type propellants. Nozzle expansion ratios upto 30 were employed and delivered vacuum lsp of 2766 Ns/kg realized. The fourth stage motor was subsequently used as the apogee motor for orbit injection of India's first geosynchronous satellite—APPLE. All these motors have been flight proven a number of times. Further design improvements have been incorporated and these motors continue to be in use. Starting in 1984 design for a large booster was undertaken. This booster employs a nominal propellant weight of 125 tonne in a 2.8 m dia casing. The motor is expected to be qualified for flight test in 1989. Side by side a high performance motor housing nearly 7 tonnes of propellant in composite casing of 2 m dia and having flex nozzle control system is also under development for upper stage application. Details of the development of the motors, their leading specifications and performance are described.

Nagappa, R.; Kurup, M. R.; Muthunayagam, A. E.

199

Micro-Rockets for the Classroom.  

ERIC Educational Resources Information Center

|Compares micro-rockets to commercial models and water rockets. Finds that micro-rockets are more advantageous because they are constructed with inexpensive and readily available materials and can be safely launched indoors. (CCM)|

Huebner, Jay S.; Fletcher, Alice S.; Cato, Julia A.; Barrett, Jennifer A.

1999-01-01

200

If Only Newton Had a Rocket.  

ERIC Educational Resources Information Center

|Shows how model rocketry can be included in physics curricula. Describes rocket construction, a rocket guide sheet, calculations and launch teams. Discusses the relationships of basic mechanics with rockets. (CW)|

Hammock, Frank M.

1988-01-01

201

Aeroacoustic Instability in Rockets  

Microsoft Academic Search

Current solid-propellant rocket instability calculations (e.g., Standard Stability Prediction Program ) account only for the evolution of acoustic energy with time. However, the acoustic component represents only part of the total unsteady system energy; additional kinetic energy resides in the shear waves that naturally accompany the acousticoscillations. Becausemost solid-rocketmotor combustion chamberconé gurationssupport gas oscillations parallel to the propellant grain, an

Gary A. Flandro; Joseph Majdalani

2003-01-01

202

The Relativistic Rocket  

Microsoft Academic Search

The equation of motion for a relativistic rocket or for any particle with a variable rest mass may be derived by applying the relativistic impulse-momentum and work-energy principles in the instantaneous rest frame. The equation of motion in this frame is in the classical non-relativistic form. The equation of motion in the observer's rest frame may then be deduced by

Kalman B. Pomeranz

1966-01-01

203

Booster rocket range safety system  

NASA Astrophysics Data System (ADS)

In response to an abort command, fragmentation of a propellant booster rocket carried on a missile is limited by positioning of annular shaped charges at axially spaced locations on the outer shell of the booster rocket. Detonation of the charges thereby severs an intermediate section of the rocket from forward and aft sections which remain attached to the missile. The intermediate section is separated from the missile by such severing action to prevent further fragmenting forces from being imparted thereto.

Renzi, John R.

1992-06-01

204

Laboratory Studies of the Stratospheric Effects of Rocket Exhaust.  

National Technical Information Service (NTIS)

The most important chlorine activation reaction that takes place in the stratosphere is the heterogeneous reaction of chlorine nitrate with hydrogen chloride to produce molecular chlorine and nitric acid. The reaction is catalytic, promoted by surfaces th...

M. J. Molina M. Haider Y. Mantz L. Gutzwiller L. T. Molina

1998-01-01

205

German scientific sounding rocket program  

NASA Astrophysics Data System (ADS)

The German scientific sounding rocket program covers four disciplines: astronomy, aeronomy, magnetosphere, material science. In each of these disciplines there are ongoing projects (e.g., INTERZODIAK, STRAFAM, MAP-WINE, CAESAR, TEXUS). The scientific and technical aspects of these projects will be described. Emphasis will be given to some late technical achievements of DFVLR's Mobile Rocket Base (MORABA) giving support to most of the rocket campaigns. DFVLR-PT is authorized to act as management agency in order to perform and to coordinate German space activities of which the sounding rocket program forms a small part. A brief description of the organization will be given.

Roehrig, O.

206

Use of a large microphone array to identify noise sources during a rocket engine test firing and a rocket launch.  

PubMed

A 70 microphone, 10 ft×10 ft, microphone phased array was built for use in the harsh environment of rocket launches. The array was setup at NASA Wallops launch pad 0A during a static test firing of Orbital Sciences' Antares engines, and again during the first launch of Antares vehicle. It was placed 400 ft away from the pad, and was hoisted on a scissor lift 40 ft above ground. The data sets provided unprecedented insights into rocket noise sources. The duct exit was found to be the primary source during the static test firing; the large amount of water injected beneath the nozzle exit quenched all other sources. The noise maps during launch were found to be time-dependent. As the engines came to full power and became louder, the primary source switched from the duct inlet to the duct exit. Further elevation of the vehicle caused spilling of the hot plume, resulting in a distributed noise map covering most of the pad. As the entire plume emerged from the duct, and the on-deck water system came to full power, the plume itself became the loudest noise source. These noise maps will help to improve the sound suppression system for future launches. PMID:24181207

Panda, Jayanta; Mosher, Robert N; Porter, Barry J

2013-11-01

207

The numerical analysis of the thrust termination process in solid rocket motors  

Microsoft Academic Search

It is pointed out that a series of pressure pulses with considerable strength will follow after opening the reversal nozzle (or auxiliary exhaust hole) in the thrust termination process of large or middle-scale solid rocket motors. Since no theoretical analysis is able to explain or predict these phenomena, this paper cites a series of cool simulation testing results, discusses the

Weimin Xie; Jinxian Zhou; Zuo Gao

1991-01-01

208

Soda-Bottle Water Rockets.  

ERIC Educational Resources Information Center

|Provides instructions for the construction and launch of a two-liter plastic soda-bottle rocket and presents the author's theory of their motion during launch. Modeled predictions are compared with actual experimental data. Explains theory behind the motion of a water rocket during launch. (LZ)|

Kagan, David; And Others

1995-01-01

209

Miniature solid propellant rocket motor.  

National Technical Information Service (NTIS)

A miniature solid-propellant rocket motor has been developed to impart a specific motion to an object deployed in space. This rocket motor effectively eliminated the need for a cold-gas thruster system or mechanical spin-up system. A low-energy igniter, a...

M. C. Grubelich M. Hagan E. Mulligan

1997-01-01

210

Viscoelastic rocket grain fracture analysis  

Microsoft Academic Search

A viscoelastic fracture analysis has been developed for rocket grain fracture predictions. The fracture analysis uses a stress intensity factor technique to predict crack velocity histories under thermal and pressurization loading conditions. The theory is compared with two-dimensional pressurized tests of two typical rocket motor geometries using the viscoelastic material, Solithane 113.

E. C. Francis; C. H. Carlton; R. E. Thompson

1974-01-01

211

Transient characteristics of rocket turbopumps  

Microsoft Academic Search

Transient characteristics of high-speed, high-pressure cryogenic turbopumps for rocket engines were examined experimentally by starting and stopping several rocket turbopumps rapidly by gas turbine drive. Aspects of transient characteristics studied were instantaneous pump head coefficient and pump efficiency, cavitation growth in the inducer during rapid acceleration, effects of the starting mode related to the propulsion system mission, and transient behavior

Takashi Shimura; Mitsuo Watanabe

1990-01-01

212

Genesis of Modern Rocket Dynamics.  

National Technical Information Service (NTIS)

Given in this book is a detailed analysis of the development of rocket dynamics from middle of the nineteenth century to 1960, inclusively. The formulation of rocket dynamics from the development of the dynamics of a particle of variable mass, aerodynamic...

A. P. Mandryka

1972-01-01

213

Cooling Tower Plume Model.  

National Technical Information Service (NTIS)

A review of recently reported cooling tower plume models yields none that is universally accepted. The entrainment and drag mechanisms and the effect of moisture on the plume trajectory are phenomena which are treated differently by various investigators....

L. D. Winiarski W. E. Frick

1976-01-01

214

Reusable sounding-rocket design  

NASA Astrophysics Data System (ADS)

As a result of the reduction of budgets for flights, the ideas of reusability and cost-effectiveness in launch vehicles are becoming more and more important. One class of rockets, in particular the sounding rockets operating in a less demanding environment, has many potentials for many more flights. By augmenting the basic rocket configuration with wings, landing gear, flight controls and guidance systems, the vehicle can be made to glide and land back at the launch site or at a specific recovery site. In this paper, the design of such a reusable rocket is presented. This design can be extended and adapted to larger vehicles, thus attaining higher altitudes required in some of the applications of sounding rockets.

Woo, Dick L. Y.; Martin, James A.

1995-03-01

215

Development of Indonesian sounding rockets  

NASA Astrophysics Data System (ADS)

The Indonesian research and development program for solid-fuel sounding rockets is reviewed, with a focus on the meteorological rocket program since 1979. Polysulfide fuels were developed, and a seven-pointed-star grain configuration was found to be optimal. Numerous single-stage rocket motors were static and flight tested, and the results are summarized. The current single-stage sounding rocket is 3036 mm long and 150 mm in diameter and weighs 79.5 kg. The two-stage prototype comprises a 1906-mm-long first stage and a 2402-mm-long second stage and weighs 129.5 kg. Both rockets have been successfully test flown carrying sun sensors, telemetry packages, and temperature, pressure, and acceleration instruments.

Djojodihardjo, H.; Subandhi, K.; Silitonga, S.

1983-10-01

216

Rocket Sled Testing  

NASA Video Gallery

Video of rocket-sled testing of the SIAD-R device, conducted in fall 2012 at China Lake, Calif. The SIAD-R is one of three supersonic deceleration devices now being prepared for flight testing by the Low-Density Supersonic Decelerator project at NASA's Jet Propulsion Laboratory in Pasadena, Calif. The devices, which slow the rate of descent for vehicles entering the atmosphere of another planet, could be used in Mars missions launching as early as 2018. For more information, visit http://www.nasa.gov/mission_pages/tdm/ldsd/ldsd_overview.html. (NASA/JPL)

Sydney B

2012-11-23

217

Design of Force Sensor Leg for a Rocket Thrust Detector  

Microsoft Academic Search

A hybrid rocket is composed of a solid fuel and a separate liquid or gaseous oxidizer. These rockets may be throttled like liquid rockets, are safer than solid rockets, and are much less complex than liquid rockets. However, hybrid rockets produce thrust oscillations that are not practical for large scale use. A lab scale hybrid rocket at the University of

Douglas Woten; Tripp McGehee; Anne Wright

2005-01-01

218

High Density Liquid Rocket Boosters for the Space Shuttle  

NASA Astrophysics Data System (ADS)

The use of high density hydrogen peroxide/kerosene liquid rocket boosters (LRB) for the Space Shuttle is investigated as a replacement for the existing solid rocket boosters (SRB). It is shown that hydrogen peroxide/kerosene outperforms both solids, LOX/Kero, and LOX/LH2 as a general booster propellant due to its high density and moderate exhaust speed. With the same propellant mass and size as that of the current SRB's, computer simulations indicate that payload mass can be increased by a third from 24,950 kg to 33,140 kg for a 28.45°, 203.7 km circular orbit. Recovery of the boosters is performed at sea.

Pietrobon, S. S.

219

Sandia Laboratories rocket program - A review  

Microsoft Academic Search

A historical review of Sandia Laboratories rocket programs is presented. From the 60 rocket systems developed at Sandia since 1957, 1225 rockets have been launched at 19 sites, worldwide. Typical rockets developed for the nuclear readiness test program are the Terrier-Sandhawk sounding rocket (boosts a 91-kg, 33-cm-diam payload to an altitude of 427 km) and the Strypi II warhead carrier

G. A. Fowler; R. C. Maydew; W. R. Barton

1976-01-01

220

Computational study of variable area ejector rocket flowfields  

NASA Astrophysics Data System (ADS)

Access to space has always been a scientific priority for countries which can afford the prohibitive costs associated with launch. However, the large scale exploitation of space by the business community will require the cost of placing payloads into orbit be dramatically reduced for space to become a truly profitable commodity. To this end, this work focuses on a next generation propulsive technology called the Rocket Based Combined Cycle (RBCC) engine in which rocket, ejector, ramjet, and scramjet cycles operate within the same engine environment. Using an in house numerical code solving the axisymmetric version of the Favre averaged Navier Stokes equations (including the Wilcox ko turbulence model with dilatational dissipation) a systematic study of various ejector designs within an RBCC engine is undertaken. It is shown that by using a central rocket placed along the axisymmetric axis in combination with an annular rocket placed along the outer wall of the ejector, one can obtain compression ratios of approximately 2.5 for the case where both the entrained air and rocket exhaust mass flows are equal. Further, it is shown that constricting the exit area, and the manner in which this constriction is performed, has a significant positive impact on the compression ratio. For a decrease in area of 25% a purely conical ejector can increase the compression ratio by an additional 23% compared to an equal length unconstricted ejector. The use of a more sharply angled conical section followed by a cylindrical section to maintain equivalent ejector lengths can further increase the compression ratio by 5--7% for a total increase of approximately 30%.

Etele, Jason

221

Effects of the Phoenix Lander descent thruster plume on the Martian surface  

Microsoft Academic Search

The exhaust plume of Phoenix's hydrazine monopropellant pulsed descent thrusters will impact the surface of Mars during its descent and landing phase in the northern polar region. Experimental and computational studies have been performed to characterize the chemical compounds in the thruster exhausts. No undecomposed hydrazine is observed above the instrument detection limit of 0.2%. Forty-five percent ammonia is measured

D. H. Plemmons; M. Mehta; B. C. Clark; S. P. Kounaves; L. L. Peach Jr; N. O. Renno; L. Tamppari; S. M. M. Young

2008-01-01

222

Near-field vector intensity measurements of a small solid rocket motor.  

PubMed

Near-field vector intensity measurements have been made of a 12.7-cm diameter nozzle solid rocket motor. The measurements utilized a test rig comprised of four probes each with four low-sensitivity 6.35-mm pressure microphones in a tetrahedral arrangement. Measurements were made with the rig at nine positions (36 probe locations) within six nozzle diameters of the plume shear layer. Overall levels at these locations range from 135 to 157 dB re 20 microPa. Vector intensity maps reveal that, as frequency increases, the dominant source region contracts and moves upstream with peak directivity at greater angles from the plume axis. PMID:20707417

Gee, Kent L; Giraud, Jarom H; Blotter, Jonathan D; Sommerfeldt, Scott D

2010-08-01

223

Study of Visible Exhaust Smoke from Aircraft Jet Engines.  

National Technical Information Service (NTIS)

The objective of this study was to relate the visibility of inflight jet exhaust to the SAE smoke number. A method based on photographic photometry was developed for measuring the optical density of smoke plumes. This method was related to visibility and ...

H. Betz J. Stockham

1971-01-01

224

Multiple propellant solid rocket motor  

Microsoft Academic Search

An integrated stage solid propellant rocket motor arrangement provides boost and repeated throttling post-boost operations on demand and includes an attitude control system. The rocket motor includes a plurality of casings for enclosing an initial boost motor, a post-boost motor, and gas generator means for producing gases that are used for reignition of the post-boost motor and as a motive

Allan J. McDonald

1994-01-01

225

Nanoparticles for solid rocket propulsion  

Microsoft Academic Search

The characterization of several differently sized aluminium powders, by BET (specific surface), EM (electron microscopy), XRD (x-ray diffraction), and XPS (x-ray photoelectron spectroscopy), was performed in order to evaluate their application in solid rocket propellant compositions. These aluminium powders were used in manufacturing several laboratory composite solid rocket propellants, based on ammonium perchlorate (AP) as oxidizer and hydroxil-terminated polybutadiene (HTPB)

L. Galfetti; L. T. DeLuca; F. Severini; L. Meda; G. Marra; M. Marchetti; M. Regi; S. Bellucci

2006-01-01

226

Facility for cold flow testing of solid rocket motor models  

NASA Astrophysics Data System (ADS)

A new cold flow test facility was designed and constructed at NASA Marshall Space Flight Center for the purpose of characterizing the flow field in the port and nozzle of solid propellant rocket motors (SRM's). A National Advisory Committee was established to include representatives from industry, government agencies, and universities to guide the establishment of design and instrumentation requirements for the new facility. This facility design includes the basic components of air storage tanks, heater, submicron filter, quiet control valve, venturi, model inlet plenum chamber, solid rocket motor (SRM) model, exhaust diffuser, and exhaust silencer. The facility was designed to accommodate a wide range of motor types and sizes from small tactical motors to large space launch boosters. This facility has the unique capability of testing ten percent scale models of large boosters such as the new Advanced Solid Rocket Motor (ASRM), at full scale motor Reynolds numbers. Previous investigators have established the validity of studying basic features of solid rocket motor development programs include the acquisition of data to (1) directly evaluate and optimize the design configuration of the propellant grain, insulation, and nozzle; and (2) provide data for validation of the computational fluid dynamics, (CFD), analysis codes and the performance analysis codes. A facility checkout model was designed, constructed, and utilized to evaluate the performance characteristics of the new facility. This model consists of a cylindrical chamber and converging/diverging nozzle with appropriate manifolding to connect it to the facility air supply. It was designed using chamber and nozzle dimensions to simulate the flow in a 10 percent scale model of the ASRM. The checkout model was recently tested over the entire range of facility flow conditions which include flow rates from 9.07 to 145 kg/sec (20 to 320 Ibm/sec) and supply pressure from 5.17 x 10 exp 5 to 8.27 x 10 exp 6 Pa. The performance of the self-pumping exhaust diffuser was verified down to exhaust pressures of 1.379 x 10 exp 4 Pa. The facility was successfully operated over the entire range of design pressures and flowrates and is available for national use by industry and government agencies requiring facilities capable of testing SRM cold flow models to support development programs or resolve problems arising on operational flight systems.

Bacchus, D. L.; Hill, O. E.; Whitesides, R. Harold

1992-02-01

227

The elusive mantle plume  

NASA Astrophysics Data System (ADS)

Mantle plumes are hypothetical hot, narrow mantle upwellings that are often invoked to explain hotspot volcanism with unusual geophysical and geochemical characteristics. The mantle plume is a well-established geological structure in computer modeling and laboratory experiments but an undisputed seismic detection of one has yet to be made. Vertically continuous low shear velocity anomalies in the upper mantle, expected for plumes, are present beneath the Afar, Bowie, Easter, Hawaii, Iceland, Louisville, McDonald, and Samoa hotspots but not beneath the other 29 hotspots in Sleep's 1990 catalog. Whether and how plumes form remain fundamental multi-disciplinary research questions. Should they exist, detection of whole-mantle plumes will depend on deployments of dense (50-100 km station spacing), wide-aperture (>1000 km) seismic networks to maximize model resolution in the transition zone and uppermost lower mantle since plume impingement upon the 660-km phase transition leaves a unique seismic imprint.

Ritsema, Jeroen; Allen, Richard M.

2003-02-01

228

Simulation of a Rocket Base Combined Cycle Exchange Inlet at Subsonic Conditions  

NASA Astrophysics Data System (ADS)

Rocket Based Combined Cycle (RBCC) engines combine the high specific impulses of air breathing engines and the large operation envelop of rockets. Such engines incorporate 4 modes of operation with the first three modes relying on the performance of a mixing duct. The performance improves with a longer mixing duct but the problem with a long mixing duct is that it increases the overall engine weight. Thus, there have been studies done by other research groups to decrease this mixing duct length. Research has been ongoing at Carleton University to design a RBCC engine concept that can potentially reduce the mixing duct length by improving mixing. This is done by using a design that expands the rocket exhaust from a singular throat through multiple clovers to a semi-annular profile. The current study focuses on the subsonic free stream flight conditions in order to analyze the rocket air interaction by using this profile. From simulations performed in ANSYS CFX 12.1, it is clear that any abrupt changes to the geometry should be avoided when designing the rocket flow path. Then in the exchange inlet / mixing duct simulations, by varying the mixing duct outlet pressure, it is found that mixing improves since the mass flow rate of air and Mach number decreases. Moreover, a comparison is done with a more conventional design that places a single rocket along the centerline (SRC). It is found that the current design outperforms the SRC configuration in terms of mixing for up to 4 mixing duct diameters downstream.

Yuen, Tommy Shi Chun

229

Dynamics of Thermochemical Plumes  

NASA Astrophysics Data System (ADS)

We investigate the dynamics of thermo-chemical plumes to enlighten the fundamental differences with purely thermal plumes. The key features of our 3D numerical model include: (1) a compressible mantle with an endothermic phase transition at 670km depth, (2) a mantle 'wind' induced by the imposed surface plate motion, (3) twenty million active tracers simulate denser material initially in the lowermost mantle, (4) plumes form naturally i.e., without imposing any temperature perturbation. First, we investigate the widely accepted head-tail structure of plumes. Our results show that thermo-chemical plumes reaching the surface may or may not have a head since, in some cases, only a narrow 'tail' of hot material is able to ascend in the upper mantle. Therefore, we suggest that the existence of a large igneous province at the onset of hotspot volcanism is not a valid prerequisite for a deep plume origin. Second, we investigate the entrainment of deep heterogeneities. Our results show the generation of narrow, long lasting, distinct filaments in the plume's tail. Therefore, the plume conduit is laterally heterogeneous, rather than concentrically zoned. Third, we calculate the shear wave velocity anomalies in the lower mantle, using the temperature field and the distribution of chemical heterogeneities provided by the convection model. The great variety of plume's shapes and sizes differs strikingly from the expected 'mushroom' shape of purely thermal plumes, bearing important implications for the interpretation of seismologically detected plumes. Finally, our model predictions will be compared with a variety of observations in the Central Pacific.

Farnetani, C. G.; Samuel, H.

2004-12-01

230

Exhaust gas recirculation apparatus  

Microsoft Academic Search

Apparatus is disclosed for recirculating combustion exhaust gases to the burner region of a Stirling cycle hot-gas engine to lower combustion temperature and reduct NO\\/sub x\\/ formation includes a first wall separating the exhaust gas stream from the inlet air stream, a second wall separating the exhaust gas stream from the burner region, and low flow resistance ejectors formed in

R. A. Egnell; B. L. Hansson

1981-01-01

231

Compression technique for plume hyperspectral images  

NASA Astrophysics Data System (ADS)

The authors recently developed a hyperspectral image output option for a standardized government code designed to predict missile exhaust plume infrared signatures. Typical predictions cover the 2- to 5-m wavelength range (2000 to 5000 cm-1) at 5 cm-1 spectral resolution, and as a result the hyperspectral images have several hundred frequency channels. Several hundred hyperspectral plume images are needed to span the full operational envelope of missile altitude, Mach number, and aspect angle. Since the net disk storage space can be as large as 100 GB, a Principal Components Analysis is used to compress the spectral dimension, reducing the volume of data to just a few gigabytes. The principal challenge was to specify a robust default setting for the data compression routine suitable for general users, who are not necessarily specialists in data compression. Specifically, the objective was to provide reasonable data compression efficiency of the hyperspectral imagery while at the same time retaining sufficient accuracy for infrared scene generation and hardware-in-the-loop test applications over a range of sensor bandpasses and scenarios. In addition, although the end users of the code do not usually access the detailed spectral information contained in these hyperspectral images, this information must nevertheless be of sufficient fidelity so that atmospheric transmission losses between the missile plume and the sensor could be reliably computed as a function of range. Several metrics were used to determine how far the plume signature hyperspectral data could be safely compressed while still meeting these end-user requirements.

Feather, B. K.; Fulkerson, S. A.; Jones, J. H.; Reed, R. A.; Simmons, M. A.; Swann, D. G.; Taylor, W. E.; Bernstein, L. S.

2005-06-01

232

Numerical studies of plume-vortex interactions  

NASA Astrophysics Data System (ADS)

A new mixing model was developed to study the initial engine exhaust plume evolution with reduced reaction mechanism for the lower stratosphere. The results show that the effects of the local lack of mixing have an inhibiting effect on ozone depletion in the near-field plume. Inclusion of heterogeneous kinetics involving formation of condensed nitric and sulfuric acid on soot particles showed that 15% of the available NOx, is converted into its inactive form. A comprehensive and efficient aerosol model coupled with chemical kinetics and the jet flow model was developed. The predictions of aerosol number density, surface area density agree with previous simulations qualitatively. The comparison of predictions between with and without the micro-mixing effect also suggests that lack of micro-mixing tends to underpredict the aerosol number density. To study the plume-vortex interaction, a parallel LES code is first validated against experimental free jet data and then applied to the study of the near-field plume-vortex interaction dynamics with gas-phase and heterogeneous chemistry. The simulation results show reasonable agreement with in-situ observations. Results indicate that a significant difference between spatial and temporal simulation exists, which affects the accuracy of the prediction of sulfuric acid aerosols in the wake. Analysis of the results also shows that spatial simulation is more suitable for the near field interaction process.

Wu, Junxiao

1999-11-01

233

The Chemistry and Diffusion of Aircraft Exhausts in the Lower Stratosphere During the First Few Hours after Fly-by.  

National Technical Information Service (NTIS)

An analysis of the hydrogen-nitrogen-oxygen reaction systems in the lower stratosphere as they are initially perturbed by individual aircraft engine exhaust plumes was conducted in order to determine whether any significant chemical reactions occur, eithe...

