Aeroacoustic flow bench

Acoustic or vibration characterization of systems in the presence of controlled air flow.

The 6NAPSE Group carries out characterizations of acoustic performance in the presence of an air flow up to 100m/s. Our engineers use an Aeraulic bench in acoustic environment.

Airflow and vibro-acoustic characterization

We carry out aeroacoustic measurement. The installation in a semi-anechoic chamber (background noise <13dBA) of this versatile means allows the acoustic or vibratory characterization of active or passive systems in the presence of controlled aeraulic flow.

The bench has an optimized and instrumented aeraulic wind tunnel, upstream of the semi-anechoic reception environment, sized to obtain a controlled laminar flow at the inlet of the systems to be characterised, whether active or passive.

Many existing solutions in the industry work in the presence of airflow and are either directly noise generators or only a noise transmission factor.
For passive systems for example, the guided propagation of an acoustic field can be weakened by acoustic absorption, by vibro-acoustic coupling with the walls, by transmission by transparency.

Principles of the acoustic field

The guided propagation of an acoustic field can be weakened by acoustic absorption, by vibro-acoustic coupling with the walls, by transmission by transparency. For active systems for example, the radiated noise is dependent on the power consumed by the “fan blower” and the operating point settings (flow rate, counterpressure) which influence the rotation speed.

The versatility of the bench makes it possible to approach different acoustic characteristics from measurements of the far radiated field or in the flow.

Electrification in the automotive sector is reshuffling the cards of participation of different sources in the passenger compartment and in particular of the ventilation unit.

Beyond the design optimizations of the units themselves, the ventilation ducts become potential very effective solutions to reduce in different ways the acoustic energy at the entrance by also integrating the notions of pressure drops.

Applications

  • Type of control possible: Blown air flow rate ramp (passive systems), Blower fan speed ramp (active systems), Operating point management.
  • Types of signals measured: Voltage, current, pressure delta, air flow, temperature, sound pressure, sound power, acceleration.
  • Possible types of analysis: Global levels vs engine speed, Fixed speeds.

Features

  • Free field sound pressure level measurements
  • Airflow Speed Control
  • Air flow measurement

Method

  • Reproduction of vehicle conditions for the use of an air conditioning and heating unit
  • Wide range of flow (0-800 kg/h) and depression (0-1000 Pa)
  • Fine adjustment of pressure drops and operating points using a pyramid system without adding noise
  • Tests carried out in a semi-anechoic chamber ISO 3745 (background noise <13dBA)

This means of characterization can be accompanied by means of measurement such as microphones, accelerometers, or even vibration mapping obtained by scanning laser vibrometry to identify areas of vibration weakness on complex geometries.

The existence of an experimental characterization means opens the way to the recalibration of digital models for assistance in the design and positioning of high-performance acoustic solutions adapted to the targets of our customers.

The flow bench is intended to be modular and the use in a Semi-Anechoic chamber makes it an exceptional means. We study your needs and analyze the possibility of adapting the bench to carry out your tests.

Contact us to discuss your needs quickly and technically!