Noise control of outdoor unit of split type air-conditioner using periodic scatterers made with array of Helmholtz resonators

Dandsena, J.; Mohapatra, Karisma; Satapathy, Alok; Jena, D.P.

doi:10.1016/j.apacoust.2021.108054

Cited by 11 publications

(5 citation statements)

References 23 publications

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“…As can be seen, over the entire frequency range of 100-5000 Hz, the trends and magnitudes of the experiment and simulation results are corresponding and particularly well compared in the frequency range of 630-1000 Hz. This firstly suggests that the simulation model is feasible for the current numerical experiments and the reported simulation results are supposed to be convinced [19,32,33,[35][36][37]. It is noted that the highest value of ∆LA eq is occurred at 1000 Hz both in experiment and simulation, followed by 800 Hz.…”

Section: Experimental Results and Comparisonmentioning

confidence: 68%

Parametric Optimization of Local Resonant Sonic Crystals Window on Noise Attenuation by Using Taguchi Method and ANOVA Analysis

et al. 2022

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Local resonant sonic crystals (LRSCs) window as a novel design has recently been proposed to achieve a good balance between noise mitigation, natural ventilation and natural lighting. In an effort to explore the feasibilities of such designs in civil residential buildings, an optimization methodology was proposed to develop a more compact LRSCs window with high noise attenuation performance in the present study. Specifically, the Taguchi method was adopted for the design of experiments on the parameters of interest and their corresponding levels, and SN ratio analysis was then applied for the parametric evaluations on the noise attenuation on specified frequencies in traffic noise (concentrated sound energy frequency range: 630–1000 Hz). Three optimal sets of design parameters on the interested frequencies, namely, 630 Hz, 800 Hz and 1000 Hz were obtained. ANOVA analysis was conducted to quantificationally identify the design parameters with statistical significance and remarkable contribution to the desired performance. Results indicate that the slit size has the most significant influence on the overall noise attenuation performance, followed by cavity width. An optimal set of design parameters to achieve the overall best noise reduction performance in the frequency range of 630–1000 Hz was finally determined by combining the SN ratio and ANOVA analysis. A prototype of the final optimized LRSCs window was then fabricated and tested in a semi-anechoic chamber. Good agreement was found between the experiment and numerical simulation. In comparison to the benchmark case, the final optimized design can achieve a further noise reduction by 2.84 dBA, 3.48 dBA and 5.56 dBA for the frequencies of 630 Hz, 800 Hz and 1000 Hz, respectively. The overall noise reduction for the interested frequency range can be promoted by 3.28 dBA. The results indicate that the proposed optimization methodology is practical and efficient in designing a high-performance LRSCs window or improving similar applications.

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Section: Experimental Results and Comparisonmentioning

confidence: 68%

Parametric Optimization of Local Resonant Sonic Crystals Window on Noise Attenuation by Using Taguchi Method and ANOVA Analysis

et al. 2022

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“…x { } denotes the primary unknown variables on the surface of the boundary element model and F a 􏼈 􏼉 is the excitation force function vector. Obtaining the primary variables through equation ( 6), the sound pressure at any point can then be calculated by using equation (4).…”

Section: Open Areamentioning

confidence: 99%

“…In air conditioning noise reduction research, Choy et al [3] focused on noise reduction in air conditioning duct systems and proposed a reinforced composite plate, highlighting the efectiveness of methods such as carbon fber and aluminum foil reinforcement in enhancing the bending stifness and transmission loss at low frequencies. Dandsena et al [4] addressed the challenge of mitigating low-frequency noise produced by split-type air conditioner outdoor units using a tunable periodic array of solid scatters, named sonic crystal with hollow compartments and perforations, achieving a signifcant overall noise reduction of 7 dB. Mao et al [5] investigated the noise characteristics of two-stage centrifugal compressors using a multilayer microperforated panel absorber designed to reduce tonal noise, particularly at the outlet pipe, and experimentally confrmed the noise reduction.…”

Section: Introductionmentioning

confidence: 99%

An Investigation of the Acoustic Enclosure of an Air Conditioning Compressor Using Response Surface Analysis and Topological Rigidity Optimization

Cao,

Yang,

et al. 2024

Shock and Vibration

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A novel split-type air conditioning system is introduced to balance usability and portability. Unlike conventional split-type systems, where the compressor is typically placed outside, this system situates the compressor within the indoor unit, which may expose users to compressor noise. There are prominent peaks in the compressor noise spectrum, particularly at the compressor operating frequency and its harmonics, notably the second and third harmonics. The research presents a multilayered acoustic enclosure specifically designed for air conditioning compressors to address this issue without modifying the compressor or indoor unit casing. In order to get better sound insulation performance, a response surface methodology (RSM) is applied to optimize the thickness ratio, open area ratio, and open area height of the acoustic enclosure with predefined thickness. In addition, topological optimization is employed to strengthen weak areas of the acoustic enclosure. Then, experimental trials using the proposed acoustic enclosure are conducted in a semianechoic chamber. Results demonstrate significant reductions in noise levels, including 7.99 dB(A), 5.69 dB(A), and 5.19 dB(A) reductions in the fundamental frequency, second harmonic, and third harmonic noise of the compressor’s operating frequency, respectively.

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“…Acoustic metamaterials are periodic structures that can control or manipulate acoustic energy as vibrations or equivalent waves. Acoustic metamaterials have diverse applications that include devices like compressors of split-type air conditioning systems 1 to the structures like buildings. 2 Similar diversity is observed in their design ranging from simple sonic crystals to advance hybrid acoustic metamaterials.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation on 2D metamaterial under normal incidence

2023

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Investigations in solid-state physics show that metamaterials, a kind of periodic material, can produce a band of frequency gap. When a sonic wave’s frequency falls into this frequency gap, it cannot propagate. Enlightened by the concept of frequency gap, researchers recently investigated various metamaterials. The search for bandgap(s) is critical in such innovations. The present letter presents the analysis of the band of frequency gap(s) for two and three-component systems as 2D period materials using the Finite Element Method. The investigation highlights the influence of geometrical parameters on the bandgap. Modelled metamaterial uses a core of aluminium, a coating of natural rubber and a matrix of air. For the lattice constant’s specified value, with the core’s increasing size, the bandgap shows to increase. The general effect of the coating leads to the flattening of the dispersion curve. For the square lattice and circular core, the bandgap appears around a net core size (with and without coating) of around 30%–32% of the lattice constant. Multiple frequency bandgaps appear of substantial sizes at the core’s threshold size, that is, when the core’s net radius is equal to half of the lattice constant. The softer material coating is found as a potential alternative to tune and control acoustic metamaterials. With a three-component system, bandgaps appear comparatively at significantly lower frequencies. Lower edge frequencies for such bandgaps are found to be independent of the core and coating size.

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Noise control of outdoor unit of split type air-conditioner using periodic scatterers made with array of Helmholtz resonators

Cited by 11 publications

References 23 publications

Parametric Optimization of Local Resonant Sonic Crystals Window on Noise Attenuation by Using Taguchi Method and ANOVA Analysis

Parametric Optimization of Local Resonant Sonic Crystals Window on Noise Attenuation by Using Taguchi Method and ANOVA Analysis

An Investigation of the Acoustic Enclosure of an Air Conditioning Compressor Using Response Surface Analysis and Topological Rigidity Optimization

Numerical investigation on 2D metamaterial under normal incidence

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