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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.

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NASA NTRS1984

European development experience on energy storage wheels for space

High speed fiber composite rotors suspended by contactless magnetic bearings were produced. European industry has acquired expertise in the study and fabrication of energy storage wheels and magnetic suspension systems for space. Sufficient energy density performance for space viability is being achieved on fully representative hardware. Stress cycle testing to demonstrate life capability and the development of burst containment structures remains to be done and is the next logical step.

Robinson, A. A.↗

NASA NTRS1985

Quasi drag free gradiometry

Gradiometers are instruments for measuring the gradient of the gravity vector. However, these devices are in varying degrees contaminated by gravity itself or by acceleration. To a large extent these problems are avoidable in orbit, and dramatic improvements in operating accuracy are envisioned. The considered improvements could lead to the possibility of detailed global gravity surveys of the earth, or other planets. An obstacle in the path toward the conduction of such surveys is related to the impossibility to demonstrate an instrument's potential orbital performance in the laboratory. A promising approach for orbital testing is possibly a procedure in which the Shuttle is operated as a drag free satellite. This procedure involves floating the gradiometer in the Shuttle bay. However, certain problems arise in connection with such a procedure. The present investigation is concerned with the possibility that the Shuttle's motion problems can be avoided through the use of a quasi-drag-free magnetic suspension.

Seaman, C. H.↗

NASA NTRS1985

Advanced Integrated Power and Attitude Control System (IPACS) study

Integrated Power and Attitude Control System (IPACS) studies performed over a decade ago established the feasibility of simultaneously satisfying the demands of energy storage and attitude control through the use of rotating flywheels. It was demonstrated that, for a wide spectrum of applications, such a system possessed many advantages over contemporary energy storage and attitude control approaches. More recent technology advances in composite material rotors, magnetic suspension systems, and power control electronics have triggered new optimism regarding the applicability and merits of this concept. This study is undertaken to define an advanced IPACS and to evaluate its merits for a space station application. System and component designs are developed to establish the performance of this concept and system trade studies conducted to examine the viability of this approach relative to conventional candidate systems. It is clearly demonstrated that an advanced IPACS concept is not only feasible, but also offers substantial savings in mass and life-cycle cost for the space station mission.

Oglevie, R. E.↗

NASA NTRS1986

Optimum transonic wind tunnel

The optimum facility to complement existing high Reynolds number transonic wind tunnels is discussed. It is proposed that the facility be cryogenic, have a total pressure of five atmospheres or less, and have a test section on the order of 4- to 5-meters square. The large size is to accommodate complicated models such as those used in propulsion testing. It is suggested that magnetic suspension and wall interference minimization and correction procedures be used. Simplicity of initial design is stressed as a means of providing for future growth opportunities.

Barnwell, R. W.↗

NASA NTRS1985

An overview of integrated flywheel technology for aerospace application

Space missions ranging from small scientific satellites to large manned spacecraft have, for many years, utilized systems of spinning flywheels to maintain vehicle attitude. These systems have included momentum and reaction wheels as well as control moment gyros. Extension of that technology to satisfy the additional tasks associated with energy storage has also been pursued. The combining of control and energy storage features into one system has been examined by NASA for space applications and demonstrated in the laboratory. The impact of technology advances in such areas as composite material rotors, magnetic suspensions, motor/generators, and electronics have prompted a re-evaluation of the viability of the flywheel storage system concept for aerospace applications. This paper summarizes the results of this re-examination and identifies shortfalls in the various technology areas.

Keckler, C. R.↗

NASA NTRS1985

Inertial energy storage for advanced space station applications

Because the NASA Space Station will spend approximately one-third of its orbital time in the earth's shadow, depriving it of solar energy and requiring an energy storage system to meet system demands, attention has been given to flywheel energy storage systems. These systems promise high mechanical efficiency, long life, light weight, flexible design, and easily monitored depth of discharge. An assessment is presently made of three critical technology areas: rotor materials, magnetic suspension bearings, and motor-generators for energy conversion. Conclusions are presented regarding the viability of inertial energy storage systems and of problem areas requiring further technology development efforts.

