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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS2023

Life Cycle Cost Modeling of High-speed Commercial Aircraft - Final Report

SpaceWorks has concluded a 9-month research and development project aimed at addressing key questions in NASA’s effort to anticipate, understand, and ultimately support the emerging high-speed commercial flight market. The current project is a continuation of the Life Cycle Cost Modeling of High-Speed Commercial Aircraft1 , which is a follow-on to a 2021 study led by Deloitte and SpaceWorks entitled Commercial Hypersonic Transportation Market Study2 . Based in part on the recommendations of these prior studies, the objectives of this current effort were to expand the trade space to include Mach 1.5 aircraft and conduct additional trade studies. These included utilizing tech stops to extend serviceable range between city pairs, mixed aircraft fleets based on market size, flight scheduling to maximize value of the travel opportunity, and scenarios with multiple service operators. Additionally, SpaceWorks conducted new market surveys and research to update air passengers’ willingness-to-pay for highspeed flights given the changes in macroeconomic conditions since the start of the Commercial Hypersonic Transportation Market Study with Deloitte. Ultimately, the new data and capability to evaluate all the trade studies were implemented in a new simulation environment called MIDAS (Multi-market Integrated Dynamic Aerospace Simulation). This sophisticated tool, implemented using AnyLogic software, utilizes agent-based and discrete event simulation (DES) techniques to provide highly detailed analysis and assessment of the high-speed aircraft market problem.

high-speed↗
NASA NTRSDate not supplied

A Multi-Architecture Approach for Implicit Computational Fluid Dynamics on Unstructured Grids

High-performance computing (HPC) architectures are trending toward manycore paradigms such as graphics processing units (GPUs). Approximately half of the top 100 publicly disclosed supercomputers in the world utilize GPU accelerators for performance. This is in contrast to a decade ago, where there were only a few such machines in the top 100. It is not currently possible to compile and run legacy central processing unit (CPU) software efficiently on GPUs without significant refactoring. Though a number of frameworks offering performance portability exist, none offer a standardized specification that is supported by all major hardware vendors. Additionally, experiences show that obtaining a high percentage of peak performance often requires architecture-specific code. This work details a pragmatic multi-architecture computational fluid dynamics library focused on aerospace problems across the speed range from low subsonic to hypersonic flows involving thermochemical nonequilibrium. A thin abstraction layer above NVIDIA CUDA C++ is utilized, which enables primarily single-source software currently capable of running efficiently on multicore CPUs, NVIDIA GPUs, AMD GPUs, and Intel GPUs. Results on various problems of interest across the speed range are presented and performance is compared between various architectures.

GPU↗
NASA NTRSDate not supplied

A Multi-Architecture Approach for Implicit Computational Fluid Dynamics on Unstructured Grids

High-performance computing (HPC) architectures are trending toward manycore paradigms such as graphics processing units (GPUs). Approximately half of the top 100 publicly disclosed supercomputers in the world utilize GPU accelerators for performance. This is in contrast to a decade ago, where there were only a few such machines in the top 100. It is not currently possible to compile and run legacy central processing unit (CPU) software efficiently on GPUs without significant refactoring. Though a number of frameworks offering performance portability exist, none offer a standardized specification that is supported by all major hardware vendors. Additionally, experiences show that obtaining a high percentage of peak performance often requires architecture-specific code. This work details a pragmatic multi-architecture computational fluid dynamics library focused on aerospace problems across the speed range from low subsonic to hypersonic flows involving thermochemical nonequilibrium. A thin abstraction layer above NVIDIA CUDA C++ is utilized, which enables primarily single-source software currently capable of running efficiently on multicore CPUs, NVIDIA GPUs, AMD GPUs, and Intel GPUs. Results on various problems of interest across the speed range are presented and performance is compared between various architectures.