G. R. Hilst

1974-01-01

234

Ballistics of a Rocket. Certain Problems of Ballistics of Long-Range Rockets.  

National Technical Information Service (NTIS)

Methods for solving some problems in rocket ballistics of long-range are examined. Attention is given to the interaction of the various parts of the rocket and the control system. Examined are flight conditions for rockets, peculiarities of rockets as a c...

A. A. Lebedev N. F. Gerasyuta

1972-01-01

235

Transpiration Cooled Throat for Hydrocarbon Rocket Engines.  

National Technical Information Service (NTIS)

The objective for the Transpiration Cooled Throat for Hydrocarbon Rocket Engines Program was to characterize the use of hydrocarbon fuels as transpiration coolants for rocket nozzle throats. The hydrocarbon fuels investigated in this program were RP-1 and...

L. R. May W. M. Burkhardt

1991-01-01

236

New Services at Andoya (Norway) Rocket Range.  

National Technical Information Service (NTIS)

Recent developments at Andoya Rocket Range (ARR) (Norway) are presented. ARR is the launch facility of the Norwegian Space Center, used for sounding rockets and balloons. The range facilities and services are continuously being developed to satisfy the va...

I. Nyheim

1991-01-01

237

German Scientific Balloon and Sounding Rocket Program.  

National Technical Information Service (NTIS)

The German space program which uses scientific balloon and sounding rocket as investigative instruments, is presented. Information on sounding rocket projects in the scientific fields of astronomy, aeronomy, magnetospheric research, and microgravity resea...

A. F. Dahl M. Otterbein

1989-01-01

238

Analysis on numerical results for stage separation with different exhaust holes  

Microsoft Academic Search

The flow field for thermal stage separation is carried out and predicted by unsteady numerical simulation with the dynamic moving grids in this work. The overset grids are applied to simulate the relative separating motion of multi-stage rocket. The flow problems and effects of different exhaust holes within the interstage under considering the design of thermal stage separation are systematically

Tzong-Hann Shieh; Tong-Miin Liou; Meng-Rong Li; Cheng-Hsin Liu; Wen-Jing Wu

2009-01-01

239

Measuring Model Rocket Engine Thrust Curves  

ERIC Educational Resources Information Center

|This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

Penn, Kim; Slaton, William V.

2010-01-01

240

Rocket Sounding of High Atmosphere Meteorological Parameters  

Microsoft Academic Search

The need for systematic data collection pertaining to meteorological parameters in the high atmosphere has led to the development of several relatively economical meteorological rocket vehicles and uncomplicated rocket payloads. The progress toward an optimum system has been encouraging during the past two years, but the over-all state of the sensor development has lagged behind rocket performance. The complexity of

K. R. Jenkins; W. L. Webb; G. Q. Clark

1960-01-01

241

Solar Pointing Attitude Rocket Control System \\/SPARCS  

Microsoft Academic Search

The SPARCS system is described and its use since Dec. 1967 is reviewed. SPARCS was developed to fulfill a requirement for a lightweight, precision, three-axis pointing control system for solar-sounding rockets. The use of sounding rockets to calibrate satellite instruments before flight for subsequent recovery and orbital flight is noted, along with the calibration of Skylab instruments with sounding rocket

J. M. Shigemoto

1982-01-01

242

Optimum design of solid rocket motor nozzles  

Microsoft Academic Search

In order to design an optimum nozzle for air-air missile solid rocket motors, a mass model of a solid rocket motor, a nozzle specifice impulse model of a solid rocket motor, and the objective function are established. Five different type of nozzles are chosen for calculation. Conical, paraboloidal, two different arcs, quadratic polynomial, and cubic polynomial. The optimization results show

Guoyao Fang; Qing Wang; Shanhui Gao

1993-01-01

243

Marine exhaust manifold and elbow  

SciTech Connect

This patent describes a marine propulsion system having an internal combustion engine exhausted through a water jacketed exhaust assembly. This patent describes improvement in a manifold portion having intake exhaust passages receiving engine exhaust; an elbow portion extending upwardly from the manifold portion and having transfer exhaust passages extending from the intake exhaust passages and communicating through a bend with a discharge exhaust passage, wherein exhaust flows upwardly from the manifold portion into the elbow portion and around the bend to the discharge exhaust passage; water jacket means around the intake exhaust passages and the transfer exhaust passages and directing water along the exterior of the intake exhaust passages and the transfer exhaust passages, wherein water flows upwardly along the manifold portion to the elbow portion and then upwardly and around the bend and then to the end of the discharge exhaust passage to mix with exhaust thereat; wall supports between the water jacket means and the elbow portion.

Lindstedt, D.H.

1992-05-05

244

Entrainment by Lazy Plumes  

NASA Astrophysics Data System (ADS)

We consider plumes with source conditions that have a net momentum flux deficit compared to a pure plume - so called lazy plumes. We examine both the case of constant buoyancy flux and buoyancy flux linearly increasing with height. By re-casting the plume conservation equations (Morton, Taylor & Turner 1956) for a constant entrainment coefficient ((?)) in terms of the plume radius (?) and the dimensionless parameter (?=frac5Q^2 B4? M^5/2) we show that the far-field flow in a plume with a linear internal buoyancy flux gain is a constant velocity lazy plume with reduced entrainment and radial growth rate. For highly lazy source conditions we derive first-order approximate solutions which indicate a region of zero entrainment near the source. These phenomena have previously been observed, however, it has often been assumed that reduced entrainment implies a reduced (?). We demonstrate that a constant (?) formulation is able to capture the behaviour of these reduced entrainment flows. Morton, B. R., Taylor, G. I. & Turner, J. S. (1956), Turbulent gravitational convection from maintained and instantaneous sources.', Proc. Roy. Soc. 234, 1-23.

Kaye, Nigel; Hunt, Gary

2004-11-01

245

Prometheus: Io's wandering plume.  

PubMed

Unlike any volcanic behavior ever observed on Earth, the plume from Prometheus on Io has wandered 75 to 95 kilometers west over the last 20 years since it was first discovered by Voyager and more recently observed by Galileo. Despite the source motion, the geometric and optical properties of the plume have remained constant. We propose that this can be explained by vaporization of a sulfur dioxide and/or sulfur "snowfield" over which a lava flow is moving. Eruption of a boundary-layer slurry through a rootless conduit with sonic conditions at the intake of the melted snow can account for the constancy of plume properties. PMID:10817989

Kieffer, S W; Lopes-Gautier, R; McEwen, A; Smythe, W; Keszthelyi, L; Carlson, R

2000-05-19

246

An investigation of the interaction between a travelling shock wave and a solid rocket motor nozzle  

Microsoft Academic Search

A gasdynamic mechanism has been identified as a potential source of combustion instability in solid-propellant rocket motors (SRMs). This mechanism involves the reinforcement of a reflected shock wave in the nozzle convergence region of an SRM's exhaust nozzle.\\u000aA shock tube apparatus was developed for the experimental component of this study. Various factors, such as the effect of different nozzle

Harmanjit Singh Chopra

2003-01-01

247

Exhaust gas purification device  

SciTech Connect

The exhaust gas purification device includes an exhaust manifold , a purification cylinder connected with the exhaust manifold through a first honey-comb shaped catalyst, and a second honeycomb shaped catalyst positioned at the rear portion of the purification cylinder. Each catalyst is supported by steel wool rings including coarse and dense portions of steel wool. The purification device further includes a secondary air supplying arrangement.

Fujiwara, H.; Hibi, T.; Sayo, S.; Sugiura, Y.; Ueda, K.

1980-02-19

248

Design of sounding rocket payloads  

Microsoft Academic Search

Contract efforts were in the design, fabrication, testing, and launch support of sounding rocket payloads and related ground support equipment. Specific areas of work related to this report include: payload structures, component packaging, deployment and eject mechanisms, diagnostic components, in-flight sequencing, power systems and control consoles. Also described are electrical and mechanical interfaces with experiments, telemetry systems, attitude control systems,

J. S. Rochefort; A. J. Yorra

1976-01-01

249

Design of sounding rocket payloads  

Microsoft Academic Search

This report is a summary of work accomplished from 1 May 1976 to 30 April 1981. Contract efforts were in the design, fabrication, testing, and launch support of sounding rocket payloads and related ground support equipment. Specific areas of work related to this report include: payload structures, component packaging, deployment and eject mechanisms, diagnostic components, in-flight sequencing, power systems and

R. L. Morin; L. J. Oconnor

1981-01-01

250

Launch Excitement with Water Rockets  

ERIC Educational Resources Information Center

|Explosions and fires--these are what many students are waiting for in science classes. And when they do occur, students pay attention. While we can't entertain our students with continual mayhem, we can catch their attention and cater to their desires for excitement by saying, "Let's make rockets." In this activity, students make simple, reusable…

Sanchez, Juan Carlos; Penick, John

2007-01-01

251

NASA's Advanced solid rocket motor  

Microsoft Academic Search

The Advanced Solid Rocket Motor (ASRM) will not only bring increased safety, reliability and performance for the Space Shuttle Booster, it will enhance overall Shuttle safety by effectively eliminating 174 failure points in the Space Shuttle Main Engine throttling system and by reducing the exposure time to aborts due to main engine loss or shutdown. In some missions, the vulnerability

Royce E. Mitchell

1993-01-01

252

Safe testing nuclear rockets economically  

Microsoft Academic Search

Several studies over the past few decades have recognized the need for advanced propulsion to explore the solar system. As early as the 1960s, Werner Von Braun and others recognized the need for a nuclear rocket for sending humans to Mars. The great distances, the intense radiation levels, and the physiological response to zero-gravity all supported the concept of using

Steven D. Howe; Bryan Travis; David K. Zerkle

2002-01-01

253

SAFE Testing Nuclear Rockets Economically  

Microsoft Academic Search

Several studies over the past few decades have recognized the need for advanced propulsion to explore the solar system. As early as the 1960s, Werner Von Braun and others recognized the need for a nuclear rocket for sending humans to Mars. The great distances, the intense radiation levels, and the physiological response to zero-gravity all supported the concept of using

Steven D. Howe; Bryan Travis; David K. Zerkle

2003-01-01

254

Multiple propellant solid rocket motor  

NASA Astrophysics Data System (ADS)

An integrated stage solid propellant rocket motor arrangement provides boost and repeated throttling post-boost operations on demand and includes an attitude control system. The rocket motor includes a plurality of casings for enclosing an initial boost motor, a post-boost motor, and gas generator means for producing gases that are used for reignition of the post-boost motor and as a motive source for the attitude control system. The boost motor and the post-boost motor are contained within the same enclosure but are separated by an internal bulkhead. The rocket motor has a plurality of nozzles, one of which is located aft of the boost motor and another located within the internal bulkhead that separates the boost and post-boost motors. The rocket motor of the invention has application in many propulsion systems, including strategic systems requiring both boost and post-boost propulsion, advanced antiballistic missile interceptors requiring boost/sustain thrust and on/off operation, and in space motors for deploying satellites by accomplishing both perigee and apogee burns with a single motor or as an on-demand orbit transfer vehicle for changing orbits.

McDonald, Allan J.

1994-03-01

255

Rocket engine condition monitoring system  

Microsoft Academic Search

It is expected that the Rocket Engine Condition Monitoring System (RECMS) program will define engine monitoring technologies and an integration approach which can be applied to engine development in support of advanced launch system objectives. The RECMS program approaches engine monitoring as a system which is fully integrated with the engine controller, vehicle monitoring system, and ground processing systems to

S. K. Hagar; J. F. Alcock

1989-01-01

256

Sounding Rocket Payload Recovery Systems.  

National Technical Information Service (NTIS)

The various systems for recovering sounding rocket payloads are discussed. Emphasis is placed on those used by the French space agency in Guiana. The two main problems are identified as: (1) absorbing the kinetic energy of the payload to prevent impact da...

J. Lerat R. Marguet

1972-01-01

257

ISS Update: VASIMR Plasma Rocket  

NASA Video Gallery

NASA Public Affairs Officer Dan Huot interviews Ken Bollweg, VASIMR Project Manager, about VASIMR (Variable Specific Impulse Magnetoplasma Rocket), recent testing progress and future applications. Questions? Ask us on Twitter @NASA_Johnson and include the hashtag #askStation. For the latest news about the space station, visit http://www.nasa.gov/station.

Russell Todd D

2012-03-09

258

From ionosonde to rocket sonde  

NASA Astrophysics Data System (ADS)

The 75th Anniversary of the American Geophysical Union (AGU) marks the discovery of the basic features of solar control of the ionosphere. A quarter of a century later our understanding of ionospheric physics was revolutionized by the early rocket era of upper air research that brought the discoveries of solar X ray and XUV radiation.

Friedman, H.

1994-10-01

259

Separation dynamics of ullage rockets  

Microsoft Academic Search

The dynamics associated with the jettisoning of spent ullage rocket systems from the parent launch vehicle is investigated. The analysis considers a spring-based mechanism employed to jettison the system hinged on to an accelerating stage. Closed-form solutions are obtained. Analytical expressions are developed for the hinge reactions. Conditions are derived for optimum separation velocity and guidelines presented for selection of

Rajeev Lochan; V. Adimurthy; K. Kumar

1994-01-01

260

Cryogenic Propellant Rocket Engine Problems.  

National Technical Information Service (NTIS)

Modern achievements and the problems of powerful Liquid Rocket Engines (LRE) for launch system main propulsion units are shown. Results of LRE research and development carried out in Russia are included. LRE's have been used since the beginning of the for...

A. Roudakov

1993-01-01

261

Groundwater contaminant plume ranking.  

National Technical Information Service (NTIS)

Containment plumes at Uranium Mill Tailings Remedial Action (UMTRA) Project sites were ranked to assist in Subpart B (i.e., restoration requirements of 40 CFR Part 192) compliance strategies for each site, to prioritize aquifer restoration, and to budget ...

1988-01-01

262

Ultraviolet Plume Instrument (UVPI).  

National Technical Information Service (NTIS)

The Ultraviolet Plume Instrument (UVPI) was launched aboard the Low-power Atmospheric Compensation Experiment (LACE) satellite on 14 Feb. 1990. Both the spacecraft and the UVPI were sponsored by the Directed Energy Office of the Strategic Defense Initiati...

D. M. Horan

1993-01-01

263

Cryopump with exhaust filter  

SciTech Connect

A cryopump is described comprising cryopanels within a vacuum vessel cooled to cryogenic temperatures to condense gases from the volume within the vacuum vessel, the vacuum vessel having an exhaust port closed by a valve during operation of the cryopump. The cryopump further comprises a filter conduit extending from the exhaust port into the volume within the vacuum vessel away from the wall of the vacuum vessel. The filter conduit is formed of porous filter material for retaining solid debris within the vacuum vessel while passing liquid and gas therethrough, the filter conduit being open away from the exhaust port to permit substantially unrestricted flow of gas to the exhaust port.

Eacobacci, M.J.; Planchard, D.C.

1987-04-07

264

Infrared Signature Modeling and Analysis of Aircraft Plume  

NASA Astrophysics Data System (ADS)

In recent years, the survivability of an aircraft has been put to task more than ever before. One of the main reasons is the increase in the usage of Infrared (IR) guided Anti-Aircraft Missiles, especially due to the availability of Man Portable Air Defence System (MANPADS) with some terrorist groups. Thus, aircraft IR signatures are gaining more importance as compared to their radar, visual, acoustic, or any other signatures. The exhaust plume ejected from the aircraft is one of the important sources of IR signature in military aircraft that use low bypass turbofan engines for propulsion. The focus of the present work is modelling of spectral IR radiation emission from the exhaust jet of a typical military aircraft and to evaluate the aircraft susceptibility in terms of the aircraft lock-on range due to its plume emission, for a simple case against a typical Surface to Air Missile (SAM). The IR signature due to the aircraft plume is examined in a holistic manner. A comprehensive methodology of computing IR signatures and its affect on aircraft lock-on range is elaborated. Commercial CFD software has been used to predict the plume thermo-physical properties and subsequently an in-house developed code was used for evaluating the IR radiation emitted by the plume. The LOWTRAN code has been used for modeling the atmospheric IR characteristics. The results obtained from these models are in reasonable agreement with some available experimental data. The analysis carried out in this paper succinctly brings out the intricacy of the radiation emitted by various gaseous species in the plume and the role of atmospheric IR transmissivity in dictating the plume IR signature as perceived by an IR guided SAM.

Rao, Arvind G.

2011-09-01

265

Enceladus' water vapor plume.  

PubMed

The Cassini spacecraft flew close to Saturn's small moon Enceladus three times in 2005. Cassini's UltraViolet Imaging Spectrograph observed stellar occultations on two flybys and confirmed the existence, composition, and regionally confined nature of a water vapor plume in the south polar region of Enceladus. This plume provides an adequate amount of water to resupply losses from Saturn's E ring and to be the dominant source of the neutral OH and atomic oxygen that fill the Saturnian system. PMID:16527971

Hansen, Candice J; Esposito, L; Stewart, A I F; Colwell, J; Hendrix, A; Pryor, W; Shemansky, D; West, R

2006-03-10

266

HCL measurements in space vehicle exhaust clouds  

SciTech Connect

The United States Space Program requires the use of large launch vehicles like the space shuttle, Titan 34D, Titan IV, and the proposed heavy-lift vehicle. These large launch systems utilize solid rocket motors to place heavy payloads into orbit. However, most solid rocket motors utilize ammonium perchlorate as an oxidizer and release an exhaust cloud, which is a dynamic mixture of water, hydrogen chloride, aluminum oxide, and aluminum chloride. Described in this presentation are two infrared monitors which are designed for HCl field measurements. One monitor, developed by Lawrence Livermore National Laboratory (LLNL), measures gaseous HCl and accounts for the presence of water and methane that absorb at the HCl wavelength. A detection limit of 0.2 ppM has been demonstrated. The second monitor, developed by Spectral Sciences, Inc., uses a unique HCl lamp which is free of interferences associated with conventional black body radiation sources. By combining the lamp with simple optics, a detection limit of 0.1 ppM has been obtained. Since much of the HCl in the ground cloud is entrained in small water droplets and the infrared technique measures only gaseous HCl, a method was required to account for aqueous HCl. The Spectral Sciences monitor features a preheater which vaporizes aerosols in the input gas stream so that total HCl can be measured. For both monitors, instrument design and operation are described in detail. 11 refs., 7 figs., 2 tabs.

Smith, M.D.; McRae, T.; Kennedy, R.; Garvis, D.; Kulp, T.; Berstein, L.S.; Bien, F.; Cheng, W.; Domingue, R.P.; Richtmeier, S.C.

1988-01-01

267

Do Plumes Suck?  

NASA Astrophysics Data System (ADS)

Geophysical observations at plumes, ridges, and arcs indicate that the the volcanic accretionary zone is much narrower than the inferred melt production region in the upwelling mantle. For ridges and arcs, lateral pressure gradients induced by advection of viscous asthenospheric mantle have been proposed as a potential mechanism for focusing melts to the accretionary center [Phipps Morgan, 1987; Spiegelman and McKenzie, 1987]. For ridges and arcs with asthenospheric viscosities >=1021 Pa?s, the magnitude of the lateral pressure gradients associated with viscous corner flow are comparable to vertical melt buoyancy (? ? g). Plumes, however, differ from ridges and arcs in that mantle flow is driven primarily by buoyancy of the upwelling solid as opposed to viscous drag induced by surface plate motions. This difference in driving forces changes the relationship between the solid flow field and the resulting pressure gradients. We use numerical models to examine the influence of lateral pressure gradients from solid advection in plumes. We calculate the stream function and pressure field in the solid induced by a buoyant cylinder beneath a stationary lithosphere using the method of Ribe and Christensen [1999] after Pozrikidis [1997]. Initial results suggest that lateral pressure gradients may draw melt into the top of the plume towards the flow stagnation point. However, the largest flow-induced pressure gradients are oriented vertically within the buoyant plume. Compression where the plume impinges on the lithospheric lid has the potential to impede the vertical migration of melt within the plume. The magnitude of the flow-induced pressure gradients scales with the strength of the buoyant upwelling. However, unlike ridges and arcs, asthenospheric viscosity has little effect on the pressure gradients, because velocity and viscosity of plume material are interdependent. We explore the possible role of these pressure gradients in melt migration at plume and ridge-plume environments. Phipps Morgan, J., Melt migration beneath mid-ocean spreading centers, Geophys. Res. Lett., 14 (12), 1238-1241, 1987. Pozrikidis, C., Introduction to theoretical and computational fluid dynamics, 675 pp., Oxford University Press, New York, 1997. Ribe, N.M., and U.R. Christensen, The dynamical origin of Hawaiian volcanism, Earth and Planet. Sci. Lett., 171, 517-531, 1999. Spiegelman, M., and D. McKenzie, Simple 2-D models for melt extraction at mid-ocean ridges and island arcs, Earth and Planetary Science Letters, 83 (1-4), 137-152, 1987.

Braun, M. G.; Sohn, R. A.; Ribe, N. M.

2001-12-01

268

Exhaust gas recirculation control valve  

Microsoft Academic Search

An exhaust gas recirculation control valve for preventing carbon and the like contained in the exhaust gas from attaching to the inner wall surface of exhaust gas paths, through which the exhaust gas from an engine of a motor car passes, thus decreasing the diameters of the paths with time. This exhaust gas recirculation control valve is provided in a

Masuda

1982-01-01

269

Automobile exhaust gas cleaner  

SciTech Connect

A cleaner for exhaust gas is described comprising: first and second perforated baffle means supported in respective first and second housings, the first housing having an exhaust gas inlet, the second housing having an exhaust gas outlet, and the first housing being situated below the second housing and connected thereto to permit the flow of exhaust gas upwardly from the first housing to the second housing, means for spraying cleaning liquid onto the first perforated baffle means and for permitting the gas to permeate therethrough and then to flow downwardly around means for deflecting the gas before moving upwardly to the second housing, the sprayed liquid falling downwardly into sump means for receiving the sprayed liquid, means for spraying cleaning liquid onto the second perforated baffle means and for permitting the gas to permeate therethrough, the sprayed liquid falling downwardly into the sump means, and means for filtering pollutants from the exhaust gas.

Pickering, J.J.

1989-04-18

270

Martian Atmospheric Plumes: Behavior, Detectability and Plume Tracing  

NASA Astrophysics Data System (ADS)

We will present our recent work simulating neutrally buoyant plumes in the martian atmosphere. This work is primarily directed at understanding the behavior of discrete plumes of biogenic tracer gases, and thus increasing our understanding of their detectability (both from orbit and from in situ measurements), and finally how to use the plumes to identify their precise source locations. We have modeled the detailed behavior of martian atmospheric plumes using MarsWRF for the atmospheric dynamics and SCIPUFF (a terrestrial state of the art plume modeling code that we have modified to represent martian conditions) for the plume dynamics. This combination of tools allows us to accurately simulate plumes not only from a regional scale from which an orbital observing platform would witness the plume, but also from an in situ perspective, with the instantaneous concentration variations that a turbulent flow would present to a point sampler in situ instrument. Our initial work has focused on the detectability of discrete plumes from an orbital perspective and we will present those results for a variety of notional orbital trace gas detection instruments. We have also begun simulating the behavior of the plumes from the perspective of a sampler on a rover within the martian atmospheric boundary layer. The detectability of plumes within the boundary layer has a very strong dependence on the atmospheric stability, with plume concentrations increasing by a factor of 10-1000 during nighttime when compared to daytime. In the equatorial regions of the planet where we have simulated plumes, the diurnal tidal “clocking” of the winds is strongly evident in the plume trail, which similarly “clocks” around its source. This behavior, combined with the strong diurnal concentration variations suggests that a rover hunting a plume source would be well suited to approach it from a particular azimuth (downwind at night) to maximize detectability of the plume and the ability to trace the plume to its precise source.

Banfield, Don; Mischna, M.; Sykes, R.; Dissly, R.

2013-10-01

271

Focused RBCC Experiments: Two-Rocket Configuration Experiments and Hydrocarbon/Oxygen Rocket Ejector Experiments.  

National Technical Information Service (NTIS)

This addendum report documents the results of two additional efforts for the Rocket Based Combined Cycle (RBCC) rocket-ejector mode research work carried out at the Penn State Propulsion Engineering Research Center in support of NASA s technology developm...

R. J. Santoro S. Pal

2003-01-01

272

The growth and decay of equatorial backscatter plumes  

NASA Astrophysics Data System (ADS)

During the past three years, a series of rocket experiments from the Kwajalein Atoll, Marshall Islands, were conducted to investigate the character of intense, scintillation-producing irregularities that occur in the nighttime equatorial ionosphere. Because the source mechanism of equatorial irregularities, believed to be the Rayleigh-Taylor instability, is analogous to that which generates plasma-density striations in a nuclear-induced environment, there is considerable interest in the underlying physics that controls the characteristics of these irregularities. A primary objective of ALTAIR investigations of equatorial irregularities is to seek an understanding of the underlying physics by establishing the relationship between meter-scale irregularities (detected by ALTAIR), and the large-scale plasma-density depletions (or 'bubbles') that contain the kilometer-scale, scintillation-producing irregularities. We describe the time evolution of backscatter 'plumes' produced by one meter equatorial field-aligned irregularities. Using ALTAIR, a fully steerable backscatter radar, to repeatedly map selected plumes, we characterize the dynamic behavior of plumes in terms of growth and a decay phase. Most of the observed characteristics are found to be consistent with equatorial-irregularity generation predicted by current theories of Rayleigh-Taylor and gradient-drift instabilities. However, other characteristics have been found that suggest key roles played by the eastward neutral wind and by altitude-modulation of the bottomside F layer in establishing the initial conditions for plume growth.

