Numer. Math. Theor. Meth. Appl. Vol. 12, No. 3, pp. 942-968 doi: 10.4208/nmtma.OA-2018-0095 August 2019 Assessment of Noise Attenuation by Thin Reflecting Barriers using Dispersion Relation Preserving Scheme Jitenjaya Pradhan 1 and Yogesh G. Bhumkar 1, ∗ 1 Scientific Computing Laboratory, School of Mechanical Sciences, IIT Bhubaneswar, Khordha 752050, Odisha, India. Received 26 August 2018; Accepted (in revised version) 17 September 2018 Abstract. Here, reduction in acoustic noise due to insertion of thin reflecting barriers has been estimated. Accurate simulations have been performed using numerical meth- ods with a near spectral resolving ability, neutral stability and the physical dispersion relation preserving ( DRP ) nature. Use of high accuracy schemes makes present ap- proach useful in analysis of an acoustic field consisting of acoustic waves with a large frequency band. Present investigation has been carried out for eight geometrically dif- ferent acoustic barriers and for nine discrete frequencies in the one-third octave band starting from 250 Hz to 1600 Hz . Use of high accuracy DRP scheme allows one to compute the complex acoustic field by accurately capturing reflection, diffraction and interference of acoustic waves. Comparison of numerically obtained sound pressure level (SPL) distributions at different heights with the available experimental results in the literature shows a good match for the case of I -shaped barrier. In order to quantify effects of acoustic source frequencies over a large band, we have extended our analysis for a frequency range of 100 Hz to 5000 Hz for the case of I -shaped barrier. Present analysis shows that the thick T -shaped barrier and grooved barrier work efficiently in the low and mid frequency range while in the higher frequency range all the barriers are equally effective due to minimal diffraction. AMS subject classifications: 65N06, 65N35 , 76D05, 35L05 Key words: DRP scheme, compact difference scheme, computational acoustics, barrier, insertion loss. 1. Introduction Identification and quantification of acoustic noise sources as well as methods to reduce acoustic noise levels in the desired region have been important research topics for many decades. Acoustic noise related problems are regularly faced by the people living inside cities as the community is constantly exposed to the road traffic noise as well as other sources of noise. Aural comfort has become an important design parameter while designing modern vehicles, residential buildings, transport stations, offices and public places. ∗ Corresponding author. Email addresses: bhumkar@iitbbs.ac.in (Y. G. Bhumkar), jp10@iitbbs.ac.in (J. Pradhan) http://www.global-sci.org/nmtma 942 c  Global-Science Press