SEARCH · Engineering Papers

Results for “Motor Design”

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.

SourceResearch connectionFrom yearThrough year

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

At least 955 records · Page 53

All sources NASA NTRS DOE OSTI

NASA NTRS1932

The Effect of Clearance Distribution on the Performance of a Compression-ignition Engine with a Precombustion Chamber

The clearance distribution in a precombustion chamber cylinder head was varied so that for a constant compression ratio of 13.5 the spherical auxiliary chambers contained 20, 35, 50, and 70 per cent of the total clearance volume. Each chamber was connected to the cylinder by a single circular passage, flared at both ends, and of a cross-sectional area proportional to the chamber volume, thereby giving the same calculated air-flow velocity through each passage. Results of engine-performance tests are presented with variations of power, fuel consumption, explosion pressure, rate of pressure rise, ignition lag, heat loss to the cooling water, and motoring characteristics. For good performance the minimum auxiliary chamber volume, with the cylinder head design used, was 35 per cent of the total clearance volume; for larger volumes the performance improves but slightly. With the auxiliary chamber that contained 35 percent of the clearance volume there were obtained the lowest explosion pressures, medium rates of pressure rise, and slightly less than the maximum power. For all clearance distributions an increase in engine speed decreased the ignition lag in seconds and increased the rate of pressure rise.

Moore, C. S.↗

NASA NTRS1997

NASA's Involvement in Technology Development and Transfer: The Ohio Hybrid Bus Project

A government and industry cooperative is using advanced power technology in a city transit bus that will offer double the fuel economy, and reduce emissions to one tenth of government standards. The heart of the vehicle's power system is a natural gas fueled generator unit. Power from both the generator and an advanced energy storage system is provided to a variable speed electric motor attached to the rear drive axle. A unique aspect of the vehicle's design is its use of "super" capacitors for recovery of energy during braking. This is the largest vehicle ever built using this advanced energy recovery technology. This paper describes the project goals and approach, results of its system performance modeling, and the status of the development team's effort.

Viterna, Larry A.↗

NASA NTRS2009

JWST OTE Development Status

This slide presentation reviews the status of the optical telescope element (OTE) for the James Webb Space Telescope (JWST). Information about the cryotests that have been performed, and the test of the Primary Mirror Segment Assembly (PMSA) is included. Also views of the progress on the secondary, tertiary Mirror Segment Assembly and the fine steering motor are included. Information is included about the status of other structures. The critical design audit (CDA) of the OTE is scheduled for October of 2009.

Keski-Kuha, Ritva↗

NASA NTRS2009

Robust Software Architecture for Robots

Robust Real-Time Reconfigurable Robotics Software Architecture (R4SA) is the name of both a software architecture and software that embodies the architecture. The architecture was conceived in the spirit of current practice in designing modular, hard, realtime aerospace systems. The architecture facilitates the integration of new sensory, motor, and control software modules into the software of a given robotic system. R4SA was developed for initial application aboard exploratory mobile robots on Mars, but is adaptable to terrestrial robotic systems, real-time embedded computing systems in general, and robotic toys.

Aghazanian, Hrand↗

NASA NTRS2004

An Engineering Look at Space Shuttle and ISS Operations

This slide presentation, in Spanish, is an overview of NASA's Space Shuttle operations and preparations for serving the International Space Station. There is information and or views of the shuttle's design, the propulsion system, the external tanks, the foam insulation, the reusable solid rocket motors, the vehicle assembly building (VAB), the mobile launcher platform being moved from the VAB to the launch pad. There is a presentation of some of the current issues with the space shuttle: cracks in the LH2 flow lines, corrosion and pitting, the thermal protection system, and inspection of the thermal protection system while in orbit. The shuttle system has served for more than 20 years, it is still a challenge to re-certify the vehicles for flight. Materials and material science remain as chief concerns for the shuttle,

Hernandez, Jose M.↗

NASA NTRS2014

Spacesuit Water Membrane Evaporator; An Enhanced Evaporative Cooling Systems for the Advanced Extravehicular Mobility Unit Portable Life Support System

