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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Hybrid Electric Drivetrain Testing and Design (CRADA CRD-17-00699 Final Report)

Hybrid electric drivetrains have recently become of a great interest in the medium and heavy-duty vehicle market as it enables substantial reduction of petroleum use, vehicle level fuel use and criteria pollutant emissions. These vehicle performance improvements are not only economically beneficial for business operations relying on large fleets of vehicles, they are also paramount for curbing energy use and the negative effects of vehicle operations on the environment. Efficient Drivetrains, Inc. (EDI), acquired in July 2018 by Cummins, Inc., is a small company focused on development of medium and heavy-duty hybrid electric drivetrains. EDI has already developed the general hardware architecture of their drivetrain system, but there is still a significant effort to be done on optimizing the system in terms of control strategies and component sizing in order to maximize the benefits of the hybrid drivetrain. Historically, hybrid electric systems have proven to deliver better fuel economy in certain applications than their conventional counterparts. Particular areas of advantageous applications are vocations with kinetically intensive transient duty cycles and operations requiring some sort of power take off whose power demand is not well matched to the size of the vehicle’s main engine, thus forcing it to operate in extremely inefficient operating modes. Hybrid drivetrains can be at a disadvantage when pressed into duty cycle operation consisting of extensive steady state highway cruise due to various design compromises optimized for more transient operation. This can also lead to increase in vehicle emissions if the system is not optimized properly. Ample opportunity for extensive optimization is needed to overcome these obstacles.

33 ADVANCED PROPULSION SYSTEMS↗
NASA NTRS1972

Ride quality research activities at NASA Langley Research Center

Ride quality research to determine criteria to describe vehicle performance characteristics which will insure passenger comfort is discussed. The manner in which disciplines of vehicle environmental dynamics, structural dynamics, and electromechanical measurements are combined to define passenger environments is described. The activities of many governmental and private agencies in the field of passenger comfort are examined.

Connor, A. B.↗
NASA NTRS1979

Application of modified profile analysis to function testing of simulated CTOL transport touchdown-performance data

The modification to the methodology of profile analysis to accommodate the testing of differences between two functions with a single test, rather than multiple tests at various values of the abscissa, is described and demonstrated for two sets of simulation-performance data. The first application was to a flight-simulation comparison of pilot-vehicle performance with a three-element refractive display to performance with a more widely used beam-splitter-reflective-mirror display system. The results demonstrate that the refractive system for out-the-window scene display provides equivalent performance to the reflective system. The second application demonstrates the detection of significant differences by modified profile-analysis procedures. This application compares the effects of two sets of pitch-axis force-feel characteristics on the sink rate at touchdown performance utilizing the refractive system. This experiment demonstrates the dependence of simulator sink-rate performance on force-feel characteristics.

Parrish, R. V.↗
NASA NTRS1989

An artificial gravity demonstration experiment

An artificial gravity experiment which is tethered to a Delta second stage and which uses the Small Expendable Deployer System is proposed. Following tether deployment, the Delta vehicle performs the required spin-up maneuver and can then be passivated. A surplus reentry vehicle houses the artificial gravity life science experiments. When the experiments are completed, the reentry phase of the experiment is initiated by synchronizing the spin of the configuration with the required deorbit impulse.

Rupp, C.↗
NASA NTRS2000

Rapid Prototyping and Evaluation of Control System Designs for Manned and Unmanned Applications

The development and optimization of flight control systems for modem fixed- and rotary- wing aircraft consume significant time and cost during aircraft development. Similarly, as unmanned aerial vehicles perform more complex tasks, sometimes autonomously, the control system design requirements for this class of vehicles, and the corresponding time and cost requirements, are also becoming significant. Therefore, for both manned and unmanned vehicles, substantial program savings can be achieved if integrated design and optimization tools are employed to shorten the design and flight-test cycle for new or upgraded,pontrol systems. To bring about this reduction in the length of the design-cycle, and therefore its cost, Madab and Simulink are being used to implement block diagrams and to rapidly evaluate the expected responses of the completed systems. In conjunction, CONDUIT (CONtrol Designer's Unified InTerface) is being used to enable the controls engineers to optimize their control laws and ensure that all the relevant quantitative criteria are satisfied.

