Modelling and measurement of crew accommodation noise exposure to a towed sonar source

The Royal Netherlands Navy operates a low-frequency active sonar consisting of a combination of a towed sonar source and receiver array in order to detect and classify objects underwater. The operation involves transmitting high power underwater sound towards an object and detecting the echo reflected by the object. Operating a towed source at...

Underwater noise measurements in the North Sea in and near the Princess Amalia Wind Farm in operation

Underwater sound radiation from subsea factories

In the oil & gas industry there is a trend towards more subsea activities such as the processing of the Oil and Gas in so-called 'subsea factories'. Regulations aimed at managing the impact of underwater sound on marine life are being put in place by different nations. Many offshore operations require an assessment of the potential impact of...

Possibilities to improve the modelling in EN 12354 for lightweight elements

The standard EN 12354 gives prediction models for the airborne and impact sound transmission between rooms in buildings. For buildings with mainly heavy, monolithic structures the standard has proven to be quite useful. However, in case of lightweight building elements the standard only gives global indications about the appropriate modelling....

Sound transmission through junctions between lightweight floors and walls: Comparison of FEM-, SEA- and measurement results

Reduction of the performance of a noise screen due to screen-induced wind-speed gradients: Numerical computations and wind-tunnel experiments

Downwind sound propagation over a noise screen is investigated by numerical computations and scale model experiments in a wind tunnel. For the computations, the parabolic equation method is used, with a range-dependent sound-speed profile based on wind-speed profiles measured in the wind tunnel and wind-speed profiles computed with computational...

Local temperature measurement and Kapitza boundary resistance

A calculation of the Kapitza boundary resistance between harmonic solids has been noted previously (Little, Can. J. Phys. 37 (1959) 334; Leung and Young, Phys. Rev. B 36 (1987) 4973) to lead to apparently paradoxical results in the limit of identical solids: instead of vanishing, the resistance tends to a finite limit. We resolve this paradox by...

A calculation model for the noise from steel railway bridges

The sound level of a train crossing a steel railway bridge is usually about 10 dB higher than on plain track. In the Netherlands there are many such bridges which, for practical reasons, cannot be replaced by more intrinsically quiet concrete bridges. A computational model is described for the estimation of noise levels due to a train crossing a...