Spacesuit Water Membrane Evaporator - Baseline heat rejection technology for the Portable Life Support System of the Advanced EMU center dot Replaces sublimator in the current EMU center dot Contamination insensitive center dot Can work with Lithium Chloride Absorber Radiator in Spacesuit Evaporator Absorber Radiator (SEAR) to reject heat and reuse evaporated water The Spacesuit Water Membrane Evaporator (SWME) is being developed to replace the sublimator for future generation spacesuits. Water in LCVG absorbs body heat while circulating center dot Warm water pumped through SWME center dot SWME evaporates water vapor, while maintaining liquid water - Cools water center dot Cooled water is then recirculated through LCVG. center dot LCVG water lost due to evaporation (cooling) is replaced from feedwater The Independent TCV Manifold reduces design complexity and manufacturing difficulty of the SWME End Cap. center dot The offset motor for the new BPV reduces the volume profile of the SWME by laying the motor flat on the End Cap alongside the TCV.

Bue, Grant C.↗

NASA NTRS2022

Novel Processing, Testing and Characterization of Copper/Carbon Nanotube (Cu/CNT) Yarn Composite Conductor

Sustainable electrified aircraft propulsion (EAP) is likely to lead to an increase in the electrical wiring contained within a single aircraft. Since the electrical resistance and mass of copper (Cu) conductors are associated with power losses, it is desirable to design high-conductivity lightweight conductor materials, thus reducing the mass of components like motor windings, low-voltage signal cables, and transmission cables for data and power to improve the overall energy efficiency. This paper describes a unique framework for manufacturing metalized carbon nanotube (CNT) composite conductors, measuring their electrical conductivity and strength, and modeling the overall conductivity and current sharing within such composites. Tensile testing was conducted on the processed composite conductor cables with the use of acoustic emission and electrical resistivity to determine stress-dependent-failure mechanisms while monitoring the electrical conductivity. The average of measured electrical conductivities of annealed Cu/CNT samples from batch 5 was greater than theoretical predictions by 9.8 percent and was also greater than the conductivity of pure annealed Cu by 4.8 percent and had comparable ultimate tensile strengths. Additionally, those Cu/CNT samples provide a 13.5% weight saving over current state of the art copper wires. Theories explaining improved intrinsic conductivity are discussed.

Metalized CNT↗

NASA NTRS2024

Effect of High-Speed Rotation on High-Temperature Superconducting Coils for High Efficiency Megawatt Motor

The use of a superconducting rotor in the High Efficiency Megawatt Motor (HEMM) comes with a number of challenges. The HEMM’s rotor must be designed so that the superconducting coil can tolerate the forces it will encounter during operation. These forces introduce considerable risk to the design of the HEMM. Because this risk cannot be adequately addressed through refined analysis, a set of experiments was deemed necessary to demonstrate that the HEMM’s superconducting coils can survive the stresses imparted by the centrifugal forces acting on the coil during full-speed operation of the machine. These experiments required spin testing a full-scale HEMM coil on a representative rotor structure at room temperature and sequentially higher rotation speeds and measuring the superconductivity response of the coil in liquid nitrogen (LN2) before and after each spin test. Tests were carried out to the full centripetal loading of a recent HEMM design. According to finite element analysis, this load produced stress components in the coil that exceed their design limit by a factor of 1 to 7.4. Although not yet confirmed, the current HEMM design is expected to produce even smaller stresses in the coil due to a 20 percent reduction in the coil’s mass and an increased volume of structural material. The only degradation of the coil that occurred during this testing resulted from a test rig failure and from the voltage taps, which are not part of the final coil design.

