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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 127 records · Page 7

All sources NASA NTRS DOE OSTI

NASA NTRS1936

Some Effects of Injection Advance Angle, Engine-Jacket Temperature, and Speed on Combustion in a Compression-Ignition Engine

An optical indicator and a high-speed motion-picture camera capable of operating at the rate of 2,000 frames per second were used to record simultaneously the pressure development and the flame formation in the combustion chamber of the NACA combustion apparatus. Tests were made at engine speeds of 570 and 1,500 r.p.m. The engine-jacket temperature was varied from 100 degrees to 300 degrees F. And the injection advance angle from 13 degrees after top center to 120 degrees before top center. The results show that the course of the combustion is largely controlled by the temperature and pressure of the air in the chamber from the time the fuel is injected until the time at which combustion starts and by the ignition lag. The conclusion is presented that in a compression-ignition engine with a quiescent combustion chamber the ignition lag should be the longest that can be used without excessive rates of pressure rise; any further shortening of the ignition lag decreased the effective combustion of the engine.

Rothrock, A M↗

NASA NTRS1946

Analysis of cooling limitations and effect of engine-cooling improvements on level-flight cruising performance of four-engine heavy bomber

The NACA has developed means, including an injection impeller and ducted head baffles, to improve the cooling characteristics of the 3350-cubic-inch-displacement radial engines installed in a four-engine heavy bomber. The improvements afforded proper cooling of the rear-row exhaust-valve seats for a wide range of cowl-flap angles, mixture strengths, and airplane speeds. The results of flight tests with this airplane are used as a basis for a study to determine the manner and the extent to which the airplane performance was limited by engine cooling. By means of this analysis for both the standard airplane and the airplane with engine-cooling modifications, comparison of the specific range at particular conditions and comparison of the cruising-performance limitations was made.

Marble, Frank E↗

NASA NTRS1988

Software engineering as an engineering discipline

The goals of the Software Engineering Institute's Education Program are as follows: to increase the number of highly qualified software engineers--new software engineers and existing practitioners; and to be the leading center of expertise for software engineering education and training. A discussion of these goals is presented in vugraph form.

Gibbs, Norman↗

NASA NTRS1993

Flight-determined engine exhaust characteristics of an F404 engine in an F-18 airplane

Personnel at the NASA Langley Research Center (NASA-Langley) and the NASA Dryden Flight Research Facility (NASA-Dryden) recently completed a joint acoustic flight test program. Several types of aircraft with high nozzle pressure ratio engines were flown to satisfy a twofold objective. First, assessments were made of subsonic climb-to-cruise noise from flights conducted at varying altitudes in a Mach 0.30 to 0.90 range. Second, using data from flights conducted at constant altitude in a Mach 0.30 to 0.95 range, engineers obtained a high quality noise database. This database was desired to validate the Aircraft Noise Prediction Program and other system noise prediction codes. NASA-Dryden personnel analyzed the engine data from several aircraft that were flown in the test program to determine the exhaust characteristics. The analysis of the exhaust characteristics from the F-18 aircraft are reported. An overview of the flight test planning, instrumentation, test procedures, data analysis, engine modeling codes, and results are presented.

Ennix, Kimberly A.↗

NASA NTRS1993

Orbital transfer rocket engine technology 7.5K-LB thrust rocket engine preliminary design

A preliminary design of an advanced LOX/LH2 expander cycle rocket engine producing 7,500 lbf thrust for Orbital Transfer vehicle missions was completed. Engine system, component and turbomachinery analysis at both on design and off design conditions were completed. The preliminary design analysis results showed engine requirements and performance goals were met. Computer models are described and model outputs are presented. Engine system assembly layouts, component layouts and valve and control system analysis are presented. Major design technologies were identified and remaining issues and concerns were listed.

Harmon, T. J.↗

NASA NTRS1998

Perceptions of Engineers Regarding Successful Engineering Team Design

The perceptions of engineers and scientists at NASA Langley Research Center toward engineering design teams were evaluated. A sample of 49 engineers and scientists rated 60 team behaviors in terms of their relative importance for team success. They also completed a profile of their own perceptions of their strengths and weaknesses as team members. Behaviors related to team success are discussed in terms of those involving the organizational culture and commitment to the team and those dealing with internal team dynamics. The latter behaviors focused on team issues occurring during the early stages of a team's existence. They included the level and extent of debate and discussion regarding methods for completing the team task and the efficient use of team time to explore and discuss methodologies critical to the problem. The discussion includes a comparison of engineering teams with the prototypical business team portrayed in the literature.

