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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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NASA NTRS1981

Turbine bypass engine - A new supersonic cruise propulsion concept

Engine performance and mission studies were carried out for a single-spool turbine bypass engine (TBE) concept. Comparisons were made between the TBE, a conventional single-spool turbojet, and the Pratt and Whitney Variable Stream Control Engine (VSCE). The airplane assumed for the study was a Mach 2.32 commercial supersonic transport. The nominal mission was a 4000 n mi total range with a 300 n mi subsonic cruise leg. The figure of merit was the minimum takeoff gross weight for the mission. Comparisons of the three engines were also made for the 4000 n mi total range with longer subsonic cruise legs.

Franciscus, L. C.↗

NASA NTRSDate not supplied

Acoustic Simulations of Two-stage Fans Behind a Supersonic Inlet

NASA created, validated, and applied a high fidelity simulation toolchain for noise prediction of a fan system for a near-term civilian supersonic aircraft engine. A high fidelity inlet and multistage fan design were acquired as the basis for physics based computational studies. The overall tone noise was computed, which was used to help improve empirical models of fan inlet noise for system analysis purposes. Additional insights were gained during the study of the fan installation details and these are shared in this paper. Both overall amplitudes and variations due to design details should be of interest to engineers tasked with designing quiet fan systems for supersonic commercial aircraft. The outlook for high-fidelity simulations of aft fan noise and installation effects will also be discussed.

fan↗

NASA NTRS1992

Definition of the 2005 flight deck environment

A detailed description of the functional requirements necessary to complete any normal commercial flight or to handle any plausible abnormal situation is provided. This analysis is enhanced with an examination of possible future developments and constraints in the areas of air traffic organization and flight deck technologies (including new devices and procedures) which may influence the design of 2005 flight decks. This study includes a discussion on the importance of a systematic approach to identifying and solving flight deck information management issues, and a description of how the present work can be utilized as part of this approach. While the intent of this study was to investigate issues surrounding information management in 2005-era supersonic commercial transports, this document may be applicable to any research endeavor related to future flight deck system design in either supersonic or subsonic airplane development.

Alter, K. W.↗

NASA NTRS2023

Acoustics of a Supersonic Mach 1.4 Axisymmetric Spike Inlet

An inlet for a supersonic commercial aircraft is analyzed for noise radiation in low-speed configuration, with auxiliary inlet open. Duct mode amplitudes generated by the fan are determined by post-processing a URANS simulation and become a boundary condition to the inlet. Far-field sound is modeled using commercial acoustics finite element software. The effect of inlet geometry and acoustic liners is simulated and discussed. Absolute levels for inlet tone noise are predicted.

Supersonics↗

NASA NTRSDate not supplied

Acoustic Simulations of Two-stage Fans Behind a Supersonic Inlet

fans↗

NASA NTRSDate not supplied

Experiment Design and Visualization Techniques for an X-59 Low-boom Variability Study

This presentation outlines the design of experiments approach and data visualization techniques for a simulation study of sonic booms from NASA’s X-59 supersonic aircraft. The X-59 will soon be flown over communities across the contiguous USA as it produces a low-loudness sonic boom, or low-boom. Survey data on human perception of low-booms will be collected to support development of potential future commercial supersonic aircraft noise regulatory standards. The macroscopic atmosphere plays a critical role in the loudness of sonic booms. The extensive sonic boom simulation study presented herein was completed to assess climatological, geographical, and seasonal effects on the variability of the X-59’s low-boom loudness and noise exposure region size in order to inform X-59 community test planning. The loudness and extent of the noise exposure region make up the “sonic boom carpet.” Two spatial and temporal resolutions of atmospheric input data to the simulation were investigated. A Fast Flexible Space-Filling Design was used to select the locations across the USA for the two spatial resolutions. Analysis of simulated X-59 low-boom loudness data within a regional subset of the northeast USA was completed using a bootstrap forest to determine the final spatial and temporal resolution of the countrywide simulation study. Atmospheric profiles from NOAA’s Climate Forecast System Version 2 database were used to generate over one million simulated X-59 carpets at the final selected 138 locations across the USA. Effects of aircraft heading, season, geography, and climate zone on low-boom levels and noise exposure region size were analyzed. Models were developed to estimate loudness metrics throughout the USA for X-59 supersonic cruise overflight, and results were visualized on maps to show geographical and seasonal trends. These results inform regulators and mission planners on expected variations in boom levels and carpet extent from atmospheric variations. Understanding potential carpet variability is important when planning community noise surveys using the X-59.

