Search NASA⌕ Search

SEARCH · Search NASA

Results for “Richmond”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

MST data exchange through the NCAR incoherent-scatter radar data base

One means of making MST (mesosphere stratosphere troposphere) radar data more easily accessible for scientific research by the general scientific community is through a centralized data base. Such a data base can be designed to readily provide information on data availability and quality, and to provide copies of data from any radar in a common format to the user. The ionospheric incoherent scatter community has established a centralized data base at NCAR that may serve not only as a model for a possible MST data base, but also as a catalyst for getting an MST data base started. (Some key elements of the NCAR data base are given.) The NCAR data base can include MST data in the same framework with relatively little extra effort. They are willing to handle MST data on a limited basis in order to permit assessment of community interest and in order to provide some experience with a centralized data base for MST data.

Richmond, A. D.↗
NASA NTRS1987

Aerodynamic measurements and thermal tests of a strain-gage balance in a cryogenic wind tunnel

An internal strain-gage balance designed and constructed in Europe for use in cryogenic wind tunnels has been tested in the Langley 0.3-Meter Transonic Cryogenic Tunnel. Part of the evaluation was made at equilibrium balance temperatures and it consisted of comparing the data taken at a tunnel stagnation temperature of 300 K with the data taken at 200 K and 110 K while maintaining either the Reynolds number or the stagnation pressure. A sharp-leading-edge delta-wing model was used to provide the aerodynamic loading for these tests. Results obtained with the balance during the force tests were found to be accurate and repeatable both with and without the use of a convection shield on the balance. An additional part of this investigation involved obtaining data on the transient temperature response of the balance during both normal and rapid changes in the tunnel stagnation temperature. The variation of the temperature with time was measured at three locations on the balance near the physical locations of the strain gages. The use of a convection shield significantly increased the time required for the balance to stabilize at a new temperature during the temperature response tests.

Boyden, Richmond P.↗
NASA NTRS1986

Advances in high chamber pressure propulsion

NASA has been involved in the development of improved high thrust booster rocket engines to meet the propulsion requirements of launch vehicles such as the Space Shuttle. Solutions that NASA/Marshall Space Flight Center pursued to accomplish the high performance, long life goals set for SSME are discussed. In addition, currently projected requirements for liquid rocket engines have identified liquid oxygen/hydrocarbon-fueled engines for booster application in the near future. These advanced hydrocarbon-fueled engines will require improvements in performance and life to be suitable for their projected missions. Raising chamber pressure to increase performance and reduce engine envelope are the key objectives in hydrocarbon-fueled engine technology. This paper traces the history of advances in high pressure rocket engine systems and the challenges it presents.

Mccool, A. A.↗
NASA NTRS1986

Status of magnetic suspension technology

The reasons for the continuing interest in the Magnetic Suspension and Balance System (MSBS) are highlighted. Typical problems that can arise because of model-support interference in a transonic wind tunnel are shown to illustrate the need for MSBS. The two magnetic suspension systems in operation at Langley are the only ones active in the U.S. One of these systems is the 13 inch MSBS which was borrowed from the Air Force Arnold Engineering Development Center. The other system is the 6 inch MSBS which was developed by MIT Aerophysics Laboratory with NASA and DOD funding. Each of these systems is combined with a subsonic wind tunnel. Ongoing research in both of these systems is covered. Last year, Madison Magnetics, Inc., completed a contractual design and cost study utilizing some advance concepts for a large MSBS which would be compatible with an 8 foot transonic wind tunnel and the highlights of the study are presented. Sverdrup Technology, Inc., recently performed a study under contract for Langley on the potential usefulness to the aerospace industry of a proposed large MSBS combined with a suitable transonic wind tunnel. The results of that study are discussed. Langley has partially funded the MSBS work at the University of Southampton for about 6 years under a grant arrangement and the major results are summarized.

Boyden, Richmond P.↗
NASA NTRS1987

Electrodynamic effects of thermospheric winds from the NCAR thermospheric general circulation model

Electrodynamic effects of thermospheric winds simulated with the NCAR thermospheric general circulation model (TGCM) were modeled and compared with observations for equinox solar minimum conditions. Two TGCM wind simulations were used: one driven only by in situ solar UV heating, the other also including lower boundary forcing that mimics the effects of upward propagating semidiurnal tides. It was found that, without tidal forcing, the TGCM winds produce ground magnetic variations that have the general pattern of observed Sq variations, but are only about half as strong. The addition of tidal forcing improved the agreement between calculated and observed magnetic variations and between calculated and observed electric fields.