Van Tassel, K. E.↗

NASA NTRS1986

Electromagnetic scattering theory

Electromagnetic scattering theory is discussed with emphasis on the general stochastic variational principle (SVP) and its applications. The stochastic version of the Schwinger-type variational principle is presented, and explicit expressions for its integrals are considered. Results are summarized for scalar wave scattering from a classic rough-surface model and for vector wave scattering from a random dielectric-body model. Also considered are the selection of trial functions and the variational improvement of the Kirchhoff short-wave approximation appropriate to large size-parameters. Other applications of vector field theory discussed include a general vision theory and the analysis of hydromagnetism induced by ocean motion across the geomagnetic field. Levitational force-torque in the magnetic suspension of the disturbance compensation system (DISCOS), now deployed in NOVA satellites, is also analyzed using the developed theory.

Bird, J. F.↗

NASA NTRS1985

Advanced optical position sensors for magnetically suspended wind tunnel models

A major concern to aerodynamicists has been the corruption of wind tunnel test data by model support structures, such as stings or struts. A technique for magnetically suspending wind tunnel models was considered by Tournier and Laurenceau (1957) in order to overcome this problem. This technique is now implemented with the aid of a Large Magnetic Suspension and Balance System (LMSBS) and advanced position sensors for measuring model attitude and position within the test section. Two different optical position sensors are discussed, taking into account a device based on the use of linear CCD arrays, and a device utilizing area CID cameras. Current techniques in image processing have been employed to develop target tracking algorithms capable of subpixel resolution for the sensors. The algorithms are discussed in detail, and some preliminary test results are reported.

Lafleur, S.↗

NASA NTRS1987

A microgravity isolation mount

The design and preliminary testing of a system for isolating microgravity sensitive payloads from spacecraft vibrational and impulsive disturbances is discussed. The Microgravity Isolation Mount (MGIM) concept consists of a platform which floats almost freely within a limited volume inside the spacecraft, but which is constrained to follow the spacecraft in the long term by means of very weak springs. The springs are realized magnetically and form part of a six degree of freedom active magnetic suspension system. The latter operates without any physical contact between the spacecraft and the platform itself. Power and data transfer is also performed by contactless means. Specifications are given for the expected level of input disturbances and the tolerable level of platform acceleration. The structural configuration of the mount is discussed and the design of the principal elements, i.e., actuators, sensors, control loops and power/data transfer devices are described. Finally, the construction of a hardware model that is being used to verify the predicted performance of the MGIM is described.

Jones, D. I.↗

NASA NTRS1987

A five component electro-optical positioning system

The development of a five-component electrooptical positioning system for detecting the location of wind tunnel models within the test section is discussed. The system consists of three low power helium-neon lasers, five linear photodiode arrays, an assembly of optics that includes lenses and mirrors, and a signal conditioner. The system has been successfully installed and is currently in use at the 13-inch magnetic suspension and balance system (MSBS) at NASA Langley Research Center. Initially the system was developed as an auxiliary model position and attitude detecting system for that facility, but it has since been modified and interfaced with a PDP minicomputer to provide position feedback for the control loop.

Tcheng, Ping↗

NASA NTRS1989

An evaluation of three experimental processes for two-dimensional transonic tests

The aerodynamic measurements in conventional wind tunnels usually suffer from the interference effects of the sting supporting the model and the test section walls. These effects are particularly severe in the transonic regime. Sting interference effects can be overcome through the Magnetic Suspension technique. Wall effects can be alleviated by: testing airfoils in conventional, ventilated tunnels at relatively small model to tunnel size ratios; treatment of the tunnel wall boundary layers; or by utilization of the Adaptive Wall Test Section (AWTS) concept. The operating capabilities and results from two of the foremost two-dimensional, transonic, AWTS facilities in existence are assessed. These facilities are the NASA 0.3-Meter Transonic Cryogenic Tunnel and the ONERA T-2 facility located in Toulouse, France. In addition, the results derived from the well known conventional facility, the NAE 5 ft x 5 ft Canadian wind tunnel will be assessed. CAST10/D0A2 Airfoil results will be used in all of the evaluations.