GPU↗
NASA NTRSDate not supplied

The Influence of Computer Architecture on Performance and Scaling for Hypersonic Flow Simulations

It is critical to understand how hypersonic simulation tools perform on a range of computational platforms. This information will aid in the acquisition of appropriate hardware and the potential refactoring of hypersonic codes to run on different systems. In this paper, we consider two representative high-speed reacting flow cases: a model Mach 8 hypersonic waverider glide vehicle and a model hydrocarbon-fueled hypersonic ramjet propulsion system. In both scenarios, the flow fields are in chemical non-equilibrium and are modeled by the multi-species reacting Navier-Stokes equations. For these simulations we use several hypersonic simulation tools, including US3D, Kestrel, FUN3D, and the JENRER© flow solver. We explore several high performance computing systems containing IntelR© XeonR© Platinum processors, AMD EPYCTM7702 processors, and NVIDIAR© Tesla V100 devices. We compare performance and strong scaling between the different systems.

CPU↗
NASA NTRS2002

Hypersonic Propulsion at Pratt and Whitney: Overview

Pratt & Whitney (P&W) is developing the technology for hypersonic components and engines. A supersonic combustion ramjet (scramjet) database was developed during the National Aero Space Plane (NASP) program using hydrogen fueled propulsion systems for space access vehicles and serves as a point of departure for the current emphasis on hydrocarbon scramjets. The Air Force Hypersonic Technology (HyTech) Office has put programs in place to develop the technologies necessary to demonstrate the operability, performance and structural durability of a liquid hydrocarbon fueled scramjet system that operates from Mach 4 to 8. Fuel-cooled superalloys and lightweight structures are being developed to improve thermal protection and durability and to reduce propulsion system weight. The application of scramjet engine technology as part of combined cycle propulsion systems is also being pursued under NASA and U.S. Air Force sponsorship. The combination of scramjet power and solid rocket booster acceleration is applicable to hypersonic cruise missiles. Scramjets that use gas turbines for low speed acceleration and scramjets using rocket power for low speed acceleration are being studied for application to reusable launch systems and hypersonic cruise vehicles. P&W's recent activities and future plans for hypersonic propulsion will be described.

Kazmar, Richard R.↗
NASA NTRS1993

Effect of aeroelastic-propulsive interactions on flight dynamics of a hypersonic vehicle

The desire to achieve orbit-on-demand access to space with rapid turn-around capability and aircraft-like processing operations has given rise to numerous hypersonic aerospace plane design concepts which would take off horizontally from a conventional runway and employ air-breathing scramjet propulsion systems for acceleration to orbital speeds. Most of these air-breathing hypersonic vehicle concepts incorporate an elongated fuselage forebody to act as the aerodynamic compression surface for a scramjet combustor module. This type of airframe-integrated scramjet propulsion system tends to be highly sensitive to inlet conditions and angle-of-attack perturbations. Furthermore, the basic configuration of the fuselage, with its elongated and tapered forebody, produces relatively low frequency elastic modes which will cause perturbations in the combustor inlet conditions due to the oscillation of the forebody compression surface. The flexibility of the forebody compression surface, together with sensitivity of scramjet propulsion systems to inlet conditions, creates the potential for an unprecedented form of aeroelastic-propulsive interaction in which deflections of the vehicle fuselage give rise to propulsion transients, producing force and moment variations that may adversely impact the longitudinal flight dynamics and/or excite the elastic modes. These propulsive force and moment variations may have an appreciable impact on the performance, guidance, and control of a hypersonic aerospace plane. The objectives of this research are to quantify the magnitudes of propulsive force and moment perturbations resulting from elastic deformation of a representative hypersonic vehicle, and to assess the potential impact of these perturbations on the vehicle's longitudinal flight dynamics.

