ISVR have developed a new software package, Train Noise Expert, to combine the functionality of the Acoutrain tool with new predictions based on the TWINS rolling noise calculation method.
The Acoutrain tool was developed in the Acoutrain EU project. It was originally intended to support virtual certification of new trains where predictions of standstill and pass-by noise are required based on a model of the sources on a train.
External noise predictions
Key features of Train Noise Expert:
- Standstill and pass-by noise predictions at ISO standard positions or user-defined positions
- Noise sources defined as points, areas and boxes with user-defined sound power / directivity as well as speed dependency
- Predictions of noise levels in 1/3 octave bands and overall A-weighted level
- Sources can be grouped together to allow source ranking and evaluation of dominant noise sources
- Vehicles can be copied and edited within a virtual train
- Inclusion of Doppler effect for moving sources
- Powerful graphical interface including 2D and 3D view of the sources and receivers relative to the train.
Rolling noise calculations
The rolling noise sources can be manually input into external noise predictions as sound power spectra, but a TWINS-based calculation is also available as an optional add-on. This allows rolling noise sound powers and pressures to be calculated for arbitrary wheel and track designs.
Key features of Train Noise Expert rolling noise calculation:
- Wheel and rail roughness spectra can be input separately
- Contact filter based on Remington or DPRS models
- Track decay rates can be based on calculated or measured values
- Wheel modal parameters derived from finite element model
- Engineering models of sound radiation including results from the latest research
Output
Sound pressure levels are calculated for any arbitrary receiver position, and/or at the ISO 3095 standard positions. For pass-by conditions, a time profile of the sound pressure level is also calculated. Results are calculated in 1/3 octave bands and can be shown with or without A-weighting. Overall results are also calculated.
Results may be grouped arbitrarily and are viewable as interactive plots in the software. Data can also be exported as data tables.
Note: the software is not intended for detailed environmental noise prediction; the propagation calculation current includes only a simple flat ground model.
Train Noise Expert is written in Java and calls various compiled executables for the calculation routines. A 64bit Windows computer is required for installation.
For more details, and to obtain a demo copy, please contact us.