Noise and Vibration Control Services

Ødegaard & Danneskiold-Samsøe assists the marine and offshore industry with noise and vibration control. Key services are:

• noise and vibration analysis and prediction
• measurement services, including troubleshooting

The company has accumulated extensive experience with a wide range of ship types, from yachts to cruise ships and VLCCs. Clients include a large number of shipowners, shipyards, naval architects and component suppliers worldwide.

3D Finite Element model used for vibration analysis of container ship. Finite Element based vibration analysis is essential to avoid vibration problems on newbuildings.

Prepare for comfort
Detailed specifications may prevent many problems during later stages of a shipbuilding project. Ødegaard & Danneskiold-Samsøe assists shipowners in preparing specifications and advises the shipbuilding industry on required precautions in order to comply with contract specifications.

Fast ferry environmental noise measurement carried out by the Ødegaard & Danneskiold-Samsøe in the city of Copenhagen.

Noise Prediction
By using our computer model, SHIPNOISE, the noise level can be predicted for all relevant sources. Based on the prediction, it is possible to select the most appropriate type of noise reducing measures, e.g. sound insulation, floating floors or viscoelastic vibration damping layers. Our prediction services can be used already at the contract negotiation stage to provide preliminary, achievable noise levels. And the prediction can also be used at later stages for the optimum design of noise reduction measures.

Vibration Analysis
Vibration analysis and prediction of vibration levels are carried out by means of the Finite Element technique. Local structures, greater substructures and global designs are analysed. Finite Element based vibration analysis is essential to avoid vibration problems on newbuildings. However, the analysis tools are also useful for troubleshooting
purposes.

Measurements and Troubleshooting
Measurements are necessary to verify noise and vibration levels during sea trials and to solve noise and vibration problems of ships in service. The troubleshooting assignments are often performed with short notice, and rely on extensive measurement equipment and experienced measurement engineers with in-depth knowledge
of noise and vibration problems.

Other measurement services include excitation tests carried out during construction to check the vibration characteristics of hull structures, employing modal analysis techniques with excitation from mechanical exciters, air-guns or impact hammers. Sub-suppliers are assisted with acoustic testing of components, for example floating floors, ceilings and lining bulkheads - advanced in-house laboratory facilities are available for this purpose.

Calculated cavitation extent for propeller operating in a nonuniform wake field. Our Boundary Element based PROPULSE computer model is used for prediction of propeller noise and vibration characteristics.

Propellers and Machinery
Ødegaard & Danneskiold-Samsøe participates in the proper choice of propeller design and aft body lines to achieve the best possible noise and vibration performance of the propeller. Our Boundary Element based PROPULSE computer model is used for prediction of propeller noise and vibration characteristics.

In order to avoid excessive movement and resonance, Ødegaard & Danneskiold-Samsøe's computer program, RESMOUNT, can be used to calculate the natural frequencies and dynamic response for resiliently mounted machinery.

Environmental Noise
Environmental noise problems arising in harbours and coastal areas are increasingly common. Ødegaard & Danneskiold-Samsøe assists with design reviews, measurements and troubleshooting, often by design of effective diesel engine silencers using the computer program, EXHAUST, or acoustic Finite Element modelling.

Pipe routing after conversion of the "Seabourn Pride" exhaust system. Ødegaard & Danneskiold-Samsøe assists with design reviews, measurements and troubleshooting for noise problems, often by design of effective diesel engine silencers using the computer program, EXHAUST.

Acoustic Quality and Privacy
For passenger ships, low background noise in the accommodation are obtained today. This means that acoustic privacy becomes an important factor for the comfort of passengers. Also the acoustic quality of large public rooms, such as dining rooms and show lounges, depends on acoustic properties which can be optimized by Ødegaard & Danneskiold-Samsøe.

Underwater Noise
Underwater noise control and signature management are important for naval and seismic ships. Ødegaard & Danneskiold-Samsøe assists with design reviews, measurements and troubleshooting.

M/S "Seabourn Pride". Silencing of the exhaust system was required to get permission for regular calling in Stockholm.

The Company
Ødegaard & Danneskiold-Samsøe was founded in 1980. Today the number of employees is about 70, more than 80% with university degrees.