Raney, David L.↗
NASA NTRS1991

Determination of the effects of heating on modal characteristics of an aluminum plate with application to hypersonic vehicles

The structural integrity of proposed high speed aircraft can be seriously affected by the extremely high surface temperatures and large temperature gradients throughout the vehicle's structure. Variations in the structure's elastic characteristics as a result of thermal effects can be seen by changes in vibration characteristics. Analysis codes that predict these changes must be correlated and verified with experimental data. Analytical and experimental modal test results are given from uniform, nonuniform, and transient thermoelastic vibration tests of a 12 x 50 x 0.19 aluminum plate. The data show the effect of heat on the modal characteristics of the plate. The results showed that frequencies decreased, damping increased, and mode shapes remained unchanged as the temperature of the plate increased. Analytical predictions provided good correlation with experimental results.

Snyder, H. Todd↗
DOE OSTI2022

Aero-Optics of Hypersonic Turbulent Boundary Layers

Aero-optics refers to optical distortions due to index-of-refraction gradients that are induced by aerodynamic density gradients. At hypersonic flow conditions, the bulk velocity is many times the speed of sound and density gradients may originate from shock waves, compressible turbulent structures, acoustic waves, thermal variations, etc. Due to the combination of these factors, aero-optic distortions are expected to differ from those common to sub-sonic and lower super-sonic speeds. This report summarizes the results from a 2019-2022 Laboratory Directed Research and Development (LDRD) project led by Sandia National Laboratories in collaboration with the University of Notre Dame, New Mexico State University, and the Georgia Institute of Technology. Efforts extended experimental and simulation methodologies for the study of turbulent hypersonic boundary layers. Notable experimental advancements include development of spectral de-aliasing techniques for highspeed wavefront measurements, a Spatially Selective Wavefront Sensor (SSWFS) technique, new experimental data at Mach 8 and 14, a Quadrature Fringe Imaging Interferometer (QFII) technique for time-resolved index-of-refraction measures, and application of QFII to shock-heated air. At the same time, model advancements include aero-optic analysis of several Direct Numerical Simulation (DNS) datasets from Mach 0.5 to 14 and development of wall-modeled Large Eddy Simulation (LES) techniques for aero-optic predictions. At Mach 8 measured and predicted root mean square Optical Path Differences agree within confidence bounds but are higher than semi-empirical trends extrapolated from lower Mach conditions. Overall, results show that aero-optic effects in the hypersonic flow regime are not simple extensions from prior knowledge at lower speeds and instead reflect the added complexity of compressible hypersonic flow physics.

36 MATERIALS SCIENCE↗
NASA NTRS1993

Proceedings of the Ninth Annual Summer Conference: NASA/USRA University Advanced Aeronautics Design Program and Advanced Space Design Program

The NASA/USRA University Advanced Design Program was established in 1984 as an attempt to add more and better design education to primarily undergraduate engineering programs. The original focus of the pilot program encompassing nine universities and five NASA centers was on space design. Two years later, the program was expanded to include aeronautics design with six universities and three NASA centers participating. This year marks the last of a three-year cycle of participation by forty-one universities, eight NASA centers, and one industry participant. The Advanced Space Design Program offers universities an opportunity to plan and design missions and hardware that would be of usc in the future as NASA enters a new era of exploration and discovery, while the Advanced Aeronautics Design Program generally offers opportunities for study of design problems closer to the present time, ranging from small, slow-speed vehicles to large, supersonic and hypersonic passenger transports. The systems approach to the design problem is emphasized in both the space and aeronautics projects. The student teams pursue the chosen problem during their senior year in a one- or two-semester capstone design course and submit a comprehensive written report at the conclusion of the project. Finally, student representatives from each of the universities summarize their work in oral presentations at the Annual Summer Conference, sponsored by one of the NASA centers and attended by the university faculty, NASA and USRA personnel and aerospace industry representatives. As the Advanced Design Program has grown in size, it has also matured in terms of the quality of the student projects. The present volume represents the student work accomplished during the 1992-1993 academic year reported at the Ninth Annual Summer Conference hosted by NASA Lyndon B. Johnson Space Center, June 14-18, 1993.