Tsunoda, R. T.

1980-02-01

273

Tomographic Constraints on Plume Imaging  

NASA Astrophysics Data System (ADS)

Recently emotions are running high in the earth science community on the debate whether or not plumes/plume-like structures are existing.\\Much of the seismological evidence for the existence of plumes stems from the tomographic imaging of structures interpreted to be hot spot related or plume-like.\\In this paper we shall review some of the recent results of tomographic imaging of plumes of different scales as well as discuss some tomographic constraints on plume imaging, such as \\# the general limitations of tomographic imaging of deep structures,\\# the issue of resolution and\\# the influence of different methodologies and/or colour-coding on the images and their interpretation.

Achauer, U.

2002-12-01

274

The OGRESS sounding rocket payload  

NASA Astrophysics Data System (ADS)

We present an overview of the Off-plane Grating Rocket for Extended Source Spectroscopy (OGRESS) sounding rocket payload based at the University of Iowa. OGRESS is designed to perform moderate resolution (R~10- 40) spectroscopy of diffuse celestial X-ray sources between 0.3 - 1.2 keV. A wire grid focuser constrains light from diffuse sources into a converging beam that feeds an array of diffraction gratings in the extreme off-plane mount. The spectrum is focused onto Gaseous Electron Multiplier (GEM) detectors. Scheduled to launch in 2014, OGRESS will obtain accurate physical diagnostics of the Cygnus Loop supernova remnant and will increase the technical readiness level of GEMs. OGRESS is the fourth-generation of similar payloads from the partnership between the University of Iowa and the University of Colorado, with higher throughput, and improved noise characteristics over its predecessors.

Rogers, T.; McEntaffer, R.; Schultz, T.; Zeiger, B.; Oakley, P.; Cash, W.

2013-09-01

275

16 CFR 1507.10 - Rockets with sticks.  

Code of Federal Regulations, 2013 CFR

...Section 1507.10 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES Ā§ 1507.10 Rockets with sticks. Rockets with sticks (including skyrockets and bottle rockets) shall...

2013-01-01

276

14 CFR 437.67 - Tracking a reusable suborbital rocket.  

Code of Federal Regulations, 2013 CFR

...false Tracking a reusable suborbital rocket. 437.67 Section 437.67 Aeronautics...67 Tracking a reusable suborbital rocket. A permittee mustā (a) During...and velocity of its reusable suborbital rocket; and (b) Provide position and...

2013-01-01

277

Design Methods in Solid Rocket Motors. 1988 Revision.  

National Technical Information Service (NTIS)

Partial contents: Advances in Solid Rocket Nozzle Design and Analysis Technology in the United States Since 1970; Design and Analysis of Solid Rocket Motor Nozzle; Composite Motor Case Design; Overall Design of Solid Rocket Motors; Design of Filament-Woun...

1988-01-01

278

Exhaust gas recirculation apparatus  

SciTech Connect

Apparatus is disclosed for recirculating combustion exhaust gases to the burner region of a Stirling cycle hot-gas engine to lower combustion temperature and reduct NO/sub x/ formation includes a first wall separating the exhaust gas stream from the inlet air stream, a second wall separating the exhaust gas stream from the burner region, and low flow resistance ejectors formed in the first and second walls for admitting the inlet air to the burner region and for entraining and mixing with the inlet air portion of the exhaust gas stream. In a preferred embodiment the ejectors are arranged around the periphery of a cylindrical burner region and oriented to admit the air/exhaust gas mixture tangentially to promote mixing. In another preferred embodiment a single annular ejector surrounds and feeds the air/exhaust gas mixture to a cylindrical burner region. The annular ejector includes an annular plate with radially-directed flow passages to provide an even distribution of the air/exhaust gas mixture to the burner region.

Egnell, R.A.; Hansson, B.L.

1981-07-14

279

Optimum design of solid rocket motor nozzles  

NASA Astrophysics Data System (ADS)

In order to design an optimum nozzle for air-air missile solid rocket motors, a mass model of a solid rocket motor, a nozzle specifice impulse model of a solid rocket motor, and the objective function are established. Five different type of nozzles are chosen for calculation. Conical, paraboloidal, two different arcs, quadratic polynomial, and cubic polynomial. The optimization results show that the models established are correct. The method can be used as a reference for other nozzle designs.

Fang, Guoyao; Wang, Qing; Gao, Shanhui

1993-06-01

280

Artificial ageing of double base rocket propellant  

Microsoft Academic Search

The ageing of double base rocket propellants (DB rocket propellants), which is a consequence of chemical reactions and physical\\u000a processes that take place over time, has significant effect on their relevant properties (e.g. chemical composition, mechanical\\u000a properties, ballistic properties, etc.). The changes of relevant properties limit the safe and reliable service life of DB\\u000a rocket propellants. This is the reason

S. Mate?i? Mušani?; M. Su?eska

2009-01-01

281

Fluid mechanics of spinning rockets  

NASA Astrophysics Data System (ADS)

This report presents the results of a detailed investigation of the influence of time-dependent combustion gas flows on the attitude dynamics of spinning rocket propelled space vehicles. The work was motivated by a need to understand the origins of a potentially serious system performance problem first detected in the PAM-D series of spin stabilized upper stages. Small wobbling (often referred to as nutation or coning) is induced during separation of the rocket motor burn. The growth ceased abruptly at motor burnout, and final cone angles as large as 17 deg were reached in some flights. The same phenomenon was encountered in two flights of the PAM-DII, a similar vehicle utilizing a larger motor. Conventional theories of spinning rocket dynamics failed to explain this behavior. Since the telemetry data shows that the severity of the problem depends on spacecraft mass properties and other system parameters, it is crucial that the origins of the instability be understood completely in order that serious mission degradation can be avoided in future orbit raising operations. A costly interim fix, which sidesteps the need to understand the physical origins of the problem, is the use of a strap-on nutation control system as used in the Air Force SGS II missions.

Flandro, G. A.; Vanmoorhem, W. K.; Shorthill, R.; Chen, K.; Woolsey, M.

1987-01-01

282

A miniature solid propellant rocket motor  

SciTech Connect

A miniature solid-propellant rocket motor has been developed to impart a specific motion to an object deployed in space. This rocket motor effectively eliminated the need for a cold-gas thruster system or mechanical spin-up system. A low-energy igniter, an XMC4397, employing a semiconductor bridge was used to ignite the rocket motor. The rocket motor was ground-tested in a vacuum tank to verify predicted space performance and successfully flown in a Sandia National Laboratories flight vehicle program.

Grubelich, M.C.; Hagan, M.; Mulligan, E.

1997-08-01

283

14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.  

Code of Federal Regulations, 2010 CFR

...Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics...OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur...

2010-01-01

284

Evidence for mantle plumes?  

PubMed

Geophysical hotspots have been attributed to partially molten asthenosphere, fertile blobs, small-scale convection and upwellings driven by core heat. Most are short-lived or too close together to be deeply seated, and do not have anomalous heat flow or temperature; many are related to tectonic features. Bourdon et al. investigate the dynamics of mantle plumes from uranium-series geochemistry and interpret their results as evidence for thermal plumes. Here we show why alternative mechanisms of upwelling and melting should be considered. PMID:18033248

Anderson, Don L; Natland, James H

2007-11-22

285

Low thrust chemical rocket technology  

NASA Astrophysics Data System (ADS)

An on-going technology program to improve the performance of low thrust chemical rockets for spacecraft on-board propulsion applications is reviewed. Improved performance and lifetime is sought by the development of new predictive tools to understand the combustion and flow physics, introduction of high temperature materials and improved component designs to optimize performance, and use of higher performance propellants. Improved predictive technology is sought through the comparison of both local and global predictions with experimental data. Predictions are based on both the RPLUS Navier-Stokes code with finite rate kinetics and the JANNAF methodology. Data were obtained with laser-based diagnostics along with global performance measurements. Results indicate that the modeling of the injector and the combustion process needs improvement in these codes and flow visualization with a technique such as 2-D laser induced fluorescence (LIF) would aid in resolving issues of flow symmetry and shear layer combustion processes. High temperature material fabrication processes are under development and small rockets are being designed, fabricated, and tested using these new materials. Rhenium coated with iridium for oxidation protection was produced by the Chemical Vapor Deposition (CVD) process and enabled an 800 K increase in rocket operating temperature. Performance gains with this material in rockets using Earth storable propellants (nitrogen tetroxide and monomethylhydrazine or hydrazine) were obtained through component redesign to eliminate fuel film cooling and its associated combustion inefficiency while managing head end thermal soakback. Material interdiffusion and oxidation characteristics indicated that the requisite lifetimes of tens of hours were available for thruster applications. Rockets were designed, fabricated, and tested with thrusts of 22, 62, 440 and 550 N. Performance improvements of 10 to 20 seconds specific impulse were demonstrated. Higher performance propellants were evaluated: Space storable propellants, including liquid oxygen (LOX) as the oxidizer with nitrogen hydrides or hydrocarbon as fuels. Specifically, a LOX/hydrazine engine was designed, fabricated, and shown to have a 95 pct theoretical c-star which translates into a projected vacuum specific impulse of 345 seconds at an area ratio of 204:1. Further performance improvment can be obtained by the use of LOX/hydrogen propellants, especially for manned spacecraft applications, and specific designs must be developed and advanced through flight qualification.

Schneider, Steven J.

1992-11-01

286

A computational study of a supersonic mixer-ejector exhaust system  

Microsoft Academic Search

An analytical model of the mixer ejector based on a PNS solver approach was used to analyze the flowfield downstream of a supersonic mixer-ejector exhaust system. The method has been used previously to analyze the plume flowfield of unshrouded mixer-type nozzles as well as the flowfield within the mixing duct of a mixer-ejector exhaust system. Calculations are presented for a

T. J. Barber

1992-01-01

287

Research Status of the Variable Specific Impulse Magnetoplasma Rocket  

NASA Astrophysics Data System (ADS)

Research in the VASIMR approach to high-power rocket propulsion has continued since 1980. The system consists of a three-stage asymmetric magnetic mirror, featuring a hybrid magnetic nozzle. Plasma is injected, heated and subsequently exhausted to provide modulated thrust and specific impulse at constant power. Plasma injector studies initially involve a modified Lorentz Force Accelerator. Other injector concepts, including helicons and hollow cathodes are briefly examined. Plasma heating methodsinvolve electron and ion cyclotron resonance, though other efficiency enhancements such as whistlers and mode coupling are being explored. Plasma detachment dynamics from the magnetic nozzle are considered. In the low temperature, high density regime, the use of a co-axial, hypersonic neutral gas boundary layer near the nozzle throat increases the thrust while triggering collisional plasma detachment. In the high temperature, low density regime, inducing time-dependent magnetic ripples in the nozzle is a potential turbulence-inducing mechanism for plasma detachment. Experimental studies currently focus on plasma injection and heating to power levels of up to 200kW in pulses of several seconds. A diagnostics set characterizes the plasma conditions throughout the system. Performance and advantages over other rocket technologies are presented in the context of a mission to Mars.

Chang-Diaz, F. R.

1997-11-01

288

Chemical Plume Source Localization  

Microsoft Academic Search

This paper addresses the problem of estimating a likelihood map for the location of the source of a chemical plume using an autonomous vehicle as a sensor probe in a fluid flow. The fluid flow is assumed to have a high Reynolds number. Therefore, the dispersion of the chemical is dominated by turbulence, resulting in an intermittent chemical signal. The

Shuo Pang; Jay A. Farrell

2006-01-01

289

Buoyant plume calculations  

SciTech Connect

Smoke from raging fires produced in the aftermath of a major nuclear exchange has been predicted to cause large decreases in surface temperatures. However, the extent of the decrease and even the sign of the temperature change, depend on how the smoke is distributed with altitude. We present a model capable of evaluating the initial distribution of lofted smoke above a massive fire. Calculations are shown for a two-dimensional slab version of the model and a full three-dimensional version. The model has been evaluated by simulating smoke heights for the Hamburg firestorm of 1943 and a smaller scale oil fire which occurred in Long Beach in 1958. Our plume heights for these fires are compared to those predicted by the classical Morton-Taylor-Turner theory for weakly buoyant plumes. We consider the effect of the added buoyancy caused by condensation of water-laden ground level air being carried to high altitude with the convection column as well as the effects of background wind on the calculated smoke plume heights for several fire intensities. We find that the rise height of the plume depends on the assumed background atmospheric conditions as well as the fire intensity. Little smoke is injected into the stratosphere unless the fire is unusually intense, or atmospheric conditions are more unstable than we have assumed. For intense fires significant amounts of water vapor are condensed raising the possibility of early scavenging of smoke particles by precipitation. 26 references, 11 figures.

Penner, J.E.; Haselman, L.C.; Edwards, L.L.

1985-01-01

290

Evaluation of Visible Plumes.  

ERIC Educational Resources Information Center

|Developed for presentation at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971, this outline discusses plumes with contaminants that are visible to the naked eye. Information covers: (1) history of air pollution control regulations, (2) need for methods of evaluating…

Brennan, Thomas

291

PLUME and research sotware  

NASA Astrophysics Data System (ADS)

The PLUME open platform (https://www.projet-plume.org) has as first goal to share competences and to value the knowledge of software experts within the French higher education and research communities. The project proposes in its platform the access to more than 380 index cards describing useful and economic software for this community, with open access to everybody. The second goal of PLUME focuses on to improve the visibility of software produced by research laboratories within the higher education and research communities. The "development-ESR" index cards briefly describe the main features of the software, including references to research publications associated to it. The platform counts more than 300 cards describing research software, where 89 cards have an English version. In this talk we describe the theme classification and the taxonomy of the index cards and the evolution with new themes added to the project. We will also focus on the organisation of PLUME as an open project and its interests in the promotion of free/open source software from and for research, contributing to the creation of a community of shared knowledge.

Baudin, Veronique; Gomez-Diaz, Teresa

2013-04-01

292

Double Diffusive Plumes  

NASA Astrophysics Data System (ADS)

Sour gas flares attempt to dispose of deadly H2S gas through combustion. What does not burn rises as a buoyant plume. But the gas is heavier than air at room temperature, so as the rising gas cools eventually it becomes negatively buoyant and descends back to the ground. Ultimately, our intent is to predict the concentrations of the gas at ground level in realistic atmospheric conditions. As a first step towards this goal we have performed laboratory experiments examining the structure of a steady state plume of hot and salty water that rises buoyantly near the source and descends as a fountain after it has cooled sufficiently. We call this a double-diffusive plume because its evolution is dictated by the different (turbulent) diffusivities of heat and salt. A temperature and conductivity probe measures both the salinity and temperature along the centreline of the plume. The supposed axisymmetric structure of the salinity concentration as it changes with height is determined by light-attenuation methods. To help interpret the results, a theory has been successfully adapted from the work of Bloomfield and Kerr (2000), who developed coupled equations describing the structure of fountains. Introducing a new empirical parameter for the relative rates of turbulent heat and salt diffusion, the predictions are found to agree favourably with experimental results.

Sutherland, Bruce; Lee, Brace

2008-11-01

293

Effect of Gaseous and Solid Simulated Jet Plumes on a 040A Space Shuttle Launch Configuration at Mach Numbers from 1.6 to 2.2.  

National Technical Information Service (NTIS)

An experimental investigation was conducted in a 9- by 7-foot supersonic wind tunnel to determine the effect of plume-induced flow separation and aspiration effects due to operation of both the orbiter and the solid rocket motors on a 0.019-scale model of...

M. J. Lanfranco V. W. Sparks A. T. Kavanaugh

1973-01-01

294

Ablation Radiation Shields for Nuclear Fusion Rockets  

Microsoft Academic Search

Pulse nuclear propulsion has been the subject of extensive studies since the 1960's. Early concepts examined external pulse propulsion where small critical mass nuclear devices are ejected from the rear of the rocket. A pusher plate absorbs some of the energy form the detonation, which ablates the plate and provides thrust for the rocket. It is also possible to have

Luis Coreano; Brice N. Cassenti

2003-01-01

295

Esrange activities: Sounding rockets, balloons and satellites  

Microsoft Academic Search

The range facilities are described in detail for the prospective user, including instrumentation launch capabilities, support facilities, and costs. High performance sounding rockets such as Aries and Nike BB can now, thanks to guidance systems, be launched above 500 km allowing the exploration of higher regions and longer observation time. Microgravity experiments using sounding rockets are successfully carried out from

A. Helger

1980-01-01

296

Computational modeling of nuclear thermal rockets  

Microsoft Academic Search

The topics are presented in viewgraph form and include the following: rocket engine transient simulation (ROCETS) system; ROCETS performance simulations composed of integrated component models; ROCETS system architecture significant features; ROCETS engineering nuclear thermal rocket (NTR) modules; ROCETS system easily adapts Fortran engineering modules; ROCETS NTR reactor module; ROCETS NTR turbomachinery module; detailed reactor analysis; predicted reactor power profiles; turbine

Steven D. Peery

1993-01-01

297

NASA Sounding Rocket Program educational outreach  

Microsoft Academic Search

Educational and public outreach is a major focus area for the National Aeronautics and Space Administration (NASA). The NASA Sounding Rocket Program (NSRP) shares in the belief that NASA plays a unique and vital role in inspiring future generations to pursue careers in science, mathematics, and technology. To fulfill this vision, the NASA Sounding Rocket Program engages in a host

P. J. Eberspeaker

2005-01-01

298

NASA Sounding Rocket Daytime Dynamo Launch Postponed  

NASA Website

The launch of two sounding rockets from the Wallops Flight Facility was scrubbed on Wednesday, July 3 due to poor weather in the area. The next attempt for these two rockets will be Thursday, July 4, with a window of 9:30-11:30 a.m.

299

Nuclear thermal rockets - next step to space  

Microsoft Academic Search

The prospects for the use of nuclear thermal rockets in manned interplanetary exploration are examined. These rockets offer the possibility for trip times on the order of a year or less in the next two decades. Mission prospects for gas-core concepts are emphasized, showing how such concepts meet the mission requirements.

S. K. Borowski; E. A. Gabris; J. Martinell

1989-01-01

300

Performance Comparison of Two Small Rocket Nozzles.  

National Technical Information Service (NTIS)

An experimental study was conducted on two small rockets (110 N thrust class) to directly compare a standard conical nozzle with a bell nozzle optimized for maximum thrust using the Rao method. In large rockets, with throat Reynolds numbers of greater tha...

L. A. Arrington B. D. Reed A. Rivera

1996-01-01

301

Behind the Scenes: 'Fishing' For Rockets  

NASA Video Gallery

In this episode of NASA "Behind the Scenes," go on board the two ships -- Liberty Star and Freedom Star -- which retrieve the shuttle's solid rocket boosters after every launch. Astronaut Mike Massimino introduces you to the crew and takes you onboard the vessels to see what it takes to pull a 150-foot rocket out of the ocean.

Jim Wilson

2011-01-31

302

Evaluation of the Pilot Rocket Scrubber.  

National Technical Information Service (NTIS)

The technical and economical feasibility of a pilot rocket scrubber was evaluated based on 23 tests of liquid and solid rocket motors with a thrust of 5,000 pounds. The initial test, using liquid fluorine and gaseous hydrogen, resulted in extensive damage...

L. Sedillo

1978-01-01

303

Design of sounding rocket payloads  

NASA Astrophysics Data System (ADS)

This report is a summary of work accomplished from 1 May 1976 to 30 April 1981. Contract efforts were in the design, fabrication, testing, and launch support of sounding rocket payloads and related ground support equipment. Specific areas of work related to this report include: payload structures, component packaging, deployment and eject mechanisms, diagnostic components, in-flight sequencing, power systems and control consoles. Also described are electrical and mechanical interfaces with experiments, telemetry systems, attitude control systems, recovery systems and other payload subsystems.

Morin, R. L.; Oconnor, L. J.

1981-07-01

304

Demilitarization of Lance rocket motors  

NASA Astrophysics Data System (ADS)

In 1992 Royal Ordnance was awarded contract by NAMSA for the demilitarization of NATO's European stock of Lance missile rocket motors. Lance is a liquid fueled surface to surface guided missile designed to give general battlefield support with either a nuclear or conventional capability at ranges of up to 130 km. The NAMSA contract required Royal Ordnance to undertake the following: (1) transportation of missiles from NATO depots in Europe to Royal Ordnance's factory at Bishopton in Scotland; (2) establishment of a dedicated demilitarization facility at Bishopton; and (3) demilitarization of live M5 and M6 training missiles by the end of 1994.

Sargent, Peter

1995-02-01

305

Stellar Ultraviolet Rocket Research Program  

NASA Astrophysics Data System (ADS)

A 1/4 meter ultraviolet spectrometer, developed to measure the ultraviolet flux from several standard type stars was flown successfully on Aerobee rockets. The ultraviolet flux from alpha Lyr, eta U Ma, zeta Oph, delta Ori, alpha CMa, beta CMa, and alpha Leo were measured. These values agreed with the OAO data obtained by Code in the 1200 to 3400 A region to + or - 9%. The design and calibration of a faint object spectrometer for observing stars and nebula with a 3 A resolution and a 3% accuracy in a 60 second observation are discussed.

306

Yes! We are Rocket Scientists!  

NSDL National Science Digital Library

Launch your middle school students' interest, incorporate hands-on/minds-on learning, and focus on inquiry learning while still meeting state and national standards by implementing the following water-bottle rocket activity into your physical science curriculum. This article is an outline of how one teacher enlisted the help of two volunteer engineers to create a powerful learning unit and cumulative review for eighth-grade physcial science students. This unit reviews what students have learned during the school year regarding force, motion, Newton's laws, gas laws, and center of gravity.

Macduff, J. T.

2006-09-01

307

Design of a Six Degree of Freedom Thrust Sensor for a Hybrid Rocket  

Microsoft Academic Search

A hybrid rocket is composed of a solid fuel and a separate liquid or gaseous oxidizer. These rockets may be throttled like liquid rockets, are safer than solid rockets, and are much less complex than liquid rockets. However, hybrid rockets produce thrust oscillations that are not practical for large scale use. A lab scale hybrid rocket at the University of

Tripp McGehee

2005-01-01

308

The exhausted horse syndrome.  

PubMed

Exhaustion occurs in most equestrian sports, but it is more frequent in events that require sustained endurance work such as endurance racing, three-day eventing, trial riding, and hunting. Exhaustion is also more likely when an unfit, unacclimatized, or unsound horse is exercised. Mechanisms that contribute to exhaustion include heat retention, fluid and electrolyte loss, acid-base imbalance, and intramuscular glycogen depletion. Clinical signs include elevated temperature, pulse, and respiratory rate; depression; anorexia; unwillingness to continue to exercise; dehydration; weakness; stiffness; hypovolemic shock; exertional myopathy; synchronous diaphragmatic flutter; atrial fibrillation; diarrhea; colic; and laminitis. Treatment includes stopping exercise; rapid cooling; rapid large volume intravenous or oral fluid administration; and nonsteroidal anti-inflammatory drug administration. PMID:9561696

Foreman, J H

1998-04-01

309

SSTO rockets. A practical possibility  

NASA Astrophysics Data System (ADS)

Most experts agree that single-stage-to-orbit (SSTO) rockets would become feasible if more advanced technologies were available to reduce the vehicle dry weight, increase propulsion system performance, or both. However, these technologies are usually judged to be very ambitious and very far off. This notion persists despite major advances in technology and vehicle design in the past decade. There appears to be four major misperceptions about SSTOs, regarding their mass fraction, their presumed inadequate performance margin, their supposedly small payloads, and their extreme sensitivity to unanticipated vehicle weight growth. These misperceptions can be dispelled for SSTO rockets using advanced technologies that could be matured and demonstrated in the near term. These include a graphite-composite primary structure, graphite-composite and Al-Li propellant tanks with integral reusable thermal protection, long-life tripropellant or LOX-hydrogen engines, and several technologies related to operational effectiveness, including vehicle health monitoring, autonomous avionics/flight control, and operable launch and ground handling systems.

Bekey, Ivan

1994-07-01

310

Laser beam propagation experiments along and across a jet engine plume  

Microsoft Academic Search

Airplane based laser systems for DIRCM, active imaging and communication are important applications attracting considerable interest. The performance of these systems in directions where the laser beam points close to or through the exhaust plume from the jet engines may be severely reduced. A trial to study these phenomena using a downscaled jet-engine test rig was carried out. The results

Markus Henriksson; Lars Sjöqvist; Dirk Seiffer; Norbert Wendelstein; Erik Sucher

2008-01-01

311

Scanning thermal plumes  

Microsoft Academic Search

Over a three-year period 800 thermal line scans of power plant plumes were made by an airborne scanner, with ground truth measured concurrently at the plants. Computations using centered finite differences in the thermal scanning imagery show a lower bound in the horizontal temperature gradient in excess of 1.6 C\\/m. Gradients persist to 3 m below the surface. Vector plots

F. L. Scarpace; R. P. Madding; T. Green

1975-01-01

312

Crossfire calibrated exhaust system  

SciTech Connect

This patent describes a dual-exhaust system for an internal combustion engine having a pair of spaced-apart pipes channeling exhaust gases from the engine towards a muffler. It comprises first and second additional pipes connected between the pair of spaced-apart pipes at substantially 45[degrees] angles with respect to each of the pair of pipes and at substantially a 90[degrees] angle with respect to each other; and wherein the first and second additional pipes are also interconnected with each other substantially at the midpoints thereof, measured along their respective lengths, and substantially midway between the pair of spaced-apart pipes.