Nowaczyk, Ronald H.↗

NASA NTRS2000

Engine System Loads Development for the Fastrac 60K Flight Engine

Early implementation of structural dynamics finite element analyses for calculation of design loads is considered common design practice for high volume manufacturing industries such as automotive and aeronautical industries. However, with the rarity of rocket engine development programs starts, these tools are relatively new to the design of rocket engines. In the new Fastrac engine program, the focus has been to reduce the cost to weight ratio; current structural dynamics analysis practices were tailored in order to meet both production and structural design goals. Perturbation of rocket engine design parameters resulted in a number of Fastrac load cycles necessary to characterize the impact due to mass and stiffness changes. Evolution of loads and load extraction methodologies, parametric considerations and a discussion of load path sensitivities are discussed.

Frady, Greg↗

NASA NTRS2007

ATK Launch Systems Engineering NASA Programs Engineering Examples

This presentation provides an overview of the work done at ATK Launch Systems with and indication of how engineering knowledge can be applied to several real world problems. All material in the presentation has been screened to meet ITAR restrictions. The information provided is a compilation of general engineering knowledge and material available in the public domain. The presentation provides an overview of ATK Launch Systems and NASA programs. Some discussion is provided about the types of engineering conducted at the Promontory plant with added detail about RSRM nozzle engineering. Some brief examples of examples of nozzle technical issues with regard to adhesives and phenolics are shared. These technical issue discussions are based on material available in the public domain.

Richardson, David↗

NASA NTRS1947

Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8, and 19XB-1 Jet-Propulsion Engines. II - Analysis of Turbine Performance of the 19B-8 Engine

Performance characteristics of the turbine in the 19B-8 jet propulsion engine were determined from an investigation of the complete engine in the Cleveland altitude wind tunnel. The investigation covered a range of simulated altitudes from 5000 to 30,000 feet and flight Mach numbers from 0.05 to 0.46 for various tail-cone positions over the entire operable range of engine speeds. The characteristics of the turbine are presented as functions of the total-pressure ratio across the turbine and the turbine speed and the gas flow corrected to NACA standard atmospheric conditions at sea level. The effect of changes in altitude, flight Mach number, and tail-cone position on turbine performance is discussed. The turbine efficiency with the tail cone in varied from a maximum of 80.5 percent to minimum of 75 percent over a range of engine speeds from 7500 to 17,500 rpm at a flight Mach number of 0.055. Turbine efficiency was unaffected by changes in altitude up to 15,000 feet but was a function of tail-cone position and flight Mach number. Decreasing the tail-pipe-nozzle outlet area 21 percent reduced the turbine efficiency between 2 and 4.5 percent. The turbine efficiency increased between 1.5 and 3 percent as the flight Mach number changed from 0.055 to 0.297.

Krebs, Richard P.↗

NASA NTRS2010

Systems Engineering Processes at NASA/SR-71 Pratt and Whitney J58 Engine

This summer I was given several opportunities at NASA's Dryden Flight Research Center (DFRC). The first opportunity was given to me by a Senior Propulsion Engineer, Kurtt Kloesel, to work in a specialized engineering discipline. My task was to research the Pratt & Whitney J58 engine that was used on the SR-71 Blackbird. I entered the data I collected into engine modeling software programs in order to receive certain outputs, such as net thrust. I also had to take a "crash course" in propulsion in order to better understand the research I was performing. To facilitate my understanding of propulsion principals and formulas, I worked many problems out of thermodynamics and propulsion textbooks and entered the given values of various situations into the modeling software.

Donastorg, Cristina↗

NASA NTRS2011

Systems Engineering Leadership Development: Advancing Systems Engineering Excellence

This slide presentation reviews the Systems Engineering Leadership Development Program, with particular emphasis on the work being done in the development of systems engineers at Marshall Space Flight Center. There exists a lack of individuals with systems engineering expertise, in particular those with strong leadership capabilities, to meet the needs of the Agency's exploration agenda. Therefore there is a emphasis on developing these programs to identify and train systems engineers. The presentation reviews the proposed MSFC program that includes course work, and developmental assignments. The formal developmental programs at the other centers are briefly reviewed, including the Point of Contact (POC)

Hall, Phil↗

NASA NTRS2009

Layered Systems Engineering Engines

A notation is described for depicting the relationships between multiple, contemporaneous systems engineering efforts undertaken within a multi-layer system-of-systems hierarchy. We combined the concepts of remoteness of activity from the end customer, depiction of activity on a timeline, and data flow to create a new kind of diagram which we call a "Layered Vee Diagram." This notation is an advance over previous notations because it is able to be simultaneously precise about activity, level of granularity, product exchanges, and timing; these advances provide systems engineering managers a significantly improved ability to express and understand the relationships between many systems engineering efforts. Using the new notation, we obtain a key insight into the relationship between project duration and the strategy selected for chaining the systems engineering effort between layers, as well as insights into the costs, opportunities, and risks associated with alternate chaining strategies.

