Programma lezingendag Akoestische innovaties

Datum: Woensdag 21 september 2022 / Locatie: Jaarbeurs MeetUp, Utrecht

Op deze lezingendag over Akoestische innovaties staan nieuwe ontwikkelingen in de akoestische wereld centraal, zowel qua producten als methodes, meetapparatuur en modelleringstechnieken. Organisatie: Margriet, Elke en Anne.

Het programma voor de lezingendag is als volgt:

09:30u Ontvangst

10:00u Jin Jack Tan – Sorama, VIPNOM – Loud vehicle detection

Traffic noise is one of the main contributors to environmental noise, with more than 100 million people affected by it in the EEA-33 member countries. There is an increasing need to monitor, detect, and take actions on vehicles that are making too much noise on the road. By integrating an acoustic camera with an automated number plate recognition (ANPR) system, the noise level and identity of the vehicles can be obtained. However, to accurately obtain the sound power level, one needs to perform a so-called virtual point noise measurement (VIPNOM). The VIPNOM technique, which is based on the use of microphone array and machine learning signal processing will be detailed. A validation based on lab measurement will also be demonstrated. VIPNOM is also applicable to other use cases, such as in measuring sound levels within the audience of a festival and monitoring noisy pub streets.

10:25u Karl Janssens – Siemens, Component-based NVH synthesis of virtual vehicle assemblies

The current trends in the automotive industry towards electric vehicles are creating increasing interest on methods to predict road/tire and electric powertrain noise early in the vehicle development process. At the same time, the capability of subjectively evaluating design choices in an interactive environment is becoming an important element for engineers addressing noise and vibration comfort of vehicles. This paper discusses a technology framework combining component based transfer path analysis (TPA) and sound synthesis for early stage comfort assessment. The technology framework is demonstrated with two application cases: a road/tire noise application and a rear axle electric powertrain use case.

10:50u Tim Rutjes / Marina Rodrigues – Delta-L/CDM Stravitec, Constrained layer damping concept used on isolated floors. Better than Concrete?

CDM Stravitec extensively investigated how the concept of constrained layer damping (CLD) could be employed to mitigate vibration radiation through structures. In the application of flooring, the CLD functions to restrict the physical movement between the rigid board layers, decreases the area of influence from the impact, reduces the energy radiation through the composite panel system to its support and subsequently reduces the energy transfer into the structure.

Understanding the sources of sound and vibration produced in fitness environments and finding effective solutions was a journey that CDM Stravitec began in the 1970s and this area of the acoustics industry has been most intensively researched as part of the development of our range of lightweight floating floors. Our research has also shown that elastomeric supports balance low-resonant frequency performance to prevent energy build-up at the driving frequencies and can achieve high levels of transmission loss which are comparable to concrete based solutions.

This presentation will present the findings of our recent research as well as some case studies.

11:15u Koffie/thee pauze

11:40u Anne de Jong – ASCEE, Parametrische arrays met ultrasound

Een parametrische akoestische array is een akoestische transducer, waarbij ultrasone “draaggolven” middels intermodulatiedistortie een geluidsgolf in het hoorbare spectrum wordt opgewekt. In deze presentatie wordt kort ingegaan op het principe, de wiskundige achtergrond en de mogelijkheden / beperkingen van deze technologie.

12:05u Kees de Blok – Bekaert Combustion Technology, Interactie tussen geluid en verbranding

Bij verbranding en warmteoverdracht binnen een compact systeem zoals industriële branders en gasturbines kunnen in de gasstroom periodieke variaties ontstaan die het vermogen en de uitstoot ongunstig beïnvloeden. In moderne pre-mix verwarmingsketels met een groot modulatie bereik leidt dit ook tot hinderlijke oscillaties met frequenties tussen 20Hz en 5kHz.

In de lezing wordt ingegaan op de onderliggende mechanismen zoals verbrandingsinstabiliteit, de vlam overdrachtsfuncties en de relatie met akoestiek.

12:25u Joost Vette – Centre of Expertise Biobased Economy / Fairm, Biobased akoestische materialen in de bouw

Mycelium composieten bestaan uit natuurlijke vezels, verbonden met mycelium door middel van een fermentatieproces. De wijde range aan eigenschappen die verkregen kunnen worden met dit volledig natuurlijk materiaal maken dit een interessante innovatie voor toepassing als biobased bouwmateriaal. In deze lezing zal worden ingegaan op de ontwikkeling van mycelium composieten voor akoestische toepassingen. Aan bod komen ontwikkelingen bij het Centre of Expertise Biobased Economy, en van startup Fairm, waar mycelium composieten worden ontwikkeld voor toepassing in binnenwanden en deuren.