Richmond, A. D.↗
NASA NTRS1988

A review of Magnetic Suspension and Balance Systems

This paper traces the development of Magnetic Suspension and Balance Systems (MSBSs) for use in wind tunnels. The expression MSBS implies a system that can both suspend a model and also measure the forces and moments acting on the model. This avoids the need for any mechanical support of the model. An MSBS uses electromagnets located outside the test section walls to create magnetic fields inside the test section. Measurement of the electrical current flowing in each of the electromagnets can be used to determine the forces and moments acting on the suspended model. An MSBS is capable of supporting a model with an internal magnetized core subject to gravity, aerodynamic, and inertial loads. The model must have a core made of either a permanent magnet, magnetized soft iron, or a solenoid. The position of the suspended body is inherently unstable. A closed-loop control system which includes a position sensing system has to control the position of the body by controlling the applied magnetic fields. This paper includes a discussion of all the known MSBSs and the outlook for larger systems.

Boyden, Richmond P.↗
NASA NTRS1988

Mapping electrodynamic features of the high-latitude ionosphere from localized observations - Technique

This paper describes a novel procedure for mapping high-latitude electric fields and currents and their associated magnetic variations, using sets of localized observational data derived from different types of measurements. The technique provides a formalism for incorporating simultaneously such different classes of data as electric fields from radars and satellites, electric currents from radars, and magnetic perturbations at the ground and at satellite heights; the technique also uses available statistical information on the averages and variances of electrodynamic fields. The technique provides a more rigorous way of quantitatively estimating high-latitude electric field and current patterns than other methods and has a capability to quantify the errors in the mapped fields, based on the distribution of available data, their errors, and the statistical variances of the fields. The technique is illustrated by an application to a substorm which was analyzed by Kamide et al. (1982) by an earlier technique.

Richmond, A. D.↗
NASA NTRS1988

Super magnets for large tunnels

The development and use of a large Magnetic Suspension and Balance System (MSBS) in wind tunnels is examined, discussing NASA-sponsored research to develop a large MSBS, and the 2 MSBS already in use. The MSBS holds the model in an arbitrary position in the wind tunnel test section and measures the forces and moments acting on the model. Technologies for building a large MSBS have been developed, and research is being done to reduce building costs. Magnetic suspension is advantageous because it completely eliminates interference from mechanical support systems such as stings or struts and it allows for easy rotation and translation of the model. Advances allowing operation at higher temperatures, probably using liquid nitrogen instead of liquid helium may reduce the cost of MSBS operation. A large MSBS would require power controllers with capacity up to 10 MW, efficiency approaching 98 percent and the ability to reverse the sign of both voltage and current. Technologies include the electro-magnetic position sensor, model positioning sensing, digital controller, and a precalibrated resistance strain-gage balance.

Boyden, Richmond P.↗
NASA NTRS1988

NASA Earth-to-orbit propulsion R and T

Information is given in viewgraph form on Earth-to-orbit propulsion research and technology, space transportation systems, spacecraft configurations, booster technology and hybrid propellant rocket engines.

Richmond, Robert J.↗
NASA NTRS1986

Advanced Earth-to-Orbit Propulsion Technology 1986, volume 2

Technology issues related to oxygen/hydrogen and oxygen/hydrocarbon propulsion are addressed. Specific topics addressed include: rotor dynamics; fatigue/fracture and life; bearings; combustion and cooling processes; and hydrogen environment embrittlement in advanced propulsion systems.

Richmond, R. J.↗
NASA NTRS1990

Mechanistic studies of the CO-oxidation reaction on catalysts for use in long-life CO2 lasers

The catalytic recombination of carbon monoxide and oxygen was studied under conditions expected to be present in a sealed E-beam CO2 laser system. These conditions are typically a gas inlet temperature of 60 C, a substoichiometric CO/O2 ratio of ca. 2.5/1 with an oxygen feed rate of ca. 5 micromoles/s, a carrier gas comprising He, N2 and CO2 in the ratio of 3:2:1, near atmospheric pressure and a gas velocity of 4 m/s. Heterogeneous catalysts, based on precious metal supported on tin oxide, have been coated onto ceramic monoliths and tested for catalytic activity and stability after a reduction/passivation step. Two catalyst systems have been chosen. These are Pt/Pd/SnO2 and Pt/Ru/SnO2. Under the conditions described above, a characteristic decline in catalytic activity is apparent for both systems, and exit gas temperature has been recognized as a sensitive parameter by which to monitor the activity changes. A semilogarithmic plot of exit temperature as a function of time has revealed two distinct processes connected with the decline in activity: one process is associated with reduction of the oxidized precious metal (at Site A), whilst the other is related to the formation and approach to steady-state of an active site at the metal/support interface (Site B).

