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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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At least 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Aqueous, QUick-Charging Battery Integration For Electric Flight Research

AQUIFER establishes technical feasibility of an early-stage technology, a high-energy density, aqueous-based, flow battery, resulting in a near-term increase of 1.7 times range over an all-electric battery, while retiring fire and explosion hazards associated with lithium-based chemistries. The Nano-electrofuel (NEF) flow battery will be integrated with a rim-driven motor (RDM) as a multi-functional design to eliminate conductive EMI and weight from long cable runs, and provide liquid cooling from the aqueous fuel. When successful, the technology provides an improved safety energy storage solution for emission-free electric propulsion in commercial aviation.

power systems↗
NASA NTRS2020

Mars 2020 Maxon Commercial Motor Development from COTS to Flight Qualified Motors, Gearbox, and Detent Brake: Issues Overcome and Lessons Learned

Building on previous collaborations, maxon and the Jet Propulsion Laboratory (JPL) established a partnership to modify Ø20mm & Ø32mm Commerical-Off-The-Shelf (COTS) BrushLess Direct Current (BLDC) flat motors and a Ø22mm planetary gearbox.The commercial design was modified to meet the requirements for the Mars2020 rover, a Class B [1], Martian surface environment, interplanetary mission, whilst maintain as much of the industrial heritage as possible. Despite numerous problems encountered during the development, these were all overcome and qualification of the design and acceptance testing for the 10 Flight Model (FM) actuators that were installed on the Mars2020 rover was completed on-time for the rover assembly schedule.

Loschiavo, Michael↗
NASA NTRS2018

Design, Fabrication, and Critical Current Testing of No-Insulation Superconducting Rotor Coils for NASA's 1.4 MW High-Efficiency Megawatt Motor

NASA Glenn Research Center is developing a 1.4 MW high-efficiency electric machine for future electrified aircraft to reduce energy consumption, emissions, and noise. This wound-field, synchronous machine employs a self-cooled, superconducting rotor to achieve excellent specific power and efficiency. This paper discusses the design and fabrication of the no-insulation high temperature superconducting (HTS) rotor coils and compares them to conventionally insulated HTS coils. Two sub-scale test coils with epoxy on only one axial face were fabricated. Critical current testing of the coils at 77 K and self field was conducted to study the influence of thermal cycling on their critical current and n-value. After two or four aggressive thermal cycles between 77 K and about 278 K (5 degree C), the critical current and n-value were nearly unchanged, indicating very little to no degradation.

electric aircraft propulsion↗
NASA NTRS1995

Improved Speed Control System for the 87,000 HP Wind Tunnel Drive

This paper describes the design, installation, and integrated systems tests for a new drive motor speed control system which was part of a recent rehab project for the NASA Lewis 8x6 Supersonic Wind Tunnel. The tunnel drive consists of three mechanically-coupled 29,000 HP wound rotor induction motors driving an axial flow compressor. Liquid rheostats are used to vary the impedance of the rotor circuits, thus varying the speed of the drive system. The new design utilizes a distributed digital control system with a dual touch screen CRT operator console to provide alarm monitoring, logging, and trending. The liquid rheostats are driven by brushtype servomotor systems with magnetostrictive linear displacement transducers used for position feedback. The new system achieved all goals for speed variations with load, motor load balance, and control of total power.

Becks, Edward A.↗
NASA NTRS1983

A 10 deg K triple-expansion Stirling-cycle cryocooler

The design of a triple expansion closed cycle Stirling cryocooler optimized for a cooling load of 50 mW at 10 K is described. The cooler was designed with the objectives of low power, low weight, compactness, low mechanical motion, low electromagnetic noise, and low output temperature fluctuations. The design employs a direct drive linear motion piston motor and a triple expansion free displacer. Piston motion is controlled by feedback from an optical position transducer. Mechanical vibrations are attenuated with a passive resonant counterbalance. Electromagnetic noise is attenuated with layered high permeability magnetic shielding. The regenerators move with the displacer within a thin titanium cold finger. The piston and displacer oscillate at 8.33 Hz on bearings and seals of reinforced Teflon. The cooler is designed to provide the desired 50 mW of cooling at 10 K with a power input of less than 100 W. The piston can be driven at a greater stroke to produce up to 200 mW of cooling with an input power of 250 W. A lead and copper cold tip heat exchanger will limit temperature fluctuations to within 0.01 K.