Electrified Aircraft Propulsion↗

NASA NTRSDate not supplied

Mitigation of High Lateral Asymmetry Rates Due to Loss of a Cruise Motor on the X-57 Mod III Aircraft

The X-57 Mod III aircraft utilizes wingtip electric motors to generate thrust. The potential benefit of wingtip propulsion is a reduction in induced drag because wingtip vortices are interrupted. Wingtip propulsors, however, pose the risk of dangerous thrust asymmetry if one of the motors abruptly stops producing full thrust. This paper examines the effects of a full-power, single-motor failure at various phases of flight for the X-57 Mod III aircraft design by way of piloted-in-the-loop simulations conducted by two National Aeronautics and Space Administration test pilots. After determining that a failure during takeoff potentially poses the highest risk of catastrophic consequences, possible mitigations to the failure were explored and evaluated through pilot simulation data, Cooper-Harper ratings, and pilot comments. The preferred mitigation was found to be an automated power reduction system that allowed for a lower pilot workload and quick reduction of the asymmetric thrust.

Ryan Wallace↗

NASA NTRSDate not supplied

Extending mARC II Arc-Jet Test Duration via Design and Implementation of Model System Cooling Sleeve

The mARC II is a 30 kW arc-jet facility at NASA Ames Research Center used to generate high-enthalpy flows for low-cost thermal protection system (TPS) technology development. Sustained operation of downstream instrumentation and material samples is constrained by thermal loading transmitted through the arc-jet test environment, limiting achievable run times and experimental throughput. This work presents the design, integration, and validation of a cooling sleeve implemented on the sweep arm drive motor feedthrough to mitigate thermal accumulation during testing. The addition of the cooling sleeve is a simple, robust upgrade that translates directly into enhanced facility capability by supporting longer run durations, reduced turnaround time, and higher throughput.

sting arm↗

NASA NTRSDate not supplied

Extending mARC II Arc-Jet Test Duration via Design and Implementation of Model System Cooling Sleeve

numerical simulations↗

NASA NTRS2020

Low Lift-to-Drag Morphing Shape Design

One advantage of the low lift-to-drag (L/D) inflatable vehicle being evaluated for the human Mars Entry, Descent, and Landing Architecture Study (EDLAS) is the lower launch mass compared to the other concepts being considered. Mass reduction is achieved by using a strong but lightweight inflatable structure and by eliminating the need for a backshell. Performance analysis has shown that additional mass savings is achievable using entry guidance technologies that reduce powered descent propellant mass by directly controlling angle of attack and sideslip, rather than the traditional bank angle control approach used by the current state-of-the-art Mars Science Laboratory entry vehicle. Two methods of implementing this guidance scheme are presented, one uses aerodynamic flaps, the other changes or morphs the shape of the inflatable aeroshell during flight. This paper describes both control methods for the EDLAS low-L/D vehicle, including the aerodynamic model of the aerosurfaces and various methods to achieve the morphing shape deflection (internal motors, shifting tori, etc.). Results of trajectory performance simulations for both the aerodynamic flap and morphing designs are also presented along with details of mechanical implementation options available to ground test the system.

Alicia Dwyer Cianciolo↗

NASA NTRS2019

Multi-Point Design and Optimization of a Turboshaft Engine for a Tiltwing Turboelectric VTOL Air Taxi

This paper describes the design of a turboshaft engine for a tiltwing air taxi application. In this case, the tiltwing air taxi is intended to fly a 400-nautical mile mission with up to fifteen passengers. Engine requirements for the concept engine are taken from aircraft system studies where thrust is produced by four propellers driven by electric motors and powered by a single gas turbine engine. The purpose of this paper is to perform a cycle design optimization that minimizes fuel consumption and weight while respecting current technology limitations to meet mission requirements. To achieve results, the engine overall pressure ratio and maximum temperature at the exit of the combustor are set as the design parameters. Several sensitivity studies are also performed to visualize optimization trends. Results of the optimization study show solutions are heavily dependent on engine cooling flow requirements and exact mission requirements. This engine is intended for use in large system optimization research.

Optimization↗

NASA NTRS1994

Design of a wheeled articulating land rover

The WALRUS is a wheeled articulating land rover that will provide Ames Research Center with a reliable, autonomous vehicle for demonstrating and evaluating advanced technologies. The vehicle is one component of the Ames Research Center's on-going Human Exploration Demonstration Project. Ames Research Center requested a system capable of traversing a broad spectrum of surface types and obstacles. In addition, this vehicle must have an autonomous navigation and control system on board and its own source of power. The resulting design is a rover that articulates in two planes of motion to allow for increased mobility and stability. The rover is driven by six conical shaped aluminum wheels, each with an independent, internally coupled motor. Mounted on the rover are two housings and a removable remote control system. In the housings, the motor controller board, tilt sensor, navigation circuitry, and QED board are mounted. Finally, the rover's motors and electronics are powered by thirty C-cell rechargeable batteries, which are located in the rover wheels and recharged by a specially designed battery charger.