Barth, R.S.

1992-09-08

313

Turbine engine exhaust gas measurements using in-situ FT-IR emission\\/transmission spectroscopy  

Microsoft Academic Search

12 An advanced multiple gas analyzer based on in-situ Fourier transform infrared spectroscopy has been used to successfully measure the exhaust plume composition and temperature of an operating gas turbine engine at a jet engine test stand. The sensor, which was optically coupled to the test cell using novel broadband hollow glass waveguides, performed well in this harsh environment (high

David F. Marran; Joseph E. Cosgrove; Jorge Neira; James R. Markham; Ronald Rutka; Richard R. Strange

2001-01-01

314

Parametric design study of laser fusion rocket  

NASA Astrophysics Data System (ADS)

Fusion offers the potential for a very high specific power and a large specific impulse. Thus, a fusion rocket is a leading candidate as a spacecraft for manned exploration of the solar system. We present here a parametric design study of the laser fusion rocket. The parameters include pellet gain (G = 300 approximately 2000), fusion repetition rate (f = 10 approximately 100Hz), and fusion fuel (DT, D(3)He). First, the mass contributed by each component of the rocket, such as the laser driver, is evaluated, and then the masses are summed over the components to obtain the total mass, which is further divided by fusion power to estimate the specific power. Using the specific power, flight performance of the rocket designs is compared. In the comparison, the figure of merit used is the minimum time required for travel of a fixed distance. We found that there exists an optimal value for each design parameter which brings about the best flight performance of the rocket. However, the optimal values thus obtained are far above the values needed for terrestrial application, although some ambiguities may exist in the values due to the lack of the data base for the design parameters. It is also found that the laser fusion rocket fueled with DT or D(3)He has the potential advantages over other propulsion systems, such as a fission rocket, for interplanetary travel.

Nakashima, Hideki; Shoyama, Hidetoshi; Kanda, Yukinori; Nakao, Yasuyuki

315

Aircraft emissions, plume chemistry, and alternative fuels: results from the APEX, AAFEX, and MDW-2009 campaigns  

NASA Astrophysics Data System (ADS)

We describe observations of aircraft emissions from the APEX, JETS-APEX2, APEX3, MDW-2009 and AAFEX campaigns. Direct emissions of HOx precursors are important for understanding exhaust plume chemistry due to their role in determining HOx concentrations. Nitrous acid (HONO) and formaldehyde are crucial HOx precursors and thus drivers of plume chemistry. At idle power, aircraft engine exhaust is unique among fossil fuel combustion sources due to the speciation of both NOx and VOCs. The impacts of emissions of HOx precursors on plume chemistry at low power are demonstrated with empirical observations of rapid NO to NO2 conversion, indicative of rapid HOx chemistry. The impacts of alternative fuels (derived from biomass, coal, and natural gas) on emissions of NOx, CO, and speciated VOCs are discussed.

Wood, E. C.; Herndon, S. C.; Timko, M.; Yu, Z.; Miake-Lye, R. C.; Lee, B. H.; Santoni, G.; Munger, J. W.; Wofsy, S.; Anderson, B.; Knighton, W. B.

2009-12-01

316

Satellite Observations of Space Shuttle Main Engine Exhaust: Vertical Diffusion and Meridional Transport  

NASA Astrophysics Data System (ADS)

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment on NASA’s Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite has observed water vapor radiances near 6.6 microns on the Earth’s limb since the TIMED launch in December, 2001. Following a space shuttle launch, SABER typically observes enhanced water vapor emission between 90-110 km altitude near the east coast of the United States, where the shuttle injects about 300 metric tons of water vapor exhaust from its three main engines. SABER has observed plumes from 20 space shuttle launches since 2002, all within 25 hours of injection. The database of observations now consists of over 80 separate plume scans, each of which is identified with a peak altitude, a peak brightness and a plume thickness. We compare these SABER shuttle plume observations with a two-dimensional diffusion model that includes photodissociation to determine whether the time evolution of the plume altitude and thickness can be reproduced. Some observations indicate that the shuttle plume is subject to rapid meridional transport. We compare the inferred meridional motion of the plumes with a satellite-derived wind climatology. We include the effects of tidal variability on the shuttle plume and determine whether there is a time of year during which the wind climatology better explains the observed meridional transport.

Stevens, M. H.; Meier, R. R.; Plane, J. M.; Emmert, J. T.; Russell, J.

2010-12-01

317

Thrust control system design of ducted rockets  

NASA Astrophysics Data System (ADS)

The investigation of the thrust control system is aroused by the need for propulsion system of ducted rockets. Firstly the dynamic mathematical models of gas flow regulating system, pneumatic servo system and ducted rocket engine were established and analyzed. Then, to conquer the discussed problems of thrust control, the idea of information fusion was proposed to construct a new feedback variable. With this fused feedback variable, the thrust control system was designed. According to the simulation results, the introduction of the new fused feedback variable is valid in eliminating the contradiction between rapid response and stability for the thrust control system of ducted rockets.

Chang, Juntao; Li, Bin; Bao, Wen; Niu, Wenyu; Yu, Daren

2011-07-01

318

Auxiliary exhaust system  

Microsoft Academic Search

An auxiliary exhaust system for use with a flue includes a conduit communicating at one end with an opening formed in the flue wall and a blower operable to introduce auxiliary air into the flue through the conduit. The conduit is angled so that the auxiliary air enters the flue with a velocity component extending in the downstream direction of

G. T. Horvat; S. D. Horvat

1984-01-01

319

Catalytic automotive exhaust aftertreatment  

Microsoft Academic Search

Catalytic exhaust aftertreatment of vehicle engines is increasingly employed to the benefit of the atmosphere quality, especially in the large urban area of the world. Both spark-ignition and compression-ignition engines benefit from the application of catalytic converters for the elimination of their main pollutants. Catalysts are further employed in various forms as regeneration aids in particulate filters of diesel engines.

Grigorios C. Koltsakis; Anastasios M. Stamatelos

1997-01-01

320

Stirring and structure in mantle starting plumes  

Microsoft Academic Search

Simple arguments show that ascending thermal plumes will entrain their surroundings as the result of coupling between conduction of heat and laminar stirring driven by the plume motion. In the initial stages of ascent of a plume fed by a continuous buoyancy flux (a starting plume) the plume consists of a large buoyant head followed by a narrow vertical conduit.

Ross W. Griffiths; Ian H. Campbell

1990-01-01

321

Effect of plume processes on aircraft impact  

Microsoft Academic Search

A versatile Gaussian plume model has been developed and used to investigate the chemistry in expanding aircraft plumes for a wide range of conditions, including the plume expansion rate, the composition of the background atmosphere, and the total time of the plume integration. The dependence of plume processing on altitude, latitude and season has been investigated in order to generate

P. F. Vohralik; L. K. Randeniya; I. C. Plumb; S. L. Baughcum

2008-01-01

322

Anchoring Atmospheric Density Models Using Observed Shuttle Plume Emissions  

NASA Astrophysics Data System (ADS)

Atmospheric number densities at a given low-earth orbit (LEO) altitude can vary by more than an order of magnitude, depending on such parameters as diurnal variations and solar activity. The MSIS atmospheric model, which includes these dependent variables as input, is reported as being accurate to ±15%. Improvement to such models requires accurate direct atmospheric measurement. Here, a means of anchoring atmospheric models is offered through measuring the size and shape of atomic line or molecular band radiance resulting from the atmospheric interaction from rocket engine plumes or gas releases in LEO. Many discrete line or band emissions, ranging from the infrared to the ultraviolet may be suitable. For this purpose we are focusing on NH(A?X), centered at 316 nm. This emission is seen in the plumes of the Shuttle Orbiter PRCS engines, is expected in the plume of any amine fueled engine, and can be observed from remote sensors in space or on the ground. The atmospheric interaction of gas releases or plumes from spacecraft in LEO are understood by comparison of observed radiance with that predicted by Direct Simulation Monte Carlo (DSMC) models. The recent Extended Variable Hard Sphere (EVHS) improvements in treating hyperthermal collisions has produced exceptional agreement between measured and modeled steady-state Space Shuttle OMS and PRCS 190-250 nm Cameron band plume radiance from CO(a?X), which is understood to result from a combination of two- and three-step mechanisms. Radiance from NH(A?X) in far field plumes is understood to result from a simpler single-step process of the reaction of a minor plume species with atomic oxygen, making it more suitable for use in determining atmospheric density. It is recommended that direct retrofire burns of amine fueled engines be imaged in a narrow band from remote sensors to reveal atmospheric number density. In principal the simple measurement of the distance between the engine exit and the peak in the steady-state radiance from LEO spacecraft can indicate atmospheric density to ~1% accuracy. Use of this radiance requires calibration by an accurate independent measurement associated with a well-resolved steady-state image of it.

Dimpfl, W. L.; Bernstien, L. S.

2010-12-01

323

Collaborative Sounding Rocket launch in Alaska and Development of Hybrid Rockets  

NASA Astrophysics Data System (ADS)

Tokai University student rocket project (TSRP) was established in 1995 for a purpose of the space science and engineering hands-on education, consisting of two space programs; the one is sounding rocket experiment collaboration with University of Alaska Fairbanks and the other is development and launch of small hybrid rockets. In January of 2000 and March 2002, two collaborative sounding rockets were successfully launched at Poker Flat Research Range in Alaska. In 2001, the first Tokai hybrid rocket was successfully launched at Alaska. After that, 11 hybrid rockets were launched to the level of 180-1,000 m high at Hokkaido and Akita in Japan. Currently, Tokai students design and build all parts of the rockets. In addition, they are running the organization and development of the project under the tight budget control. This program has proven to be very effective in providing students with practical, real-engineering design experience and this program also allows students to participate in all phases of a sounding rocket mission. Also students learn scientific, engineering subjects, public affairs and system management through experiences of cooperative teamwork. In this report, we summarize the TSRP's hybrid rocket program and discuss the effectiveness of the program in terms of educational aspects.

Ono, Tomohisa; Tsutsumi, Akimasa; Ito, Toshiyuki; Kan, Yuji; Tohyama, Fumio; Nakashino, Kyouichi; Hawkins, Joseph

324

Upwelling relaxation and estuarine plumes  

NASA Astrophysics Data System (ADS)

After coastal upwelling, the water properties in the nearshore coastal region close to estuaries is determined by the race between the new estuarine plume traveling along the coast and the upwelled front (a marker for the old upwelled plume and the coastal pycnocline) returning to the coast under downwelling winds. Away from an estuary, downwelling winds can return the upwelled front to the coast bringing less dense water nearshore. Near the estuary, the estuarine plume can arrive along the coast and return less dense water to the nearshore region before the upwelled front returns to the coast. Where the plume brings less dense water to the coast first, the plume keeps the upwelled front from returning to the coast. In this region, only the plume and the anthropogenic input and larvae associated with the plume waters influence the nearshore after upwelling. We quantify the extent of the region where the plume is responsible for bringing less dense water to the nearshore and keeping the upwelled front from returning to the coast after upwelling. We successfully tested our predictions against numerical experiments and field observations of the Chesapeake plume near Duck, North Carolina. We argue that this alongshore region exists for other estuaries where the time-integrated upwelling and downwelling wind stresses are comparable.

Rao, Shivanesh; Pringle, James; Austin, Jay

2011-09-01

325

Mantle plumes and continental tectonics.  

PubMed

Mantle plumes and plate tectonics, the result of two distinct modes of convection within the Earth, operate largely independently. Although plumes are secondary in terms of heat transport, they have probably played an important role in continental geology. A new plume starts with a large spherical head that can cause uplift and flood basalt volcanism, and may be responsible for regional-scale metamorphism or crustal melting and varying amounts of crustal extension. Plume heads are followed by narrow tails that give rise to the familiar hot-spot tracks. The cumulative effect of processes associated with tail volcanism may also significantly affect continental crust. PMID:17744717

Hill, R I; Campbell, I H; Davies, G F; Griffiths, R W

1992-04-10

326

Solid rocket motor temperature sensitivity  

SciTech Connect

The temperature sensitivity of the propellant and the solid rocket motor are described by several different temperature sensitivity coefficients. This enabled the derivation of three different relationships for the temperature sensitivity coefficient pi(sub K). To demonstrate this, two different propellants were used wherein the values of pi(sub K) were generated and compared. It was observed that the expressions are of equal complexity and offer ease of use. All involve only the burning rate data and the use of the parameters in St. Roberts burning rate low. It is also suggested that the most general expression for the sensitivity coefficient should be used since it is a true pi(sub K) relationship having the partial derivatives taken with the motor geometry held constant. 11 refs.

Osborn, J.R.; Heister, S.D. [Purdue Univ, West Lafayette, IN (United States)

1994-11-01

327

Solar Dynamics Observatory's (SDO) Atlas V rocket  

NASA Video Gallery

Moments after launch, the Solar Dynamics Observatory's (SDO) Atlas V rocket flew past a sundog hanging suspended in the blue Florida sky and, with a rippling flurry of shock waves, destroyed it. Credit: Anna Herbs

Melissa Quijada

2011-02-14

328

Design and Fabrication of Sounding Rocket Payloads.  

National Technical Information Service (NTIS)

An ongoing effort has been maintained from February 1971 through January 1972 providing engineering design, fabrication, test and field support services concerned with various sounding rocket payloads. A concise summary of the details relative to each pay...

R. E. Kenyon

1972-01-01

329

Space Storable Rocket Technology (SSRT) Basic Program.  

National Technical Information Service (NTIS)

The Space Storable Rocket Technology Program (SSRT) was conducted to establish a technology for a new class of high performance and long life bipropellant engines using space storable propellants. The results are described. Task 1 evaluated several charac...

M. L. Chazen T. Mueller A. R. Casillas D. Huang

1992-01-01

330

Transpiration Cooled Throat for Hydrocarbon Rocket Engines.  

National Technical Information Service (NTIS)

This program's objective was to characterize the use of hydrocarbon fuels as transpiration coolants for rocket nozzle throats. The hydrocarbon fuels investigated in this program were RP-1 and methane. To adequately characterize the above transpiration coo...

L. May W. M. Burkhardt

1991-01-01

331

German Scientific Balloon and Sounding Rocket Program.  

National Technical Information Service (NTIS)

Sounding rocket projects in astronomy, aeronomy, magnetospheric research, material sciences, and life sciences under microgravity are described. Balloon projects in astronomy and aeronomy are presented. Satellite projects including AMPTE, SOHO, Cluster, S...

A. F. Dahl M. Otterbein

1987-01-01

332

History of Solid Rocket Propulsion and Aerojet.  

National Technical Information Service (NTIS)

Much of the early history of rocket propulsion has not been the subject of organized historical documentation, and with the passage of time, and proliferation of organizational changes, the prospects for developing a clear picture of past events and fadin...

P. D. Umholtz

1999-01-01

333

Ariane - The rocket system with a future  

NASA Astrophysics Data System (ADS)

The present state an prospects of the Ariane Rocket are discussed. The market for Ariane, its operational punctuality and reliability are examined. The economicality and uses of Ariane's serial production is addressed, and the competition that Ariane faces is considered.

Jaeger, Ralph-Werner

1992-06-01

334

Contemporary computational modeling of Nuclear Thermal Rockets  

NASA Astrophysics Data System (ADS)

A computational package is presented for the simulation and in-depth analysis of Nuclear Thermal Rocket (NTR) propulsion systems. The package integrates a number of modular component codes modeling major NTR components and includes a system of multidimensional computer codes for the analysis of the nuclear and thermal fluid design of the nuclear reactor. The computational package is used to perform a cycle analysis to define a cermet fueled nuclear rocket engine, the XNR2000.

Peery, Steven D.; Parsley, Randy C.; Anghaie, Samim; Feller, Gerald J.

1992-09-01

335

Computational modeling of nuclear thermal rockets  

NASA Astrophysics Data System (ADS)

The topics are presented in viewgraph form and include the following: rocket engine transient simulation (ROCETS) system; ROCETS performance simulations composed of integrated component models; ROCETS system architecture significant features; ROCETS engineering nuclear thermal rocket (NTR) modules; ROCETS system easily adapts Fortran engineering modules; ROCETS NTR reactor module; ROCETS NTR turbomachinery module; detailed reactor analysis; predicted reactor power profiles; turbine bypass impact on system; and ROCETS NTR engine simulation summary.

Peery, Steven D.

336

Instrumentation of UALR labscale hybrid rocket motor  

Microsoft Academic Search

The Central Arkansas Combustion Group has used a NASA EPSCoR grant to improve the instrumentation and control of its labscale hybrid rocket facility. The research group investigates fundamental aspects of combustion in hybrid rocket motors. This paper describes the new instrumentation, provides examples of measurements taken, and describes novel instrumentation which is in the process of development. A six degree-of-freedom

Andrew B. Wright; Warfield Teague; Ann M. Wright; Edmond W. Wilson

2006-01-01

337

Pattern classification approach to rocket engine diagnostics  

Microsoft Academic Search

This paper presents a systems level approach to integrate state-of-the-art rocket engine technology with advanced computational techniques to develop an integrated diagnostic system (IDS) for future rocket propulsion systems. The key feature of this IDS is the use of advanced diagnostic algorithms for failure detection as opposed to the current practice of redline-based failure detection methods. The paper presents a

Tulpule

1989-01-01

338

Machine Learning for Rocket Propulsion Health Monitoring  

Microsoft Academic Search

This paper describes the initial results of applying two machine-learning-based unsupervised anomaly detection algorithms, Orca and GritBot, to data from two rocket propulsion testbeds. The first testbed uses historical data from the Space Shuttle Main Engine. The second testbed uses data from an experimental rocket engine test stand located at NASA Stennis Space Center. The paper describes four candidate anomalies

Mark Schwabacher

2005-01-01

339

Hybrid rocket engine, theoretical model and experiment  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to build a theoretical model for the hybrid rocket engine/motor and to validate it using experimental results. The work approaches the main problems of the hybrid motor: the scalability, the stability/controllability of the operating parameters and the increasing of the solid fuel regression rate. At first, we focus on theoretical models for hybrid rocket motor and compare the results with already available experimental data from various research groups. A primary computation model is presented together with results from a numerical algorithm based on a computational model. We present theoretical predictions for several commercial hybrid rocket motors, having different scales and compare them with experimental measurements of those hybrid rocket motors. Next the paper focuses on tribrid rocket motor concept, which by supplementary liquid fuel injection can improve the thrust controllability. A complementary computation model is also presented to estimate regression rate increase of solid fuel doped with oxidizer. Finally, the stability of the hybrid rocket motor is investigated using Liapunov theory. Stability coefficients obtained are dependent on burning parameters while the stability and command matrixes are identified. The paper presents thoroughly the input data of the model, which ensures the reproducibility of the numerical results by independent researchers.

Chelaru, Teodor-Viorel; Mingireanu, Florin

2011-06-01

340

Advanced Solid Rocket Launcher and Its Evolution  

NASA Astrophysics Data System (ADS)

The research on next generation solid propellant rockets is actively underway in various spectra. JAXA is developing the Advanced Solid Rocket (ASR) as a successor to the M-V launch vehicle, which was utilized over past ten years for space science programs including planetary missions. ASR is a result of the development of the next generation technology including a highly intelligent autonomous check-out system, which is connected to not only the solid rocket but also future transportation systems. It is expected to improve the efficiency of the launch system and double the cost performance. Far beyond this effort, the passion of the volunteers among the industry-government-academia cooperation has been united to establish the society of the freewheeling thinking “Next generation Solid Rocket Society (NSRS)”. It aims at a larger revolution than what the ASR provides so that the order of the cost performance is further improved. A study of the Low melting temperature Thermoplastic Propellant (LTP) is now at the experimental stage, which is expected to reform the manufacturing process of the solid rocket propellant and lead to a significant increase in cost performance. This paper indicates the direction of the big flow towards the next generation solid-propellant rockets: the concept of the intelligent ASR under development; and the innovation behind LTP.

Morita, Yasuhiro; Imoto, Takayuki; Habu, Hiroto; Ohtsuka, Hirohito; Hori, Keiichi; Koreki, Takemasa; Fukuchi, Apollo; Uekusa, Yasuyuki; Akiba, Ryojiro

341

Automobile exhaust purifying system  

SciTech Connect

An exhaust purifying system is described for an automobile internal combustion engine which comprises, in combination; a catalytic converter disposed on an exhaust system of the engine and having a catalyst; a temperature detecting means for detecting a signal indicative of the temperature of the catalyst; a total engine operating hour detecting means for detecting a signal indicative of the total operating hour over which the engine has been operated; a spark timing control means for controlling the spark timing to retard when the temperature detecting means detects that the temperature of the catalyst is lower than a predetermined value; a retard time correcting means for increasing the amount of control performed by the spark timing control means with increase within a predetermined range detected by the total engine operating hour detecting means.

Hayama, N.; Yoshimura, T.; Tanikawa, Y.

1986-03-11

342

Diesel exhaust aftertreatment 1996  

SciTech Connect

The papers in this volume deal in the main with the two most common forms of aftertreatment technology. The first is the trap oxidizer, which is a system for trapping and filtering the particulate matter from the exhaust gas and periodically removing it by thermal oxidation. This process is commonly known as regeneration. The second is the diesel oxidation catalyst. Similar in many ways to the flow through a converter in passenger cars, it oxidizes the soluble organic fraction of the diesel exhaust as well as gaseous hydrocarbons and carbon monoxide. This catalyst is being used in production volumes in heavy duty trucks in the US beginning in 1994. Several papers in this volume deal with the development experience of this converter application. There also is included a series of papers by trap and filter manufacturers dealing with improved materials, making their devices more durable. Papers have been processed separately for inclusion on the data base.

NONE

1996-09-01

343

Exhaust gas filter  

Microsoft Academic Search

An exhaust gas filter is described for removing diesel particulates comprising a honeycomb of porous sintered ceramic fiber composite sheets, the honeycomb having channels with alternate ends of the channels closed. The ceramic fiber composite sheets have a bulk density of from 0.1 to 0.8 g\\/cmĀ³ and consists of from 40 wt. % to 96 wt. % ceramic fiber having

T. Kusuda; T. Mihara; M. Yonemura; S. Kuwano

1987-01-01

344

Exhaust Emission Catalyst Technology  

Microsoft Academic Search

New technologies, incorporating the platinum group metals, are available to meet the exhaust emission regulations for cars, light-duty and heavy-duty vehicles and motorcycles being adopted by the European Union for implementation during the new century. These technologies include low light-off catalysts, more themlly-durable catalysts, impmved substrate technology, hydrocarbon adsorbers, electrically heated catalysts, DeNOx catalysts and adsorbers, selective catalytic reduction and

Dirk Bosteels; Robert A. Searles

345

Atmospheric chemistry in volcanic plumes.  

PubMed

Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and heterogeneous reactions on aerosol particles that have previously been unexplored for this type of volcanic plumes. Key features of these measurements can be reproduced by numerical models such as the one employed in this study. The model shows sustained high levels of reactive bromine in the plume, leading to extensive ozone destruction, that, depending on plume dispersal, can be maintained for several days. The very high concentrations of sulfur dioxide in the volcanic plume reduces the lifetime of the OH radical drastically, so that it is virtually absent in the volcanic plume. This would imply an increased lifetime of methane in volcanic plumes, unless reactive chlorine chemistry in the plume is strong enough to offset the lack of OH chemistry. A further effect of bromine chemistry in addition to ozone destruction shown by the model studies presented here, is the oxidation of mercury. This relates to mercury that has been coemitted with bromine from the volcano but also to background atmospheric mercury. The rapid oxidation of mercury implies a drastically reduced atmospheric lifetime of mercury so that the contribution of volcanic mercury to the atmospheric background might be less than previously thought. However, the implications, especially health and environmental effects due to deposition, might be substantial and warrant further studies, especially field measurements to test this hypothesis. PMID:20368458

von Glasow, Roland

2010-04-05

346

LAMP Observes the LCROSS Plume  

NASA Video Gallery

This video shows LAMP’s view of the LCROSS plume. The first half of the animation shows the LAMP viewport scanning across the horizon, passing through the plume, and moving on. The second half of the animation shows how data generated from a previous orbit was used to reduce noise in the observed data.

gsfcvideo

2010-10-20

347

Mantle plumes and flood basalts  

Microsoft Academic Search

We discuss the geological, geophysical, and petrological observations that constrain the nature of mantle convection in plumes, and show how theoretical models of mantle plumes have developed over the past three decades. The large volumes of lava emplaced in geologically short periods as flood basalts are generated mainly by decompression melting of abnormally hot mantle brought to the base of

R. S. White; D. P. Mckenzie

1995-01-01

348

Exhaust gas reactor  

SciTech Connect

A reactor for the oxidation of unburned and partially burned components in the exhaust gas from an internal combustion engine comprising a chamber which is substantially circular in cross sections perpendicular to its axis, one or more inlet pipes which pass a mixture of exhaust gas and air substantially tangentially into the chamber near to one end thereof, and an outlet pipe near to the other end of the chamber and which is so arranged that exhaust gas leaves the chamber substantially tangentially. The tangential inlet and tangential outlet of gases minimizes energy losses in the gas passing through the reactor. The ratio of the cross-sectional areas of the inlet pipe(s) to reactor chamber is preferably from 1:9 to 25:36, and similar ranges of crosssectional area ratios are preferred for the outlet pipe and chamber. The ratio of the length of the reaction chamber to diameter is preferably from 1:1 to 4:1. The chamber may be cylindrical or divergent from inlet end to outlet end and may be thermally insulated.

