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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Results of investigations on a 0.0405 scale model PRR version of the NR-SSV orbiter in the North American Aeronautical Laboratory low speed wind tunnel

Experimental aerodynamic investigations were conducted in a low speed wind tunnel on a scale model space shuttle vehicle (SSV) orbiter. The purpose of the test was to investigate the longitudinal and lateral-directional aerodynamic characteristics of the space shuttle orbiter. Emphasis was placed on model component, wing-glove, and wing-body fairing effects, as well as elevon, aileron, and rudder control effectiveness. Angles of attack from - 5 deg to + 30 deg and angles of sideslip of - 5 deg, 0 deg, and + 5 deg were tested. Static pressures were recorded on base, fuselage, and wing surfaces. Tufts and talc-kerosene flow visualization techniques were also utilized. The aerodynamic force balance results are presented in plotted and tabular form.

Kingsland, R. B.↗
NASA NTRS1973

Results of investigations on a 0.0405 scale model ATP version of the NR-SSV orbiter in the North American Aeronautical Laboratory low speed wind tunnel

Experimental aerodynamic investigations were conducted on a scale model space shuttle vehicle (SSV) orbiter. The purpose of the test was to investigate the longitudinal and lateral-directional aerodynamic characteristics. Emphasis was placed on model component, wing-glove, and wing-body fairing effects, as well as elevon, aileron, and rudder control effectiveness. Angles of attack from - 5 deg to + 30 deg and angles of sideslip from - 5 deg to + 10 deg were tested. Static pressures were recorded on base, fuselage, and wing surfaces. Tufts and talc-kerosene flow visualization techniques were also utilized. The aerodynamic force balance results are presented in plotted and tabular form.

Mennell, R.↗
NASA NTRS1973

Experimental investigations of an 0.0405 scale Space Shuttle Configuration 3 orbiter to determine subsonic stability characteristics. Volume 1: OA21A

Experimental aerodynamic investigations were conducted in a low speed wind tunnel from May 21 through June 4 and from June 18 through June 25, 1973 on a 0.0405 scale -139B model Space Shuttle Vehicle (SSV) orbiter. The purpose of the test was to investigate the longitudinal and lateral-directional subsonic aerodynamic characteristics of the proposed PRR Space Shuttle orbiter. Emphasis was placed on component buildup effects, elevon, rudder, body flaps, rudder flare effectiveness, and canard and speed brake development. Angles of attack from -4 deg. to 24 deg. and angles of sideslip of -10 deg. to 10 deg. were tested. Static pressures were recorded on the base. The aerodynamic force balance results are presented in plotted and tabular form.

Cameron, B. W.↗
NASA NTRS1974

Experimental investigations of an 0.0405 scale space shuttle configuration 3 orbiter to determine subsonic stability characteristics (OA21A/OA21B), volume 2

Aerodynamic investigations were conducted in a low speed wind tunnel from June 18 through June 25, 1973 on a 0.0405 scale -139B model Space Shuttle Vehicle orbiter. The purpose of the test was to investigate the longitudinal and lateral-directional subsonic aerodynamic characteristics of the proposed PRR Space Shuttle Orbiter. Emphasis was placed on component buildup effects, elevon, rudder, body flaps, rudder flare effectiveness, and canard and speed brake development. Angles of attack from -4 to 24 and angles of sideslip of -10 to 10 were tested. Static pressures were recorded on the base. The aerodynamic force balance results are presented in plotted and tabular form.

Cameron, B. W.↗
NASA NTRS1992

The 12-foot pressure wind tunnel restoration project model support systems

The 12 Foot Pressure Wind Tunnel is a variable density, low turbulence wind tunnel that operates at subsonic speeds, and up to six atmospheres total pressure. The restoration of this facility is of critical importance to the future of the U.S. aerospace industry. As part of this project, several state of the art model support systems are furnished to provide an optimal balance between aerodynamic and operational efficiency parameters. Two model support systems, the Rear Strut Model Support, and the High Angle of Attack Model Support are discussed. This paper covers design parameters, constraints, development, description, and component selection.

Sasaki, Glen E.↗
NASA NTRS1994

Low-Noise Rotorcraft Blades

Blades of helicopter rotors, tilt rotors, and like reshaped to reduce noise, according to proposal. Planform features combination of rearward and forward sweep. Forward sweep over large outer portion of blade constitutes primary noise-reduction feature. Relieves some of compressive effect in tip region, with consequent reduction of noise from compressive sources. Performance at high advance ratio improved. Cabin vibration and loading noise reduced by load-averaging effect of double-sweep planform. Aft-swept section provides balancing of aerodynamic and other dynamic forces on blade along 1/4-chord line of straight inboard section and along projection of line to outermost blade radius. Possible for hub-hinge forces and moments to remain within practical bounds. Provides stabilizing blade forces and moments to counteract any instability caused by forward sweep.

