Search NASA⌕ Search

SEARCH · Search NASA

Results for “HYPERSONIC SPEED”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Low speed aerodynamic characteristics of a lifting-body hypersonic research aircraft configuration

An experimental investigation of the low-speed longitudinal, lateral, and directional stability characteristics of a lifting-body hypersonic research airplane concept was conducted in a low-speed tunnel with a 12-foot (3.66-meter) octagonal test section at the Langley Research Center. The model was tested with two sets of horizontal and vertical tip controls having different planform areas, a center vertical tail and two sets of canard controls having trapezoidal and delta planforms, and retracted and deployed engine modules and canopy. This investigation was conducted at a dynamic pressure of 239.4 Pa (5 psf) (Mach number of 0.06) and a Reynolds number of 2 million based on the fuselage length. The tests were conducted through an angle-of-attack range of 0 deg to 30 deg and through horizontal-tail deflections of 10 deg to minus 30 deg. The complete configuration exhibited excessive positive static longitudinal stability about the design center-of-gravity location. However, the configuration was unstable laterally at low angles of attack and unstable directionally throughout the angle-of-attack range. Longitudinal control was insufficient to trim at usable angles of attack. Experiments showed that a rearward shift of the center of gravity and the use of a center-located vertical tail would result in a stable and controllable vehicle.

Penland, J. A.↗
NASA NTRS1996

Materials Research for High Speed Civil Transport and Generic Hypersonics-Metals Durability

This report covers a portion of an ongoing investigation of the durability of titanium alloys for the High Speed Civil Transport (HSCT). Candidate alloys need to possess an acceptable combination of properties including strength and toughness as well as fatigue and corrosion resistance when subjected to the HSCT operational environment. These materials must also be capable of being processed into required product forms while maintaining their properties. Processing operations being considered for this airplane include forming, welding, adhesive bonding, and superplastic forming with or without diffusion bonding. This program was designed to develop the material properties database required to lower the risk of using advanced titanium alloys on the HSCT.

Schulz, Paul↗
NASA NTRS2023

Overview of Commercial High-Speed Market Studies and NASA’s Hypersonic Technology Project

Presenting a 40-minute Throughout the history of aviation, there has been a continual desire to develop aircraft that can go higher, faster, and farther. Within each of these broad goals, significant achievements have been made in aeronautics over the decades. Specialized military aircraft can reach the edges of the atmosphere and regularly fly at supersonic speeds, with the Concorde bringing transatlantic supersonic flight to the public. In addition, commercial subsonic aircraft regularly fly nonstop flights of over 7000 nautical miles with flight times lasting over 15 hours. Each of these achievements have been enabled by research and development on the technologies required to overcome these barriers. As major technical challenges for high-speed/hypersonic flight have been overcome, the next questions that arise relate to what precisely is a viable commercial high-speed/hypersonic vehicle and what is the market for it. In 2020, NASA funded two studies to provide an independent assessment of the economic viability of high-speed/hypersonic transportation and some high level guidance on the design requirements of such a vehicle. Results from these market studies will be presented as well as insight into how these results are being used to inform ongoing strategic planning efforts in this research area within NASA’s Hypersonic Technology project.

High-Speed Independent Market Studies↗
NASA NTRS1960

Low-Speed Aerodynamic Characteristics of a Model of a Hypersonic Research Airplane at Angles of Attack up to 90 deg for a Range of Reynolds Numbers

Static force tests have been made at low subsonic speeds for a model of a hypersonic research airplane in the Langley high-speed 7- by 10-foot tunnel to determine the aerodynamic forces and moments up to an angle of attack of 90 deg for a range of Reynolds numbers. The Reynolds numbers, based on the mean aerodynamic chord, ranged from 740,000 to 1,900,000, which correspond to dynamic pressures from 15 to 100 lb/sq ft (Mach numbers from 0.10 to 0.27). The model was tested in the clean configuration with various horizontal-tail settings, horizontal tail off, lower rudder off, fuselage alone, and with various size strakes and slats on the nose of the model. Representative results of the present investigation are presented in plotted form, and a tabulation of all the data obtained is presented in a table. Appreciable effects on side force, yawing moment, and pitching moment are indicated by changes in Reynolds number for angles of attack of 40 to 90 deg.