Camarsa, M.; Cocchiara, F.; Garcea, G.P.

1981-11-24

349

Spectroscopic characteristics of polar plumes  

NASA Astrophysics Data System (ADS)

Extreme ultraviolet observations of plumes in polar coronal holes are presented and their spectroscopic signatures discussed. The study focuses on the base of plumes seen on the disk of the Sun with the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory (SOHO) satellite. Spectroscopic diagnostic techniques are applied to characterise the plumes in terms of density, temperature, emission measure and element abundance. Attention is drawn to the particular limitations of some of the techniques when applied to plume structures. In particular, we revisit the Widing & Feldman (1992) findings of a plume having a large first ionization potential (FIP) effect of 10, showing that instead the Skylab data are consistent with no FIP effect. We present for the first time CDS-GIS (grazing incidence spectrometer) observations of a plume. These observations have been used to confirm the results obtained from normal incidence (NIS) observations. We find that polar plumes exhibit the same characteristics as the Elephant's Trunk equatorial plume. The most striking characteristic of the plume bases is that they are near-isothermal with a peak emission measure at transition region temperatures =~ 8 x 105 K. At these temperatures, plumes have averaged densities Nlo {e} =~ 1.2 x 109 cm-3, about twice the value of the surrounding coronal hole region. Element abundances in the plumes are found to be close to photospheric, with the exception of neon which appears to be depleted by 0.2 dex relative to oxygen. The absence of a significant FIP effect in plumes is consistent with fast solar wind plasma, although it is not sufficient to prove a link between the two. Finally, we present a comparison between GIS spectra and the SOHO EIT (EUV Imaging Telescope) broad-band images, showing that temperatures derived from the EIT ratio technique are largely overestimated, for plumes and coronal holes. This is partly due to the fact that the so called ``Fe XII 195 Å'' and ``Fe XV 284 Å'' filters are not isothermal, and in coronal holes and plumes lower-temperature lines dominate the EIT signal.

Del Zanna, G.; Bromage, B. J. I.; Mason, H. E.

2003-02-01

350

Falling plumes in bacterial bioconvection  

NASA Astrophysics Data System (ADS)

Experiments by Kessler on bioconvection in laboratory suspensions of bacteria (Bacillus subtilis), contained in a deep chamber, reveal the development of a thin upper boundary layer of cell-rich fluid which becomes unstable, leading to the formation of falling plumes. We use the continuum description of such a suspension developed by Hillesdon et al. (1995) as the basis for a theoretical model of the boundary layer and an axisymmetric plume. If the boundary layer has dimensionless thickness [lambda] [double less-than sign] 1, the plume has width [lambda]1/2. A similarity solution is found for the plume in which the cell flux and volume flux can be matched to those in the boundary layer and in the bulk of the suspension outside both regions. The corresponding model for a two-dimensional plume fails to give a self-consistent solution.

Metcalfe, Aisling M.; Pedley, T. J.

2001-10-01

351

Low cost guidance for the Multiple Launch Rocket System (MLRS) artillery rocket  

Microsoft Academic Search

The US Army Aviation and Missile Command has demonstrated the application of advanced technology to significantly improve the accuracy and range of the Multiple Launch Rocket System (MLRS) through the Guided MLRS Advanced Technology Demonstration (ATD). The addition of a cost-effective guidance and control package to the rocket results in a weapon system that can defeat the target at ranges

A. E. Gamble; P. N. Jenkins

2001-01-01

352

Transient combustion in hybrid rockets  

NASA Astrophysics Data System (ADS)

Hybrid rockets regained interest recently as an alternative chemical propulsion system due to their advantages over the solid and liquid systems that are currently in use. Development efforts on hybrids revealed two important problem areas: (1) low frequency instabilities and (2) slow transient response. Both of these are closely related to the transient behavior which is a poorly understood aspect of hybrid operation. This thesis is mainly involved with a theoretical study of transient combustion in hybrid rockets. We follow the methodology of identifying and modeling the subsystems of the motor such as the thermal lags in the solid, boundary layer combustion and chamber gasdynamics from a dynamic point of view. We begin with the thermal lag in the solid which yield the regression rate for any given wall heat flux variation. Interesting phenomena such as overshooting during throttling and the amplification and phase lead regions in the frequency domain are discovered. Later we develop a quasi-steady transient hybrid combustion model supported with time delays for the boundary layer processes. This is integrated with the thermal lag system to obtain the thermal combustion (TC) coupled response. The TC coupled system with positive delays generated low frequency instabilities. The scaling of the instabilities are in good agreement with actual motor test data. Finally, we formulate a gasdynamic model for the hybrid chamber which successfully resolves the filling/emptying and longitudinal acoustic behavior of the motor. The TC coupled system is later integrated to the gasdynamic model to obtain the overall response (TCG coupled system) of gaseous oxidizer motors with stiff feed systems. Low frequency instabilities were also encountered for the TCG coupled system. Apart from the transient investigations, the regression rate behavior of liquefying hybrid propellants such as solid cryogenic materials are also studied. The theory is based on the possibility of enhancement of regression rate by the entrainment mass transfer from a liquid layer formed on the fuel surface. The predicted regression rates are in good agreement with the cryogenic experimental findings obtained recently at Edwards Airforce Base with a frozen pentane and gaseous oxygen system.

Karabeyoglu, Mustafa Arif

1998-09-01

353

NASA's Advanced solid rocket motor  

NASA Astrophysics Data System (ADS)

The Advanced Solid Rocket Motor (ASRM) will not only bring increased safety, reliability and performance for the Space Shuttle Booster, it will enhance overall Shuttle safety by effectively eliminating 174 failure points in the Space Shuttle Main Engine throttling system and by reducing the exposure time to aborts due to main engine loss or shutdown. In some missions, the vulnerability time to Return-to-Launch Site aborts is halved. The ASRM uses case joints which will close or remain static under the effects of motor ignition and pressurization. The case itself is constructed of the weldable steel alloy HP 9-4-0.30, having very high strength and with superior fracture toughness and stress corrosion resistance. The internal insulation is strip-wound and is free of asbestos. The nozzle employs light weight ablative parts and is some 5,000 pounds lighter than the Shuttle motor used to date. The payload performance of the ASRM-powered Shuttle is 12,000 pounds higher than that provided by the present motor. This is of particular benefit for payloads delivered to higher inclinations and/or altitudes. The ASRM facility uses state-of-the-art manufacturing techniques, including continuous propellant mixing and direct casting.

Mitchell, Royce E.

354

Quasi-One-Dimensional Modeling of Pulse Detonation Rocket Engines.  

National Technical Information Service (NTIS)

This viewgraph presentation provides information on the engine cycle of a pulse detonation rocket engine (PDRE), models for optimizing the performance of a PDRE, and the performance of PDREs in comparison to Solid State Rocket Engines (SSREs).

C. I. Morris

2003-01-01

355

Future Modeling Needs in Pulse Detonation Rocket Engine Design.  

National Technical Information Service (NTIS)

This paper presents a performance model rocket engine design that takes advantage of pulse detonation to generate thrust. The contents include: 1) Introduction to the Pulse Detonation Rocket Engine (PDRE); 2) PDRE modeling issues and options; 3) Discussio...

B. Meade D. Talley D. Mueller D. Tew M. Guidos D. Seymour

2001-01-01

356

Asbestos as a Potential Health Hazard in Rocket Motor Technology.  

National Technical Information Service (NTIS)

The presence of airborne asbestos fibers was monitored in areas used for static firing and post firing inspections of rocket motors and the manufacture of rocket motor components containing asbestos. In most locations, the concentration of asbestos fibers...

A. Wilkie

1981-01-01

357

I've Been Shot by a Rocket.  

ERIC Educational Resources Information Center

|Presents detailed descriptions and diagrams for having students build their own syringe-powered rockets. Describes how the students can learn about variables that influence the stability of the rockets flight. (PR)|

Riss, Pam Helfers; Niccum, Edward C.

1994-01-01

358

Fundamental Rocket Injector/Spray Programs at the Phillips Laboratory.  

National Technical Information Service (NTIS)

The performance and stability of liquid rocket engines is determined to a large degree by atomization, mixing, and combustion processes. Control over these processes is exerted through the design of the injector. Injectors in liquid rocket engines are cal...

D. G. Talley

1993-01-01

359

Second and Third Sounding Rockets Launched from the Marshall Islands  

NASA Website

The Equatorial Vortex Experiment was successfully conducted on May 7 from the Marshall Islands when a NASA Terrier-Oriole sounding rocket was launched followed by the launch of a Terrier-Improved Malemute sounding rocket 90 seconds later.

360

Volatile nanoparticle formation and growth within a diluting diesel car exhaust.  

PubMed

A major source of particle number emissions is road traffic. However, scientific knowledge concerning secondary particle formation and growth of ultrafine particles within vehicle exhaust plumes is still very limited. Volatile nanoparticle formation and subsequent growth conditions were analyzed here to gain a better understanding of "real-world" dilution conditions. Coupled computational fluid dynamics and aerosol microphysics models together with measured size distributions within the exhaust plume of a diesel car were used. The impact of soot particles on nucleation, acting as a condensational sink, and the possible role of low-volatile organic components in growth were assessed. A prescribed reduction of soot particle emissions by 2 orders of magnitude (to capture the effect of a diesel particle filter) resulted in concentrations of nucleation-mode particles within the exhaust plume that were approximately 1 order of magnitude larger. Simulations for simplified sulfuric acid-water vapor gas-oil containing nucleation-mode particles show that the largest particle growth is located in a recirculation zone in the wake of the car. Growth of particles within the vehicle exhaust plume up to detectable size depends crucially on the relationship between the mass rate of gaseous precursor emissions and rapid dilution. Chassis dynamometer measurements indicate that emissions of possible hydrocarbon precursors are significantly enhanced under high engine load conditions and high engine speed. On the basis of results obtained for a diesel passenger car, the contributions from light diesel vehicles to the observed abundance of measured nucleation-mode particles near busy roads might be attributable to the impact of two different time scales: (1) a short one within the plume, marked by sufficient precursor emissions and rapid dilution; and (2) a second and comparatively long time scale resulting from the mix of different precursor sources and the impact of atmospheric chemistry. PMID:21516935

Uhrner, Ulrich; Zallinger, Michael; von Löwis, Sibylle; Vehkamäki, Hanna; Wehner, Birgit; Stratmann, Frank; Wiedensohler, Alfred

2011-04-01

361

Bubble plumes and the Coanda effect  

Microsoft Academic Search

This paper describes the mean gas fraction distribution in the two-phase flow of a gas–liquid bubble plume set to develop adjacent either to a wall or to another bubble plume. When this happens, the plume exhibits a type of Coanda effect, bending either towards the wall or the other plume. The local mean gas fraction measurements are carried out using

Atila P. Silva Freire; Davi D'E. Miranda; Leonardo M. S. Luz; Guilherme F. M. Franca

2002-01-01

362

Consort and Joust sounding rockets for microgravity research  

NASA Astrophysics Data System (ADS)

Descriptions are given of the hardware and techniques used for five launches of the Consort and Joust sounding rockets with payloads for short periods of microgravity payload research. The Consort rockets can provide about seven minutes of microgravity conditions for about 300 kg of payload, and the Joust rocket can yield over 14 minutes for 240 kg. These rockets provide effective means for experiments involving foam formation, bioprocessing, polymer processing, and accelerometers.

Wessling, F. C.; Maybee, G. W.

1992-08-01

363

Device for exhaust gas recycling  

SciTech Connect

A device for exhaust gas recycling is proposed which controls the amount of recycled exhaust gas in an internal combustion engine equipped with an injection unit so that a certain air factor is attained. The device comprises a closing element for the exhaust gas return conduit, which latter terminates into the intake manifold, this closing element being suitably constituted by a throttle valve and being directly connected to the adjusting lever or control rod of the injection pump. If this connection is established via a resilient linkage between the adjusting lever and the exhaust gas return valve, then the thus-recycled amount of exhaust gas can be dimensioned so that a specific quantity of recycled exhaust gas is associated with a specific angular position of the adjusting lever.

Banzhaf, W.; Stumpp, G.

1980-10-28

364

Comprehensive simultaneous shipboard and airborne characterization of exhaust from a modern container ship at sea.  

PubMed

We report the first joint shipboard and airborne study focused on the chemical composition and water-uptake behavior of particulate ship emissions. The study focuses on emissions from the main propulsion engine of a Post-Panamax class container ship cruising off the central coast of California and burning heavy fuel oil. Shipboard sampling included micro-orifice uniform deposit impactors (MOUDI) with subsequent off-line analysis, whereas airborne measurements involved a number of real-time analyzers to characterize the plume aerosol, aged from a few seconds to over an hour. The mass ratio of particulate organic carbon to sulfate at the base of the ship stack was 0.23 +/- 0.03, and increased to 0.30 +/- 0.01 in the airborne exhaust plume, with the additional organic mass in the airborne plume being concentrated largely in particles below 100 nm in diameter. The organic to sulfate mass ratio in the exhaust aerosol remained constant during the first hour of plume dilution into the marine boundary layer. The mass spectrum of the organic fraction of the exhaust aerosol strongly resembles that of emissions from other diesel sources and appears to be predominantly hydrocarbon-like organic (HOA) material. Background aerosol which, based on air mass back trajectories, probably consisted of aged ship emissions and marine aerosol, contained a lower organic mass fraction than the fresh plume and had a much more oxidized organic component. A volume-weighted mixing rule is able to accurately predict hygroscopic growth factors in the background aerosol but measured and calculated growth factors do not agree for aerosols in the ship exhaust plume. Calculated CCN concentrations, at supersaturations ranging from 0.1 to 0.33%, agree well with measurements in the ship-exhaust plume. Using size-resolved chemical composition instead of bulk submicrometer composition has little effect on the predicted CCN concentrations because the cutoff diameter for CCN activation is larger than the diameter where the mass fraction of organic aerosol begins to increase significantly. The particle number emission factor estimated from this study is 1.3 x 10(16) (kg fuel)(-1), with less than 1/10 of the particles having diameters above 100 nm; 24% of particles (>10 nm in diameter) activate into cloud droplets at 0.3% supersaturation. PMID:19673244

Murphy, Shane M; Agrawal, Harshit; Sorooshian, Armin; Padró, Luz T; Gates, Harmony; Hersey, Scott; Welch, W A; Lung, H; Miller, J W; Cocker, David R; Nenes, Athanasios; Jonsson, Haflidi H; Flagan, Richard C; Seinfeld, John H

2009-07-01

365

Spectroscopic investigation of colliding plasma plumes  

NASA Astrophysics Data System (ADS)

Time-resolved and space-resolved spectroscopic and imaging studies of colliding carbon plumes are reported, with the aim of understanding the dynamics of the ablated plume in comparison to single-plume carbon plasma. Laser produced colliding plumes and single plume were studied under vacuum (of the order 5 × 10- 5 mbar) in a nitrogen environment using a flat graphite target. Due to the interaction of energetic particles of two colliding plumes, a new particle layer is formed that stagnate for a longer time than the seed plasma. Variation of the plume front and dimension of the stagnation layer with time are also reported.

Singh, Ravi Pratap; Gupta, Shyam L.; Thareja, R. K.

2013-10-01

366

Advanced small rocket chambers. Basic program and option 2: Fundamental processes and material evaluation  

NASA Astrophysics Data System (ADS)

Propellants, chamber materials, and processes for fabrication of small high performance radiation cooled liquid rocket engines were evaluated to determine candidates for eventual demonstration in flight-type thrusters. Both storable and cryogenic propellant systems were considered. The storable propellant systems chosen for further study were nitrogen tetroxide oxidizer with either hydrazine or monomethylhydrazine as fuel. The cryogenic propellants chosen were oxygen with either hydrogen or methane as fuel. Chamber material candidates were chemical vapor deposition (CVD) rhenium protected from oxidation by CVD iridium for the chamber hot section, and film cooled wrought platinum-rhodium or regeneratively cooled stainless steel for the front end section exposed to partially reacted propellants. Laser diagnostics of the combustion products near the hot chamber surface and measurements at the surface layer were performed in a collaborative program at Sandia National Laboratories, Livermore, CA. The Material Sample Test Apparatus, a laboratory system to simulate the combustion environment in terms of gas and material temperature, composition, and pressure up to 6 Atm, was developed for these studies. Rocket engine simulator studies were conducted to evaluate the materials under simulated combustor flow conditions, in the diagnostic test chamber. These tests used the exhaust species measurement system, a device developed to monitor optically species composition and concentration in the chamber and exhaust by emission and absorption measurements.

Jassowski, Donald M.

1993-09-01

367

The Alabama Space and Rocket Center: The Second Decade.  

ERIC Educational Resources Information Center

The Alabama Space and Rocket Center in Huntsville, the world's largest rocket and space museum, includes displays illustrating American rocket history, exhibits and demonstrations on rocketry principles and experiences, and simulations of space travel. A new project includes an integrated recreational-educational complex, described in the three…

Buckbee, Edward O.

1983-01-01

368

Studies of energy management technology of solid rocket motors  

Microsoft Academic Search

This paper presents the advantages of using solid rocket motors with energy management technology in tactical missiles. The special kind of rocket motor provides significant expansion of missile flight altitude and range. The energy management features of rocket motors permit airframes with reduced wing size, weight and drag, and also provide the possibility of thrust vector control for end-game maneuvering

Jinqi Yin

1993-01-01

369

Ignition transient calculations in the Space Shuttle solid rocket motor  

Microsoft Academic Search

The work presented is part of an effort to develop a multidimensional ignition transient model for large solid propellant rocket motors. On the Space Shuttle, the ignition transient in the slot is induced when the igniter, itself a small rocket motor, is fired into the head-end portion of the main rocket motor. The computational results presented in this paper consider

Rhonald M. Jenkins; Winfred A. Foster Jr.

1993-01-01

370

The Alabama Space and Rocket Center: The Second Decade.  

ERIC Educational Resources Information Center

|The Alabama Space and Rocket Center in Huntsville, the world's largest rocket and space museum, includes displays illustrating American rocket history, exhibits and demonstrations on rocketry principles and experiences, and simulations of space travel. A new project includes an integrated recreational-educational complex, described in the three…

Buckbee, Edward O.

1983-01-01

371

Hybrid rocket motor testing at Nammo Raufoss A\\/S  

Microsoft Academic Search

Hybrid rocket motor technology and the use of hybrid rockets have gained increased interest in recent years in many countries. A typical hybrid rocket consists of a tank containing the oxidizer in either liquid or gaseous state connected to the combustion chamber containing an injector, inert solid fuel grain and nozzle. Nammo Raufoss A\\/S has for almost 40 years designed

Jan-Erik Rųnningen; Nils Kubberud

2005-01-01

372

Sounding rocket and balloon flight safety philosophy and methodologies  

Microsoft Academic Search

NASA's sounding rocket and balloon goal is to successfully and safely perform scientific research. This is reflected in the design, planning, and conduct of sounding rocket and balloon operations. The purpose of this paper is to acquaint the sounding rocket and balloon scientific community with flight safety philosophy and methodologies, and how range safety affects their programs. This paper presents

R. J. Beyma

1986-01-01

373

Solar Pointing Attitude Rocket Control System /SPARCS/  

NASA Astrophysics Data System (ADS)

The SPARCS system is described and its use since Dec. 1967 is reviewed. SPARCS was developed to fulfill a requirement for a lightweight, precision, three-axis pointing control system for solar-sounding rockets. The use of sounding rockets to calibrate satellite instruments before flight for subsequent recovery and orbital flight is noted, along with the calibration of Skylab instruments with sounding rocket payloads. The gyroless SPARCS weights under 36 lb, is 6 in. in diam, and is self-contained regarding electronics, pneumatics, gas supply, electrical power, and coarse solar sensors. A two-axis sensor measures pitch and yaw error relative to the solar vector, and functions by pointing the longitudinal axis toward the radiometric center of the sun. Pointing errors cause voltages which activate pneumatic valves, allowing miniature gas jets to zero the pointing error. SPARCS has been used successfully on 100 missions.

Shigemoto, J. M.

1982-05-01

374

Laser-fusion rocket for interplanetary propulsion  

SciTech Connect

A rocket powered by fusion microexplosions is well suited for quick interplanetary travel. Fusion pellets are sequentially injected into a magnetic thrust chamber. There, focused energy from a fusion Driver is used to implode and ignite them. Upon exploding, the plasma debris expands into the surrounding magnetic field and is redirected by it, producing thrust. This paper discusses the desired features and operation of the fusion pellet, its Driver, and magnetic thrust chamber. A rocket design is presented which uses slightly tritium-enriched deuterium as the fusion fuel, a high temperature KrF laser as the Driver, and a thrust chamber consisting of a single superconducting current loop protected from the pellet by a radiation shield. This rocket can be operated with a power-to-mass ratio of 110 W gm/sup -1/, which permits missions ranging from occasional 9 day VIP service to Mars, to routine 1 year, 1500 ton, Plutonian cargo runs.

Hyde, R.A.

1983-09-27

375

Exhaust gas recirculation valve assembly  

SciTech Connect

This paper describes an exhaust gas recirculation valve assembly. It comprises: a base having an exhaust gas chamber through which exhaust gas passes; a pintle valve assembly having a valve member disposed within the exhaust gas chamber and a valve stem extending outwardly of the chamber through an opening therein; an actuator, maintained in a fixed relationship to the base, coupling means, extending between the valve stem and the armature and configured to allow lateral movement of the valve stem relative to the armature to compensate for misalignment of the actuator relative to the base thereby preventing the misalignment from affecting the reciprocal operation of the pintle valve assembly relative to the base.

Grey, T.J.; Braun, C.N.; Palmer, D.O.

1991-06-04

376

Electrical Charging of Volcanic Plumes  

NASA Astrophysics Data System (ADS)

Many explosive terrestrial volcanic eruptions are accompanied by lightning and other atmospheric electrical phenomena. The plumes produced generate large perturbations in the surface atmospheric electric potential gradient and high charge densities have been measured on falling volcanic ash particles. The complex nature of volcanic plumes (which contain gases, solid particles, and liquid drops) provides several possible charging mechanisms. For plumes rich in solid silicate particles, fractoemission (the ejection of ions and atomic particles during fracture events) is probably the dominant source of charge generation. In other plumes, such as those created when lava enters the sea, different mechanisms, such as boiling, may be important. Further charging mechanisms may also subsequently operate, downwind of the vent. Other solar system bodies also show evidence for volcanism, with activity ongoing on Io. Consequently, volcanic electrification under different planetary scenarios (on Venus, Mars, Io, Moon, Enceladus, Tethys, Dione and Triton) is also discussed.

James, M. R.; Wilson, L.; Lane, S. J.; Gilbert, J. S.; Mather, T. A.; Harrison, R. G.; Martin, R. S.

377

Electrical Charging of Volcanic Plumes  

NASA Astrophysics Data System (ADS)

Many explosive terrestrial volcanic eruptions are accompanied by lightning and other atmospheric electrical phenomena. The plumes produced generate large perturbations in the surface atmospheric electric potential gradient and high charge densities have been measured on falling volcanic ash particles. The complex nature of volcanic plumes (which contain gases, solid particles, and liquid drops) provides several possible charging mechanisms. For plumes rich in solid silicate particles, fractoemission (the ejection of ions and atomic particles during fracture events) is probably the dominant source of charge generation. In other plumes, such as those created when lava enters the sea, different mechanisms, such as boiling, may be important. Further charging mechanisms may also subsequently operate, downwind of the vent. Other solar system bodies also show evidence for volcanism, with activity ongoing on Io. Consequently, volcanic electrification under different planetary scenarios (on Venus, Mars, Io, Moon, Enceladus, Tethys, Dione and Triton) is also discussed.

James, M. R.; Wilson, L.; Lane, S. J.; Gilbert, J. S.; Mather, T. A.; Harrison, R. G.; Martin, R. S.

2008-06-01

378

Investigation of temperature and gas concentration distributions in hot exhausts (airplanes and burners) by scanning imaging FTIR spectrometry  

NASA Astrophysics Data System (ADS)

The Scanning Infrared Gas Imaging System of High Resolution (SIGIS-HR) was used to perform non-intrusive measurements of a Boeing 737 and a diesel powered burned (used as a hot gas producer). During the measurements it was observed that the selection of the optimal measurement positions into the plume, visualised by an infrared image from a real-time infrared camera in which the emission intensity of different field of view (FOV) positions into the plume are plotted in false colours, is possible very precisely. This enhanced considerably the probability of detection of infrared radiation emitted by a hot gas plume (e. g. from an in-service aircraft at the ground) for the objective to determine composition and temperature of the exhausts. Using this improved localization of the optimum measurement position into the hot exhaust plume the temperature and the concentrations of CO and NO were calculated. Additionally, the spatial distribution of gas temperature and concentrations of CO, CO2 and NO into the exhaust plume were determined.