Newman, W.↗
NASA NTRS1984

Electrodynamic Tethers. 1: Power Generator in LEO. 2: Thrust for Propulsion and Power Storage

An electrodynamic tether consists of a long insulated wire in space whose orbital motion cuts across lines of magnetic flux to produce an induce voltage that in typical low orbits averages about 200 v/km. Such a system should be capable of generating substantial electrical power, at the expense of IXB drag acting on its orbital energy. If a reverse current is driven against the induced voltage, the system should act as a motor producing IXB thrust. A reference system was designed, capable of generating 20 KW of power into an electrical load located anywhere along the wire at the expense of 2.6N (20,000 J/sec) drag on the wire. In an ideal system, the conversion between mechanical and electrical energy would reach 100% efficiency. In the actual system part of the 20 KW is lost to internal resistance of the wire, plasma and ionosphere, while the drag force is increased by residual air drag. The 20 KW PMG system as designed is estimated to provide 18.7 KW net power to the load at total drag loss of 20.4 KJ/sec, or an overall efficiency of 92%. Similar systems using heavier wire appear capable of producing power levels in excess of 1 Megawatt at voltages of 2-4 KV, with conversion efficiency between mechanical and electrical power better than 95%. The hollow cathode based system should be readily reversible from generator to motor operation by driving a reverse current using onboard power.

Mccoy, J. E.↗
NASA NTRS2012

Metallic Rotor Sizing and Performance Model for Flywheel Systems

The NASA Glenn Research Center (GRC) is developing flywheel system requirements and designs for terrestrial and spacecraft applications. Several generations of flywheels have been designed and tested at GRC using in-house expertise in motors, magnetic bearings, controls, materials and power electronics. The maturation of a flywheel system from the concept phase to the preliminary design phase is accompanied by maturation of the Integrated Systems Performance model, where estimating relationships are replaced by physics based analytical techniques. The modeling can incorporate results from engineering model testing and emerging detail from the design process.

Moore, Camille J.↗
NASA NTRS1994

Data communication network at the ASRM facility

This three-year project (February 1991 to February 1994) has involved analyzing and helping to design the communication network for the Advanced Solid Rocket Motor (ASRM) facility at Yellow Creek, near Iuka, MS. The principal concerns in the analysis were the bandwidth (both on average and in the worst case) and the expandability of the network. As the communication network was designed and modified, a careful evaluation of the bandwidth of the network, the capabilities of the protocol, and the requirements of the controllers and computers on the network was required. The overall network, which was heterogeneous in protocol and bandwidth, needed to be modeled, analyzed, and simulated to obtain some degree of confidence in its performance capabilities and in its performance under nominal and heavy loads. The results of our analysis did have an impact on the design and operation of the ASRM facility. During 1993 we analyzed many configurations of this basic network structure. The analyses are described in detail in Section 2 and 3 herein. Section 2 reports on an analysis of the whole network. The preliminary results of that research indicated that the most likely bottleneck as the network traffic increased would be the hubs. Thus a study of Cabletron hubs was initiated. The results of that study are in Section 3. Section 4 herein reports on the final network configuration analyzed. When the ASRM facility was mothballed in December of 1993, this was basically the planned and partially installed network. A briefing was held at NASA/MSFC on December 7, 1993, at which time our final analysis and conclusions were disseminated. This report contains a written record of most of the information disseminated at that briefing.

Moorhead, Robert J., III↗
NASA NTRSDate not supplied

Stationary Testing of a Pulse Tube Cryocooler Designed to Rotate at 6800 RPM with the Superconducting Rotor of an Electric Machine

Electrified aircraft are being developed to increase the efficiency and reduce the cost of operating subsonic transport aircraft. Achieving a substantial impact necessitates focusing on single- and twin-aisle aircraft which use propulsion systems with >20 MW ratings. For these aircraft, multi-MW superconducting electric machines are being developed due to their high specific power and high efficiency. Most of these electric machines employ superconductors on their rotor, thereby requiring cryogenic cooling of the rotating system. An attractive solution is to conductively cool the rotor using a cryocooler that rotates with the rotor. NASA has been developing a 50 K pulse tube cryocooler for its High Efficiency Megawatt Motor (HEMM) that can operate while rotating at 6,800 rpm. The design of this cryocooler and testing of its linear motor have been discussed in prior work. This presentation presents the first measurements of the complete HEMM cryocooler. The design and results of a stationary (non-rotating) test of the cryocooler are described.