Bowman, James S., Jr.↗
NASA NTRS1989

Low-speed, high-lift aerodynamic characteristics of slender, hypersonic accelerator-type configurations

Two investigations were conducted in the Langley 14 by 22 Foot Subsonic Tunnel to determine the low-speed aerodynamic characteristics of a generic hypersonic accelerator-type configuration. The model was a delta wing configuration incorporating a conical forebody, a simulated wrap-around engine package, and a truncated conical aftbody. Six-component force and moment data were obtained over a range of attack from -4 to 30 degrees and for a sideslip range of + or - 20 degrees. In addition to tests of the basic configuration, component build-up tests were conducted; and the effects of power, forebody nose geometry, canard surfaces, fuselage strakes, and engines on the lower surface alone were also determined. Control power available from deflections of wing flaps and aftbody flaps was also investigated and found to be significantly increased during power-on conditions. Large yawing moments resulted from asymmetric flow fields exhibited by the forebody as revealed by both surface pressure data and flow visualization. Increasing nose bluntness reduced the yawing-moment asymmetry, and the addition of a canard eliminated the yawing-moment asymmetry.

Gatlin, Gregory M.↗
NASA NTRS1995

Hypersonic aerodynamics test facility using the external propulsion accelerator

The use of the External propulsion Accelerator (EPA) for launching models of hypersonic aerodynamic configurations into an instrumented ballistic range is discussed. The aerodynamic model is encased inside an axisymmetric projectile designed to be accelerated to high speed in the EPA. Accelerator lengths required to achieve hypersonic speeds are estimated to vary from 10 meters for Mach 7, 40 meters for Mach 10, 150 meters for Mach 15, and 700 meters for Mach 30, assuming a limit of 50,000 g's acceleration. For a model span of 10 cm to 25 cm, the launch tube diameters are 40 cm and 100 cm, respectively. Using this EPA launcher will enable exact simulation of hypersonic flight in ground facilities where both the gas composition and pressure can be controlled in the ballistic range.

Rom, J.↗
NASA NTRS1990

Aeronautical facility requirements into the 2,000's

This paper delineates and speculates upon aeronautical systems, trends, and requirements into the 2,000's and indicates ground facility capability enhancements which are needed to support these devlopments. New facility capabilities required include (1) higher Reynolds number at low speeds especially for the high-lift and vortex hazard problems, (2) low-disturbance, high-speed aerodynamic and hypersonic propulsion facilities for transition and mixing studies, (3) large-scale and relatively long test-time hypersonic propulsion tunnels to allow multidisciplinary integration, (4) a large-scale, high-speed acoustics facility for en route noise minimization, (5) a large-scale ballistic range for planetary entry studies, and (6) development of advanced (full simultaneous 3-space and time) nonintrusive instrumentation for CFD transition/turbulence modeling/code validation and interacting flow physics determination.

Beach, H. L., Jr.↗
NASA NTRS1994

Numerical Simulation of Supersonic Compression Corners and Hypersonic Inlet Flows Using the RPLUS2D Code

A two-dimensional computational code, PRLUS2D, which was developed for the reactive propulsive flows of ramjets and scramjets, was validated for two-dimensional shock-wave/turbulent-boundary-layer interactions. The problem of compression corners at supersonic speeds was solved using the RPLUS2D code. To validate the RPLUS2D code for hypersonic speeds, it was applied to a realistic hypersonic inlet geometry. Both the Baldwin-Lomax and the Chien two-equation turbulence models were used. Computational results showed that the RPLUS2D code compared very well with experimentally obtained data for supersonic compression corner flows, except in the case of large separated flows resulting from the interactions between the shock wave and turbulent boundary layer. The computational results compared well with the experiment results in a hypersonic NASA P8 inlet case, with the Chien two-equation turbulence model performing better than the Baldwin-Lomax model.