Mansur, M. Hossein↗
NASA NTRS2008

Ares I-X Flight Test Vehicle Similitude to the Ares I Crew Launch Vehicle

The Ares I-X Flight Test Vehicle is the first in a series of flight test vehicles that will take the Ares I Crew Launch Vehicle design from development to operational capability. The test flight is scheduled for April 2009, relatively early in the Ares I design process so that data obtained from the flight can impact the design of Ares I before its Critical Design Review. Because of the short time frame (relative to new launch vehicle development) before the Ares I-X flight, decisions about the flight test vehicle design had to be made in order to complete analysis and testing in time to manufacture the Ares I-X vehicle hardware elements. This paper describes the similarities and differences between the Ares I-X Flight Test Vehicle and the Ares I Crew Launch Vehicle. Areas of comparison include the outer mold line geometry, aerosciences, trajectory, structural modes, flight control architecture, separation sequence, and relevant element differences. Most of the outer mold line differences present between Ares I and Ares I-X are minor and will not have a significant effect on overall vehicle performance. The most significant impacts are related to the geometric differences in Orion Crew Exploration Vehicle at the forward end of the stack. These physical differences will cause differences in the flow physics in these areas. Even with these differences, the Ares I-X flight test is poised to meet all five primary objectives and six secondary objectives. Knowledge of what the Ares I-X flight test will provide in similitude to Ares I as well as what the test will not provide is important in the continued execution of the Ares I-X mission leading to its flight and the continued design and development of Ares I.

Huebner, Lawrence D.↗
NASA NTRS2009

Ares I-X Flight Test Vehicle Similitude to the Ares I Crew Launch Vehicle

The Ares I-X Flight Test Vehicle is the first in a series of flight test vehicles that will take the Ares I Crew Launch Vehicle design from development to operational capability. Ares I-X is scheduled for a 2009 flight date, early enough in the Ares I design and development process so that data obtained from the flight can impact the design of Ares I before its Critical Design Review. Decisions on Ares I-X scope, flight test objectives, and FTV fidelity were made prior to the Ares I systems requirements being baselined. This was necessary in order to achieve a development flight test to impact the Ares I design. Differences between the Ares I-X and the Ares I configurations are artifacts of formulating this experimental project at an early stage and the natural maturation of the Ares I design process. This paper describes the similarities and differences between the Ares I-X Flight Test Vehicle and the Ares I Crew Launch Vehicle. Areas of comparison include the outer mold line geometry, aerosciences, trajectory, structural modes, flight control architecture, separation sequence, and relevant element differences. Most of the outer mold line differences present between Ares I and Ares I-X are minor and will not have a significant effect on overall vehicle performance. The most significant impacts are related to the geometric differences in Orion Crew Exploration Vehicle at the forward end of the stack. These physical differences will cause differences in the flow physics in these areas. Even with these differences, the Ares I-X flight test is poised to meet all five primary objectives and six secondary objectives. Knowledge of what the Ares I-X flight test will provide in similitude to Ares I - as well as what the test will not provide - is important in the continued execution of the Ares I-X mission leading to its flight and the continued design and development of Ares I.

Huebner, Lawrence D.↗
NASA NTRS2022

PCBoom Version 7 Technical Reference

PCBoom is a suite of sonic boom propagation programs that applies full three-dimensional ray tracing based on geometrical acoustics. It predicts sonic boom ground waveforms and footprints from supersonic flight vehicles performing arbitrary maneuvers using a variety of built-in or user-supplied nearfield vehicle source definitions. It also computes loudness metrics, ground signature locations, and sonic boom propagation times. The nomenclature "PC" in PCBoom denotes that the programs were historically targeted to run on a personal computer. PCBoom provides a valuable contribution toward sonic boom research as illustrated by the following examples: • PCBoom allows for quick “what if” type predictions for a multitude of sonic boom scenarios, including low boom design iteration work. • The detailed flight planning capabilities allow for flight conditions and waypoints to be provided to pilots to generate booms needed for research. • PCBoom allows for post-flight analysis of as-flown trajectories with measured weather data. • PCBoom has been used in sonic boom damage claim cases to determine claim veracity.

PCBoom↗
NASA NTRSDate not supplied

Verification of the Generalized Aerospace Simulation in Simulink (R)

NASA uses six-degrees-of-freedom (6-DOF) simulations tools to design, test, develop Guidance Navigation and Control (GN&C) software, and certify vehicle performance prior to flight. Therefore, it is critical that the 6-DOF tools used for vehicle design and certification are validated. The focus of this work is the vali-dation of the NASA Marshall Space Flight Center 6-DOF “GeneraLized Aero-space Simulation in Simulink” (GLASS) framework tool. The GLASS tool framework is currently used to support NASA GN&C insight for the Human Landing System (HLS) project, simulating vehicle dynamics during lunar descent and as-cent. The GLASS framework utilizes the off-the-shelf Mathworks ® Simscape Multibody® toolbox to model vehicle multi-body dynamics. NASA’s Engineering and Safety Center (NESC) provides a set of 6-DOF simulation verification “check cases” that are available to any user needing to verify 6-DOF tools. The check cases contain seventeen atmospheric and twenty-six orbital test scenarios are provided to validate equations of motion, environmental models (e.g., atmosphere, gravitation, and geodesy) and tool propagators. This paper compares GLASS 6-DOF simulation results against the NESC check cases’ results via simulation-to-simulation comparisons. The comparisons demonstrate that GLASS simulation results are “in family” with the outputs of the applicable NASA NESC check cases and verifies the GLASS core framework dynamics and the correct implementation of the check case scenario models.