Flores-Jardines, Edgar; Schäfer, Klaus; Harig, Roland; Rusch, Peter; Grutter, Michel

2005-10-01

379

Wildfire plume electrical conductivity  

NASA Astrophysics Data System (ADS)

Wildfires are weakly ionized gas. The ionization is mainly due to plant's inorganic ash content species (more especially potassium), that are emitted from thermally decomposing plant structure into the flame during combustion. The amount of ionization in flames with potassium impurities is influenced by both the temperature and the amount potassium impurities in the flame. A numerical experiment was conducted using a local thermal equilibrium-based model to study the influence of inorganic wildfire contents on wildfire electrical conductivity. Simulated very high intensity wildfires (21-90 MWm-1) were used to quantify steady-state electrical conductivity. Its variation with wildfire plume height is important for high voltage power flashover research. In the simulation, vegetation potassium content was varied from 0.50% to 3.0% on dry weight basis, a reflection of its content in natural vegetation. The model predicted a maximum conductivity of 0.053 mhom-1 in 90 MWm-1 crown fire in vegetation with 3.0% potassium content. A 90 MWm-1 crown fire in vegetation with potassium content of 0.5% was predicted to produce a maximum conductivity of 0.022 mhom-1. Electrical conductivities were lower for a shrub fire with an intensity of 21 MWm-1. The model predicted conductivities of 0.0021 and 0.0009 mhom-1 for potassium content of 3.0 and 0.5% in vegetation, respectively.

Mphale, Kgakgamatso; Heron, Malcom

2007-09-01

380

Exhaust gas sensors  

SciTech Connect

The automotive industry needed a fast, reliable, under-the-hood method of determining nitrogen oxides in automobile exhaust. Several technologies were pursued concurrently. These sensing technologies were based on light absorption, electrochemical methods, and surface mass loading. The Y-12 plant was selected to study the methods based on light absorption. The first phase was defining the detailed technical objectives of the sensors--this was the role of the automobile companies. The second phase was to develop prototype sensors in the laboratories--the national laboratories. The final phase was testing of the prototype sensors by the automobile industries. This program was canceled a few months into what was to be a three-year effort.

Hiller, J. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Miree, T.J. [Ford Motor Co., Allen Park, MI (United States)

1997-02-09

381

Meteorological assessment of SRM exhaust products' environmental impact. Final report  

SciTech Connect

The environmental impact of solid rocket motor (SRM) exhaust products discharged into the free air stream upon the launching of space vehicles that depend upon SRM boosters to obtain large thrust was assessed. The emission of Al/sub 2/O/sub 3/ to the troposphere from the SRMs in each Shuttle launch is considered. The Al/sub 2/O/sub 3/ appears as particles suitable for heterogeneous nucleation of hydrochloric acid which under frequently occurring atmospheric conditions may form a highly acidic rain capable of damaging property and crops and of impacting upon the health of human and animal populations. The cloud processes leading to the formation of acid rain and the concentration of the acid that then reaches the ground, and the atmospheric situations that lead to the production of cloud and rain at and near a launch site, and the prediction of weather conditions that may permit or prohibit a launch operation are studied.

Dingle, A.N.

1982-01-01

382

Automotive Fuel and Exhaust Systems.  

ERIC Educational Resources Information Center

|Materials are provided for a 14-hour course designed to introduce the automotive mechanic to the basic operations of automotive fuel and exhaust systems incorporated on military vehicles. The four study units cover characteristics of fuels, gasoline fuel system, diesel fuel systems, and exhaust system. Each study unit begins with a general…

Irby, James F.; And Others

383

Plumes, orogenesis, and supercontinental fragmentation  

NASA Astrophysics Data System (ADS)

A time-space relationship between large igneous provinces (LIPS), present day hot spots, and the fragmentation of Pangea has been documented over several decades, but the cause of fragmentation has remained elusive. LIPS are regarded either as the result of impingement of a mantle plume on the base of the lithosphere, or as the initial products of adiabatic decompression melting of anomalously hot mantle. Do LIPS therefore constitute evidence of an active role for plumes from the deep mantle in supercontinental fragmentation, or are they merely the first indications of a large-scale but near-surface tectonic process? Two long recognized and enigmatic orogenic events may offer a solution to this geologically important 'chicken or egg' conundrum. The reconstructed early Mesozoic Gondwanide fold belt of South America, southern Africa, and Antarctica, could have resulted from 'plume-modified orogeny', flattening of a downgoing lithospheric slab due to the buoyancy of a plume rising beneath a continental margin subduction zone. If so, the ˜180 Ma Karroo and Ferrar LIPS associated with the opening of the ocean basin between East and West Gondwanaland at ˜165 Ma resulted from impingement of this plume and are unrelated to the thermal insulation of the shallow mantle beneath Gondwanaland. It would then follow that the plume itself played an active, possibly critical, role in the initial breakup of the supercontinent. The Late Paleozoic 'Ancestral Rockies' deformation in the southwestern United States could be yet another example of orogeny driven by a plume that initiated the break-up of Pangea approximately 15 Myr earlier in the Central Atlantic region.

Dalziel, I. W. D.; Lawver, L. A.; Murphy, J. B.

2000-05-01

384

Moving Material into Space Without Rockets.  

ERIC Educational Resources Information Center

In response to conventional rocket demands on fuel supplies, electromagnetic launches were developed to give payloads high velocity using a stationary energy source. Several orbital mechanics problems are solved including a simple problem (radial launch with no rotation) and a complex problem involving air resistance and gravity. (DH)

Cheng, R. S.; Trefil, J. S.

1985-01-01

385

Remote rocket engine leak detection techniques  

NASA Astrophysics Data System (ADS)

Optical imaging techniques have been successfully used for detection of leaks in rocket engine components using introduced gases such as sulfur hexafluoride and nitrous oxide. The approach used and past applications of the technology are described. The potential for direct detection of launch system propellant leaks is discussed.

Maram, J. M.

1993-06-01

386

Commercial application of rocket engine technology  

Microsoft Academic Search

The technology developed to produce rocket engine propulsion system for space satellites and moon landings has been applied to the design of compact combustion and heat exchange equipment intended for use in the commercial field. An initial application of this technology to the design of a steam generating system to be used by electric utilities in the production of peaking

A. D. Lucci; D. R. Hodson

1975-01-01

387

Measurements of Reactive Gaseous Rocket Injector Admittances  

Microsoft Academic Search

This paper describes the results of an experimental study that was concerned with the quantitative determination of the capabilities of the combustion processes associated with coaxial gaseous propellant rocket injectors to drive combustor pressure oscillations. The data, obtained by employing the modified impedance tube technique with compressed air as the oxidizer and acetylene gas as the fuel, describe the frequency

B. A. JANARDAN; B. R. DANIEL; W. A. BELL; B. T. ZINN

1979-01-01

388

Skylark sounding rocket for space processing experiments  

Microsoft Academic Search

Attention is given to the design features of the Skylark Sounding Rocket, including payload services, experiment bays, telemetry, the recovery parachute, and the motor kit. Skylark's performance is discussed in terms of sources of acceleration after payload\\/motor separation and motor combinations suitable for space processing. Optional Skylark equipment is outlined, noting horizon sensors, roll control, instrumentation, and cameras. Skylark's reaction

J. B. Hilton

1977-01-01

389

Nuclear Rocket Using Indigenous Martian Fuel NIMF.  

National Technical Information Service (NTIS)

In the 1960's, Nuclear Thermal Rocket (NTR) engines were developed and ground tested capable of yielding isp of up to 900 s at thrusts up to 250 klb. Numerous trade studies have shown that such traditional hydrogen fueled NTR engines can reduce the inerti...

R. Zubrin

1991-01-01

390

Contemporary computational modeling of Nuclear Thermal Rockets  

Microsoft Academic Search

A computational package is presented for the simulation and in-depth analysis of Nuclear Thermal Rocket (NTR) propulsion systems. The package integrates a number of modular component codes modeling major NTR components and includes a system of multidimensional computer codes for the analysis of the nuclear and thermal fluid design of the nuclear reactor. The computational package is used to perform

Steven D. Peery; Randy C. Parsley; Samim Anghaie; Gerald J. Feller

1992-01-01

391

Turbopump options for nuclear thermal rockets  

Microsoft Academic Search

Several turbopump options for delivering liquid nitrogen to nuclear thermal rocket (NTR) engines were evaluated and compared. Axial and centrifugal flow pumps were optimized, with and without boost pumps, utilizing current design criteria within the latest turbopump technology limits. Two possible NTR design points were used, a modest pump pressure rise of 1,743 psia and a relatively higher pump pressure

W. R. Bissell; S. V. Gunn

1992-01-01

392

Lunar mission design using nuclear thermal rockets  

Microsoft Academic Search

The NERVA-class Nuclear Thermal Rocket (NTR), with performance nearly double that of advanced chemical engines, has long been considered an enabling technology for human missions to Mars. NTR engines address the demanding trip time and payload delivery needs of both cargo-only and piloted flights. But NTR can also reduce the Earth launch requirements for manned lunar missions. First use of

Michael L. Stancati; John T. Collins; Stanley K. Borowski

1991-01-01

393

Lunar mission design using Nuclear Thermal Rockets  

Microsoft Academic Search

The NERVA-class Nuclear Thermal Rocket (NTR), with performance nearly double that of advanced chemical engines, has long been considered an enabling technology for human missions to Mars. NTR engines address the demanding trip time and payload delivery needs of both cargo-only and piloted flights. But NTR can also reduce the Earth launch requirements for manned lunar missions. First use of

Michael L. Stancati; John T. Collins; Stanley K. Borowski

1991-01-01

394

Nuclear thermal rocket engine operation and control  

Microsoft Academic Search

The operation of a typical Rover\\/Nerva-derived nuclear thermal rocket (NTR) engine is characterized and the control requirements of the NTR are defined. A rationale for the selection of a candidate diverse redundant NTR engine control system is presented and the projected component operating requirements are related to the state of the art of candidate components and subsystems. The projected operational

Stanley V. Gunn; Margarita T. Savoie; Rolv Hundal

1993-01-01

395

Government Relations: It's Not Rocket Science  

ERIC Educational Resources Information Center

|Many people in the early childhood education field are afraid of government relations work, intimidated by politicians, and believe the whole process is unseemly. The author asserts that they should not be afraid nor be intimidated because government relations is not rocket science and fundamentally officeholders are no different from the rest of…

Radway, Mike

2007-01-01

396

RADIATION-MEASURING SYSTEMS OF SOVIET ROCKETS  

Microsoft Academic Search

The second and third Sputniks and all Soviet space rockets and spaceship-; satellites were equipped with radiationmeasuring systems comprising scintillation ; and gasdischarge counters and shaping, amplification, and scaling circuits. The ; scintillation counters use photomultipliers having either 40 x 40 Nal(Tl) or 20 x ; 20 Csl(Tl) cylindrical crystals. Both types have a gain of ~5.10ā“. The ; highvoltage

P. V. Vakulov; N. N. Goryunov; Yu. I. Logachev; E. N. Sosnovets

1961-01-01

397

NASA, ATK Successfully Test Solid Rocket Motor  

NASA Video Gallery

With a loud roar and mighty column of flame, NASA and ATK Aerospace Systems successfully completed a two-minute, full-scale test of the largest and most powerful solid rocket motor designed for flight. The motor is potentially transferable to future heavy-lift launch vehicle designs.

Jim Wilson

2010-08-31

398

Transportation of General Rocket Fuel Components  

Microsoft Academic Search

In order for toxic substances such as rocket fuel components to be safely transported, correct safety measures must be carried out and emergency and first aid equipment must be available. While transporting by a motor column such measures as having empty tanks on hand incase of leakage, an ambulance on hand incase of accidents, and radio contact between all members

Safar Safarov

399

SpaceX Launches Falcon 9 Rocket  

NASA Video Gallery

Space Exploration Technologies' (SpaceX) successfully launched its Falcon 9 rocket from Complex-40 at Cape Canaveral Air Force Station at 2:45 p.m. EDT on June 4. This commercial launch by SpaceX is a pathfinder for the first NASA Commercial Orbital Transportation Services development flight planned for later this summer.

Jim Wilson

2010-06-04

400

Ignition transient analysis of solid rocket motor  

Microsoft Academic Search

A 1-D numerical model based on the SIMPLE is developed to predict the pressure and thrust behavior of space shuttle solid rocket motors. The present model solves the conservation equations through the attached nozzle as well as in the combustion chamber. Numerical results were seen to agree qualitatively well with the test data by controlling the wetted perimeter in the

Samuel S. Han

1992-01-01

401

Solid rocket motor nozzle flexseal design sensitivity  

Microsoft Academic Search

On solid rocket motors, direction is controlled by controlling the thrust vector. To achieve this, the nozzle usually incorporates a flexseal that allows the nozzle to vector (or rotate) in any direction. The flexseal has a core of alternating layers of elastomer pads and metal or composite shims. Flexseal core design is an iterative process. An estimate of the flexseal

James R. Donat

1993-01-01

402

Telemetry package for Super Loki sounding rocket  

Microsoft Academic Search

Summary form only given. Given the special requirements of the payload area of the Super Loki sounding rocket the author examines two options for the telemetry package. The first option consists in relying totally on GPS (Global Positioning System) antenna and a translator attached to the vehicle. This translator will continuously download the navigation messages picked from GPS satellites to

S. Fateih

1992-01-01

403

A rocket for the 21st century  

NASA Astrophysics Data System (ADS)

Various aspects of the Delta Clipper Experimental (DC-X) single-stage-to-orbit (SSTO) rocket are discussed. Specific topics covered include the following: its ties to the Strategic Defense Initiative (SDI), costs, design, flight tests, and project progress. Photographs of the DC-X in flight and on the ground are presented.

Ressmeyer, Roger H.

1994-02-01

404

Internal Environment of Solid Rocket Nozzles.  

National Technical Information Service (NTIS)

Solid rocket motor nozzle environment was studied in cold flow modeling and in motor firings. The emphasis in the work was on the effects of the condensed phase in wall impingement and radiation. In motor firings using H2 - O2 - Al2O3 - H2O, emissivity va...

F. C. Price VV. A. Marple R. H. Williams R. A. Dupuis H. L. Moody

1964-01-01

405

Rocket Measurement of the Nitric Oxide Dayglow  

Microsoft Academic Search

from 1500 to 3200 A. The rocket's attitudecontrol system aimed the spectrometer at the zenith during the ascent and at the horizon during the descent. Spectral scans of the ultraviolet dayglow were obtained in the zenith direction in the altitude range from 76 to 114 km, and also (with greatly increased intensity) during the scan of the horizon. The most

CHARLES A. B ARTH

1964-01-01

406

Multiple Propellent Grain for Rocket Motors.  

National Technical Information Service (NTIS)

The rocket motor charge is composed of a plurality of propellants of prescribed and graduated burning rates, advantageous contours and dimensions such that the burning of all of the propellants in a grain ends at the same time. This result is accomplished...

J. V. Braun W. S. Bacon

1965-01-01

407

Solid rocket motor internal flow during ignition  

Microsoft Academic Search

A numerical procedure is presented for the analysis of the internal flow in a solid rocket motor (SRM) during the ignition transient period of operation, along with the results obtained when this computer code was applied to several motors. The purpose of this code development effort was to achieve a detailed picture of the unsteady flowfield for a SRM of

W. A. Johnston

1995-01-01

408

Finite Area Combustor Theoretical Rocket Performance.  

National Technical Information Service (NTIS)

Previous to this report, the computer program of NASA SP-273 and NASA TM-86885 was capable of calculating theoretical rocket performance based only on the assumption of an infinite area combustion chamber (IAC). An option was added to this program which n...

S. Gordon B. J. McBride

1988-01-01

409

Physical attachment of sensors in rocket engines  

Microsoft Academic Search

The bonding of sensor elements to rocket engine components by means of rapid radiation heating (RRH) drastically reduces the processing time required; neither is vacuum processing needed, as in conventional bonding processes. RRH bonding involves the melting of a brazing alloy by the heat that is radiatively delivered from a source to the sample surface, followed by sample conduction; the

Craig A. Blue; Mark T. Robson; Y.-Q. Jiang; Ray Y. Lin

1991-01-01

410

Rockets: Physical Science Teacher's Guide with Activities.  

ERIC Educational Resources Information Center

|Rockets have evolved from simple tubes filled with black powder into mighty vehicles capable of launching a spacecraft out into the galaxy. The guide begins with background information sections on the history of rocketry, scientific principles, and practical rocketry. The sections on scientific principles and practical rocketry are based on Isaac…

Vogt, Gregory L.; Rosenberg, Carla R., Ed.

411

Rocket Propulsion Research at Lewis Research Center.  

National Technical Information Service (NTIS)

A small contingent of engineers at NASA LeRC pioneered the basic research on liquid propellants for rockets shortly after World War 2. Carried on through the 1950s, this work influenced the important early decisions made by Abe Silverstein when he took ch...

V. P. Dawson

1992-01-01

412

Orbit transfer rocket engine technology program  

Microsoft Academic Search

An advanced near term (1990's) space-based Orbit Transfer Vehicle Engine (OTVE) system was designed, and the technologies applicable to its construction, maintenance, and operations were developed under Tasks A through F of the Orbit Transfer Rocket Engine Technology Program. Task A was a reporting task. In Task B, promising OTV turbomachinery technologies were explored: two stage partial admission turbines, high

N. B. Gustafson; T. J. Harmon

1993-01-01

413

Modular rocket engine control software (MRECS)  

Microsoft Academic Search

The Modular Rocket Engine Control Software (MRECS) Program is a technology demonstration effort designed to advance the state-of-the-art in launch vehicle propulsion systems. Its emphasis is on developing and demonstrating a modular software architecture for a generic, advanced engine control system that will result in lower software maintenance (operations) costs. It effectively accommodates software requirements changes that occur due to

C. Tarrant; J. Crook

1997-01-01

414

Liquid Film Cooling in Rocket Engines.  

National Technical Information Service (NTIS)

A one-dimensional analytical model of liquid film cooling in rocket engine combustion chambers is developed and compared with existing data. The vapor generated at the liquid interface greatly decreases the convective heat flux and is treated as a 'transi...

W. M. Grisson

1991-01-01

415

Advanced Solid Rocket Motor nozzle development status  

Microsoft Academic Search

This paper presents a status update of the design and development of an improved nozzle for the Advanced Solid Rocket Motor (ASRM). The ASRM nozzle incorporates advanced state-of-the-art design features and materials which contribute to enhanced safety, reliability, performance, and producibility for the space shuttle boosters. During 1992 the nozzle design progressed through a successful Preliminary Design Review (PDR). An

W. J. Kearney; J. D. Moss

1993-01-01

416

GASOLINE VEHICLE EXHAUST PARTICLE SAMPLING STUDY  

SciTech Connect

The University of Minnesota collaborated with the Paul Scherrer Institute, the University of Wisconsin (UWI) and Ricardo, Inc to physically and chemically characterize the exhaust plume from recruited gasoline spark ignition (SI) vehicles. The project objectives were: (1) Measure representative particle size distributions from a set of on-road SI vehicles and compare these data to similar data collected on a small subset of light-duty gasoline vehicles tested on a chassis dynamometer with a dilution tunnel using the Unified Drive Cycle, at both room temperature (cold start) and 0 C (cold-cold start). (2) Compare data collected from SI vehicles to similar data collected from Diesel engines during the Coordinating Research Council E-43 project. (3) Characterize on-road aerosol during mixed midweek traffic and Sunday midday periods and determine fleet-specific emission rates. (4) Characterize bulk- and size-segregated chemical composition of the particulate matter (PM) emitted in the exhaust from the gasoline vehicles. Particle number concentrations and size distributions are strongly influenced by dilution and sampling conditions. Laboratory methods were evaluated to dilute SI exhaust in a way that would produce size distributions that were similar to those measured during laboratory experiments. Size fractionated samples were collected for chemical analysis using a nano-microorifice uniform deposit impactor (nano-MOUDI). In addition, bulk samples were collected and analyzed. A mixture of low, mid and high mileage vehicles were recruited for testing during the study. Under steady highway cruise conditions a significant particle signature above background was not measured, but during hard accelerations number size distributions for the test fleet were similar to modern heavy-duty Diesel vehicles. Number emissions were much higher at high speed and during cold-cold starts. Fuel specific number emissions range from 1012 to 3 x 1016 particles/kg fuel. A simple relationship between number and mass emissions was not observed. Data were collected on-road to compare weekday with weekend air quality around the Twin Cities area. This portion of the study resulted in the development of a method to apportion the Diesel and SI contribution to on-road aerosol.

Kittelson, D; Watts, W; Johnson, J; Zarling, D Schauer,J Kasper, K; Baltensperger, U; Burtscher, H

2003-08-24

417

Bromine oxidation in volcanic plumes  

NASA Astrophysics Data System (ADS)

Volcanoes are very strong sources of hydrogen, carbon, sulphur and halogen compounds, as well as of particles. Some gases only behave as passive tracers; others interact and affect the formation, growth or chemical characteristics of aerosol particles in a complex system. Recent measurements of halogen radicals in volcanic plumes showed that volcanic plumes are chemically very active. Kinetic considerations (Oppenheimer et al., 2006) and detailed calculations with an atmospheric chemistry model (Bobrowski et al., 2007) explain the halogen chemistry mainly with photochemical reactions involving both, the gas and particle phase. They reproduce the measured gas-phase concentrations quite well. However, temporal evolution of BrO in the early plume is not well described in the models. The understanding of chemical kinetics of BrO formation is still not complete. Recent measurement results (Vogel et al., 2008) do not fit with initial model calculation. The new data lead to the suggestion that the BrO formation could be much faster during the first few minutes after emission than initially suggested. Old and recent data sets will be confronted, compared and possible causes of their differences discussed. The measurements considered were taken at Mt. Etna (Italy), Villarica (Chile), and Popocatépetl (Mexico) volcanoes. Additionally, at Mt Etna the emission consists of up to four individual plumes from four summit craters. The differences between the individual plumes have been investigated during the last years and will be presented.

Bobrowski, N.; Vogel, L.; Kern, C.; Giuffrida, G. B.; Delgado-Granados, H.; Platt, U.

2009-04-01

418

Economics of exhaustible resources  

SciTech Connect

This dissertation deals with various issues of resource depletion, beginning with a rather comprehensive review of the literature. The resource scarcity is the first issue dealt with, where differentiation is made between Ricardian and Pure scarcities of exhaustible resources. While the Ricardian scarcity is properly acknowledged and modeled in the resource literature, the fact that the resource stocks are always decreasing with extraction (i.e., the pure scarcity) is overlooked. One important conclusion of the scarcity analysis is that the steady-state point defining the equilibrium values for the nonresource output to capital and the resource flow to resource stock ratios, is found to be a moving one, as a result of the increasing scarcity mechanism. Another observation about the literature is that there is a marked bias in favor of long run, developed economies' problems and resource inputs as opposed to the problems of developing economies and resource exports. Thus, a theoretical framework is developed where not only resource inputs and exports are analyzed but resource exports are advanced as a vehicle for development. Within the context of this theoretical framework, it is concluded that optimality dictates that the resource inputs and exports, expressed per unit of the capital stock, be declining over time. Furthermore, the resource exports are proposed as the domestic substitute for foreign aid.

Rabhan, S.A.

1986-01-01

419

Material Damage from Impacts of Lunar Soil Particles Ejected by the Rocket Exhaust of Landing Spacecraft.  

National Technical Information Service (NTIS)

This paper details the experimentation of lunar stimulant sandblasting. This was done to understand the damage that landing spacecraft on the moon will have to a permanent lunar outpost. The sandblasting was done with JSC-1A onto glass coupons. Correlatio...

A. C. Wittbrodt P. T. Metzger

2008-01-01

420

Photoelectrons in the Enceladus plume  

NASA Astrophysics Data System (ADS)

The plume of Enceladus is a remarkable plasma environment containing several charged particle species. These include cold magnetospheric electrons, negative and positive water clusters, charged nanograins, and "magnetospheric photoelectrons" produced from ionization of neutrals throughout the magnetosphere near Enceladus. Here we discuss observations of a population newly identified by the Cassini Plasma Spectrometer (CAPS) electron spectrometer instrument—photoelectrons produced in the plume ionosphere itself. These were found during the E19 encounter, in the energetic particle shadow where penetrating particles are absent. Throughout E19, CAPS was oriented away from the ram direction where the clusters and nanograins are observed during other encounters. Plume photoelectrons are also clearly observed during the E9 encounter and are also seen at all other Enceladus encounters where electron spectra are available. This new population, warmer than the ambient plasma population, is distinct from, but adds to, the magnetospheric photoelectrons. Here we discuss the observations and examine the implications, including the ionization source these electrons provide.

Coates, A. J.; Wellbrock, A.; Jones, G. H.; Waite, J. H.; Schippers, P.; Thomsen, M. F.; Arridge, C. S.; Tokar, R. L.