Vee Diagram↗

NASA NTRS2018

Engineering Elegant Systems: Postulates, Principles, and Hypotheses of Systems Engineering

Definition: System Engineering is the engineering discipline which integrates the system functions, system environment, and the engineering disciplines necessary to produce and/or operate an elegant system; Elegant System - A system that is robust in application, fully meeting specified and adumbrated intent, is well structured, and is graceful in operation. Primary Focus: System Design and Integration: Identify system couplings and interactions; Identify system uncertainties and sensitivities; Identify emergent properties; Manage the effectiveness of the system. Engineering Discipline Integration: Manage flow of information for system development and/or operations; Maintain system activities within budget and schedule. Supporting Activities: Process application and execution.

Watson, Michael D.↗

NASA NTRS2016

Creating Systems Engineering Products with Executable Models in a Model-Based Engineering Environment

Applying systems engineering across the life-cycle results in a number of products built from interdependent sources of information using different kinds of system level analysis. This paper focuses on leveraging the Executable System Engineering Method (ESEM) which automates requirements verification (e.g. power and mass budget margins and duration analysis of operational modes) using executable SysML models. The particular value proposition is to integrate requirements, and executable behavior and performance models for certain types of system level analysis. The models are created with modeling patterns that involve structural, behavioral and parametric diagrams, and are managed by an open source Model Based Engineering Environment (named OpenMBEE). This paper demonstrates how the ESEM is applied in conjunction with OpenMBEE to create key engineering products (e.g. operational concept document) for the Alignment and Phasing System (APS) within the Thirty Meter Telescope (TMT) project, which is under development by the TMT International Observatory (TIO).

MBSE↗

NASA NTRSDate not supplied

Tail-mounted engine Architecture and Design for the Subsonic Single Aft Engine Electrofan Aircraft

This paper describes the turbofan engine architecture for SUbsonic Single Aft eNgine (SUSAN) Electrofan is, a transformative concept hybrid electric aircraft. SUSAN has a single tail-mounted turbofan engine that produces a portion of the requires thrust and drives a 20MW electric generator which in turn provides the power to the 16 electric propulsors located on the wing responsible for producing the remainder of the required thrust. The atypical operation of the turbofan due to the large levels of power extraction from the low pressure turbine (LPT) is described here. This paper investigates the most efficient engine architecture to enable this unique operation, as well as exploring natural gas as an alternative fuel for SUSAN.

EAP↗

NASA NTRS1951

Experimental Investigation of Air-cooled Turbine Blades in Turbojet Engine IX : Evaluation of the Durability of Noncritical Rotor Blades in Engine Operation

The durability of five different structural or cooling configurations or combination of both of air-cooled blades made of noncritical materials was investigated in a modified turbojet engine. The greater part of the investigation was conducted at an engine speed of 11,500 rpm, a turbine-inlet temperature of approximately 1670 degrees F, and a cooling-air to combustion gas flow ratio per blade of 0.05. The results of the investigation indicated that air-cooled blades made of noncritical metals can be operated for extended periods of time in engines at current inlet temperatures; however, before these blades are considered completely satisfactory for gas-turbine application, some means such as coatings is required to inhibit the oxidation of the blades.

TURBINES - BLADES - COOLING↗

NASA NTRS1972

Experimental evaluation of a TF30-P-3 turbofan engine in an altitude facility: Afterburner performance and engine-afterburner operating limits

For distortion free steady state operation at the maximum (full afterburning) throttle position, the afterburner combustion efficiency decreased from 0.91 to 0.68 as engine inlet Reynolds number index was reduced from 0.80 to 0.25. Engine afterburner operational limits were obtained for transient and fixed throttle operation over a range of engine inlet distortions. At limiting conditions, time histories of pressures in the fan compressor during throttle transients between military and maximum showed the development of rotating stall in the fan hub which quickly propagated and produced complete stall in the high pressure compressor.

Mcaulay, J. E.↗

NASA NTRS1973

An airline study of advanced technology requirements for advanced high speed commercial transport engines. 2: Engine preliminary design assessment

The advanced technology requirements for an advanced high speed commercial transport engine are presented. The results of the phase 2 study effort cover the following areas: (1) general review of preliminary engine designs suggested for a future aircraft, (2) presentation of a long range view of airline propulsion system objectives and the research programs in noise, pollution, and design which must be undertaken to achieve the goals presented, (3) review of the impact of propulsion system unreliability and unscheduled maintenance on cost of operation, (4) discussion of the reliability and maintainability requirements and guarantees for future engines.

Sallee, G. P.↗