Acoustics of a Helmholtz Resonator Aligned Parallel with Flow: A Computational Study VS. Experiments

Abstract

I. INTRODUCTIONA variety of analytical, computational, and experimental studies is available in literature to investigate the acoustic behaviour of HRs since they are extensively used in many applications, such as the breathing system of internal combustion engines and compressors [1]- [3]. One of the critical factors influencing their acoustic performance is the presence of mean flow. A recent study [4], for example, examines this effect for a HR with its neck oriented perpendicular to flow. The emphasis of the present study remains the flow effect as applied, however, to a different orientation of a ("charged") HR, where the silencer of [4] is now aligned parallel to the incident flow as illustrated in Fig. 1. Multidimensional time domain computations are performed to predict the acoustic behaviour of this HR. These predictions are then compared with experimental results on a flow-impedance tube setup, which is described in [4]. In the setup, pressure transducers are located at two upstream (referred to as locations 1 and 2 hereafter) and two downstream locations (3 and 4), 4 cm apart from each other, for capturing the pressure fluctuations which are then used to calculate the acoustic attenuation in terms of transmission loss.Following this Introduction, Section II briefly describes the solution method. Computational results and their comparison with experimental data are presented in Section III, followed by concluding remarks in Section IV. Manuscript