Stauffer, Larry↗

NASA NTRS1976

Utilization of solid-propellant upper stages in STS payload orbital operations

The main purpose of this report is to discuss techniques of trajectory design, maneuver execution, and stage loading that are compatible with the use of SRM's (solid rocket motors) which, once ignited, must burn to propellant depletion. It is anticipated that some shuttle payloads will use non-IUS (interim upper stage) solid propellant kick stages; therefore this subject is also pertinent to shuttle flights other than those involving the use of the IUS. The SRM utilization techniques can be divided into two major categories: (1) those in which the stage performance is adjusted to match the velocity increment magnitude requirements of a preselected trajectory, and (2) those in which the trajectory is designed to match the velocity increment magnitude capability of the stage(s).

Wilson, S. W.↗

NASA NTRS1991

Comparative Flow Path Analysis and Design Assessment of an Axisymmetric Hydrogen Fueled Scramjet Flight Test Engine at a Mach Number of 6.5

NASA has contracted with the Central Institute of Aviation Motors CIAM to perform a flight test and ground test and provide a scramjet engine for ground test in the United States. The objective of this contract is to obtain ground to flight correlation for a supersonic combustion ramjet (scramjet) engine operating point at a Mach number of 6.5. This paper presents results from a flow path performance and thermal evaluation performed on the design proposed by the CIAM. This study shows that the engine will perform in the scramjet mode for stoichiometric operation at a flight Mach number of 6.5. Thermal assessment of the structure indicates that the combustor cooling liner will provide adequate cooling for a Mach number of 6.5 test condition and that optional material proposed by CIAM for the cowl leading-edge design are required to allow operation with or without a type IV shock-shock interaction.

McClinton, C.↗

NASA NTRS2011

Design and Implementation of a Mechanical Control System for the Scanning Microwave Limb Sounder

The Scanning Microwave Limb Sounder (SMLS) will use technological improvements in low noise mixers to provide precise data on the Earth's atmospheric composition with high spatial resolution. This project focuses on the design and implementation of a real time control system needed for airborne engineering tests of the SMLS. The system must coordinate the actuation of optical components using four motors with encoder readback, while collecting synchronized telemetric data from a GPS receiver and 3-axis gyrometric system. A graphical user interface for testing the control system was also designed using Python. Although the system could have been implemented with a FPGA-based setup, we chose to use a low cost processor development kit manufactured by XMOS. The XMOS architecture allows parallel execution of multiple tasks on separate threads-making it ideal for this application and is easily programmed using XC (a subset of C). The necessary communication interfaces were implemented in software, including Ethernet, with significant cost and time reduction compared to an FPGA-based approach. For these reasons, the XMOS technology is an attractive, cost effective, alternative to FPGA-based technologies for this design and similar rapid prototyping projects.

Mars Science Laboratory Robotics↗

NASA NTRS1988

Lunar material transport vehicle

The proposed vehicle, the Lunar Material Transport Vehicle (LMTV), has a mission objective of efficient lunar soil material transport. The LMTV was designed to meet a required set of performance specifications while operating under a given set of constraints. The LMTV is essentially an articulated steering, double-ended dump truck. The vehicle moves on four wheels and has two identical chassis halves. Each half consists of a chassis frame, a material bucket, two wheels with integral curvilinear synchronous motors, a fuel cell and battery arrangement, an electromechanically actuated dumping mechanism, and a powerful microprocessor. The vehicle, as designed, is capable of transporting up to 200 cu ft of material over a one mile round trip per hour. The LMTV is capable of being operated from a variety of sources. The vehicle has been designed as simply as possible with attention also given to secondary usage of components.

Fisher, Charles D.↗