Zuppardi, Gennaro↗

NASA NTRS1988

Cryogenic wind tunnels for high Reynolds number testing

This paper begins with a brief review of cryogenic wind tunnels and their use for high Reynolds number testing. Emphasis is on operational experience and recent aerodynamic tesing in the NASA Langley 0.3-m Transonic Cryogenic Tunnel (TCT). Specific area covered in this paper include development of test techniques and aerodynamic testing in cryogenic tunnels. Details of research experience in developing model construction techniques, including airfoils as thin as 5 percent, are given. The use of advanced testing techniques to increase the value of cryogenic tunnels to the research community is recommended. These include adaptive wall test sections using solid but flexible top and bottom walls and magnetic suspension and balance systems.

Kilgore, Robert A.↗

NASA NTRS1988

A CAD approach to magnetic bearing design

A design methodology has been developed at the Magnetic Bearing Research Laboratory for designing magnetic bearings using a CAD approach. This is used in the algorithm of an interactive design software package. The package is a design tool developed to enable the designer to simulate the entire process of design and analysis of the system. Its capabilities include interactive input/modification of geometry, finding any possible saturation at critical sections of the system, and the design and analysis of a control system that stabilizes and maintains magnetic suspension.

Jeyaseelan, M.↗

NASA NTRS1988

High-temperature processing of oxide superconductors and superconducting oxide-silver oxide composite

High temperature processing was found to partially convert the green 211 phase oxide to 123 phase. High Tc superconductivity was observed in Bi-Sr-Cu-O and Y-Sr-Cu-O systems prepared using the same heat treatment process. High temperature processing presents an alternative synthetic route in the search for new high Tc superconductors. An unusual magnetic suspension with enhancement in critical current density was observed in the 123 and AgO composite.

Wu, M. K.↗

NASA NTRS1989

Magnets promise productivity

The use of advanced magnetic suspension and balance systems (MSBS) in wind tunnels is examined. The advantages of MSBS are discussed, including accurate dynamic stability and free manipulation of the model aircraft allowing the free-flying model to respond dynamically to aerodynamic forces. Examples of wind tunnel tests employing MSBS are presented, including tests of a hypersonics parasol wing configuration and the simulation of the ejection of the crew-escape module from an aircraft.

Lawing, Pierce L.↗

NASA NTRS1989

Subsonic sting interference on the drag of a family of slanted-base ogive-cylinders

Support interference free drag measurements on a range of slanted-base ogive-cylinders are made using the NASA Langley 13 inch Magnetic Suspension and Balance System. Comparison is made to measurements with a dummy sting support. Significant support interferences are found at most test conditions. Further comparison is made between interference free base pressures, obtained using remote telemetry, and sting cavity pressures.

Britcher, Colin P.↗

NASA NTRS1990

Subsonic sting interference on the aerodynamic characteristics of a family of slanted-base ogive-cylinders

Support interference free drag, lift, and pitching moment measurements on a range of slanted base ogive cylinders were made using the NASA Langley 13 inch magnetic suspension and balance system. Typical test Mach numbers were in the range 0.04 to 0.2. Drag results are shown to be in broad agreement with previous tests with this configuration. Measurements were repeated with a dummy sting support installed in the wind tunnel. Significant support interferences were found at all test conditions and are quantified. Further comparison is made between interference free base pressures, obtained using remote telemetry, and sting cavity pressures.

Britcher, Colin P.↗

NASA NTRS1989

Cryogenic wind tunnels

Cryogenic wind tunnels and their use for high Reynolds number testing are reviewed. Emphasis is given to operational and aerodynamic testing experience in the NASA Langley 0.3-m Transonic Cryogenic Tunnel. Areas covered include development of test techniques and aerodynamic testing in cryogenic tunnels. The use of advanced testing techniques to increase the value of cryogenic tunnels is recommended. These include adaptive wall test sections, using solid but flexible top and bottom walls, and magnetic suspension and balance systems.

Kilgore, Robert A.↗