Source record↗
NASA NTRS1977

Structural analysis of ultra-high speed aircraft structural components

The buckling characteristics of a hypersonic beaded skin panel were investigated under pure compression with boundary conditions similar to those found in a wing mounted condition. The primary phases of analysis reported include: (1) experimental testing of the panel to failure; (2) finite element structural analysis of the beaded panel with the computer program NASTRAN; and (3) summary of the semiclassical buckling equations for the beaded panel under purely compressive loads. A comparison of each of the analysis methods is also included.

Lenzen, K. H.↗
NASA NTRS1991

Evaluation of on-board hydrogen storage methods f or high-speed aircraft

Hydrogen is the fuel of choice for hypersonic vehicles. Its main disadvantage is its low liquid and solid density. This increases the vehicle volume and hence the drag losses during atmospheric flight. In addition, the dry mass of the vehicle is larger due to larger vehicle structure and fuel tankage. Therefore it is very desirable to find a fuel system with smaller fuel storage requirements without deteriorating the vehicle performance substantially. To evaluate various candidate fuel systems, they were first screened thermodynamically with respect to their energy content and cooling capacities. To evaluate the vehicle performance with different fuel systems, a simple computer model is developed to compute the vehicle parameters such as the vehicle volume, dry mass, effective specific impulse, and payload capacity. The results indicate that if the payload capacity (or the gross lift-off mass) is the most important criterion, only slush hydrogen and liquid hydrogen - liquid methane gel shows better performance than the liquid hydrogen vehicle. If all the advantages of a smaller vehicle are considered and a more accurate mass analysis can be performed, other systems using endothermic fuels such as cyclohexane, and some boranes may prove to be worthy of further consideration.

Akyurtlu, Ates↗
NASA NTRS1996

Supersonic Channel Concept for Enhancement of Lift/Drag Ratio

The concept studied during the summer NASA/ASEE Fellowship provides a means of lowering drag and a means for directional control of supersonic and hypersonic vehicles. Low drag and efficient directional control are essential for the success of aircraft, atmospheric entry vehicles, missiles, and other vehicles in supersonic and hypersonic flight. Drag reduction can result in increased vehicle range, increased speed, improved fuel efficiency, increased lift/drag ratio, and increased climb rate. For high supersonic and hypersonic vehicles heat transfer considerations dictate the design of the nose and leading edge. The heat transfer to such vehicles is most severe at stagnation points which occur on the leading edges and nose of the vehicle. Theoretical formulations, experimental data, and semi-empirical formulas all agree in the fact that stagnation point heat transfer is inversely proportional to the square root of the nose or leading edge radius. Thus, the noses and leading edges of supersonic and hypersonic vehicles are typically blunted so that the heat transfer and structural loads will be manageable. However, much of the wave drag experienced by these vehicles is due to nose blunting.

Ruffin, Stephen M.↗
NASA NTRS2013

Iodine Tagging Velocimetry and Mechanism in the Hypersonic Near Wake of a MultiPurpose Crew Vehicle

This study demonstrates a new molecular tagging velocimetry (MTV) method for velocity measurements of high speed flow. It demonstrates offbody Iodine Tagging Velocimetry (ITV) in the hypersonic near wake of a MultiPurpose Crew Vehicle (MPCV) model. Experiments are performed in the NASA-Langley 31-inch Mach 10 air wind tunnel. A 0.5% I2 / N2 mixture is seeded on the leeward backshell of the model using a pressure tap. I2 laser-induced fluorescence is excited along a 5.5 mm line using an ArF excimer laser near 193 nm. Results indicate I2 absorbs at least 2 photons to produce iodine ions and electrons. These recombine as the tagged region is displaced downstream to produce I (2P3/2) whose emission is monitored at 206 nm. Results at P0 = 2.41 MPa (350 psi), T0 = 990K, and 10 micro-sec transit times produce velocities from 630-820 m/sec across the I2 seeded jet at a distance of 38.2 mm (25.5 jet diameters) downstream from the jet orifice. Maximum wake jet velocities near the shear layer are 59% of freestream velocity.