X-59↗

NASA NTRS2018

Evaluation of Low Noise Integration Concepts and Propulsion Technologies for Future Supersonic Civil Transports

This report covers the entire effort of GE Global Research's NASA Prime Contract NNC15CA02C "Evaluation of Low Noise Integration Concepts and Propulsion Technologies for Future Supersonic Civil Transports". GE Global Research was supported by GE Aviation and Lockheed Martin in exploring the potential of wing shielding, flight path optimization, and jet noise technology to target aggressive community noise levels of 10 EPNdB lower than Chapter 14 for a future (mid-term) commercial supersonic transport aircraft.

fan noise↗

NASA NTRS2015

Experimental and Computational Sonic Boom Assessment of Lockheed-Martin N+2 Low Boom Models

Flight at speeds greater than the speed of sound is not permitted over land, primarily because of the noise and structural damage caused by sonic boom pressure waves of supersonic aircraft. Mitigation of sonic boom is a key focus area of the High Speed Project under NASA's Fundamental Aeronautics Program. The project is focusing on technologies to enable future civilian aircraft to fly efficiently with reduced sonic boom, engine and aircraft noise, and emissions. A major objective of the project is to improve both computational and experimental capabilities for design of low-boom, high-efficiency aircraft. NASA and industry partners are developing improved wind tunnel testing techniques and new pressure instrumentation to measure the weak sonic boom pressure signatures of modern vehicle concepts. In parallel, computational methods are being developed to provide rapid design and analysis of supersonic aircraft with improved meshing techniques that provide efficient, robust, and accurate on- and off-body pressures at several body lengths from vehicles with very low sonic boom overpressures. The maturity of these critical parallel efforts is necessary before low-boom flight can be demonstrated and commercial supersonic flight can be realized.

Cliff, Susan E.↗

NASA NTRS1975

Jet aircraft emissions during cruise: Present and future

Forecasts of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are compared to cruise emission for present day aircraft. The forecasts are based on: (1) knowledge of emission characteristics of combustors and augmentors; (2) combustion research in emission reduction technology, and (3) trends in projected engine designs for advanced subsonic or supersonic commercial aircraft. Recent progress that was made in the evolution of emissions reduction technology is discussed.

Grobman, J. S.↗

NASA NTRSDate not supplied

Off-Design Analysis of Axisymmetric External-Compression Supersonic Inlets for Mach 1.4 to 2.0

Supersonic axisymmetric, external-compression inlets designed for freestream Mach numbers of Mach 1.4, 1.7, and 2.0 were evaluated to characterize their off-design performance. The inlets were characterized as isolated from the airframe with freestream conditions, engine-face geometry, and flow rates established from a reference NASA commercial aircraft concept. The off-design performance was characterized using computational fluid dynamics (CFD) simulations. The study characterized the off-design performance at the cruise condition for variations in the inlet flow rate, angle-of-attack, and freestream Mach number. Also characterized was the inlet performance at take-off and approach-to-landing conditions for which the use of auxiliary intakes was included. The inlet performance was characterized by the flow rates, total pressure recovery and distortion, and drag. An understanding of the off-design performance of the axisymmetric inlets provides information for the selection of inlets for commercial supersonic aircraft.

Supersonic Inlets↗

NASA NTRSDate not supplied

Off-Design Analysis of Axisymmetric External-Compression Supersonic Inlets for Mach 1.4 to 2.0

Supersonic Inlets↗

NASA NTRS2016

Preliminary Computational Study for Future Tests in the NASA Ames 9 foot' x 7 foot Wind Tunnel

The NASA Advanced Air Vehicles Program, Commercial Supersonics Technology Project seeks to advance tools and techniques to make over-land supersonic flight feasible. In this study, preliminary computational results are presented for future tests in the NASA Ames 9 foot x 7 foot supersonic wind tunnel to be conducted in early 2016. Shock-plume interactions and their effect on pressure signature are examined for six model geometries. Near- field pressure signatures are assessed using the CFD code USM3D to model the proposed test geometries in free-air. Additionally, results obtained using the commercial grid generation software Pointwise Reigistered Trademark are compared to results using VGRID, the NASA Langley Research Center in-house mesh generation program.

Pearl, Jason M.↗

NASA NTRS2023

Acoustics of a Supersonic Mach 1.4 Axisymmetric Spike Inlet

An engine inlet for a supersonic commercial aircraft is analyzed for noise radiation in low-speed configurations for which auxiliary inlet doors are open. Duct modes generated by the fan are estimated by post-processing unsteady Reynold averaged Navier-Stokes (URANS) simulations of the fan and are used as boundary conditions to the inlet domain. Far-field inlet radiated tone levels are computed using commercial acoustics finite element software. The results indicated that the inlet tone levels at cutback and sideline conditions are higher by more than 20 dB than the approach levels.

