SEARCH · Search NASA

Results for “Fuel cost”

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 235 records · Page 13

All sources NASA NTRS DOE OSTI

NASA NTRS1985

Advanced Prop-fan Engine Technology (APET) single- and counter-rotation gearbox/pitch change mechanism

The preliminary design of advanced technology (1992) prop-fan engines for single-rotation prop-fans, the conceptual design of the entire propulsion system, and an aircraft evaluation of the resultant designs are discussed. Four engine configurations were examined. A two-spool engine with all axial compressors and a three-spool engine with axial/centrifugal compressors were selected. Integrated propulsion systems were designed in conjunction with airframe manufacturers. The design efforts resulted in 12,000 shaft horsepower engines installed in over the installations with in-line and offset gearboxes. The prop-fan powered aircraft used 21 percent less fuel and cost 10 percent less to operate than a similar aircraft powered by turbofan engines with comparable technology.

Reynolds, C. N.↗

NASA NTRS1988

Spacecraft flight simulation: A human factors investigation into the man-machine interface between an astronaut and a spacecraft performing docking maneuvers and other proximity operations

The anticipated increase in rendezvous and docking activities in the various space programs in the Space Station era necessitates a renewed interest in manual docking procedures. Ten test subjects participated in computer simulated docking missions in which the influence of initial velocity was examined. All missions started from a resting position of 304.8 meters (1000 feet) along the space station's +V-bar axis. Test subjects controlled their vehicle with a translational hand controller and digital auto pilot which are both virtually identical to their space shuttle counterparts. While the 0.1 percent rule (range rate is equal to 0.1 percent of the range) used by space shuttle pilots is comfortably safe, it is revealed to be extremely inefficient in terms of time and not justifiable in terms of marginal safety. Time is worth money, not only because of training and launch costs, but because the sooner a pilot and spacecraft return from a mission, the sooner they can begin the next one. Inexperienced test subjects reduced the costs of simulated docking by close to a factor of 2 and achieved safe dockings in less than 4 percent of the time the baseline approach would entail. This reduction in time can be used to save lives in the event of an accident on orbit, and can tremendously reduce docking costs if fuel is produced from waste water on orbit.

Brody, Adam R.↗

NASA NTRS1991

Polymers And Riblets Reduce Hydrodynamic Skin Friction

Polymers injected into riblet grooves dramatically reduce polymer flow rate required for drag reduction. Polymer solution injected into valleys of grooves through array of holes or slots angled downstream to keep injected streams within grooves. Injection repeated some distance downstream because volumes of grooves finite and polymer becomes depleted as slowly pulled from groove by turbulence. Potentially useful for oil tankers as means of markedly reducing cost of fuel and used extensively on submarines, other ships, and other marine vehicles.

Bushnell, Dennis M.↗

NASA NTRS1999

Development of Formation Deployment and Intialization Concepts

NASA's Cross-Cutting Technology Development Program identified formation flying as a key enabler for the next generation Earth and Sciences campaign. It is hoped that this technology will allow a distributed network of autonomous satellites to act collaboratively as a single collective unit paving the way for extensive co-observing campaigns, coordinated multi-point observing programs, improved space-based interferometry, and entirely new approaches to conducting science. APL as a team member with GSFC, funded by the Earth Sciences and Technology Organization (ESTO), investigated formation deployment and initialization concepts which is central to the formation flying concept. This paper presents the analytical approach and preliminary results of the study. The study investigated a simple mission involving the deployment of six micro-satellites, one at a time, from a bus. At the initialization state, the satellites fly in an along-track trajectory separated by nominal spacing. The study entailed the development of a two-body (bus and satellite) relative motion propagator based on Clohessy-Wiltshire (C-W) equations with drag from which the relative motion of the micro-satellites is deduced. This code was used to investigate cluster development characteristics subject to "tip-off' (ejection) conditions. Results indicate that cluster development is very sensitive to the ballistic coefficients of the bus and satellites, and to relative ejection velocity. This information can be used to identify optimum deployment parameters, along with accuracy bounds for a particular mission, and to develop a cluster control strategy minimizing global fuel and cost. A suitable control strategy concept has been identified, however, it needs to be developed further.

Badesha, Surjit S.↗

NASA NTRS2002

Restoring Redundancy to the MAP Propulsion System

The Microwave Anisotropy Probe is a follow-on to the Differential Microwave Radiometer instrument on the Cosmic Background Explorer. Sixteen months before launch, it was discovered that from the time of the critical design review, configuration changes had resulted in a significant migration of the spacecraft's center of mass. As a result, the spacecraft no longer had a viable backup control mode in the event of a failure of the negative pitch axis thruster. Potential solutions to this problem were identified, such as adding thruster plume shields to redirect thruster torque, adding mass to, or removing it from, the spacecraft, adding an additional thruster, moving thrusters, bending thrusters (either nozzles or propellant tubing), or accepting the loss of redundancy for the thruster. The impacts of each solution, including effects on the mass, cost, and fuel budgets, as well as schedule, were considered, and it was decided to bend the thruster propellant tubing of the two roll control thrusters, allowing that pair to be used for back-up control in the negative pitch axis. This paper discusses the problem and the potential solutions, and documents the hardware and software changes that needed to be made to implement the chosen solution. Flight data is presented to show the propulsion system on-orbit performance.