6-Dof↗
NASA NTRSDate not supplied

Verification of the Generalized Aerospace Simulation in Simulink

NASA uses six-degrees-of-freedom (6-DOF) simulations tools to design, test, develop Guidance Navigation and Control (GN&C) software, and certify vehicle performance prior to flight. Therefore, it is critical that the 6-DOF tools used for vehicle design and certification are validated. The focus of this work is the validation of the NASA Marshall Space Flight Center 6-DOF “GeneraLized Aerospace Simulation in Simulink” (GLASS) framework tool. The GLASS tool framework is currently used to support NASA GN&C insight for the Human Landing System (HLS) project, simulating vehicle dynamics during lunar descent and ascent. The GLASS framework utilizes the off-the-shelf Mathworks (R) Simscape (TM) Multibody (TM) toolbox to model vehicle multi-body dynamics. NASA’s Engineering and Safety Center (NESC) provides a set of 6-DOF simulation verification “check cases” that are available to any user needing to verify 6-DOF tools. The check cases contain seventeen atmospheric and twenty-six orbital test scenarios are provided to validate equations of motion, environmental models (e.g., atmosphere, gravitation, and geodesy) and tool propagators. This paper compares GLASS 6-DOF simulation results against the NESC check cases’ results via simulation-to-simulation comparisons. The comparison demonstrates that GLASS simulation results are “in family” with the outputs of the applicable NASA NESC check-cases and verify the GLASS core framework dynamics and the implementation of the check case scenario models.

6-Dof↗
NASA NTRS2010

Evaluation of Dual Pressurized Rover Operations During Simulated Planetary Surface Exploration

Introduction: A pair of small pressurized rovers (Space Exploration Vehicles, or SEVs) is at the center of the Global Point-of-Departure architecture for future human planetary exploration. Simultaneous operation of multiple crewed surface assets should maximize productive crew time, minimize overhead, and preserve contingency return paths. Methods: A 14-day mission simulation was conducted in the Arizona desert as part of NASA?s 2010 Desert Research and Technology Studies (DRATS). The simulation involved two SEV concept vehicles performing geological exploration under varied operational modes affecting both the extent to which the SEVs must maintain real-time communications with mission control ("Continuous" vs. "Twice-a-Day") and their proximity to each other ("Lead-and-Follow" vs. "Divide-and-Conquer"). As part of a minimalist lunar architecture, no communications relay satellites were assumed. Two-person crews consisting of an astronaut and a field geologist operated each SEV, day and night, throughout the entire 14-day mission, only leaving via the suit ports to perform simulated extravehicular activities. Standard metrics enabled quantification of the habitability and usability of all aspects of the SEV concept vehicles throughout the mission, as well as comparison of the extent to which the operating modes affected crew productivity and performance. Practically significant differences in the relevant metrics were prospectively defined for the testing of all hypotheses. Results and Discussion: Data showed a significant 14% increase in available science time (AST) during Lead-and-Follow mode compared with Divide-and-Conquer, primarily because of the minimal overhead required to maintain communications during Lead-and-Follow. In Lead-and-Follow mode, there was a non-significant 2% increase in AST during Twice-a-Day vs. Continuous communications. Situational awareness of the other vehicle?s location, activities, and contingency return constraints were enhanced during Lead-and-Follow and Twice-a-Day communications modes due to line-of-sight and direct SEV-to-SEV communication. Preliminary analysis of Scientific Data Quality and Observation Quality metrics showed no significant differences between modes.

Abercromby, Andrew F. J.↗
NASA NTRS2023

PCBoom Version 7.3 User's Guide

PCBoom is a suite of sonic boom propagation programs that applies full three-dimensional ray tracing based on geometrical acoustics. It predicts sonic boom ground waveforms (signatures) and footprints from supersonic flight vehicles performing arbitrary maneuvers using a variety of built-in or user supplied near-field vehicle source definitions. It also computes loudness metrics, ground signature locations, and sonic boom propagation times. The nomenclature "PC" in PCBoom denotes that the programs were historically targeted to run on a Personal Computer.