Kapoor, Kamlesh↗
NASA NTRS2019

Considerations for Femtosecond Laser Electronic Excitation Tagging in High-Speed Flows

Femtosecond laser electronic excitation tagging (FLEET) is an unseeded method for molecular tagging which offers valuable opportunities for measurement of high-speed (transonic, supersonic or hypersonic) flows. The unique nature of high-speed testing demands certain performance from FLEET such as satisfactory signal-to-noise ratio (SNR) at depressed static conditions (i.e., low temperatures, pressures and densities), wide dynamic range for velocity determination (especially single-shot), and measurements with acceptable accuracy and precision. This dissertation strives to evaluate FLEET in those regards and provide strategies to maximize the method's capabilities. A zero-dimensional kinetics model in nitrogen explains FLEET signal changes with pressure/density and/or temperature in terms of plasma-chemical reactions. Poorly known rate coefficients are tuned by comparing model output to measurements, with temporal agreement up to several hundred nanoseconds. Modeling reveals that initial signal peaks at reduced density because of slowed temporal evolution (and decay) of excited populations. Low temperatures enhance signal by enlarging cluster ion populations which contribute to excited species via electron-ion dissociative recombination. A purpose-built free jet facility provides experimental validation of the kinetics model and assesses FLEET velocimetry in low temperature and pressure/density conditions. Signal, lifetime, accuracy and precision results are obtained from unheated subsonic through Mach 4.0 operation of the facility, with best results noted. FLEET measurements of a sweeping jet (SWJ) actuator in compressible operation showcase its advantages in a highly unsteady jet containing subsonic through supersonic velocities. FLEET velocimetry is performed in the device's internal and external flow fields, with the latter compared to hot-wire anemometry. Internal measurements reveal the absence of shockwaves theorized to occur at high pressure ratios. Simultaneous qualitative measurements of compressible jet mixing are shown as a proof-of-concept. Overall, the work demonstrates that previous understanding of SWJ incompressible operation readily extends into the compressible realm. Practical aspects of performing FLEET velocimetry are detailed, along with strategies for improving measurement quality. Determination of a fundamental precision in nitrogen and air is attempted. Experiments show that increasing time delay and/or SNR improves velocimetry precision. A comparison of five camera systems indicates sensors with larger pixels capture higher SNR data and produce more precise results.

FLEET↗
NASA NTRS1990

The need for a hypersonic demonstrator

The requirement for research aircraft and demonstrator vehicles has been seriously challenged by tight budgets and erroneous impressions that aeronautical technology has matured to a point where the value added by flight research and/or demonstration is not sufficient to offset the costs. While this issue may be debatable with respect to subsonic/transonic speeds, such is not the case for high-speed (supersonic and hypersonic) operation. The aerodynamic performance, weight/payload fractions, and thermodynamic problems are such that small margins of error can be tantamount to the vehicle being unable to reach its design point or so inefficient as to render it useless. This paper addresses some of the critical design considerations and operational constraints which make it mandatory to carry out flight research and develop a demonstrator vehicle in order that the risks be reduced to an acceptable level to assure technology readiness for viable hypersonic flight.

Ayers, T. G.↗
NASA NTRS2006

An Overview of the Role of Systems Analysis in NASA's Hypersonics Project

NASA's Aeronautics Research Mission Directorate recently restructured its Vehicle Systems Program, refocusing it towards understanding the fundamental physics that govern flight in all speed regimes. Now called the Fundamental Aeronautics Program, it is comprised of four new projects, Subsonic Fixed Wing, Subsonic Rotary Wing, Supersonics, and Hypersonics. The Aeronautics Research Mission Directorate has charged the Hypersonics Project with having a basic understanding of all systems that travel at hypersonic speeds within the Earth's and other planets atmospheres. This includes both powered and unpowered systems, such as re-entry vehicles and vehicles powered by rocket or airbreathing propulsion that cruise in and accelerate through the atmosphere. The primary objective of the Hypersonics Project is to develop physics-based predictive tools that enable the design, analysis and optimization of such systems. The Hypersonics Project charges the systems analysis discipline team with providing it the decision-making information it needs to properly guide research and technology development. Credible, rapid, and robust multi-disciplinary system analysis processes and design tools are required in order to generate this information. To this end, the principal challenges for the systems analysis team are the introduction of high fidelity physics into the analysis process and integration into a design environment, quantification of design uncertainty through the use of probabilistic methods, reduction in design cycle time, and the development and implementation of robust processes and tools enabling a wide design space and associated technology assessment capability. This paper will discuss the roles and responsibilities of the systems analysis discipline team within the Hypersonics Project as well as the tools, methods, processes, and approach that the team will undertake in order to perform its project designated functions.

