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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 1,099 records · Page 61
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

Assessment of the Microbial Control Measures for the Temperature and Humidity Control Subsystem Condensing Heat Exchanger of the International Space Station

In August 1997 NASA/ Marshall Space Flight Center (MSFC) began a test with the objective of monitoring the growth of microorganisms on material simulating the surface of the International Space Station (ISS) Temperature and Humidity Control (THC) Condensing Heat Exchanger (CHX). The test addressed the concerns of potential uncontrolled microbial growth on the surface of the THC CHX subsystem. For this study, humidity condensate from a closed manned environment was used as a direct challenge to the surfaces of six cascades in a test set-up. The condensate was collected using a Shuttle-type CHX within the MSFC End-Use Equipment Testing Facility. Panels in four of the six cascades tested were coated with the ISS CHX silver impregnated hydrophilic coating. The remainder two cascade panels were coated with the hydrophilic coating without the antimicrobial component, silver. Results of the fourteen-month study are discussed in this paper. The effects on the microbial population when drying vs. not-drying the simulated THC CHX surface are also discussed.

Roman, Monsi C.↗
NASA NTRS2001

Space Station Environmental Control and Life Support System Purge Control Pump Assembly Modeling and Analysis

Preliminary results from a thermal/flow analysis of the Purge Control Pump Assembly (PCPA) indicate that pump performance (mass flow rate) is enhanced via cooling of the housing and lowering of the inlet vapor quality. Under a nominal operational profile (25% duty cycle or less), at the maximum motor dissipation, it appears that the peristaltic tubing temperature will still remain significantly below the expected UPA condenser temperature (78 F max versus approximately 105 F in the condenser) permitting condensation in the pump head.

Schunk, R. Gregory↗
NASA NTRS2004

Thermal Control Utilizing an Thermal Control Utilizing an Two-Phase Loop with High Heat Flux Source

The electric field applied in dielectric fluids causes an imbalance in the dissociation-recombination reaction generated free space charges. The generated charges are redistributed by the applied electric field resulting in the heterocharge layers in the Vicinity of the electrodes. Proper design of the electrodes generates net axial flow motion pumping the fluid. The electrohydrodynamic (EHD) conduction pump is a new device that pumps dielectric fluids utilizing heterocharge layers formed by imposition of electrostatic fields. This paper evaluates the experimental performance of a two-phase breadboard thermal control loop consisting of an EHD conduction pump, condenser, pre-heater, high heat flux evaporator (HE), transport lines, and reservoir (accumulator). The generated pressure head and the maximum applicable heat flux are experimentally determined at various applied voltages and sink temperatures. Recovery from dryout condition by increasing the applied voltage to the pump is also demonstrated.

Jeong, Seong-Il↗
NASA NTRS1947

Fundamentals of the Control of Gas-Turbine Power Plants for Aircraft: Principles of Control Common to Jet, Turbine-Propeller Jet, and Ducted-Fan Jet Power Plants - Part 2

After defining the aims and requirements to be set for a control system of gas-turbine power plants for aircraft, the report will deal with devices that prevent the quantity of fuel supplied per unit of time from exceeding the value permissible at a given moment. The general principles of the actuation of the adjustable parts of the power plant are also discussed.

Kuehl, H.↗
NASA NTRS2004

Dynamic Response of X-37 Hot Structure Control Surfaces Exposed to Controlled Reverberant Acoustic Excitation

This document represents a compilation of three informal reports from reverberant acoustic tests performed on X-37 hot structure control surfaces in the NASA Langley Research Center Structural Acoustics Loads and Transmission (SALT) facility. The first test was performed on a carbon-silicone carbide flaperon subcomponent on February 24, 2004. The second test was performed on a carbon-carbon ruddervator subcomponent on May 27, 2004. The third test was performed on a carbon-carbon flaperon subcomponent on June 30, 2004.

Grosveld, Ferdinand W.↗
NASA NTRS2001

Compressor Flow Control Concepts: UEET Compressor Flow Control Modeling - 2

Several passive flow control devices have been modeled computationally in the Swift CFD code. The models were applied to the first stage rotor and stator of the baseline UEET compressor in an attempt to improve efficiency and/or stall margin. The devices included suction surface bleed, tip injection, self-aspirated rotors, area-ruled casing, and vortex generators. The models and computed results will be described in the presentation. None of the results have shown significant gains in efficiency; however, casing vortex generators have shown potential improvements in stall margin.

Chima, Rodrick V.↗
NASA NTRS2013

Orion Multi-Purpose Crew Vehicle Active Thermal Control and Environmental Control and Life Support Development Status

The Orion Multi-Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in 2014. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the completing the components which are on EFT1. Additional development work has been done to keep the remaining component progressing towards implementation for a flight tests in of EM1 in 2017 and in and EM2 in 2020. This paper covers the Orion ECLS development from April 2012 to April 2013.

Lewis, John F.↗
NASA NTRS2016

Bearingless Flywheel Systems, Winding and Control Schemes, and Sensorless Control

Flywheel systems are disclosed that provide increased energy density and operational effectiveness. A first bearingless motor and a second bearingless motor may be configured to simultaneously suspend the central rotor in a radial direction and to rotate the central rotor. However, certain implementations may have one motor or more than two motors, depending on the design. A plurality of the flywheel systems may be collectively controlled to perform community energy storage with higher storage capacities than individual flywheel systems.