electrified aircraft propulsion↗
NASA NTRS1990

Monitoring thermal impact resulting from solid rocket motor test operations

The use of remote sensing is discussed with respect to determining the thermal conditions and the immediate environmental effects of large-scale rocket propulsion tests. Data acquired during a test firing of a solid rocket motor are presented including thermal data and surface temperatures from before, during, and after the firing. Thermal impact directly behind the nozzle is assessed, temperature values within the plume are determined, and data are generated for use in an environmental monitoring system which can analyze and forecast impact. The airborne multispectral scanner and thermocouples behind the solid rocket motor discerned that radiant temperatures are higher than predictions indicate and that the testing affects 34 acres of ground. The results are of use in determining the design and area required for developing testing facilities for rocket motors.

Davis, Bruce A.↗
NASA NTRS2002

Space Shuttle Five-Segment Booster (Short Course)

NASA is considering upgrading the Space Shuttle by adding a fifth segment (FSB) to the current four-segment solid rocket booster. Course materials cover design and engineering issues related to the Reusable Solid Rocket Motor (RSRM) raised by the addition of a fifth segment to the rocket booster. Topics cover include: four segment vs. five segment booster, abort modes, FSB grain design, erosive burning, enhanced propellant burn rate, FSB erosive burning model development and hardware configuration.

Graves, Stanley R.↗
DOE OSTI2024

High power density compact drive integrated motor for electric transportation

This project, initially part of OPEN 2018, and subsequently the ASCEND effort, targeted demonstration of significant enhancements in internal permanent magnet (IPM) motor torque and power density for current and future ground and air electric transportation applications. These were achieved through: (1) embedded two-phase system thermal management, (2) coupled, multi-scale electrical-electromagnetic-thermal-mechanical co-design and optimization, (3) size and weight reduction of motor and drive electronics through elimination of redundant cooling and coupling hardware, and (4) higher efficiency operation of SiC wide bandgap power electronics packaging through high temperature operation (200 oC). The proposed approach utilizes a single dielectric coolant for closed loop two-phase thermal management, and a combined heat rejection unit for the IPM and drive. Wick assisted liquid delivery for evaporative thermal management is utilized for the motor, and the drive electronics utilize the same coolant in flow boiling within the cold plate structures. Through the use of three-dimensional packaging for SiC, and novel drive topologies with reduced switching losses, significant increases in power density and compactness were targeted.

33 ADVANCED PROPULSION SYSTEMS↗
NASA NTRS2006

Precision Linear Actuators for the Spherical Primary Optical Telescope Demonstration Mirror

The Spherical Primary Optical Telescope (SPOT) is an ongoing research effort at Goddard Space Flight Center developing wavefront sensing and control architectures for future space telescopes. The 03.5 m SPOT telescope primary mirror is comprised20f 6, 0.86 m hexagonal mirror segments arranged in a single ring, with the central segment missing . The mirror segments are designed for laboratory use and are not light-weighted to reduce cost. Each primary mirror segment is actuated and has tip, tilt, and piston rigid body motions. Additionally, the radius of curvature of each mirror segment may be varied mechanically3. To provide these degrees of freedom, the SPOT mirror segment assembly requires linear actuators capable of 10 nm resolution over a total stroke of 5 mm. These actuators must withstand high static loads as they must support the mirror segment, which has a mass of approx.100 kg. A stepper motor driving a differential satellite roller screw was designed to meet these demanding requirements. Initial testing showed that the actuator is capable of sub-micron repeatability over the entire 6mm range, and was limited by 100-200 nm measurement noise levels present in the facility. Further testing must be accomplished in an isolated facility with a measurement noise floor of < 5 nm. Such a facility should be ready for use at GSFC in the early summer of 2006, and will be used to better characterize this actuator.

Budinoff, Jason↗
NASA NTRS2006

Precision Linear Actuators for the Spherical Primary Optical Telescope Demonstration Mirror

The Spherical Primary Optical Telescope (SPOT) is an ongoing research effort at Goddard Space Flight Center developing wavefront sensing and control architectures for future space telescopes. The 03.5-m SPOT telescope primary mirror is comprise9 of six 0.86-m hexagonal mirror segments arranged in a single ring, with the central segment missing. The mirror segments are designed for laboratory use and are not lightweighted to reduce cost. Each primary mirror segment is actuated and has tip, tilt, and piston rigid-body motions. Additionally, the radius of curvature of each mirror segment may be varied mechanically. To provide these degrees of freedom, the SPOT mirror segment assembly requires linear actuators capable of <lO-nm resolution over a total stroke of 5 mm. These actuators must withstand high static loads as they must support the mirror segment, which has a mass of -100 kg. A stepper motor driving a differential satellite roller screw was designed to meet these demanding requirements. Initial testing showed that the actuator is capable of sub-micron repeatability over the entire 6-mm range, and was limited by 100-200 nm measurement noise levels present in the facility. Further testing must be accomplished in an isolated facility with a measurement noise floor of <5 nm. Such a facility should be ready for use at GSFC in the early summer of 2006, and will be used to better characterize this actuator.

