Denis Blanchet has developed a wide expertise in very different fields.  He has learned over the years the benefit of teaming up with other experts when necessary to ensure a positive and fruitful outcome of any projects.  His many international contacts developed over the years has made him a strong ally to have when dealing with difficult, unchartered VA applications.  Our offering is therefore diverse and potential projects that differ from our existing experience are more than welcome.

Windnoise

Turbulent flow generated around a high speed train is of great importance for train acoustics design team because of the potential noise that can migrate to the interior of the cabin. Understanding the physical phenomena involved in the coupling of the turbulences with the train structural panels allows for the creation of an accurate predictive model of windnoise. This simulation model can be quite useful in the design of quieter vehicle by impacting the source of turbulences by modifying the shape of various component of the train such as deflectors, front end, general aerodynamics, pantograph shape and its cavity, addition of enclosure and so on… Quieter designs can also be achieved by modifying the path energy takes to reach the interior of the vehicle. In this case, changing the properties of the glasses (acoustics glasses [5,10]) or other structural panels or their mounting strategy. See technical papers for more details [18,29,30,34,35,39,42,44,46,47,50,51,52] and [53] for a review of the latest results obtained with the “German Working Group on Windnoise”. The fundamental principles described in the papers can directly be applied to high speed train applications.

Driver’s cabin modelling

As the driver’s cabin of a train is a work environment, the sound pressure levels must meet regulatory levels for the train to be certified for travel. Noise in the conductor’s cabin come from various sources such as electric motors, gearboxes, dampers, wheel/rail interaction and from windnoise. With today’s simulation tools, it is possible to build simulation models that can accurately represent the structure of the train and examine where are the weak paths through which vibration and acoustic energy migrates inside the train cabin. dBVibroAcoustics can help you understand the key aspects of predictive model building to obtain a simulation model ready for design change analysis [20,21].

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Speech intelligibility

Safety regulations force train manufacturers to comply with speech intelligibility index. The objective is to ensure that the passengers hear clearly the public announcements delivered through the speaker system of the train. It has been shown that various simulation methods can be used to predict the speech intelligibility of a train cabin. See [49] for an example of prediction of STI using a combination of BEM and SEA. The same paper compares these results with a combination of Raytracing and SEA approach which provides the same level of accuracy at a fraction of the computing time. dBVibroAcoustics can help you understand the key aspects of predicting speech intelligibility before any prototypes are available for testing.