Brooks, Thomas F.↗
NASA NTRS2007

TBCC Inlet Experiments and Analysis

A research plan is being implemented at NASA to investigate inlet mode transition for turbine-based combined-cycle (TBCC) propulsion for the hypersonic community. Unresolved issues have remained on how to design an inlet system to supply both a turbine engine and a ram/scramjet flowpath that operate with both high performance and stability. The current plan is aimed at characterizing the design, performance and operability of TBCC inlets through a series of experiments and analyses. A TBCC inlet has been designed that is capable of high performance (near MIL-E-5008B recovery) with smooth transitioning characteristics. Traditional design techniques were used in an innovative approach to balance the aerodynamic and mechanical constraints to create a new TBCC inlet concept. The inlet was designed for top-end Mach 7 scramjet speeds with an over/under turbine that becomes cocooned beyond its Mach 4 peak design point. Conceptually, this propulsion system was picked to meet the needs of the first stage of a two-stage to orbit vehicle. A series of increasing fidelity CFD-based tools are being used throughout this effort. A small-scale inlet experiment is on-going in the GRC 1'x1' Supersonic Wind Tunnel (SWT). Initial results from both the CFD analyses and test are discussed showing that high performance and smooth mode transitions are possible. The effort validates the design and is contributing to a large-scale inlet/propulsion test being planned for the GRC 10' x10' SWT. This large-scale effort provide the basis for a Combined Cycle Engine Testbed, (CCET), that will be able to address integrated propulsion system and controls objectives.

Saunders, Dave↗
NASA NTRS1934

Preliminary Wind-Tunnel and Flight Tests of a Balanced Split Flap, Special Report

One disadvantage that has been apparent in the operation of split flaps as used to date is the time and effort required to operate them. In this communication an investigation is being made of possible means for balancing them aerodynamically to make their operation easier. Several arrangements have been tested in the 7 by 210 foot wind tunnel, and the results of the wind-tunnel tests as well as preliminary flight tests on one of the more promising forms are given in this paper.

Weick, Fred E.↗
NASA NTRS1985

A preliminary investigation of the dynamic force-calibration of a magnetic suspension and balance system

The aerodynamic forces and moments acting upon a magnetically suspended wind tunnel model are derived from calibrations of suspension electro magnet currents against known forces. As an alternative to the conventional calibration method of applying steady forces to the model, early experiences with dynamic calibration are outlined, that is a calibration obtained by oscillating a model in suspension and deriving a force/current relationship from its inertia force and the unsteady components of currents. Advantages of dynamic calibration are speed and simplicity. The two methods of calibration applied to one force component show good agreement.

Goodyer, M. J.↗
NASA NTRS1983

The coupled aeroelastic response of turbomachinery blading to aerodynamic excitations

An energy balance technique is developed to predict the coupled bending-torsion mode aerodynamically forced response of an airfoil. In this technique, the energy input to the airfoil system per cycle of oscillation is generated by gust forces and moments and, under certain conditions, the self-induced aerodynamic forces and moments. The energy dissipation per cycle is associated with the structural damping, the static moment term for coupled motions, and under certain conditions, the self-induced aerodynamic forces and moments. The effects of the various aerodynamic parameters on the coupled forced response are then considered.In particular, the effects of the inlet Mach number, the interblade phase angle, the level of structural damping, and the cascade geometry on the coupled bending-torsion aerodynamically forced response of a flat plate airfoil cascade are demonstrated.

Hoyniak, D.↗
NASA NTRS2004

Linear and Nonlinear Analyses of a Wind-Tunnel Balance

The NASA Langley Research Center (LaRC) has been designing strain-gauge balances for utilization in wind tunnels since its inception. The utilization of balances span a wide variety of aerodynamic tests. A force balance is an inherently critically stressed component due to the requirements of measurement sensitivity. Force balance stress analysis and acceptance criteria are under review due to LaRC wind tunnel operational safety requirements. This paper presents some of the analyses done at NASA LaRC. Research and analyses were performed in order to investigate the structural integrity of the balances and better understand their performance. The analyses presented in this paper are helpful in understanding the overall behavior of an existing balance and can also be used in design of new balances to enhance their performance. As a first step, maximum load combination is used for linear structural analysis. When nonlinear effects are encountered, the analysis is extended to include the nonlinearities. Balance 1621 is typical for LaRC designed balances and was chosen for this study due to its traditional high load capacity, Figure 1. Maximum loading occurs when all 6 components are applied simultaneously with their maximum value allowed (limit load). This circumstance normally will not occur in the wind tunnel. However, if it occurs, is the balance capable of handling the loads with an acceptable factor of safety? Preliminary analysis using Pro/Mechanica indicated that this balance might experience nonlinearity. It was decided to analyze this balance by using NASTRAN so that a nonlinear analysis could be conducted. Balance 1621 was modeled and meshed in PATRAN for analysis in NASTRAN. The model from PATRAN/NASTRAN is compared to the one from Pro/Mechanica. For a complete analysis, it is necessary to consider all the load cases as well as use a dense mesh near all the edges. Because of computer limitations, it is not feasible to analyze model with the dense mesh near all edges. In the present study, the dense mesh is limited to the surface on the end of the axial sections.

Karkehabadi, R.↗