PCBoom↗
NASA NTRS1995

STS-67 Space Shuttle mission report

The STS-67 Space Shuttle Program Mission Report provides the results of the orbiter vehicle performance evaluation during this sixty-eighth flight of the Shuttle Program, the forty-third flight since the return to flight, and the eighth flight of the Orbiter vehicle Endeavour (OV-105). In addition, the report summarizes the payload activities and the performance of the External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle Main Engines (SSME). The serial numbers of the other elements of the flight vehicle were ET-69 for the ET; 2012, 2033, and 2031 for SSME's 1, 2, and 3, respectively; and Bl-071 for the SRB's. The left-hand RSRM was designated 360W043A, and the right-hand RSRM was designated 360L043B. The primary objective of this flight was to successfully perform the operations of the ultraviolet astronomy (ASTRO-2) payload. Secondary objectives of this flight were to complete the operations of the Protein Crystal Growth - Thermal Enclosure System (PCG-TES), the Protein Crystal Growth - Single Locker Thermal Enclosure System (PCG-STES), the Commercial Materials Dispersion Apparatus ITA Experiments (CMIX), the Shuttle Amateur Radio Experiment-2 (SAREX-2), the Middeck Active Control Experiment (MACE), and two Get-Away Special (GAS) payloads.

Fricke, Robert W., Jr.↗
NASA NTRS1987

Auxiliary propulsion technology for advanced Earth-to-orbit vehicles

The payload which can be delivered to orbit by advanced Earth-to-Orbit vehicles is significantly increased by advanced subsystem technology. Any weight which can be saved by advanced subsystem design can be converted to payload at Main Engine Cut Off (MECO) given the same launch vehicle performance. The auxiliary propulsion subsystem and the impetus for the current hydrogen/oxygen technology program is examined. A review of the auxiliary propulsion requirements of advanced Earth-to-Orbit (ETO) vehicles and their proposed missions is given first. Then the performance benefits of hydrogen/oxygen auxiliary propulsion are illustrated using current shuttle data. The proposed auxiliary propulsion subsystem implementation includes liquid hydrogen/liquid oxygen (LH2/LO2) primary Reaction Control System (RCS) engines and gaseous hydrogen/gaseous oxygen (GH2/GO2) vernier RCS engines. A distribution system for the liquid cryogens to the engines is outlined. The possibility of providing one dual-phase engine that can operate on either liquid or gaseous propellants is being explored, as well as the simultaneous firing of redundant primary RCS thrusters to provide Orbital Maneuvering System (OMS) level impulse. Scavenging of propellants from integral main engine tankage is proposed to utilize main engine tank residuals and to combine launch vehicle and subsystem reserves.

Schneider, Steven J.↗
NASA NTRS1976

A hybrid airship concept for Naval missions

A preliminary analysis of a hybrid semibuoyant delta-planform airship was performed using a computer synthesis program. The delta-planform hull shape was studied parametrically to determine the effects on vehicle performance for two Navy antisubmarine missions. The effects of buoyancy ratio, design speed, and altitude were also studied. The results suggest that long-range mission vehicles require a near buoyant or fully buoyant design and that there is no special advantage to the use of a lifting-body hull shape. For shorter-range missions, hybrid vehicles may have merit, and optimum vehicle buoyancy varies depending on whether a minimum-weight or minimum-fuel-consumption design is desired. As compared with conventionally shaped airships, the benefits, if any, from a lifting-body configuration will be limited to missions requiring relatively higher flight speeds.

Harper, M.↗
NASA NTRS1994

Project Genesis: Mars in situ propellant technology demonstrator mission

Project Genesis is a low cost, near-term, unmanned Mars mission, whose primary purpose is to demonstrate in situ resource utilization (ISRU) technology. The essence of the mission is to use indigenously produced fuel and oxidizer to propel a ballistic hopper. The Mars Landing Vehicle/Hopper (MLVH) has an Earth launch mass of 625 kg and is launched aboard a Delta 117925 launch vehicle into a conjunction class transfer orbit to Mars. Upon reaching its target, the vehicle performs an aerocapture maneuver and enters an elliptical orbit about Mars. Equipped with a ground penetrating radar, the MLVH searches for subsurface water ice deposits while in orbit for several weeks. A deorbit burn is then performed to bring the MLVH into the Martian atmosphere for landing. Following aerobraking and parachute deployment, the vehicle retrofires to a soft landing on Mars. Once on the surface, the MLVH begins to acquire scientific data and to manufacture methane and oxygen via the Sabatier process. This results in a fuel-rich O2/CH4 mass ratio of 2, which yields a sufficiently high specific impulse (335 sec) that no additional oxygen need be manufactured, thus greatly simplifying the design of the propellant production plant. During a period of 153 days the MLVH produces and stores enough fuel and oxidizer to make a 30 km ballistic hop to a different site of scientific interest. At this new location the MLVH resumes collecting surface and atmospheric data with the onboard instrumentation. Thus, the MLVH is able to provide a wealth of scientific data which would otherwise require two separate missions or separate vehicles, while proving a new and valuable technology that will facilitate future unmanned and manned exploration of Mars. Total mission cost, including the Delta launch vehicle, is estimated to be $200 million.

Acosta, Francisco Garcia↗