Supersonics↗

NASA NTRSDate not supplied

TPSAS-NF1676L-20030-DND

Sonic booms from recently proposed supersonic aircraft designs developed with advanced tools are predicted to be quieter than those from previous designs. The possibility of developing a low-boom flight demonstration vehicle for conducting community response studies has attracted international interest. These studies would provide data to guide development of a preliminary noise certification standard for commercial supersonic aircraft. An affordable approach to conducting these studies suggests the use of a sub-scale experimental aircraft. Due to the smaller size and weight of the sub-scale vehicle, the resulting sonic boom is expected to contain spectral characteristics that differ from that of a full-scale vehicle. To determine the relevance of using a sub-scale aircraft for community annoyance studies, a laboratory study was conducted to verify that these spectral differences do not significantly affect human response. Indoor annoyance was evaluated for a variety of sonic booms predicted for several different sizes of vehicles. Previously reported results compared indoor annoyance for the different sizes using the metric Perceived Level (PL) at the exterior of the structure. Updated results include analyses with other candidate noise metrics, nonlinear regression, and specific boom duration effects.

Alexandra Loubeau↗

NASA NTRS2017

Top-Mounted Propulsion Test Plans (TMP17)

NASA recently completed a study of propulsion cycles and nozzle types applicable to a 70-passenger, M1.6 supersonic airliner, paying especial attention to the noise produced during landing and take-off. The results of the study were validated in a model-scale test at NASA Glenn last summer. The findings of that study and test, along with other studies, have resulted in a new strategy for achieving the Commercial Supersonic Technologys goals for noise and performance. Key to that strategy is moving the propulsion to the top-side of the vehicle and modifying the nozzle and inlet to maximally shield the propulsion noise while maintaining efficient operation. Installed exhaust configurations have been designed to minimize the exhaust noise using new acoustic design tools. A test planned for the fall of 2017 will validate both the new design tools and the low-noise concept using a new translating phased array. During the test, questions regarding modifications of convected waves in the jet near-field that are key to new understandings of aft jet noise will be addressed. Also, to better tie rig results to real-world measurements, a model-scale version of a nozzle that was flight tested by Glenn Research Center in 2001 will be tested.

Jet noise↗

NASA NTRS1992

Black carbon (soot) aerosol in the lower stratosphere and upper troposphere

As determined by impactor samplers flown on ER-2 and DC-8 aircraft, black carbon aerosol (BCA) mass loadings in the stratosphere average 0.6 nanograms per standard cubic meter, or 0.01 percent of the total aerosol. Upper tropospheric BCA increases to 0.3 percent. Low stratospheric concentration is commensurate with present commercial air traffic fuel consumption, given the following assumptions: the BCA emissions are 0.1 grams per kilogram of fuel consumed, 10 percent of route mileage is above the tropopause, and average BCA stratospheric residence time is about one year. Taking BCA into account, the stratospheric single scatter albedo is about 0.99. Using parameters for planned supersonic commercial aircraft, whose emissions will be predominantly in the stratosphere, it is shown that such traffic will double stratospheric BCA concentration. This would reduce the aerosol single scattering albedo by one percent, and double the BCA surface area that is available for heterogeneous chemistry.

Pueschel, R. F.↗

NASA NTRS1980

Bibliography of Supersonic Cruise Research (SCR) program from 1977 to mid-1980

The supersonic cruise research (SCR) program, initiated in July 1972, includes system studies and the following disciplines: propulsion, stratospheric emission impact, structures and materials, aerodynamic performance, and stability and control. In a coordinated effort to provide a sound basis for any future consideration that may be given by the United States to the development of an acceptable commercial supersonic transport, integration of the technical disciplines was undertaken, analytical tools were developed, and wind tunnel, flight, and laboratory investigations were conducted. The present bibliography covers the time period from 1977 to mid-1980. It is arranged according to system studies and the above five SCR disciplines. There are 306 NASA reports and 135 articles, meeting papers, and company reports cited.

Hoffman, S.↗

NASA NTRS1974

Forecast of jet engine exhaust emissions for future high altitude commercial aircraft

Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are presented. The forecasts are based on: (1) current knowledge of emission characteristics of combustors and augmentors; (2) the current status of combustion research in emission reduction technology; (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft. Results are presented for cruise conditions in terms of an emission index, g pollutant/kg fuel. Two sets of engine exhaust emission predictions are presented: the first, based on an independent NASA study and the second, based on the consensus of an ad hoc committee composed of industry, university, and government representatives. The consensus forecasts are in general agreement with the NASA forecasts.

Grobman, J.↗