Experimental Validation of a CFD Model to Predict Performance of a Motorbike Silencer

In this paper we perform a validation study of a finite-volume model developed to predict the performance of a motorbike silencer. The computational setting has been defined to closely fit the tests conditions, obtained on a test-bench where the mass flow rate through the device is measured for several inlet-outlet pressure gradients. The comparison with the experimental measurements has shown that numerical data reproduce the effective trends of mass flow rate, although underestimation of 20% on average is present. Moreover, this discrepancy has shown to slightly increase with the raising of the overall pressure gradient. Neither the adoption of different mesh sizes nor computational settings for the turbulence modelling has allowed to obtain a reduction in the uncertainty of results. Therefore, the finite-volume model seems to be promising in the analysis of different design proposals while less effective in the prediction of the absolute performance of a motorbike silencer.