Keyword: Noise

Briefs: Aerospace

A system of nozzles and pylons that redistributes jet exhaust noise sources upstream to reduce jet noise has been developed. Certain aircraft configurations install the propulsion...

Briefs: Aerospace

Researchers at NASA's Armstrong Flight Research Center (AFRC) recently completed a study of the feasibility of aerial towing an unpiloted, sub-scale vehicle to supersonic flight conditions to examine...

Briefs: Electronics & Computers

Front-end electronics for capacitive sensors typically include a preamplifier followed by a filter. The preamplifier provides low-noise amplification of the signals induced in the sensor...

Briefs: Aerospace

NASA Langley Research Center has developed two new implementations of acoustic liners for aircraft noise reduction whereby curved channels within tight spaces can be outfitted to provide noise...

Briefs: Aerospace

NASA Langley Research Center, in collaboration with Boeing and Lockheed Martin, has developed a new external acoustic liner for aircraft noise reduction. While the acoustic liner can be placed on any...

Articles: Sensors/Data Acquisition

This column presents technologies that have applications in commercial areas, possibly creating the products of tomorrow. To learn more about each technology, see the contact information provided for that...

Briefs: Software
Acoustic Propagation and Emulation Toolset (APET)

Currently, APET includes a modified version of the Rotorcraft Noise Model (RNM, version 7). It also includes the newly developed Spectral Attenuation Method (SAM), which contains the Ray Tracing Program (RTP) and two versions of a Green's Function Parabolic Equation (GFPE) code. The third...

Briefs: Sensors/Data Acquisition
Briefs: Photonics/Optics

Measurements of the cosmic microwave background are a powerful probe of the early universe. Part-per-million fluctuations in the intensity of background trace the...

Briefs: Sensors/Data Acquisition

NASA's Langley Research Center has developed a magnetometer that takes advantage of the unique variable permeability properties of Metglas 2714A magnetic...

Briefs: Test & Measurement

NASA’s Langley Research Center researchers developed DAMAS using an iterative algorithm to deconvolute noise signals, allowing for more...

Briefs: Test & Measurement
Method of Adjusting Acoustic Impedances for Impedance-Tunable Acoustic Segments

NASA’s Langley Research Center researchers have developed an adaptive noise-reduction system that optimizes impedance in an aircraft engine. Aerospace and automotive engineers can take advantage of this innovative system that offers a superior approach to noise...

Briefs: Aerospace

NASA’s Langley Research Center researchers have developed a novel noise reduction system for jet engines. Aircraft jet engine noise is a major issue for airports, the...

Briefs: Aerospace
Improvements to the Functional Beamforming Formula

The purpose of this work is to improve the signal-to-noise ratio of acoustic measurements made in a wind tunnel with a microphone phased array. The functional beamforming method is improved to compensate for effects of acoustic propagation through turbulence, and to correct for inaccurate...

Briefs: Aerospace

This technology is a new type of aircraft pylon design for noise control. A pylon connects the engine to the airframe of an aircraft. This design uses air passing through the pylon to actively...

Briefs: Mechanical & Fluid Systems

NASA’s Langley Research Center has created novel flow effector technology for separation control and enhanced mixing. The technology allows for variable shape control of aircraft structure through...

Briefs: Software
Reducing Sensor and Readout Circuitry Noise in Digital Domain Using Reference Pixels

One of the main heritage tools used in scientific and engineering data spectrum analysis is the Fourier Integral Transform and its high-performance digital equivalent — the Fast Fourier Transform (FFT). The Fourier view of nonlinear mechanics that has existed...

Briefs: Software
Fourier Transform Spectrometer Performance Modeling

This software models the performance of a Fourier transform spectrometer (FTS). More specifically, it is able to add a number of noise/error sources to the interferogram and transform the errors back to the spectral domain.

Briefs: Manufacturing & Prototyping
A Statistically Based Approach to Broadband Liner Design and Assessment

The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more...

Briefs: Test & Measurement
Technique to Measure Degradation of Submillimeter-Wave Spectrometer Response to Local Oscillator Phase Noise

High-resolution submillimeter-wave spectroscopy is based on the heterodyne principle, where the incident signal is down-converted to a low intermediate frequency (IF) by nonlinear mixing with a local oscillator (LO) signal. The IF...

Briefs: Photonics/Optics

Measurements of the cosmic micro wave background are a powerful probe of the early universe. Part-per-million fluctuations in the intensity of background trace the initial...

Briefs: Aerospace
Autonomous Leading-Edge Slat Device for Reduction of Aeroacoustic Noise Associated with Aircraft Wings

Conventional transport aircraft wing design is driven mainly by cruise efficiency, i.e., adequate lift is generated at high speed for level flight with minimal drag. Conventional high-lift systems (leading edge slats and trailing edge flaps)...

Briefs: Aerospace
Aircraft Engine Exhaust Nozzle System for Jet Noise Reduction

Conventional aircraft typically include propulsion engines that are under the wing or tail surfaces. Each propulsion engine system includes an engine housed in a nacelle with an inlet and a nozzle system. Primary component noise sources from the engine system include the noise...

Briefs: Electronics & Computers

Microwave spectroscopy is an invaluable tool for studying the structure, dynamics, and even the handedness of gas phase species....

Briefs: Propulsion

This technology is based on a model-scale experiment simulating a test facility where an engine exhaust is discharged into a duct....

Briefs: Electronics & Computers
Rigorous Antenna Noise Temperature Calculation Method for International Space Station Visiting Spacecraft

The temperature of the orbiting space station’s Sun-facing side could be up to 250 °F (≈120 °C) and will be a significant antenna noise temperature contributor for visiting spacecraft communication and tracking systems during...

Briefs: Software
Advanced Numerical Integration Techniques for High-Fidelity SDE Spacecraft Simulation

Simulation study is an integral part of the validation of navigation algorithms for spacecraft. While it is possible to come up with an estimate of a navigation algorithm’s performance with a low-fidelity system model, the mathematical analysis is intractable...

Briefs: Robotics, Automation & Control
Tension-Stiffened and Tendon-Actuated Space Manipulators

The Space Shuttle Remote Manipulator System (SRMS) and Space Station Remote Manipulator System (SSRMS) have proven the benefit of long-reach manipulators, with the reach of both manipulators in the l5-18-m class. Manipulators with greater reach provide many benefits. The SRMS’s limited...

Briefs: Aerospace
Blended Cutout Flap for Reduction of Jet-Flap Interaction Noise

An aircraft trailing edge device, coupled with an aircraft wing, provides a reduction in jet-flap interaction noise while preserving the aerodynamic load capacity of the trailing edge. Embodiments of the present invention provide a trailing edge flap device that includes a center...