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...

The effect of floating deck structures on underwater radiated noise

A concept for underwater machinery noise mitigation of future civil and military ships is the application of a common deck structure, supporting multiple machines, which is installed on resilient mounts on the ship's foundation structure. TNO is addressing the availability and testing of tools to be able to set realistic targets for the radiated...

LF airport ground noise mitigation using scattering sections

Ground noise due to aircraft starting from the Amsterdam airport runway ‘Polderbaan’ has been an issue since its construction in 2003. Take off operation in headwind conditions causes downwind sound propagation towards a residential area situated 2,5 km Southwest of the runway. Due to the large propagation distance, the wind- and ground...

VENOLIVA - Vehicle Noise Limit Values - comparison of two noise emission test methods. Final Report

The permissible sound level of road vehicles is part of the EU vehicle type approval legislation, as laid down in EU Directive 70/157/EEC [1] and in the UN-ECE Regulation No 51 [2] , which specifies the test method for the noise emission test. Since 1984 several studies [48] [49] [50] [51] [52] showed that the test method, that had been in force...

A barrier for low frequency noise from starting aircraft: Comparison between numerical and scale model results

Amsterdam Airport Schiphol has organized a competition to design a noise mitigating measure along the 'Polderbaan' runway. Its main goal is to reduce the low frequency (LF) ground noise from starting aircraft. The winning concept is a flexible parabolic shaped noise barrier positioned relatively close to the runway. There is a large distance...