In-Flight Vibration Environment of the NASA F-15B Flight Test Fixture
In-Flight Vibration Environment of the NASA F-15B Flight Test Fixture

Author:

Publisher:

Published: 2002

Total Pages: 34

ISBN-13:

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Flight vibration data are analyzed for the NASA F- 1 5B/Flight Test Fixture 11 test bed. Understanding the in-flight vibration environment benefits design and integration of experiments on the test bed. The power spectral density (PSD) of accelerometer flight data is analyzed to quantify the in-flight vibration environment from a frequency of 15 Hz to 1325 Hz. These accelerometer data are analyzed for typical flight conditions and maneuvers. The vibration data are compared to flight-qualification random vibration test standards. The PSD levels in the lateral axis generally are greater than in the longitudinal and vertical axes and decrease with increasing frequency. At frequencies less than approximately 40 Hz, the highest PSD levels occur during takeoff and landing.

In-Flight Vibration Environment of the NASA F-15b Flight Test Fixture
In-Flight Vibration Environment of the NASA F-15b Flight Test Fixture

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-06

Total Pages: 32

ISBN-13: 9781720580195

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Flight vibration data are analyzed for the NASA F-15B/Flight Test Fixture II test bed. Understanding the in-flight vibration environment benefits design and integration of experiments on the test bed. The power spectral density (PSD) of accelerometer flight data is analyzed to quantify the in-flight vibration environment from a frequency of 15 Hz to 1325 Hz. These accelerometer data are analyzed for typical flight conditions and maneuvers. The vibration data are compared to flight-qualification random vibration test standards. The PSD levels in the lateral axis generally are greater than in the longitudinal and vertical axes and decrease with increasing frequency. At frequencies less than approximately 40 Hz, the highest PSD levels occur during takeoff and landing. Peaks in the PSD data for the test fixture occur at approximately 65, 85, 105-110, 200, 500, and 1000 Hz. The pitch-pulse and 2-g turn maneuvers produce PSD peaks at 115 Hz. For cruise conditions, the PSD level of the 85-Hz peak is greatest for transonic flight at Mach 0.9. From 400 Hz to 1325 Hz, the takeoff phase has the highest random vibration levels. The flight-measured vibration levels generally are substantially lower than the random vibration test curve.Corda, Stephen and Franz, Russell J. and Blanton, James N. and Vachon, M. Jake and DeBoer, James B.Armstrong Flight Research CenterF-15 AIRCRAFT; VIBRATION TESTS; FLIGHT TESTS; RANDOM VIBRATION; FIXTURES; POWER SPECTRA; FLIGHT CONDITIONS; STEADY STATE; AIRCRAFT MANEUVERS; ACCELEROMETERS

Initial Flight Tests of the NASA F-15B Propulsion Flight Test Fixture
Initial Flight Tests of the NASA F-15B Propulsion Flight Test Fixture

Author: Nathan Palumbo

Publisher:

Published: 2002

Total Pages: 20

ISBN-13:

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Flights of the F-1513/Propulsion Flight Test Fixture (PFTF) with a Cone Drag Experiment (CDE) attached have been accomplished at NASA Dryden Flight Research Center. Mounted underneath the fuselage of an F-15B airplane, the PFTF provides volume for experiment systems and attachment points for propulsion experiments. A unique feature of the PFTF is the incorporation of a six-degree-of-freedom force balance. The force balance mounts between the PFTF and experiment and measures three forces and moments. The CDE has been attached to the force balance for envelope expansion flights. This experiment spatially and inertially simulates a large propulsion test article. This report briefly describes the F-15B airplane, the PFTF, and the force balance. A detailed description of the CDE is provided.

Initial Flight Tests of the NASA F-15b Propulsion Flight Test Fixture
Initial Flight Tests of the NASA F-15b Propulsion Flight Test Fixture

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-06-21

Total Pages: 32

ISBN-13: 9781721526345

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Flights of the F-15B/Propulsion Flight Test Fixture (PFTF) with a Cone Drag Experiment (CDE) attached have been accomplished at NASA Dryden Flight Research Center. Mounted underneath the fuselage of an F-15B airplane, the PFTF provides volume for experiment systems and attachment points for propulsion experiments. A unique feature of the PFTF is the incorporation of a six-degree-of-freedom force balance. The force balance mounts between the PFTF and experiment and measures three forces and moments. The CDE has been attached to the force balance for envelope expansion flights. This experiment spatially and inertially simulates a large propulsion test article. This report briefly describes the F-15B airplane, the PFTF, and the force balance. A detailed description of the CDE is provided. Force-balance ground testing and stiffness modifications are described. Flight profiles and selected flight data from the envelope expansion flights are provided and discussed, including force-balance data, the internal PFTF thermal and vibration environment, a handling qualities assessment, and performance capabilities of the F-15B airplane with the PFTF installed. Palumbo, Nathan and Moes, Timothy R. and Vachon, M. Jake Armstrong Flight Research Center NASA/TM-2002-210736, NAS 1.15:210736, H-2507

The F-15b Lifting Insulating Foam Trajectory (Lift) Flight Test
The F-15b Lifting Insulating Foam Trajectory (Lift) Flight Test