Balla, R. Jeffrey↗
NASA NTRSDate not supplied

Evaluation of Transport-Equations-Based Transition Models for High-Speed Boundary Layers Using OVERFLOW

Accurate modeling of laminar-turbulent transition is crucial for the design of hypersonic flight systems. However, the current transition models used in production CFD codes are insufficient for high-speed flows. Many extensions to low-speed models have been suggested; however, a thorough verification and validation effort is needed before these models can be used in design settings. Challenges include potentially missing details of the model implementation requirements and/or a complete specification of the input parameters needed to replicate the test findings. A meaningful assessment of the generalization capability of these models is also hindered by a lack of information regarding the specific flow configurations and associated grids employed for model calibration. As a key first step toward model verification, we present an independent assessment of two recently proposed models for high-speed transition, namely, a model within the SST-𝛾 framework and a model based on the SST-𝛾 – 𝜈 𝐿 equations. These models are implemented in the NASA OVERFLOW 2.3e solver and their performance in predicting first mode, second mode, and crossflow transition has been evaluated for several test cases in the supersonic and hypersonic regimes. Besides the test cases employed by the model developers, which could have also been used for model calibration, the present assessment includes supplementary configurations that contribute to an unbiased assessment of the models. The outcomes presented in this study indicate the potential for the models to be applied to high-speed flight configurations. Key steps toward future improvements to these models are also outlined.

CFD↗
NASA NTRS1989

Propulsion over a wide Mach number range

Criteria is presented to assess the relative merits of different propulsion systems. Previous references focus mainly on subsonic or low supersonic flight speeds. The main focus here is on a higher range, from low supersonic to orbital velocities. Air breathing propulsion systems for hypersonic flight persent the engine designer with circumstances that differ in important fundamental ways from those encountered in engines designed for operation at subsonic or low supersonic speeds. This analysis highlights the importance of various features of hypersonic engine design. Since the performance of hypersonic engines are energy limited, unlike low speed engines which are stagnation pressure limited, the efficient use of the energy of the fuel used is critical to minimize the take-off fuel mass fraction of the vehicle. Furthermore, since the required energy increase of a vehicle per incremental speed change increases with speed, the engine must be designed to operate efficiently at high speed. An analysis of engine performance in terms of entropy changes of the flow passing through the engine allows comparison of various engine designs as well as a convenient method to determine the effect of individual engine component efficiencies on overall engine performance.

Resler, Edwin L., Jr.↗
NASA NTRS2024

A Summary of the 2023 Joint High-Speed Boundary Layer Transition Workshop

A joint workshop between the Air Force Office of Scientific Research, the Office of Naval Research, and the NASA Hypersonic Technology Project was held in June 2023 on the topic of high-speed boundary-layer transition. The purpose of this workshop was to gather subject matter experts in the areas of supersonic and hypersonic boundary-layer transition in the areas of geometries of interest, computational methods, facilities and diagnostics, flight experiments, flow control, and new approaches and to discuss the current state of the art in the field. As gaps and accomplishments were identified, roadmaps were also created to guide future investments in these areas. The top recommendations are (1) to define relevant common geometries of interest that can be worked by multiple research groups; (2) improve modeling of high-enthalpy flows involving chemistry and ablation, studies of receptivity of freestream disturbances and atmospheric particulates into the boundary layer, surface feature characterization and modeling of changes to geometry; (3) design and determine viable flow control methods; and (4) move towards incorporating boundary layer transition prediction into a standard practice for design of high-speed vehicles. To execute this last recommendation successfully, investments beyond fundamental (basic and early applied) research are needed.

boundary layer transition↗