2013-08-01

421

46 CFR 169.609 - Exhaust systems.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Internal Combustion Engine Installations Ā§ 169.609 Exhaust systems. Engine exhaust installations and associated...

2011-10-01

422

46 CFR 169.609 - Exhaust systems.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Internal Combustion Engine Installations Ā§ 169.609 Exhaust systems. Engine exhaust installations and associated...

2012-10-01

423

Modeling Leaking Gas Plume Migration  

SciTech Connect

In this study, we obtain simple estimates of 1-D plume propagation velocity taking into account the density and viscosity contrast between CO{sub 2} and brine. Application of the Buckley-Leverett model to describe buoyancy-driven countercurrent flow of two immiscible phases leads to a transparent theory predicting the evolution of the plume. We obtain that the plume does not migrate upward like a gas bubble in bulk water. Rather, it stretches upward until it reaches a seal or until the fluids become immobile. A simple formula requiring no complex numerical calculations describes the velocity of plume propagation. This solution is a simplification of a more comprehensive theory of countercurrent plume migration that does not lend itself to a simple analytical solution (Silin et al., 2006). The range of applicability of the simplified solution is assessed and provided. This work is motivated by the growing interest in injecting carbon dioxide into deep geological formations as a means of avoiding its atmospheric emissions and consequent global warming. One of the potential problems associated with the geologic method of sequestration is leakage of CO{sub 2} from the underground storage reservoir into sources of drinking water. Ideally, the injected green-house gases will stay in the injection zone for a geologically long time and eventually will dissolve in the formation brine and remain trapped by mineralization. However, naturally present or inadvertently created conduits in the cap rock may result in a gas leak from primary storage. Even in supercritical state, the carbon dioxide viscosity and density are lower than those of the indigenous formation brine. Therefore, buoyancy will tend to drive the CO{sub 2} upward unless it is trapped beneath a low permeability seal. Theoretical and experimental studies of buoyancy-driven supercritical CO{sub 2} flow, including estimation of time scales associated with plume evolution, are critical for developing technology, monitoring policy, and regulations for carbon dioxide geologic sequestration protecting the sources of potable water.

Silin, Dmitriy; Patzek, Tad; Benson, Sally M.

2007-08-20

424

Opacity meter for monitoring exhaust emissions from non-stationary sources  

DOEpatents

Method and apparatus for determining the opacity of exhaust plumes from moving emissions sources. In operation, a light source is activated at a time prior to the arrival of a diesel locomotive at a measurement point, by means of a track trigger switch or the Automatic Equipment Identification system, such that the opacity measurement is synchronized with the passage of an exhaust plume past the measurement point. A beam of light from the light source passes through the exhaust plume of the locomotive and is detected by a suitable detector, preferably a high-rate photodiode. The light beam is well-collimated and is preferably monochromatic, permitting the use of a narrowband pass filter to discriminate against background light. In order to span a double railroad track and provide a beam which is substantially stronger than background, the light source, preferably a diode laser, must provide a locally intense beam. A high intensity light source is also desirable in order to increase accuracy at the high sampling rates required. Also included is a computer control system useful for data acquisition, manipulation, storage and transmission of opacity data and the identification of the associated diesel engine to a central data collection center.

Dec, John Edward (Livermore, CA)

2000-01-01

425

Photographic Measurements of USAF Aircraft Plume Rise.  

National Technical Information Service (NTIS)

This report includes data and results which were obtained during plume rise experimentation. Aircraft plumes were photographed using the smoke-producing F-102 drones, and Thunderbird T-38 aircraft. The second set of experiments indicated that, under low w...

P. D. Music J. S. Hunt D. F. Naugle

1977-01-01

426

Experiments on a turbulent plume: Shape analyses  

Microsoft Academic Search

Shape change of turbulent plume after its ejection was studied from experimentsNew methods to characterize plume shape were devised to define 4 regimesFor the same Reynolds number regime onset times become earlier with buoyancy

Shogo Kitamura; Ikuro Sumita

2011-01-01

427

OZONE FORMATION IN POLLUTANT PLUMES: A REACTIVE PLUME MODEL WITH ARBITRARY CROSSWIND RESOLUTION  

EPA Science Inventory

A new two-layer reactive plume model is developed, in which arbitrary crosswind resolution of the emission field of each precursor is preserved, and dynamic plume-plume and plume-background interactions are explictly accomodated. The model has a hybrid formulation, having Lagrang...

428

AXAIR and PUFF-PLUME Comparison  

SciTech Connect

A test version of AXAIR has been prepared to compare with PUFF-PLUME. The test version of AXAIR applies the same meteorological conditions as PUFF-PLUME and also the dispersion coefficients have been changed to be the same as those in PUFF-PLUME. The test version of AXAIR and PUFF-PLUME produce virtually the same doses with the differences being less than 3% for the select cases with similar input. Differences and similarities in the models are also addressed.

Simpkins, A.A.; Kurzeja, R.J.

1995-09-28

429

Plasma plume MHD power generator and method  

Microsoft Academic Search

A method is described of generating power at a situs exposed to the solar wind which comprises creating at separate sources at the situs discrete plasma plumes extending in opposed directions, providing electrical communication between the plumes at their source and interposing a desired electrical load in the said electrical communication between the plumes.

1993-01-01

430

K-2 Titan IV Stratospheric Plume Dispersion.  

National Technical Information Service (NTIS)

Video images were recorded of the plume from the K-2 Titan IV launched 2 July 1996 from Cape Canaveral Air Station. These images were used to infer plume motion and expansion near an altitude of 30 km in the stratosphere. The plume was observed to move ac...

E. J. Beiting R. A. Klingberg

1997-01-01

431

Structure and dynamics of sheared mantle plumes  

Microsoft Academic Search

An extensive series of laboratory experiments is used to investigate the behavior of sheared thermal plumes. The plumes are generated by heating a small circular plate on the base of a cylindrical tank filled with viscous fluid and then sheared by rotating a horizontal lid at the fluid surface. The motion of passive tracers in the plumes is visualized by

Ross C. Kerr; Catherine Mériaux

2004-01-01

432

The Rise of Moist, Buoyant Plumes  

Microsoft Academic Search

The governing equations for a moist, buoyant plume in a cross wind are presented. A comparison of the energy equations for saturated and unsaturated plumes, the subject of some previous controversy, shows that the form of the two equations is identical only when the saturated plume is in a saturated atmosphere. In this case, the moist adiabatic lapse rate replaces

Jeffrey C. Weil

1974-01-01

433

Laboratory investigation of a single mantle plume  

Microsoft Academic Search

Although many have studied the chemistry and dynamics of mantle plumes, fundamental questions remain. These can be grouped into two general issues: a) Plume structure and dynamical interaction with the surrounding mantle, b) The degree of entrainment and mixing in mantle plumes of chemically distinct material from the deep mantle. We address these fundamental questions by performing detailed fluid dynamical

Aline Cotel

2005-01-01

434

Numerical Simulations of Europa Hydrothermal Plumes  

Microsoft Academic Search

The liquid water interiors of Europa and other icy moons of the outer solar system are likely to be driven by geothermal heating from the sea floor, leading to the development of buoyant hydrothermal plumes. These plumes potentially control icy surface geomorphology, and are of interest to astrobiologists. We have performed a series of simulations of these plumes using the

J. C. Goodman; E. Lenferink

2009-01-01

435

Ridge suction drives plume-ridge interactions  

Microsoft Academic Search

Deep-sourced mantle plumes, if existing, are genetically independent of plate tectonics. When the ascending plumes approach lithospheric plates, interactions between the two occur. Such interactions are most prominent near ocean ridges where the lithosphere is thin and the effect of plumes is best revealed. While ocean ridges are mostly passive features in terms of plate tectonics, they play an active

Y. Niu; R. Hékinian

2003-01-01

436

MATHEMATICAL MODEL FOR MULTIPLE COOLING TOWER PLUMES  

EPA Science Inventory

A mathematical model is developed for the prediction of plume properties such as excess plume temperature, humidity and liquid phase moisture (water droplet), plume trajectory, width, and dilution at the merging locations and the beginning and ending points of the visible part of...

437

Esrange activities: Sounding rockets, balloons and satellites  

NASA Astrophysics Data System (ADS)

The range facilities are described in detail for the prospective user, including instrumentation launch capabilities, support facilities, and costs. High performance sounding rockets such as Aries and Nike BB can now, thanks to guidance systems, be launched above 500 km allowing the exploration of higher regions and longer observation time. Microgravity experiments using sounding rockets are successfully carried out from the range. Land recovery is necessary in this case. Since 1978 Esrange has been operating a Landsat remote sensing satellite receiving station as part of ESA's ground station network, Earthnet. Additional installations for reception and processing of SPOT and Landsat (D) data are planned. A satellite tracking and control station is envisaged in the near future.

Helger, A.

1980-06-01

438

14 CFR 101.22 - Special provisions for large model rockets.  

Code of Federal Regulations, 2010 CFR

...false Special provisions for large model rockets. 101.22 Section 101.22 Aeronautics...RULES MOORED BALLOONS, KITES, UNMANNED ROCKETS AND UNMANNED FREE BALLOONS Unmanned Rockets Ā§ 101.22 Special provisions for...

2009-01-01

439

14 CFR 101.26 - Operating limitations for Class 3-Advanced High-Power Rockets.  

Code of Federal Regulations, 2010 CFR

...limitations for Class 3-Advanced High-Power Rockets. 101.26 Section 101.26 Aeronautics...RULES MOORED BALLOONS, KITES, UNMANNED ROCKETS AND UNMANNED FREE BALLOONS Unmanned Rockets Ā§ 101.26 Operating limitations for...

2009-01-01

440

14 CFR 437.95 - Inspection of additional reusable suborbital rockets.  

Code of Federal Regulations, 2013 CFR

...Inspection of additional reusable suborbital rockets. 437.95 Section 437.95 ...Inspection of additional reusable suborbital rockets. A permittee may launch or reenter additional reusable suborbital rockets of the same design under the...

2013-01-01

441

Modeling Leaking Gas Plume Migration.  

National Technical Information Service (NTIS)

In this study, we obtain simple estimates of 1-D plume propagation velocity taking into account the density and viscosity contrast between CO(sub 2) and brine. Application of the Buckley-Leverett model to describe buoyancy-driven countercurrent flow of tw...

D. Silin S. M. Benson T. Patzek

2007-01-01

442

Near Field of Starting Plumes  

Microsoft Academic Search

Although steady jets and plumes have been studied extensively in the past, there is relatively little known about the initial stages of starting buoyant jets. The present investigation examined buoyancy-driven flows resulting from cylindrical containers w ith length to diameter ratios (L\\/D) between 2 and 13. Density ratios up to ten percent were utilized. A technique was developed to release

H. Johari; M. Gharib; D. Dabiri

1997-01-01

443

Degradation of rocket insulator at high temperature  

Microsoft Academic Search

The degradation of a rocket insulator compound based on ethylene propylene diene rubber (EPDM) containing asbestor, cork and iron oxide (Fe2O3) as fillers has been studied at high temperature (up to 600°) by using differential thermal analysis (DTA) and thermogravimetry (TG). The changes in physical properties on high-temperature aging are also reported. EPDM gum vulcanizates involving different types of diene,

A. S. Deuri; K. Bhowmick

1987-01-01

444

Adhesion in Solid Propellant Rocket Motors  

Microsoft Academic Search

Plasma treatment of EPDM-based rocket motor insulation materials may change the peel strength between these materials and polyurethane polymers by a factor of 0.1 to 10. The matching of surface energies seems to be important for this adhesion process. The surface tension of the components was measured to between 30 and 50 mNm. The total surface energy of the insulation could

Kai Frode Grythe; Finn Knut Hansen; Torbjųrn Olsen

2007-01-01

445

Single Stage Rocket Performance: Prediction and Test  

Microsoft Academic Search

An explicit three-dimensional, finite-volume Navier-Stokes solver with finile-rate H2\\/air combustion kinetics has been developed and calibrated to accurately and efficiently compute installed engine performance for complete single-stage-rocket (SSR) configurations. The Navier-Stokes formulation directly couples the global fluid dynamic, species continuity and transport equations for turbulent kinetic energy and dissipation resulting in increased solution robustness and accuracy. Comparisons of predicted and

THOMAS P. GIELDA; T. Mark Walter; RAMESH K. AGARWAL

1994-01-01

446

Reliability Estimation Methods for Liquid Rocket Engines  

NASA Astrophysics Data System (ADS)

Reliability estimation using the dispersive, binominal distribution method has been traditionally used to certify the reliability of liquid rocket engines, but its estimation sometimes disagreed with the failure rates of flight engines. In order to take better results, the reliability growth model and the failure distribution method are applied to estimate the reliability of LE-7A engines, which have propelled the first stage of H-2A launch vehicles.

Hirata, Kunio; Masuya, Goro; Kamijo, Kenjiro

447

The Enigmatic Mr Hale and his Rockets  

NASA Astrophysics Data System (ADS)

This paper is a revised version of the biographical section of the entry which was the co-winner of the 1970 Robert H. Goddard Essay Award sponsored by the National Space Club. (The other section of the paper covered Hale's rockets.) This also marks the first time the biographical section has been published in its entirety since until now only abbreviated versions have appeared in print.

Winter, F. H.

448

Ignition transient analysis of solid rocket motor  

NASA Astrophysics Data System (ADS)

A 1-D numerical model based on the SIMPLE is developed to predict the pressure and thrust behavior of space shuttle solid rocket motors. The present model solves the conservation equations through the attached nozzle as well as in the combustion chamber. Numerical results were seen to agree qualitatively well with the test data by controlling the wetted perimeter in the head-end star-section of the motor and the erosive burning rate of the solid propellent.

Han, Samuel S.

449

Vortex shedding from solid rocket propellant inhibitors  

Microsoft Academic Search

Vortex shedding frequency caused by the protrusion of inhibitors into the flow field of a solid rocket motor is investigated by experimental and mathematical models. The time dependent Navier-Stokes equations are solved using a finite difference technique assuming incompressible, two-dimensional flow under both laminar and turbulent flow conditions. For laminar flow, explicit solutions are obtained using a vorticity-transport equation in

P. H. Shu; R. H. Sforzini; W. A. Foster Jr.

1986-01-01

450

XDT in Solid Rocket Propellant by Large Steel Flyer Plate  

Microsoft Academic Search

Several experiments of the impact explosion of solid rocket propellant on the command destruction of rocket motor have been performed by solid rocket propellants of 460 to 1000 kg impacting a steel plate of 1100mm in diameter and 100 mm in thickness. Impact velocities were varied from 130m\\/s to 185 m\\/s. Strong explosions were observed at impact velocity higher than

K. Tanaka; K. Noda; Y. Hyodo; H. Nakamura; K. Kosaka; T. Nakayama; M. Katayama; A. Takeba

1999-01-01

451

Ablation Radiation Shields for Nuclear Fusion Rockets  

NASA Astrophysics Data System (ADS)

Pulse nuclear propulsion has been the subject of extensive studies since the 1960's. Early concepts examined external pulse propulsion where small critical mass nuclear devices are ejected from the rear of the rocket. A pusher plate absorbs some of the energy form the detonation, which ablates the plate and provides thrust for the rocket. It is also possible to have the device detonate in an enclosed chamber (i.e., internal pulse propulsion). Again, in this case, ablation is the primary method for applying the thrust. Ablation can not only provide thrust but it can also aid in the dissipation of the heat in a neutron radiation shield. Since high-energy neutrons will be abundant in deuterium-tritium fusion reactions, fusion rockets that use this reaction usually are designed with a radiator to dissipate the heat from the shield. These radiators usually require a considerable mass. Carbon and tungsten ablative shields may be considerably more effective. Ablation and radiation are compared as mechanisms to dissipate the heat. Although ablation is shown to provide a considerable mass saving heat loses at the surfaces will create thermal gradients that will adversely effect the ablation rate, and may significantly increase the mass loss.

Coreano, Luis; Cassenti, Brice N.

2003-01-01

452

Scale-model rocket experiments (SRE)  

NASA Astrophysics Data System (ADS)

The Scale model Rocket Experiments (SRE) were conducted in August and September 1997 as a part of the Ballistic Missile Defense Organization (BMDO) Advanced Sensor Technology Program (ASTP) and Discriminating Interceptor Technology Program (DITP). Rome Laboratory (RL) efforts under this effort for ASTP involves the following technology areas: sensor fusion algorithms, high performance processors, and sensor modeling and simulation. In support of the development, test and integration of these areas, Rome Laboratory performed the scale model rocket experiments. This paper details the experiments and results of the scaled rocket experiment as a cost effective, risk reduction experiment to test fusion processor algorithms in a real time environment. The goals of the experiment were to launch, track, fuse, and collect multispectral data from Visible, IR, RADAR and LADAR sensors. The data was collected in real time and was interfaced to the RL-HPC (PARAGON) for real time processing. In June 1997 RL performed the first tests of the series on static targets. The static firings tested data transfers and safety protocols. The RL (Hanscom) IR cameras were calibrated and the proper gain settings were acquired. The next phase of the SRE testing, August 12/13 1997, involved the launching, tracking and acquiring digital IR data into the HPC. In September, RL implemented the next phase of the experiments by incorporating a LADAR and an additional IR sensor from Phillips Laboratory into the system. This paper discusses the success and future work of the SRE.

Wynne, Douglas G.; Barnell, Mark D.

1998-07-01

453

Nuclear Thermal Rocket Element Environmental Simulator (NTREES)  

NASA Astrophysics Data System (ADS)

To support a potential future development of a nuclear thermal rocket engine, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The test device simulates the environmental conditions (minus the radiation) to which nuclear rocket fuel components could be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner as to accurately reproduce the temperatures and heat fluxes normally expected to occur as a result of nuclear fission while at the same time being exposed to flowing hydrogen. This project is referred to as the Nuclear Thermal Rocket Element Environment Simulator or NTREES. The NTREES device is located at the Marshall Space flight Center in a laboratory which has been modified to accommodate the high powers required to heat the test articles to the required temperatures and to handle the gaseous hydrogen flow required for the tests. Other modifications to the laboratory include the installation of a nitrogen gas supply system and a cooling water supply system. During the design and construction of the facility, every effort was made to comply with all pertinent regulations to provide assurance that the facility could be operated in a safe and efficient manner. The NTREES system can currently supply up to 50 kW of inductive heating to the fuel test articles, although the facility has been sized to eventually allow test article heating levels of up to several megawatts.

Emrich, William J.

2008-01-01

454

Solid rocket motor internal flow during ignition  

SciTech Connect

A numerical procedure is presented for the analysis of the internal flow in a solid rocket motor (SRM) during the ignition transient period of operation, along with the results obtained when this computer code was applied to several motors. The purpose of this code development effort was to achieve a detailed picture of the unsteady flowfield for a SRM of arbitrary design during this period of ignition delay, propellant ignition, flame spreading, and chamber filling/pressurization. The approach was to combine an unsteady, axisymmetric solution of the equations of inviscid fluid motion (Euler equations) with simple models for the convective and radiative heat transfer to the propellant surface during the run up to ignition. An unsteady, one-dimensional heat conduction solution for the propellant grain is coupled to this unsteady flow solution in order to calculate the propellant surface temperature. This solution, together with a surface temperature ignition criterion, determines the ignition delay and flame spreading. First, data were used from a Titan 5-1/2-segment solid rocket motor static firing to fix an unknown constant in the heat transfer model. Then, the computer code was applied to two solid rocket motors, Titan 7-segment and Space Shuttle, for which time-dependent chamber pressure measurements were available from static firings. Good agreement with the data was obtained. 17 refs.

Johnston, W.A. [Aerospace Corp, El Segundo, CA (United States)

1995-05-01

455

Rocket Car on an Inclined Plane Model  

NSDL National Science Digital Library

The Ejs Rocket Car on an Inclined Plane model displays a car on an inclined plane. When the car reaches the bottom of the incline, it can be set to bounce (elastic collision) with the stop attached to the bottom of the incline. The car consists of the car body, two rotating front wheels, and two rotating rear wheels. The incline angle (in radians) can be changed via a textbox and the rocketās thrust can be changed via a slider. In addition the car can be dragged to its initial position. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting āOpen Ejs Modelā from the pop-up menu item. Ejs Rocket Car on an Inclined Plane model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_mech_newton_RocketCarOnInclinedPlane.jar file will run the program if Java is installed. Ejs is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models. Additional Ejs models for classical mechanics are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or Ejs.

Christian, Wolfgang; Franciscouembre; Belloni, Mario

2008-10-29

456

Commercial and institutional kitchen exhaust systems  

SciTech Connect

This article addresses design requirements for commercial and institutional kitchen exhaust systems. The topics of the article include design considerations, toilet exhaust, dishwasher exhaust, grease hood exhaust, codes and standards, design concerns, common problems, and fire suppression. A side bar on ducts, plenums and housings is also included.

McGuire, A.B. (McGuire Engineers, Chicago, IL (United States))

1993-05-01

457

Andųya Rocket Range, Norway - a toolbox for space research  

NASA Astrophysics Data System (ADS)

Andųya Rocket Range (ARR) is responsible for all scientific related balloon and sounding rocket operations in Norwegian territory. From its location far north of the Arctic Circle, ARR provides complete services for launching, data acquisition, recovery and ground instrumentation support. The launching service are offered from sites on the mainland of Norway and from Svalbard. The Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR), with its wide range of ground-based instruments, contributes to rocket and balloon campaigns with important information about the Arctic atmosphere. Combined measurements by rockets, balloons, aircraft and ALOMAR make ARR a valuable toolbox for space research in "the green Arctic".

Bųen, Kjell; Mikalsen, Per-Arne

2001-08-01

458

Impact and mitigation of stratospheric ozone depletion by chemical rockets  

SciTech Connect

The American Institute of Aeronautics and Astronautics (AIAA) conducted a workshop in conjunction with the 1991 AIAA Joint Propulsion Conference in Sacramento, California, to assess the impact of chemical rocket propulsion on the environment. The workshop included recognized experts from the fields of atmospheric physics and chemistry, solid rocket propulsion, liquid rocket propulsion, government, and environmental agencies, and representatives from several responsible environmental organizations. The conclusion from this workshop relative to stratospheric ozone depletion was that neither solid nor liquid rocket launchers have a significant impact on stratospheric ozone depletion, and that there is no real significant difference between the two.

Mcdonald, A.J. (Thiokol Corp., Brigham City, UT (United States))

1992-03-01

459

Plasma Outflows Within Polar Coronal Plumes  

NASA Astrophysics Data System (ADS)

Plasma outflow velocities within polar coronal plumes and their contribution to the fast solar wind are a matter of controversy. We investigate the plasma dynamics within plumes through the analysis of high cadence and spatial resolution observations from the Solar Dynamic Observatory (SDO) jointly with STEREO and Hinode data. This analysis allows us to address the source of heating and plasma acceleration inside polar plumes and therefore obtain constraint on the contribution of plumes to the fast solar wind. Our results provide important constraints of theoretical model dealing with the formation and evolution of polar coronal plumes.

Raouafi, N.; Stenborg, G.; Vourlidas, A.

2011-12-01

460

Coordinated Auroral Experiment using Scatter and Rockets (CAESAR): A sounding rocket project to study the magnetosphere  

NASA Astrophysics Data System (ADS)

Two identical payloads to investigate magnetic substorm phenomena, launched by the three stage Skylark 12 sounding rocket, are presented. To avoid sensitivity loss of the magnetic sensors, nonmagnetic materials are used. Stringent requirements are set up by the experiments on electromagnetic shielding. Experiments are boom mounted during their measurement phase; sensors are radially deployed. The 3rd motor stage remains attached to the payload during the measurement phase to avoid an increase of nutation during deployment of the booms. An active attitude control system is therefore not necessary. The launch window is from 24 Jan, to end of March 1984, from the Andoya Rocket Range in Norway.

Schrieder, W.; Henkel, R.

1983-06-01

461

Powerful liquid rocket engine (LRE) created by NPO Energomash for up to date space rockets  

NASA Astrophysics Data System (ADS)

The main characteristics and design of liquid rocket engines for Proton, Zenit, and Energia launch vehicles are described. Particular attention is given to RD-253 engine using N2O4 and UDMH propellants, and RD-170 and RD-120 engines based on Lox and Kerosene propellants. The RD-170 and RD-120 engines are considered to be the culmination of high pressure staged combustion and oxidizer rich turbine drive rocket engine experience. The RD-170 was verified with significant overstress testing to provide necessary data for the operational health monitoring life prediction system.

Tkachenko, Yurij N.; Limerick, Charles D.

1993-06-01

462

Plasma plume MHD power generator and method  

DOEpatents

Highly-conducting plasma plumes are ejected across the interplanetary magnetic field from a situs that is moving relative to the solar wind, such as a spacecraft or an astral body, such as the moon, having no magnetosphere that excludes the solar wind. Discrete plasma plumes are generated by plasma guns at the situs extending in opposite directions to one another and at an angle, preferably orthogonal, to the magnetic field direction of the solar wind plasma. The opposed plumes are separately electrically connected to their source by a low impedance connection. The relative movement between the plasma plumes and the solar wind plasma creates a voltage drop across the plumes which is tapped by placing the desired electrical load between the electrical connections of the plumes to their sources. A portion of the energy produced may be used in generating the plasma plumes for sustained operation.