ODonnell, James R., Jr.↗

NASA NTRS2004

Reliable and Affordable Control Systems Active Combustor Pattern Factor Control

Active, closed-loop control of combustor pattern factor is a cooperative effort between Honeywell (formerly AlliedSignal) Engines and Systems and the NASA Glenn Research Center to reduce emissions and turbine-stator vane temperature variations, thereby enhancing engine performance and life, and reducing direct operating costs. Total fuel flow supplied to the engine is established by the speed/power control, but the distribution to individual atomizers will be controlled by the Active Combustor Pattern Factor Control (ACPFC). This system consist of three major components: multiple, thin-film sensors located on the turbine-stator vanes; fuel-flow modulators for individual atomizers; and control logic and algorithms within the electronic control.

McCarty, Bob↗

NASA NTRS2005

A Survey of Intelligent Control and Health Management Technologies for Aircraft Propulsion Systems

Intelligent Control and Health Management technology for aircraft propulsion systems is much more developed in the laboratory than in practice. With a renewed emphasis on reducing engine life cycle costs, improving fuel efficiency, increasing durability and life, etc., driven by various government programs, there is a strong push to move these technologies out of the laboratory and onto the engine. This paper describes the existing state of engine control and on-board health management, and surveys some specific technologies under development that will enable an aircraft propulsion system to operate in an intelligent way--defined as self-diagnostic, self-prognostic, self-optimizing, and mission adaptable. These technologies offer the potential for creating extremely safe, highly reliable systems. The technologies will help to enable a level of performance that far exceeds that of today s propulsion systems in terms of reduction of harmful emissions, maximization of fuel efficiency, and minimization of noise, while improving system affordability and safety. Technologies that are discussed include various aspects of propulsion control, diagnostics, prognostics, and their integration. The paper focuses on the improvements that can be achieved through innovative software and algorithms. It concentrates on those areas that do not require significant advances in sensors and actuators to make them achievable, while acknowledging the additional benefit that can be realized when those technologies become available. The paper also discusses issues associated with the introduction of some of the technologies.

Litt, Jonathan S.↗

NASA NTRS2010

International Launch Vehicle Selection for Interplanetary Travel

In developing a mission strategy for interplanetary travel, the first step is to consider launch capabilities which provide the basis for fundamental parameters of the mission. This investigation focuses on the numerous launch vehicles of various characteristics available and in development internationally with respect to upmass, launch site, payload shroud size, fuel type, cost, and launch frequency. This presentation will describe launch vehicles available and in development worldwide, then carefully detail a selection process for choosing appropriate vehicles for interplanetary missions focusing on international collaboration, risk management, and minimization of cost. The vehicles that fit the established criteria will be discussed in detail with emphasis on the specifications and limitations related to interplanetary travel. The final menu of options will include recommendations for overall mission design and strategy.

Ferrone, Kristine↗

NASA NTRS2011

Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

Deep space missions with large payloads require high specific impulse and relatively high thrust to achieve mission goals in reasonable time frames.1,2 Conventional storable propellants produce average specific impulse. Nuclear thermal rockets capable of producing high specific impulse are proposed. Nuclear thermal rockets employ heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000 K), and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited.3 The primary concern is the mechanical failure of fuel elements that employ high-melting-point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. The purpose of the testing is to obtain data to assess the properties of the non-nuclear support materials, as-fabricated, and determine their ability to survive and maintain thermal performance in a prototypical NTR reactor environment of exposure to hydrogen at very high temperatures. The fission process of the planned fissile material and the resulting heating performance is well known and does not therefore require that active fissile material be integrated in this testing. A small-scale test bed designed to heat fuel element samples via non-contact radio frequency heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

Bradley, D. E.↗

NASA NTRS2011

Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing (CFEET)

No abstract available

Bradley, David E.↗

NASA NTRS2011

Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

Deep space missions with large payloads require high specific impulse (Isp) and relatively high thrust in order to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average Isp. Nuclear thermal rockets (NTR) capable of high Isp thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high temperature hydrogen exposure on fuel elements is limited. The primary concern is the mechanical failure of fuel elements which employ high-melting-point metals, ceramics or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via non-contact RF heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

Bradley, David E.↗

NASA NTRS2017

A NASA Approach to Safety Considerations for Electric Propulsion Aircraft Testbeds

