Sound absorption and transmission loss of 3D printed wood fibre reinforced poly lactic acid with functionally graded perforations R. Sailesh, Mrityunjay Doddamani, Lenin Babu Mailan Chinnapandi, L. Yuvaraj, Jeyaraj Pitchaimani Wood Material Science and Engineering, 2024 The effect of wood fibre reinforcement on acoustic properties of 3D printed poly lactic acid samples having varying cross-section perforation and functionally graded spherical perforations is presented. Acoustic characteristics like sound absorption as well as transmission loss are obtained using an impedance tube setup. Results revealed the benefits due to the addition of wood fibres in PLA improved samples’ sound transmission loss characteristics significantly. The sound absorption curve peaks shifted to low-frequency regions which are favourable to living beings. The material can be used in acoustic insulation for structural and transportation applications, especially where eco-friendliness and aesthetics are of major concern.
Experimental and numerical investigation on sound absorption characteristics of 3D printed coupled-cavity integrated passive element systems Loganathan Yuvaraj, Subramanian Jeyanthi, Lenin Babu Mailan Chinnapandi, Jeyaraj Pitchaimani Journal of Low Frequency Noise Vibration and Active Control, 2022 In aerospace applications, most of the components are made of composite materials due to the high strength-to-weight ratio. However, those composite structures are poor in sound absorption; for instance, payload fairing used in the launch vehicle system experiences broadband noise. Tuned Helmholtz resonator (HR) is being used to control few dominant low frequencies, and other frequency is left untreated. In this study, the acoustic mode of the rectangular cavity has been suppressed by a novel design of integrated passive elements (IPEs), which comprises a Helmholtz resonator, micro-perforated panel, and polyurethane foam. The proposed design reduces the noise level in Low-Mid-High frequencies, which is more efficient than passive elements used to control a single target frequency. The integrated passive components fabricated using the 3D printing technique are tested experimentally in an impedance tube to quantify the sound absorption coefficient, and the results are compared with the theoretical result. Further, the study presents a simplified approach for numerical simulation of fabricated samples coupled to a rectangular cavity system, which is validated experimentally. The overall sound pressure level (OSPL) results of the proposed design achieve 4–6 dB noise level reduction in [Formula: see text] octave frequency band.
Development of Active CO2Emission Control for Diesel Engine Exhaust Using Amine-Based Adsorption and Absorption Technique Solomon Jenoris Muthiya, L. Natrayan, L. Yuvaraj, Mohankumar Subramaniam, Joshuva Arockia Dhanraj, Wubishet Degife Mammo Adsorption Science and Technology, 2022 Diesel-powered transportation is considered an efficient method of transportation; this sees the increase in the demand for the diesel engine. But diesel engines are considered to be one of the largest contributors to environmental pollution. The automobile sector accounts for the second-largest source for increasing CO2 emission globally. In this experiment, a suitable postcombustion treatment to control CO2 emission from IC engine exhaust is developed and tested. This work focuses to control CO2 emission by using the chemical adsorbent technique in diesel engine exhaust. An amine-based liquid is used to adsorb the CO2 molecules first and absorb over the amines from the diesel engine exhaust. Three types of amino solutions (L-alanine, L-aspartic acid, and L-arginine) were prepared for 0.3 mole concentrations, and the CO2 absorption investigation is performed in each solution by passing the diesel exhaust. A suitable CO2 adsorption trap is developed and tested for CO2 absorption. The experiments were performed in a single-cylinder diesel engine under variable load conditions. The eddy current dynamometer is used to apply appropriate loads on the engine based on the settings. The AVL DIGAS analyzer was used to measure the CO2, HC, and CO emissions. An uncertainty analysis is carried out on the experimental results to minimize the errors in the results. The effective CO2 reduction was achieved up to 85%, and simultaneous reduction of HC and CO was also observed.
Experimental Analysis and Optimization of Tribological Properties of Self-Lubricating Aluminum Hybrid Nanocomposites Using the Taguchi Approach Vinoth Kumar Selvaraj, S. Jeyanthi, Raja Thiyagarajan, M. Senthil Kumar, L. Yuvaraj, P. Ravindran, D. M. Niveditha, Yigezu Bantirga Gebremichael Advances in Materials Science and Engineering, 2022 In recent times, tribological properties are gaining and grabbing great attention in metal matrix composites. They can provide significant benefits such as a lower coefficient of friction, wear resistance, high strength, and stiffness. Considering all these parameters, this research article mainly focuses on developing an aluminum hybrid nanocomposite material fabricated by powder metallurgy. Then, the results were examined using a pin-on-disk apparatus. Further optimization techniques such as the Taguchi approach under Design of Experiments have been adopted to obtain a minimal outcome of various assumed parameters such as A. percentage weight fraction of graphite content (Gr), B. the sliding distance, C. the sliding speed, and D. the stress applied. In addition, we have chosen parameters such as friction and wear loss for optimizing the outcome, including the main effect plots for the S-N ratio and the Analysis of Variance (ANOVA) approach. Based on the experimental results, we have noticed that friction and wear loss coefficient increase with increased applied load and sliding distance. Also, it was noted that there was a slight decrease in the coefficient of friction and wear loss when an increment was made in the graphite content, respectively. It was perceived that the sample containing 10% of graphite (Gr) could create a self-lubricating effect that significantly reduced wear loss and the coefficient of friction. Finally, by considering all these achieved results, aluminum nanocomposites can be employed in automobile, defense, and aerospace applications as they can reduce the weight of the components with improved wear behavior and more thermal stability.