Budinoff, Jason↗
NASA NTRS2017

NASA's Space Launch System: Systems Engineering Approach for Affordability and Mission Success

NASA is working toward the first launch of a new, unmatched capability for deep space exploration, with launch readiness planned for 2018. The initial Block 1 configuration of the Space Launch System will more than double the mass and volume to Low Earth Orbit (LEO) of any launch vehicle currently in operation - with a path to evolve to the greatest capability ever developed. The program formally began in 2011. The vehicle successfully passed Preliminary Design Review (PDR) in 2013, Key Decision Point C (KDPC) in 2014 and Critical Design Review (CDR) in October 2015 - nearly 40 years since the last CDR of a NASA human-rated rocket. Every major SLS element has completed components of test and flight hardware. Flight software has completed several development cycles. RS-25 hotfire testing at NASA Stennis Space Center (SSC) has successfully demonstrated the space shuttle-heritage engine can perform to SLS requirements and environments. The five-segment solid rocket booster design has successfully completed two full-size motor firing tests in Utah. Stage and component test facilities at Stennis and NASA Marshall Space Flight Center are nearing completion. Launch and test facilities, as well as transportation and other ground support equipment are largely complete at NASA's Kennedy, Stennis and Marshall field centers. Work is also underway on the more powerful Block 1 B variant with successful completion of the Exploration Upper Stage (EUS) PDR in January 2017. NASA's approach is to develop this heavy lift launch vehicle with limited resources by building on existing subsystem designs and existing hardware where available. The systems engineering and integration (SE&I) of existing and new designs introduces unique challenges and opportunities. The SLS approach was designed with three objectives in mind: 1) Design the vehicle around the capability of existing systems; 2) Reduce work hours for nonhardware/ software activities; 3) Increase the probability of mission success by focusing effort on more critical activities.

Hutt, John J.↗
NASA NTRS2003

Safer Roadside Crash Walls Would Limit Deceleration

The figure depicts the aspects of a proposed deceleration-limiting design for crash walls at the sides of racetracks and highways. The proposal is intended to overcome the disadvantages of both rigid barriers and kinetic-energy-absorbing barriers of prior design. Rigid barriers can keep high-speed crashing motor vehicles from leaving roadways and thereby prevent injury to nearby persons and objects, but they can also subject the occupants of the vehicles to deceleration levels high enough to cause injury or death. Kinetic-energy-absorbing barriers of prior design reduce deceleration levels somewhat, but are not designed to soften impacts optimally; moreover, some of them allow debris to bounce back onto roadways or onto roadside areas, and, in cases of glancingly incident vehicles, some of them can trap the vehicles in such a manner as to cause more injury than would occur if the vehicles were allowed to skid along the rigid barriers. The proposed crash walls would (1) allow tangentially impacting vehicles to continue sliding along the racetrack without catching them, (2) catch directly impacting vehicles to prevent them from injuring nearby persons and objects, and (3) absorb kinetic energy in a more nearly optimum way to limit decelerations to levels that human occupants could survive.

Schneider, William C.↗
NASA NTRS1992

Application of composite materials to impact-insensitive munitions

An approach is outlined for developing bullet-impact-insensitive munitions based on composite materials that provide rapid venting of the rocket-motor case. Impact experiments are conducted with test specimens of hybrid laminates of graphite/epoxy and epoxy reinforcing with woven glass fibers. The dynamic strain response and initial impact force are measured with strain gauges, and perforation damage is examined in the plates. The results show that impact damage can be designed by means of parametric variations of the fiber, matrix, and ply orientations. It is suggested that rocket-motor cases can be designed with composite materials to provide rapid venting during the failure mode. The experimental ballistic testing performed provides data that can be used comparatively with analytical data on composite materials.

Neradka, Vincent F.↗