Electric, hybrid-electric, and turbo-electric distributed propulsion technologies and concepts are beginning to gain traction in the aircraft design community, as they can provide improvements in operating costs, noise, fuel consumption, and emissions compared to conventional internal combustion or Brayton-cycle powered vehicles. NASA is building multiple demonstrators and testbeds to buy down airworthiness and flight safety risks for these new technologies, including X-57 Maxwell, HEIST, Airvolt, and NEAT.

electric propulsion↗

NASA NTRS2018

Air Traffic Management Technology Demonstration - 3 (ATD-3) Multi-Flight Common Route (MFCR) Concept of Operations Version 1.0

NASA's Multi Flight Common Route (MFCR) automation represents one element of those technologies focusing primarily on delay recovery in the en route phase of flight. Delay recovery is an attenuation of flight-time delay, accomplished by periodically revising weather-avoidance routing as the convective weather system evolves. MFCR is intended for use by Traffic Management Coordinators (TMCs) in Air Route Traffic Control Centers (ARTCCs, or Centers) and traffic management specialists (TMSs) in the Air Traffic Control System Command Center (ATCSCC). MFCR leverages existing weather, airspace, and traffic data, as well as improvements in navigation, surveillance, communication, and digital information technologies, to build on existing ATM automation and address some of the shortcomings associated with strategic traffic flow management initiatives and weather forecasting uncertainties. These capabilities provide significant potential benefits in the form of time, fuel, and cost savings. The concept of operations described in this document describes MFCR functionality as delivered by NASA to the FAA in December 2017, including a list of potential enhancements that may be realized when the system is fielded.

conops↗

NASA NTRSDate not supplied

TPSAS-NF1676L-18391-DND

Vehicle weight is a primary driver for most NASA missions. Reducing vehicle weight can: - Expand mission capability - Reduce launch costs - Reduce fuel consumption - Systems analysis shows that reducing materials mass by 20% leads to a 30% reduction in launch vehicle gross weight - Same study indicates a 50% reduction in materials mass reduces launch vehicle gross weight by >60%, enables potential single stage to orbit designs - Additional multifunctionality: thermal, radiation protection, sensing capabilities, no corrosion Potential Impact: Produce advanced lightweight structural BNNT composites with higher thermal stability, no corrosion, high toughness, sensing/actuation, and radiation shielding effectiveness.

Cheol Park↗

NASA NTRS2021

Environmental Benefits Assessment of the Traffic Aware Strategic Aircrew Requests Concept

Reduction of greenhouse gas emissions has been a focus area of the scientific community for the past several years. Specifically, the aviation industry has set goals to reduce greenhouse gas emissions, providing a sustainable transportation mechanism with minimal impacts on the environment. This reduction must be accomplished through several means, including advanced technology, sustainable propulsion, efficient air traffic management, and improved operations. A potential solution for improving operations in an efficient air traffic management system is the Traffic Aware Strategic Aircrew Requests (TASAR) concept. The TASAR concept applies onboard automation for the purpose of advising the pilot of route modifications that would be beneficial to the flight, leading to a decrease in direct operating costs through fuel burn reduction and shorter flight times. This report discusses analyses that provide an estimate of the potential environmental benefits that result from the application of the TASAR concept. The data used for this benefits assessment was gathered during an operational evaluation on revenue flights with an airline partner between July 2018 and April 2019. The analyses in this report determined that there are impactful potential environmental benefits to be realized using the TASAR concept.

TASAR, Digital TASAR, 4D TASAR, SATM, Green Aviati↗

NASA NTRS1976

The thermal efficiency and cost of producing hydrogen and other synthetic aircraft fuels from coal

A comparison is made of the cost and thermal efficiency of producing liquid hydrogen, liquid methane and synthetic aviation kerosene from coal. These results are combined with estimates of the cost and energy losses associated with transporting, storing, and transferring the fuels to aircraft. The results of hydrogen-fueled and kerosene-fueled aircraft performance studies are utilized to compare the economic viability and efficiency of coal resource utilization of synthetic aviation fuels.

Witcofski, R. D.↗

NASA NTRS1977

The thermal efficiency and cost of producing hydrogen and other synthetic aircraft fuels from coal

Witcofski, R. D.↗

NASA NTRS1986

Stratified charge rotary engine for general aviation

A development history, a current development status assessment, and a design feature and performance capabilities account are given for stratified-charge rotary engines applicable to aircraft propulsion. Such engines are capable of operating on Jet-A fuel with substantial cost savings, improved altitude capability, and lower fuel consumption by comparison with gas turbine powerplants. Attention is given to the current development program of a 400-hp engine scheduled for initial operations in early 1990. Stratified charge rotary engines are also applicable to ground power units, airborne APUs, shipboard generators, and vehicular engines.

Mount, R. E.↗