Dawood, Talat↗
NASA NTRS1990

Applications of low temperature CO-oxidation catalysts to breathable gases

Modifications of tin oxide/precious metal catalysts described for use in CO2 lasers have also been developed for use in other applications; namely, as low temperature CO oxidation components in fire escape hoods/masks for mines, aircrafts, hotels, and offices and in sealed environments, such as hyperbaric chambers and submarines. Tin oxide/precious metal catalysts have been prepared on a variety of high surface area cloth substrates for application in fire escape hoods. These show high and stable CO oxidation capability (10 to the 4th power ppm CO reduced to 10 to the 1st power ppm CO) at GHSV of 37,000 h(-1) with water saturated inlet gas at body heat (37 C) and below. Water vapor plays an important role in the surface state/performance of tin oxide catalyst. Water-resistant formulations have been produced by the introduction of transition metal promoters. Tin oxide/precious metal catalysts have also been developed for CO oxidation in the North Sea diving environment. These are currently in use in a variety of hyperbaric chambers and diving vehicles. Ambient temperature operation and resistance to atmospheric water vapor have been demonstrated, and as a result, they offer a viable alternative to hopcalite or heated catalyst systems. A new range of non-tin oxide based low temperature CO oxidation catalysts is described. They are based on reducible metal oxides promoted with previous metals. Preliminary data on selected materials in the form of both cloth artifacts and shaped pellets are presented. They are expected to be applicable both to the breathable gas application area and to CO2 lasers.

Noordally, Ehsan↗
NASA NTRS1989

Earth-to-orbit propulsion for the 21st century

This paper presents an overview of NASA's liquid and solid rocket and air-breathing propulsion research programs along with some recent accomplishments. Attention is focused on two contrasting, but complementary, space transportation system elements. One is directed toward the unmanned delivery of massive and/or bulky 'space cargo' to low earth orbit. The other is tailored to the transportation of humans and light priority cargo in smaller manned piloted vehicles.

Rosen, Robert↗
NASA NTRS1989

Space radiation shielding analysis and dosimetry for the Space Shuttle program

Active and passive radiation dosimeters have been flown on every Space Shuttle mission to measure the naturally-occurring, background Van Allen and galactic cosmic radiation doses that astronauts and radiation-sensitive experiments and payloads receive. A review of the various models utilized at the NASA/Johnson Space Center, Radiation Analysis and Dosimetry is presented. An analytical shielding model of the Shuttle was developed as an engineering tool to aid in making premission radiation dose calculations and is discussed in detail. The anatomical man models are also discussed. A comparison between the onboard dosimeter measurements for the 24 Shuttle missions to date and the dose calculations using the radiation environment and shielding models is presented.

Atwell, William↗
NASA NTRS1991

Ionospheric convection response to changing IMF direction

By combining ground-based and satellite-based measurements of ionospheric electric fields, conductivities and magnetic perturbations, it was possible to examine the characteristics of instantaneous, ionospheric convection patterns associated with changing directions of the interplanetary magnetic field (IMF). In response to a rapid southward-to-northward turning of the IMF on July 23, 1983, the ionospheric convection reconfigured over a period of 40 minutes. The configuration changed from a conventional two-cell pattern to a contracted four-cell pattern, with reversed convection cells in the high-latitude dayside, associated with a strong potential drop of about 75 kV. Later, in response to a gradual rotation of the IMF from the +Z through the -Y toward the -Z direction, the nightside cells disappeared and the dawn cell in the reversed pair wrapped around and displaced the dusk cell until a conventional two-cell pattern was reestablished, largely in accord with the qualitative model of Crooker (1988). The results suggest that multiple cells can arise as a result of strong southward to northward transitions in the IMF. They appear to persist for sometime thereafter.

Knipp, D. J.↗
NASA NTRS1992

A thermosphere/ionosphere general circulation model with coupled electrodynamics

A new simulation model of upper atmospheric dynamics is presented that includes self-consistent electrodynamic interactions between the thermosphere and ionosphere. This model calculates the dynamo effects of thermospheric winds, and uses the resultant electric fields and currents in calculating the neutral and plasma dynamics. A realistic geomagnetic field geometry is used. Sample simulations for solar maximum equinox conditions illustrate two previously predicted effects of the feedback. Near the magnetic equator, the afternoon uplift of the ionosphere by an eastward electric field reduces ion drag on the neutral wind, so that relatively strong eastward winds can occur in the evening. In addition, a vertical electric field is generated by the low-latitude wind, which produces east-west plasma drifts in the same direction as the wind, further reducing the ion drag and resulting in stronger zonal winds.

Richmond, A. D.↗
NASA NTRS1993

Subsonic static and dynamic stability characteristics of the test technique demonstrator NASP configuration

The paper describes the procedure used for and the results obtained of wind-tunnel tests of the National Aerospace Plane (NASP) configuration, which were conducted in the NASA Langley Research Center High Speed Tunnel using a blended body NASP configuration designed by the research center. Static and dynamic stability characteristics were measured at Mach numbers 0.3, 0.6, and 0.8. In addition to tests of the baseline configuration, component buildup tests with a canard surface and with a body flap were carried out. Results demonstrated a positive static stability of the baseline configuration, except at the higher angles of attack at Mach 0.8. A good agreement was found between the inphase dynamic parameters and the corresponding static data.

Boyden, Richmond P.↗