Research Article
Development of Sonic Crystal Noise Barriers with Simulations and Experimental Validations in Acoustic Chamber
Issue:
Volume 14, Issue 4, August 2026
Pages:
50-67
Received:
23 August 2026
Accepted:
4 September 2026
Published:
20 September 2026
Abstract: Sonic Crystal Noise Barriers (SCNBs) exploit Bragg scattering in periodic scatterer arrays to attenuate road traffic noise without the visual and aerodynamic penalties of solid walls. Despite growing computational interest, a persistent gap remains between idealised simulation predictions and measured laboratory performance, largely because viscothermal dissipation and diffraction losses are routinely omitted from numerical models. This study presents a systematic, two-phase hybrid methodology to address this gap: first, forty-four Finite Element Method (FEM) configurations were evaluated in COMSOL Multiphysics by varying filling fraction (ff = 0.1-0.5), cylinder diameter (d = 0.02-0.1 m), and lattice constant (α) to identify parameter-dependent trends in A-weighted transmission loss (TLa). Second, fifteen representative prototype configurations were fabricated from acrylic and tested inside an anechoic/reverberation acoustic chamber to validate the computational model across the full 50-4000 Hz range. Simulations predicted a peak TLa of 45.8 dB for ff = 0.3, d = 0.07 m, α = 0.113 m in a 2 × 4 array, while the highest experimentally measured TLa was 10.1 dB for ff = 0.5, d = 0.07 m, α = 0.088 m in a 2 × 6 array. Although quantitative agreement was not achieved, the rank ordering of configurations by TLa was consistent between simulation and experiment across all five filling fractions, confirming the predictive reliability of the computational model for comparative design screening. The observed over-prediction is attributed primarily to viscothermal energy losses, diffraction effects, and material absorption not captured in the idealised 2D lossless model, which reveals that cylinder diameter and lattice constant are the primary drivers of simulated TLa, whereas fill fraction dominates the experimental TLa response, with a 2-row depth identified as the optimal configuration depth for mid-range diameters. These findings provide a validated, data-driven design framework for cost-effective SCNB development and clarify the modelling corrections required to improve quantitative fidelity.
Abstract: Sonic Crystal Noise Barriers (SCNBs) exploit Bragg scattering in periodic scatterer arrays to attenuate road traffic noise without the visual and aerodynamic penalties of solid walls. Despite growing computational interest, a persistent gap remains between idealised simulation predictions and measured laboratory performance, largely because viscoth...
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Research Article
Interpretation of Aeromagnetic Data to Assess Structures and Solid Mineral Potentials at Kataeregi and Its Environ, Niger State, Nigeria
Issue:
Volume 14, Issue 4, August 2026
Pages:
68-82
Received:
25 May 2026
Accepted:
5 June 2026
Published:
15 October 2026
DOI:
10.11648/j.ajpa.20261404.12
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Abstract: The objective of the study are to delineate structurally controlled mineralisation zone in the study area and map out subsurface structures below the ground surface that play host to minerals (fractured zones, fault lines and lithologic contact). The mineralisation potential of Kataeregi (Latitudes 09º21ꞌN and 09º25ꞌN and Longitudes 006º17ꞌE and 006º22ꞌE) and its environs have been investigated using aeromagnetic data. Aeromagnetic data acquired from Nigeria Geological Survey Agency was used to analyse and interpret the magnetic signatures using different filters. The 3-DEuler deconvolution map locate and estimate the depth to various anomalous bodies with depth to source body between 30 m and 428.5 m. The results revealed lineaments trending majorly in NE-SW directions. The FVD anomaly map established the oval and linear shapes anomalies with values between -5.78 to 0.34 nT/m, the ASA amplitude map reveals wide range of values between 0.03 to 0.76 nT/m, the TDR map showed variations in anomalies with values ranging from -0.06 to 1.42 rad/m. The unveiled subsurface structural features are responsible for hosting mineralised deposits. The highlighted lineament represents the short wavelength magnetic anomalies which cut across the migmatite gneiss and amphibolites schist of the study area. The depth was estimated using a window size of 2550 m width and a maximum depth tolerance of 14%. Generally, these suggested that these lineaments reflect real continuous fault/fractures in depth.
Abstract: The objective of the study are to delineate structurally controlled mineralisation zone in the study area and map out subsurface structures below the ground surface that play host to minerals (fractured zones, fault lines and lithologic contact). The mineralisation potential of Kataeregi (Latitudes 09º21ꞌN and 09º25ꞌN and Longitudes 006º17ꞌE and 00...
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Chin-to Wat