Author: National Aeronautics and Space Adm Nasa

Publisher: Independently Published

Published: 2018-09-21

Total Pages: 60

ISBN-13: 9781723897986

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A series of flight tests has been performed to assess the structural survivability of space shuttle external tank debris, known as divots, in a real flight environment. The NASA F-15B research test bed aircraft carried the Aerodynamic Flight Test Fixture configured with a shuttle foam divot ejection system. The divots were released in flight at subsonic and supersonic test conditions matching points on the shuttle ascent trajectory. Very high-speed digital video cameras recorded the divot trajectories. The objectives of the flight test were to determine the structural survivability of the divots in a real flight environment, assess the aerodynamic stability of the divots, and provide divot trajectory data for comparison with debris transport models. A total of 10 flights to Mach 2 were completed, resulting in 36 successful shuttle foam divot ejections. Highspeed video was obtained at 2,000 pictures per second for all of the divot ejections. The divots that were cleanly ejected remained structurally intact. The conical frustum-shaped divots tended to aerodynamically trim in both the subsonic and supersonic free-stream flow.Corda, Stephen and Whiteman, Donald and Tseng, Ting and Machin, RicardoArmstrong Flight Research Center; Johnson Space CenterFLIGHT TESTS; FOAMS; INSULATION; F-15 AIRCRAFT; COMPUTATIONAL FLUID DYNAMICS; ASCENT TRAJECTORIES; SPACE SHUTTLES; DEBRIS; EXTERNAL TANKS; FRUSTUMS; FREE FLOW; SUBSONIC FLOW; SUPERSONIC FLOW; PHOTOGRAMMETRY; HIGH SPEED CAMERAS; FLIGHT ENVELOPES; DEGREES OF FREEDOM; PANELS; STRUCTURAL RELIABILITY; DIGITAL TO VOICE TRANSLATORS

F-15B/flight Test Fixture II : a Test Bed for Flight Research
F-15B/flight Test Fixture II : a Test Bed for Flight Research

Author: David M. Richwine

Publisher:

Published: 1996

Total Pages: 46

ISBN-13:

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NASA Dryden Flight Research Center has developed a second-generation flight test fixture for use as a generic test bed for aerodynamic and fluid mechanics research. The Flight Test Fixture II (FTF-II) is a low-aspect-ratio vertical fin-like shape that is mounted on the centerline of the F-15B lower fuselage. The fixture is designed for flight research at Mach numbers to a maximum of 2.0. The FTF-II is a composite structure with a modular configuration and removable components for functional flexibility. This report documents the flow environment of the fixture, such as surface pressure distributions and boundary-layer profiles, throughout a matrix of conditions within the F-15B/FTF-II flight envelope. Environmental conditions within the fixture are presented to assist in the design and testing of future avionics and instrumentation. The intent of this document is to serve as a user's guide and assist in the development of future flight experiments that use the FTF-II as a test bed. Additional information enclosed in the appendices has been included to assist with more detailed analyses, if required.

Validation of Force Limited Vibration Testing at NASA Langley Research Center
Validation of Force Limited Vibration Testing at NASA Langley Research Center

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-06-20

Total Pages: 36

ISBN-13: 9781721573219

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Vibration tests were performed to develop and validate the forced limited vibration testing capability at the NASA Langley Research Center. The force limited vibration test technique has been utilized at the Jet Propulsion Laboratory and other NASA centers to provide more realistic vibration test environments for aerospace flight hardware. In standard random vibration tests, the payload is mounted to a rigid fixture and the interface acceleration is controlled to a specified level based on a conservative estimate of the expected flight environment. In force limited vibration tests, both the acceleration and force are controlled at the mounting interface to compensate for differences between the flexible flight mounting and rigid test fixture. This minimizes the over test at the payload natural frequencies and results in more realistic forces being transmitted at the mounting interface. Force and acceleration response data was provided by NASA Goddard Space Flight Center for a test article that was flown in 1998 on a Black Brant sounding rocket. The measured flight interface acceleration data was used as the reference acceleration spectrum. Using this acceleration spectrum, three analytical methods were used to estimate the force limits. Standard random and force limited vibration tests were performed and the results are compared with the flight data. Rice, Chad and Buehrle, Ralph D. Langley Research Center NASA/TM-2003-212404, L-18280, NAS 1.15:212404

Proceedings of the European Test and Telemetry Conference ettc2022
Proceedings of the European Test and Telemetry Conference ettc2022

Author: The European Society of Telemetry

Publisher: BoD – Books on Demand

Published: 2022-10-14

Total Pages: 242

ISBN-13: 3756845354

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The way we prepare and analyse tests has evolved, as well as the way we perform and conduct those tests. However, we all concluded that the face-to-face exchange could not be replaced by any digital event. The ettc2022 was the first in-person telemetry event since the outbreak of the pandemic in 2020. The conference presented a dense technical program of more than 40 high quality papers, merged in the Conference Proceedings. As always, you could find the latest and most promising methods here but also hardware and software ideas for the telemetry solutions of tomorrow.