Product —  04th Nov 2019

Inspirational approaches for acoustical solutions in ship and offshore structures at ICA 2019

In September 2019, Geislinger was invited to open the session for acoustics of ships and offshore structures at the International Congress on Acoustics (ICA) in Aachen, Germany.

The ICA is the world’s largest and most important conference for all fields of acoustics. It is organized every three years and this time included more than 1500 abstracts presented to over 1700 participants. The main purpose of the ICA is to promote international development and collaboration in all fields of acoustics including research, development, education, and standardization.

Picture 1: ICA 2019 took place at the Eurogress Aachen. Picture by Sabine Schmidt, “das design plus“, Aachen, Copyright DEGA e.V.
Picture 1: ICA 2019 took place at the Eurogress Aachen. Picture by Sabine Schmidt, “das design plus“, Aachen, Copyright DEGA e.V.

The session for acoustics of ships and offshore structures was opened by Dr. Lothar Kurtze, the acoustic expert at Geislinger, with a presentation about an “Innovative solution to reduce the transfer of structure-borne noise in couplings”. Geislinger presented that modern couplings for ships, and especially for mega yachts, have to fulfill various tasks. Located between the gearbox and the propeller shaft, they minimize the transfer of structure-borne noise while transmitting high torque levels. In addition, they must resist high misalignments due to very softly mounted frames of the ship’s engine and gearbox.

To fulfill these partly contradictory demands, innovative approaches are essential. Therefore, Geislinger has developed the Geislinger Silenco® Coupling which is made from a combination of glass and carbon fibers, elastomer layers, and steel.

After the design phase, couplings like the Geislinger Silenco® are tested on Geislinger’s unique acoustic test bed. Figure 2 shows the typical noise reduction of a Geislinger Silenco® coupling for a medium speed engine. Here, the structure borne noise was measured directly in front of (black) and behind the coupling (red) on the test rig using real engine noise as an input-signal.

Picture 2: Noise reduction of a Geislinger Silenco® Coupling for a medium speed engine. Picture 3: The Geislinger Silenco® Coupling is a lightweight coupling solution with high acoustic sound attenuation.
Picture 2: Noise reduction of a Geislinger Silenco® Coupling for a medium speed engine. Picture 3: The Geislinger Silenco® Coupling is a lightweight coupling solution with high acoustic sound attenuation.

Validation on the Geislinger Test bed is usually followed by tests with real propulsion systems like Advanced Electric Drives in the 4 MW-range. The presentation showed how the new couplings have been successfully validated during the vessel’s sea trials.

It has been of particular interest to the audience that Geislinger’s couplings can significantly reduce the noise radiation into a ship’s structure as well as into the ocean. Measurements have proven that they are able to fulfill the requirements for an ultra-silent propulsion – this is also a benefit to the environment.

The complex field of the acoustic optimization will also be presented during the Torsional Vibration Symposium, May 13-15, 2020 in Salzburg. The full paper is available for download here.

Source: Proceedings of the 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019, Aachen