Acoustic behaviour of 3D printed bio-degradable micro-perforated panels with varying perforation cross-sections R. Sailesh, L. Yuvaraj, Jeyaraj Pitchaimani, Mrityunjay Doddamani, Lenin Babu Mailan Chinnapandi Applied Acoustics, 2021 Influence of perforations having arbitrarily varying cross-sections on the acoustic behaviour of 3D printed bio-degradable panels made of Poly Lactic Acid (PLA) is presented. Circular perforations having six different types of cross-sectional variations namely convergent-divergent (CD), divergent-convergent (DC), convergent (C), divergent (D) with two different perforation diameters are realized using Fused Filament Fabrication (FFF) based 3D printing. Sound absorption and transmission loss characteristics of these perforated panels are estimated through impedance tube technique. Results revealed that sound absorption of perforated panels with varying cross-section is better than uniform cross-sectional perforation for the given frequency range. Among, the different cross-sectional variations explored, comparable and lower transmission losses are exhibited by DC and D perforation pattern with respect to constant diameter 1 mm panel. The sound transmission results of all other five specimens were significantly higher than constant diameter 8 mm panel and observed to be increasing with frequency. Geometrical perforation variations are noted to be a very crucial factor in designing soundproof panels as presented in this work. The experimental results are compared with the numerical results and found to be in good agreement. Such numerical analysis paves the guidelines for designing optimum perforation geometries prior to the on-field testing of the functional prototypes.
Design and simulation of multilayer hybrid foam material for acoustic application L. Yuvaraj, S. Jeyanthi, Lenin Babu Mailan Chinnapandi, Elammaran Jayamani International Journal for Simulation and Multidisciplinary Design Optimization, 2021 New acoustic multilayer absorber fabricated by coupling closed-cell metallic foam and open-cell polymeric foam, which aimed to develop a practical use of metallic foam in the noise control application. In prior, the individual sound absorption coefficient of both foam materials with different thicknesses measured by the impedance tube method as per ASTM E-1050. Using inverse characterization technique, the intrinsic properties needed for five parameter models in a numerical study are predicted. The measured characteristic impedance, complex wave propagation, and sound absorption coefficient of the individual foams are in close agreement with the prediction. Subsequently, a different configuration of multilayer absorber is modeled using obtained properties, and their acoustic performance is evaluated. The result indicates that the coupling of polymeric foam with metallic one exhibits enhanced sound absorption and usage of closed-cell metallic foam in noise control material. Furthermore, the result demonstrates that absorption capability entirely relies on the placement of polymeric foam in the configuration. The proposed hybrid multilayer absorber coupled with test bench car for interior acoustic study, where 5–30 dB is reduction is noticed in 1/3rd octave plot.
Influence of Magnesium Hydroxide Fillers on Acoustic, Thermal, and Flame Retardant Properties of Pu Foam L. Yuvaraj, S. Jeyanthi, Digvijay D. Kadam, R. G. Ajai Lecture Notes in Mechanical Engineering, 2021 Polyurethane foam is a versatile material for many applications like acoustic, thermal insulation, as well as for energy absorption. The main aim of this paper is to improve acoustic properties by adding weight percentage of 2, 4, and 6 of magnesium hydroxide (Mg(OH)2) micro-particles in polyurethane (Pu) foam. To investigate the influence of micro-particles on acoustic properties, the samples are tested in an impedance tube to measure sound absorption coefficient. The experimental results are compared to finite element results predicted from Johnson–Champoux–Allard model. For thermal properties, the samples are experimented in thermal conductivity and fire retardant test. The results indicate that the significant improvement in the acoustic and thermal properties due to the addition of magnesium hydroxide.
Sound absorption of multilayer micro perforated panel with Helmholtz Resonator Mount Inter Noise 2019 Madrid 48th International Congress and Exhibition on Noise Control Engineering, 2019
Numerical and experimental characterization of acoustic porous material - A review International Journal of Mechanical Engineering and Technology, 2017
An investigation on chemical treatment of phenol formaldehyde with natural fibers for brake pads Journal of Chemical and Pharmaceutical Sciences, 2015