12:50u Lunchpauze

13:30u Sjoerd van Ophem – KU Leuven, Fysica-gedreven virtuele sensoren voor vibroakoestische toepassingen

Fysica-gedreven virtuele sensoren combineren traditionele metingen (microfoons, accelerometers,….) met numerieke modellen in een toestandschatter om zo de voordelen van beide aanpakken te kunnen combineren. In deze lezing wordt uitgelegd hoe zo’n virtuele sensor geconstrueerd kan worden voor vibroakoestische systemen aan de hand van verscheidene voorbeelden.

13:55u Jesse van der Kolk – Blue Heart Engineering, Learning to fly: The interlinked physics of traveling wave thermoacoustics

Small, consistent steps done at the right time can lead to significant effects and do so more efficiently in general. What if it’s possible to apply this principle to multiple domains of physics and engineering? In this talk, the interlinked world of traveling wave thermoacoustics heating and refrigeration is discussed. It’s shown how small thermal fluctuations in acoustics can be amplified by combining electrodynamics, and mass spring motion dynamics.

The talk will show a thermoacoustic heat pump driven by an electrical mass spring actuator and an acoustic circuit. This system forces Stirling conditions on the acoustic wave in a regenerator sandwiched between heat exchangers such that heat can be pumped against a temperature gradient. A small intro will be given into using RLC and 1d thermoacoustic modeling, to simplify and connect the different physic domains. With this method general interdependent effects become more obvious and better engineering and overall optimization choices can be made in the mechanical, thermal, electrical, and acoustic domain.

14:20u Stijn Jonckheere – Siemens, High-order adaptive element-based techniques for time-harmonic acoustics

In many engineering applications, solutions of the Helmholtz equation which governs acoustics are required over a broad frequency range, i.e. the audible range from 20 Hz to 20 kHz. The nature of the solution and the requirements in terms of resolution vary drastically over this range. Instead of using a set of increasingly refined meshes, which is commonly used in computational acoustics but poses many practical issues, a more efficient computational framework is presented. This consists in relying on a single mesh resolved with an high-order adaptive finite element approach. When combined with efficient a-priori error indicators, this strategy allows to naturally adjust the resolution across the frequency range to reach a user defined target accuracy.

14:45u Pauze koffie/thee

15:05u Bram Cuyx / Sreenivasa Upadhyaya (Wim Buyens) – SoundTalks, Health monitoring of livestock animals with sound

In this presentation we will introduce how to monitor respiratory health in pig farms by using sound. We will focus on two technical challenges. First, we will discuss how to detect and localise cough events using an optimal mass transport based method. Second, we will proceed to discuss sound event classification methods and challenges when using neural networks.

15:30u Varvara Kouznetsova – TU/e, Metafoams: an innovative solution for low frequency noise reduction

This talk will present a new concept of acoustic metafoams. Metafoams combine the performance of conventional acoustic foams on the market, which are effective in the reduction of mid- and high frequency noise, and additionally act in the low frequency regime. For this, small particles are introduced in the foam pores. The resonance of these particles interacts with the low frequency acoustic waves causing their attenuation.  In contrast to other solutions combining these two effects, the proposed approach introduces particles which are smaller or in the  order of the size of the foam pores, which should potentially allow for efficient large volume manufacturing of metafoams.

15:55u Michael Dittrich – TNO, Innovatieve meetmethodes voor spoorweggeluid – EU-project TRANSIT

In het EU-project TRANSIT worden meetmethoden ontwikkeld voor bronscheiding van geluid van treinpassages. Dergelijke methodes worden relevanter wegens de toename van hogesnelheidstreinverkeer en uiteenlopend ontwerp van railvoertuigen. De voorziene toepassingen zijn voor typekeuring, bronsterktebepaling en stil ontwerp.

De meetmethodes omvatten scheiding van tractie- en aerodynamisch geluid van rolgeluid, en scheiding van de rolgeluidbijdragen van trein en spoor. Ook worden methodes ontwikkeld voor de scheiding van wiel- en railruwheid en transpositie tussen meetlocaties.

16:20u Afsluiten en borrel om na te praten