Jansen, Ralph H↗
NASA NTRS2018

Launch Control System / Spaceport Command and Control

NASA is developing the next generation launch vehicle that will take astronauts further into space than any previous manned vehicle. This project has many facets and one of them, the Spaceport Command and Control System (SCCS), was the primary focus of my work during this internship. A vital ability of SCCS is the communication from the firing rooms to the ground support equipment for the vehicle on the launch pad. During this internship, I was part of the Computer Systems Hardware Team, a group of engineers who handle the computer and networking aspects of the SCCS project. My job was to construct, handle, and test computer and network machines, configurations and cables.

Barbaro, Mark A.↗
NASA NTRS2019

Launch Control System / Spaceport Command and Control System

National Aeronautics and Space Administration (NASA) is currently developing the next generation launch vehicle that will take American astronauts, from American soil, even further into space. Our project for this semester dealt with the Spaceport Command and Control System (SCCS). SCCS provides a means of communication between the Firing Rooms and ground support equipment for the vehicle on the launch pad. For this internship, we became part of the Computer Systems Hardware Team. This team of engineers handle the computer and networking aspects of SCCS. During this internship, we learned about Linux operating systems and network configuration.

Ferrell, Sean P.↗
NASA NTRS2017

Autonomous Guidance Navigation and Control for Agile Quadrotors Using Polynomial Trajectory Planning and L1 Adaptive Control

We address the challenge to allow efficient autonomous flight in real world environments, both indoor and outdoor. We use a straight-line SE-SCP (Spherical Expansion and Sequential Convex Programming) [algorithm] to find an initial route through the environment and minimum snap trajectory generation using piecewise polynomials. Then, we implement an adaptive robust control able to address some robustness issues for quadrotors in outdoor flight, such as mass variation and wind disturbances. Coupling these techniques we allow high-speed and aggressive autonomous flight through obstacle-dense indoor environments, as well as address outdoor disturbances.

Landolfi, Mattia↗
NASA NTRS2019

Generalizability of Manual Control Skills Between Control Tasks of Varying Difficulty

This paper presents the results of an experiment that was performed at NASA Ames Research Center using 18 participants in two different groups who trained a task for ten days, with the goal of identifying how skill generalization would occur between two similar tasks of varying difficulty. A cybernetic approach was used. The first group was trained in a simple one-dimensional tracking task and transferred to a difficult two-dimensional tracking task. For the second group, this was reversed. Training with a simple task before transferring to the difficult task resulted in a slower convergence to final performance. However, it did allow participants to start with a better initial performance in the difficult task. Furthermore, after training with a simple task, participants controlled with a higher gain and generated lower lead time constants. However, possibly due to the number of participants, this experiment did not find any statistical evidence to support the conclusion that training with a simple task version helps in learning a more complex task.

skill generalizability↗
NASA NTRS2019

Generalizability of Manual Control Skills between Control Tasks of Varying Difficulty

This paper presents the results of an experiment that was performed at NASA Ames Research Center using 18 participants in two different groups who trained a task for ten days, with the goal of identifying how skill generalization would occur between two similar tasks of varying difficulty. A cybernetic approach was used. The first group was trained in a simple one-dimensional tracking task and transferred to a difficult two-dimensional tracking task. For the second group, this was reversed. Training with a simple task before transferring to the difficult task resulted in a slower convergence to final performance. However, it did allow participants to start with a better initial performance in the difficult task. Furthermore, after training with a simple task, participants controlled with a higher gain and generated lower lead time constants. However, possibly due to the number of participants, this experiment did not find any statistical evidence to support the conclusion that training with a simple task version helps in learning a more complex task.

Pieters, Marc A.↗
DOE OSTI2019

Fused Global-Local Economic Model Predictive Control for Real-Time Eco-Optimal Control of a Heavy Duty Truck

This paper introduces a fused global-local economic model predictive control (MPC) with varying time steps for maximizing the fuel economy of a heavy-duty truck, where global MPC is performed over a long horizon using cloud-based dynamic programming (DP), and local MPC is performed on-board the vehicle using sequential quadratic programming (SQP). Because of the computational complexity of DP, an in-depth analysis of how the discretization levels, time constant, and horizon length influence the energy savings and computational complexity of online DP has been performed. The fused optimization technique has been evaluated over different route profiles, accounting for traffic, using a medium-fidelity proprietary Volvo model. Results show 4-7% fuel savings, as compared to a baseline model.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2022

System and method for engine control with pressure reactive device to control combustion timing

The present disclosure relates to a system for controlling ignition of an intake charge directed into an internal combustion engine. The system may have a movable component operably associated with at least one of a piston of the engine or a combustion chamber of the engine. The movable component may be tuned to deflect in response to a predetermined pressure being reached in a cylinder in which the piston is housed. The movable component operates to deflect in response to the predetermined pressure being reached in the cylinder as the piston travels toward top dead center during its compression stroke, to change a compression ratio of the engine.

Killingsworth, Nicholas↗