Aerospace Solutions

Flight Test - Interior Noise

The assessment of aircraft interior noise levels is becoming an important parameter for aircraft manufacturers.

These days, human comfort (distribution of noise regarding frequency content and location, and speech index and other sound quality parameters) is more important than ever for both passengers and crew.

Brüel & Kjær offers compact and distributed multi-channel recording systems and hand-held instrumentation fully configured with microphones, signal conditioning digitizers and application software.

> Learn more about the PULSE Platform
> Read more about Sound Quality
> Read more about Noise Source Identification
> Download the data sheet for Hand-held Sound Intensity System
> Download the data sheet for PULSE Software
> See the PULSE Hardware configurations
> The FACE Project

Flight Test - Exterior Noise

Global air traffic is forecast to triple between 2000 and 2015 and, if this demand is to be met, more than 5000 new aircraft will have to be built each year. The aeronautics industry therefore faces a massive challenge to satisfy demand for environmentally friendly air travel.

Increased awareness of noise around airports is leading to stricter legislation. In order to overcome a major barrier to air traffic growth, the aeronautics industry is facing one of its biggest challenges – to make aircraft more acceptable by reducing noise from all possible sources including engines, nacelles, and airframes.

Distributed multichannel recording and analyzer systems fully configured with microphones, signal conditioning digitizers and application software are all available from Brüel & Kjær.

> Case Study: Flight Testing at Aermacchi
> Read more about Noise Source Identification
> Learn more about the PULSE Platform
> PULSE Time File Management
> Acoustic Holography
> Download the data sheet for PULSE Software
> Download the data sheet for PULSE Hardware
> The SILENCE(R) Project
> Sound level meters Type 2250 and 2260
> Airport Noise Monitoring

Acoustic Signature

The accurate measurement and analysis of the acoustic signature of gas turbine or pure jet engines used in military aircraft is normally carried out in an engine test cell. A number of special microphones are placed close to the engine casing. Very high sound pressure levels can be produced.

Brüel & Kjær has a range of special microphones for this type of application that can be used at an SPL of up to 180 dB. A PULSE data acquisition system can conveniently be connected to the microphones using long cables, placed at a safe distance from the noise source. The test data can be viewed in real-time and also saved for further post processing.

Acoustic measurements are also carried out to investigate the effects of high sound pressure levels on other engine components and to ensure that the noise parameters measured in the test cell can be accurately reproduced in different test setups.

> The revolutionary surface microphone Type 4948
> See relevant acoustic transducers
> Case Study: Anecom AeroTest GmbH – Quality Acoustic Measurements
> Magazine article: Rolls-Royce
> Magazine article: Boeing
> Learn more about the PULSE Platform

Engine Test Cells

Our PULSE platform is extensively used for R&D noise and vibration data acqusition and analysis in engine test cells. The performance and reliability of components such as fans, turbines and gearboxes can be tested using both traditional vibroacoustic test methods, and coldflow and cascade coldflow tests to evaluate their performance under aerodynamic loading.  Test data can be viewed in real time and saved for post-processing.

A safety system can be built into the test system. If PULSE monitors vibration levels above a predetermined level, a signal can be sent to the test cell PLC to shutdown the test and so avoid damage.

Reports can be generated by PULSE and configured to your individual requirements.

> See example of report generated by PULSE
> Learn more about the PULSE Platform

Vibration Test

For general vibration and environmental testing, Brüel & Kjær solutions include state-of-the-art digital closed-loop controllers, and a range of advanced vibration exciters (shakers).

For tasks such as fatigue and material testing, using our PULSE data acquisition system, all operational conditions can be simulated in the test lab using pre recorded field data or a comprehensive range of excitation types. It is extensively used to test and analyse the vibration parameters of components and systems used in the aerospace industry.

Small, compact and lightweight, PULSE can also be used to measure vibration both on the ground and during flight testing. Test data can be to recorded for post-processing and also viewed in real-time.

> Case Study: Alenia Aeronautica
> See solutions for structural analysis

On-Ground Testing

PULSE Vibration Check System for Aircraft Engines.
To ensure the maintenance of helicopter engines and to optimise the up-time of the aircraft, Brüel & Kjær has developed a system for the field verification on the ground of specific engines based on PULSE Type 3560 B hardware and dedicated software.

Vibration measurements are made according to the procedures specified by the engine manufacturer, Turbomeca, in their Maintenance Manual.

> Data sheet for PULSE Vibration Check System for Aircraft Engines

Engine Certification

With increasing focus on the reduction of noise from gas turbine power plants, we can supply complete systems for conformance testing.

Recently, a noise measurement system using state-of-the-art technology was installed at Rolls-Royce’s facility at Hucknall in the UK. The turnkey installation enables noise measurements and analysis to be made simultaneously on up to 128 channels. The data is used to confirm compliance of Rolls-Royce engines to international noise standards and for extensive R&D applications.

> Case Study: Anecom AeroTest GmbH – Quality Acoustic Measurements
> Case Study: Rolls-Royce
> Download the data sheet for PULSE Software
> Download the data sheet for PULSE Hardware