Hammer, James H. (Livermore, CA)

1993-01-01

463

Hydrothermal plumes along the East Pacific Rise, 8 deg 40 min to 11 deg 50 min N: Plume distribution and relationship to the apparent magmatic budget  

NASA Astrophysics Data System (ADS)

The interactions between hydrothermal circulation and large-scale geological and geophysical characteristics of the mid-ocean ridge cannot be ascertained without large-scale views of the pattern of hydrothermal venting. Such multi-ridge-segment surveys of venting are accomplished most efficiently by mapping the distribution and intensity of hydrothermal plumes. In November 1991, we mapped hydrothermal temperature (Delta(theta)) and light attenuation (Delta(c)) anomalies above the East Pacific Rise (EPR) continuously from 8 deg 40 min to 11 deg 50 min N, a fast spreading ridge crest portion bisected by the Clipperton Transform Fault. Plume distributions show a precise correlation with the distribution of active vents where video coverage of the axial caldera is exhaustive. Elsewhere in the study area the sketchy knowledge of vent locations gleaned from scattered camera tows predicts only poorly the large-scale hydrothermal pattern revealed by our plume studies. Plumes were most intense between 9 deg 42 min and 9 deg 54 min N, directly over a March/April, 1991, seafloor eruption. These plumes had exceptionally high Delta(c)/Delta(theta) ratios compared to the rest of the study area; we suggest that the phase-separated gas-rich vent fluids discharging here fertilize an abundant population of bacteria. Hydrothermal plume distributions define three categories: intense and continuous, weak and discontinuous and negligible. The location of each category is virtually congruent with areas that are, respectively, magmatically robust, magmatically weak and magmatically starved, as inferred from previous measurements of axial bathymetric undulations, cross-axis inflation and magma chamber depth and continuity. This congruency implies a fine-scale spatial and temporal connection between magmatic fluctuations and hydrothermal venting. We thus speculate that, at least along this fast spreading section of the EPR, cyclic replenishment, eruption and freezing of the thin axial melt lens exerts greater control over hydrothermal venting than the more enduring zones of crystal mush and hot rock. We found intense, and continuous, plumes along 33% of the surveyed ridge crest, an observation implying that any point on the ridge is, on average, hyrothermally active one-third of the time. Combining this result with the 20% plume coverage found along the medium-rate Juan de Fuca Ridge suggests that superfast (approximately 150 mm/yr) spreading rates should support vigorous venting along approximately 50% of their length, if spreading rate and along-axis plume coverage are linearly related.

Baker, E. T.; Feely, R. A.; Mottl, M. J.; Sansone, F. T.; Wheat, C. G.; Resing, J. A.; Lupton, J. E.

1994-11-01

464

Particle size distribution measurements in a subscale motor for the Ariane 5 solid rocket booster  

NASA Astrophysics Data System (ADS)

An experimental determination of the combustion-chamber aluminum oxide particle-size distribution for the Ariane 5 Solid Rocket Booster is carried out. A subscale motor using a helium injection technique for quenching the reaction products is designed, manufactured and tested. A 30 percent helium-mass flow rate injection close to the head-end of the combustion chamber is found to give an exhaust aluminum oxide particle-size distribution representative of the combustion chamber distribution. A laser light-scattering technique and a particle-capturing technique are used and large particles found with both sizing techniques. A stretched particle size volume distribution with particle diameters ranging from 1 to 120 microns, with a maximum around 45 microns is demonstrated.

Traineau, J. C.; Kuentzmann, P.; Prevost, M.; Tarrin, P.; Delfour, A.

1992-07-01

465

Teaching the Mantle Plumes Debate  

NASA Astrophysics Data System (ADS)

There is an ongoing debate regarding whether or not mantle plumes exist. This debate has highlighted a number of issues regarding how Earth science is currently practised, and how this feeds into approaches toward teaching students. The plume model is an hypothesis, not a proven fact. And yet many researchers assume a priori that plumes exist. This assumption feeds into teaching. That the plume model is unproven, and that many practising researchers are skeptical, may be at best only mentioned in passing to students, with most teachers assuming that plumes are proven to exist. There is typically little emphasis, in particular in undergraduate teaching, that the origin of melting anomalies is currently uncertain and that scientists do not know all the answers. Little encouragement is given to students to become involved in the debate and to consider the pros and cons for themselves. Typically teachers take the approach that “an answer” (or even “the answer”) must be taught to students. Such a pedagogic approach misses an excellent opportunity to allow students to participate in an important ongoing debate in Earth sciences. It also misses the opportunity to illustrate to students several critical aspects regarding correct application of the scientific method. The scientific method involves attempting to disprove hypotheses, not to prove them. A priori assumptions should be kept uppermost in mind and reconsidered at all stages. Multiple working hypotheses should be entertained. The predictions of a hypothesis should be tested, and unpredicted observations taken as weakening the original hypothesis. Hypotheses should not be endlessly adapted to fit unexpected observations. The difficulty with pedagogic treatment of the mantle plumes debate highlights a general uncertainty about how to teach issues in Earth science that are not yet resolved with certainty. It also represents a missed opportunity to let students experience how scientific theories evolve, warts and all. Working with students to enable them to participate in the evolution of the subject and to share in the excitement of major developments is surely the best way to attract them to science.

Foulger, G. R.

2010-12-01

466

Design and test of a small two stage counter-rotating turbine for rocket engine application  

NASA Astrophysics Data System (ADS)

The aerodynamic design and rig test evaluation of a small counter-rotating turbine system is described. The technology represented by this turbine is being developed for application in an advanced upper stage rocket engine turbopump. This engine will employ an oxygen/hydrogen expander cycle and achieve high performance through efficient combustion, high combustion pressure, and high area ratio exhaust nozzle expansion. Engine performance goals require that the turbopump drive turbines achieve high efficiency at low gas flow rates. The low flow rates result in very small airfoil diameter, height and chord. The high efficiency and small size requirements present a challenging turbine design problem. The unconventional approach employed to meet this challenge is described, along with the detailed design process and resulting airfoil configurations. The method and results of full scale aerodynamic performance evaluation testing of both one and two stage configurations, as well as operation without the secondary stage stator are presented. The overall results of this effort illustrate that advanced aerodynamic design tools and hardware fabrication techniques have provided improved capability to produce small high performance turbines for advanced rocket engines.

Huber, F. W.; Branstrom, B. R.; Finke, A. K.; Johnson, P. D.; Rowey, R. J.; Veres, J. P.

1993-06-01

467

Dual-mode Operation of a Rocket-Ramjet Combined Cycle Engine  

NASA Astrophysics Data System (ADS)

One-dimensional evaluation of Ramjet-mode operation was carried out on a rocket-ramjet combined cycle engine model. For simplicity, instantaneous mixing between the airflow and rocket exhaust, instantaneous heat release, and pressure recovery by a normal-shock wave were assumed. Shock wave location was so decided that the heat release at the injection (heat addition) location was to thermally-choke the combustion gas flow. By changing the injection location, it was shown that a further downstream injection resulted in a further thrust production and a further fuel flow rate requirement for choking, and a lesser specific impulse. Balancing the thrust production and the specific impulse in terms of the launch vehicle acceleration performance should be pursued. The total pressure loss within the engine model was dominated by the shock wave location, not depended on injection location and fuel flow rate, so that having shock wave penetration to further upstream location was beneficial both for thrust production in the engine and at the external nozzle.

Tomioka, Sadatake; Tani, Koichiro; Masumoto, Ryo; Ueda, Shuuichi

468

Automotive catalytic converter exhaust system  

SciTech Connect

Disclosed is a vehicle exhaust system containing a three-way catalytic converter. An insulated flexible duct connects the outlet of the engine exhaust manifold with the inlet of the three-way catalytic converter to retain the exhaust engine gases at a temperature greater than the ignition temperature of the threeway catalyst in the catalytic converter. The insulated flexible duct is preferably made of an inner flexible metal conduit surrounded by fibrous insulation which in turn is surrounded on the outside by a second flexible metal conduit. The system is economical, contains no active elements which would require maintenance or could get out of order, is adaptable to motor vehicles of all types (especially automobiles, light trucks and vans) including those powered by either gasoline and diesel engines and entirely eliminates the need for expensive and complicated light-off catalysts in the system.

Pallo, J.M.; Previte, S.J.; Schafer, W.

1982-08-24

469

RocketCam systems for providing situational awareness on rockets, spacecraft, and other remote platforms  

NASA Astrophysics Data System (ADS)

Space-borne imaging systems derived from commercial technology have been successfully employed on launch vehicles for several years. Since 1997, over sixty such imagers - all in the product family called RocketCamTM - have operated successfully on 29 launches involving most U.S. launch systems. During this time, these inexpensive systems have demonstrated their utility in engineering analysis of liftoff and ascent events, booster performance, separation events and payload separation operations, and have also been employed to support and document related ground-based engineering tests. Such views from various vantage points provide not only visualization of key events but stunning and extremely positive public relations video content. Near-term applications include capturing key events on Earth-orbiting spacecraft and related proximity operations. This paper examines the history to date of RocketCams on expendable and manned launch vehicles, assesses their current utility on rockets, spacecraft and other aerospace vehicles (e.g., UAVs), and provides guidance for their use in selected defense and security applications. Broad use of RocketCams on defense and security projects will provide critical engineering data for developmental efforts, a large database of in-situ measurements onboard and around aerospace vehicles and platforms, compelling public relations content, and new diagnostic information for systems designers and failure-review panels alike.

Ridenoure, Rex

2004-09-01

470

Advanced Small Rocket Chambers. Option 3: 110 1BF IR-Re Rocket, Volume 2.  

National Technical Information Service (NTIS)

This is the second part of a two-part report that describes the AJ10-221, a high performance iridium-coated rhenium (Ir-Re) 110 lbf (490N) welded rocket chamber with 286:1 area ratio nozzle. This engine was designed, built, and hot fired for over 6 hours ...

D. M. Jassowski L. Schoenman

1995-01-01

471

Microbial populations in contaminant plumes  

USGS Publications Warehouse

Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation.

Haack, S. K.; Bekins, B. A.

2000-01-01

472

The Norwegian balloon and sounding rocket program 1989-1992  

Microsoft Academic Search

The Norwegian sounding rocket and balloon programs are reviewed. The aim of these programs is to perform investigations into ionospheric and magnetospheric processes. These investigations are supplemented by a wide range of ground based support instrumentation. Tests with recovery of payloads will be carried out at Andoya Rocket Range, partly as preparation for microgravity experiments. The overall program for the

B. N. Andersen; A. Gundersen

1989-01-01

473

Andųya Rocket Range, Norway - a toolbox for space research  

Microsoft Academic Search

Andųya Rocket Range (ARR) is responsible for all scientific related balloon and sounding rocket operations in Norwegian territory. From its location far north of the Arctic Circle, ARR provides complete services for launching, data acquisition, recovery and ground instrumentation support. The launching service are offered from sites on the mainland of Norway and from Svalbard. The Arctic Lidar Observatory for

Kjell Bųen; Per-Arne Mikalsen

2001-01-01

474

Sounding rocket flight data summary, 1966-1976  

Microsoft Academic Search

This report is a summary listing of all AFGL sounding rockets launched from 1966 to 1976. Listed data includes the launch time, date, place, and number; the type of rocket launched; the name of the project scientist; the impact time, range, azimuth, apogee time, and altitude; payload weight and length; the recovery, ACS type, and performance; experiments flown; support systems;

C. N. Stark; A. K. Williams

1978-01-01

475

Japan's new solid-rocket booster and its derivative launcher  

NASA Astrophysics Data System (ADS)

The current status of the design and development of the Japanese H-II SRB and its derivative launch vehicle is presented. Four full-scale static firing tests of the solid rocket motor have been conducted and the flight hardware is presently in production. Attention is given to the solid rocket booster configuration, design features, thrust vector control, and component development.

Miyazawa, Masafumi; Fukushima, Yukio; Miyaba, Hiroshi; Hosomura, Tateo; Asai, Tatsuro

1992-08-01

476

Computational neutronic analysis of the nuclear vapor thermal rocket engine  

Microsoft Academic Search

Calculational procedures and results are presented for the neutronic analysis of the Nuclear Vapor Thermal Reactor (NVTR) rocket engine. The NVTR, in a rocket engine, uses modified NERVA geometry and systems with the solid fuel replaced by highly enriched (>85%) uranium tetrafluoride (UF[sub 4]) vapor. In the NVTR, the hydrogen propellant is the primary coolant, is physically separated from the

E. T. Dugan; Y. Watanabe; S. Kuras; I. Maya; N. J. Diaz

1992-01-01

477

Rockets and Aerial Photography: a High-school Research Project  

Microsoft Academic Search

Building and launching a rocket was a great opportunity to learn more deeply several topics of high-school physics. Pressure, action and reaction, speed and acceleration, terminal velocity, air drag and several other physics concepts and laws were explored during the building and launching of an amateur experimental rocket that was also used for aerial photography. This project was also a

R. Gunter; S. Watanabe; M. Saba

2008-01-01

478

The development of space solid rocket motors in China  

Microsoft Academic Search

China has undertaken to research and develop composite solid propellant rocket motors since 1958. At the request of the development of space technology, composite solid propellant rocket motor has developed from small to large, step by step. For the past thirty eight years, much progress has made, many technical obstacles, such as motor design, case materials and their processing technology,

Huang Jianding; Ye Dingyou

1997-01-01

479

Thermodynamic extrapolation of theoretic specific impulse of solid rocket motor  

Microsoft Academic Search

A comparison of the theoretic specific impulse calculated by the extrapolation method with that of the thermodynamic computation is presented. The first and second partial derivatives of some thermodynamic functions and solid rocket motor performance parameters, such as theoretical specific impulse and characteristic velocity, are derived on the basis of a solid rocket motor (SRM) thermodynamic computation. Subsequently, the SRM

Mingchu Liu

1992-01-01

480

Rocket Sled Blast Simulation Feasibility Study. Volume III. Environmental Development.  

National Technical Information Service (NTIS)

A series of environmental tests was conducted during the development of the Rocket Sled Blast Simulation Technique. This technique used a rocket sled to propel a full-scale reentry vehicle through simulated nuclear environments. Three free-air TNT detonat...

C. A. Fisher R. J. Pucik J. H. Suttle M. D. Smith

1968-01-01

481

Theoretical and Experimental Analysis of the Physics of Water Rockets  

ERIC Educational Resources Information Center

|A simple rocket can be made using a plastic bottle filled with a volume of water and pressurized air. When opened, the air pressure pushes the water out of the bottle. This causes an increase in the bottle momentum so that it can be propelled to fairly long distances or heights. Water rockets are widely used as an educational activity, and…

Barrio-Perotti, R.; Blanco-Marigorta, E.; Fernandez-Francos, J.; Galdo-Vega, M.

2010-01-01

482

ROCKET MEASUREMENT OF MIDLATITUDE AIRGLOW AND PARTICLE PRECIPITATION  

Microsoft Academic Search

Midlatitude night airglow and particle fluxes have been measured simultaneously with a Nike-Apache rocket fired from Wallops Island, Virginia, near midnight and new moon in July 1964. The rocket carried two photometers, three Geiger counters and two scintillators, and two magnetometers as aspect sensors. The experiment conclusively demonstrated with three independent techniques that midlatitude 5577 A night airglow is not

B. J. OBrien; F. R. Allum; H. C. Goldwire

1965-01-01

483

Fertilization of frog eggs on a sounding rocket in space  

Microsoft Academic Search

During the TEXUS-17 flight (April\\/May 1988) eggs of a higher organism, the anuran amphibian Xenopus laevis, have for the first time been successfully fertilized under microgravity on a Sounding Rocket. This result also implies that Life Sciences Experiments of Short Duration can be carried out on Sounding Rockets. The latter can therefore function as additional carriers for such experiments. Histological

G. A. Ubbels; W. Berendsen; J. Narraway

1989-01-01

484

The German scientific balloon and sounding rocket program  

Microsoft Academic Search

The German space program which uses scientific balloon and sounding rocket as investigative instruments, is presented. Information on sounding rocket projects in the scientific fields of astronomy, aeronomy, magnetospheric research, and microgravity research, is provided. The scientific balloon projects are performed with emphasis on astronomical and aeronomical research. The projects undertaken after 1987 are identified as are preparations and plans

A. F. Dahl; Manfred Otterbein

1989-01-01

485

An example of successful international cooperation in rocket motor technology  

Microsoft Academic Search

The history of over 25 years of cooperation between Pratt & Whitney, San Jose, CA, USA and Snecma Moteurs, Le Haillan, France in solid rocket motor and, in one case, liquid rocket engine technology is presented. Cooperative efforts resulted in achievements that likely would not have been realized individually. The combination of resources and technologies resulted in synergistic benefits and

M. Berdoyes

2002-01-01

486

The Effect of Atmospheric Pressure on Rocket Thrust -- Part I.  

ERIC Educational Resources Information Center

|The first of a two-part question asks: Does the total thrust of a rocket depend on the surrounding pressure? The answer to this question is provided, with accompanying diagrams of rockets. The second part of the question (and answer) are provided in v20 n7, p479, Oct 1982 of this journal. (Author/JN)|

Leitner, Alfred

1982-01-01

487

13. Historic drawing of rocket engine test facility layout, including ...  

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

13. Historic drawing of rocket engine test facility layout, including Buildings 202, 205, 206, and 206A, February 3, 1984. NASA GRC drawing number CF-101539. On file at NASA Glenn Research Center. - Rocket Engine Testing Facility, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

488

Stress waves in an elastic rocket subjected to thrust loading  

Microsoft Academic Search

Stress wave pattern in an elastic rocket due to a sudden axial thrust loading is investigated. The rocket structure is assumed to be a nonhomogeneous elastic bar, and finite element method is employed in the investigation by averaging the elemental properties of each element. Dynamic deflections and stresses are determined and the corresponding wave patterns are discussed.

J. R. Banerjee; K. Ramadasa; B. Ramabhat

1977-01-01

489

Nuclear thermal rocket nozzle testing and evaluation program  

Microsoft Academic Search

Performance characteristics of the Nuclear Thermal Rocket can be enhanced through the use of unconventional nozzles as part of the propulsion system. In this report, the Nuclear Thermal Rocket nozzle testing and evaluation program being conducted at the NASA Lewis Research Center is outlined and the advantages of a plug nozzle are described. A facility description, experimental designs and schematics

Kenneth O. Davidian; Kenneth J. Kacynski

1993-01-01

490

Nuclear thermal rocket nozzle testing and evaluation program  

Microsoft Academic Search

Performance characteristics of the Nuclear Thermal Rocket can be enhanced through the use of unconventional nozzles as part of the propulsion system. The Nuclear Thermal Rocket nozzle testing and evaluation program being conducted at the NASA Lewis is outlined and the advantages of a plug nozzle are described. A facility description, experimental designs and schematics are given. Results of pretest

Kenneth O. Davidian; Kenneth J. Kacynski

1993-01-01

491

A case for Mars: A case for nuclear thermal rockets  

Microsoft Academic Search

It is now possible to make general comparisons of candidate propulsion systems for human exploration of Mars. Preliminary review indicates that the propulsion system most likely to meet all mission requirements is the Nuclear Thermal Rocket (NTR). Advanced cryogenic chemical propulsion systems achieve a maximum specific impulse (Isp) of about 470 seconds. The Nuclear Engine for Rocket Vehicle Application (NERVA)

J. E. Neuman; D. H. Van Haaften; W. W. Madsen

1990-01-01

492

Rocket-Borne probes for charged ionospheric aerosol particles  

Microsoft Academic Search

Two types of rocket-borne probes are described for detecting charged aerosol particles in the ionosphere. The first are flat charge-collecting surfaces on the skin of the rockets that have returned data in four experimental campaigns. The collection surfaces have permanent magnets behind them that shield the probes from electrons. Some of the probes also have an electrical bias to repel

Scott Robertson; Byron Smiley; Mihaly Horįnyi; Zoltan Sternovsky; J. Gumbel; J. Stegman

2004-01-01

493

A Plasma Rocket Demonstration on the International Space Station  

Microsoft Academic Search

in the development of a magneto-plasma rocket for several years. This type of rocket could be used in the future to propel interplanetary spacecraft. One feature of this concept is the ability to vary its specific impulse so that it can be operated in a mode that maximizes propellant efficiency or a mode that maximizes thrust. For this reason the

A. J. Petro

2002-01-01

494

‘RCHX-1STORM’ first Slovenian meteorological rocket program  

Microsoft Academic Search

Astronautic and Rocket Society Celje (ARSC) formed a special working team for research and development of a small meteorological hail suppression rocket in the 70th. The hail suppression system was established in former Yugoslavia in the late 60th as an attempt to protect important agricultural regions from one of the summer's most vicious storm. In this time Slovenia was a

Aleksander Kerstein; Drago Matko; Amalija Trauner; Zvone Britovšek

2004-01-01

495

Modular Dissected Cryogenic Solid-Rocket Propellant Grains  

Microsoft Academic Search

The paper deals with the concept of cryogenic solid-rocket propellant grains where the definition of solid propellants is not restricted to ambient temperature. Special cryogenic high-energy propellants, boundary layer combustion in solid propulsion and performance of cryogenic solid rockets are considered in turn.

Roger E Lo

2002-01-01

496

The DXL and STORM sounding rocket mission  

NASA Astrophysics Data System (ADS)

The objective of the Diffuse X-ray emission from the Local Galaxy (DXL) sounding rocket experiment is to distinguish the soft X-ray emission due to the Local Hot Bubble (LHB) from that produced via Solar Wind charge exchange (SWCX). Enhanced interplanetary helium density in the helium focusing cone provides a spatial variation to the SWCX that can be identified by scanning through the focusing cone using an X-ray instrument with a large grasp. DXL consists of two large proportional counters refurbished from the Aerobee payload used during the Wisconsin All Sky Survey. The counters utilize P-10 fill gas and are covered by a thin Formvar window (with Cyasorb UV-24 additive) supported on a nickel mesh. DXL's large grasp is 10 cm2 sr for both the 1/4 and 3/4 keV bands. DXL was successfully launched from White Sands Missile Range, New Mexico on December 12, 2012 using a Terrier Mk70 Black Brant IX sounding rocket. The Sheath Transport Observer for the Redistribution of Mass (STORM) instrument is a prototype soft X-ray camera also successfully own on the DXL sounding rocket. STORM uses newly developed slumped micropore (`lobster eye') optics to focus X-rays onto a position sensitive, chevron configuration, microchannel plate detector. The slumped micropore optics have a 75 cm curvature radius and a polyimide/aluminum filter bonded to its surface. STORM's large field-of-view makes it ideal for imaging SWCX with exospheric hydrogen for future missions. STORM represents the first flight of lobster-eye optics in space.

Thomas, Nicholas E.; Carter, Jenny A.; Chiao, Meng P.; Chornay, Dennis J.; Collado-Vega, Yaireska M.; Collier, Michael R.; Cravens, Thomas E.; Galeazzi, Massimiliano; Koutroumpa, Dimitra; Kujawski, Joseph; Kuntz, K. D.; Kuznetsova, Maria M.; Lepri, Susan T.; McCammon, Dan; Morgan, Kelsey; Porter, F. Scott; Prasai, Krishna; Read, Andy M.; Robertson, Ina P.; Sembay, Steve F.; Sibeck, David G.; Snowden, Steven L.; Uprety, Youaraj; Walsh, Brian M.

2013-09-01

497

Parametric Study of Water Rocket for Optimum Flight  

NASA Astrophysics Data System (ADS)

Parametric study is conducted to find the optimum condition of water rocket for long flight, provided that the tank volume is prescribed. The parameters considered in the present study are the initial air pressure, water volume fraction, empty rocket mass, launching angle and bottle diameter which significantly affect the flight performance of water rocket. First, we calculate the temporal changes in tank pressure, water and air issue speeds and thrust, on the basis of a simple physical model which has been experimentally validated. Then, this model is incorporated into the equation of motion to calculate the ballistic flight of water rocket with various parameter values. As a result, it is found that PET bottles in the market are one of the most suitable for use as the pressure tank of water rocket.

Ota, Takayuki; Umemura, Akira

498

Non-stationary heat behaviour of liquid propellant rocket engines  

NASA Astrophysics Data System (ADS)

The transient behaviour of the liquid propellant rocket engine is accompanied by non-stationary heat processes in the combustion chamber, the cooling jacket, and the injector. Based on the analysis of the phenomena, which take place in the liquid propellant rocket engine after cut-off command, the major stages of the curve of the rocket thrust drop were defined. A mathematical model of heat processes is suggested, which includes the calculation of transient heat transfer in the chamber, and the detection of boiling-up of the liquid fuel components in the cooling jacket and in the injector. The determination of the law of the rocket thrust drop and a calculation of the after-effect impulse (AEI) are presented. The calculated transient heat flux the combustion chamber and the transient wall temperatures were compared with experimental data, which were received during starting, and with the impulsive behaviour of the liquid propellant rocket engine.

Prysnyakov, V. F.; Serebryansky, V. N.

499

Nuclear thermal rocket engine operation and control  

NASA Astrophysics Data System (ADS)

The operation of a typical Rover/Nerva-derived nuclear thermal rocket (NTR) engine is characterized a