Robinson, Jeffrey S.↗
NASA NTRS1990

Propulsion technology for National Aero-Space Plane

America's entrée in the world of hypersonics is spearheaded by the National Aero-Space Plane program. Although the concept of hypersonic flight at speeds above Mach 6 has been investigated before in many countries, the efforts begun in the 1960's in the United States did not result in a major new capability. Many valid principles were examined, a good data base was developed, but a demonstration was not pursued with the priorities assigned to the space program at that time. During the 1970's, our hypersonic effort dwindled to a few dedicated research efforts which refined propulsion, aerodynamics, and computational fluid dynamics principles. To make real progress in the 1980's, and beyond, a focus and a rekindled effort was needed. The National Aero-Space Plane program provides that focus of activities. Through the demonstration of single-stage-to-orbit (SSTO) capabilities in a manned vehicle capable of normal aircraft-like operations, the United States seeks to revitalize our advanced hypersonics research, spearhead the rapid development of technology, and conclusively demonstrate through flight testing that the age of hypersonics has arrived. This paper briefly describes the growth of the National Aero-Space Plane program, its objectives, its National team organization, and the schedule now envisioned for the remainder of the program. The primary emphasis of the paper is National Aero-Space Plane propulsion technology. Key technical challenges are noted and a discussion of progress relative to those challenges associated with propulsion is presented.

Computational fluid dynamics↗
NASA NTRS2012

Body weight of advanced concept hypersonic aircraft

In this paper, preliminary qualitative and quantitative comparisons of the body weight of five hypersonic aircraft configurations are conducted. The five configurations are briefly described as follows: (1) a wing-and-body arrangement with a power-law, circular cross-section body and a delta wing; (2) an all-body vehicle with delta planform and elliptical cross-sections; (3) a wingless wave rider configuration; (4) a winged wave rider configuration; and (5) the spacewing concept, an oblique flying wing at low speed that yaws to 90 deg sweep and flies end-on at hypersonic speeds. The vehicles are defined by their external moldline geometries and by the interior arrangement of their fuel tanks and other components. Intersecting, circular-lobed tankage is used in vehicles with noncircular bodies. The nonusable volume of such concepts is calculated. The structural concept, structural materials, Thermal Protection System, and heat load are allowed to vary with vehicle longitudinal station. Relative strengths and weaknesses of the various hypersonic aircraft concepts in terms of body weight are summarized.

Mark D Ardema↗
NASA NTRS2017

Applications of Radiative Heating for Space Exploration

Vehicles entering planetary atmospheres at high speeds (6 - 12 kms) experience intense heating by flows with temperatures of the order 10 000K. The flow around the vehicle experiences significant dissociation and ionization and is characterized by thermal and chemical non-equilibrium near the shock front, relaxing toward equilibrium. Emission from the plasma is intense enough to impart a significant heat flux on the entering spacecraft, making it necessary to predict the magnitude of radiative heating. Shock tubes represent a unique method capable of characterizing these processes in a flight-similar environment. The Electric Arc Shock tube (EAST) facility is one of the only facilities in its class, able to produce hypersonic flows at speeds up to Mach 50. This talk will review the characterization of radiation measured in EAST with simulations by the codes DPLR and NEQAIR, and in particular, focus on the impact these analyses have on recent missions to explore the solar system.

simulations↗