Yuvaraj L
@vit.ac.in
Research Associate
VELLORE INSTITUTE OF TECHNOLOGY
RESEARCH INTERESTS
Acoustics, Noise control engineering, Lightweight composite
Scopus Publications
Scopus Publications
R. Sailesh, Mrityunjay Doddamani, Lenin Babu Mailan Chinnapandi, L. Yuvaraj, and Jeyaraj Pitchaimani
Informa UK Limited
Loganathan Yuvaraj, Subramanian Jeyanthi, Lenin Babu Mailan Chinnapandi, and Jeyaraj Pitchaimani
SAGE Publications
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.
R. Sailesh, L. Yuvaraj, Mrityunjay Doddamani, Lenin Babu Mailan Chinnapandi, and Jeyaraj Pitchaimani
Elsevier BV
Vinoth Kumar Selvaraj, S. Jeyanthi, Raja Thiyagarajan, M. Senthil Kumar, L. Yuvaraj, P. Ravindran, D. M. Niveditha, and Yigezu Bantirga Gebremichael
Hindawi Limited
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.
N. Venkatesh, H.G. Hanumanthraju, K.P. Prashanth, B.K. Venkatesha, and L. Yuvaraj
Elsevier BV
Solomon Jenoris Muthiya, L. Natrayan, L. Yuvaraj, Mohankumar Subramaniam, Joshuva Arockia Dhanraj, and Wubishet Degife Mammo
Hindawi Limited
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.
R. Sailesh, L. Yuvaraj, Jeyaraj Pitchaimani, Mrityunjay Doddamani, and Lenin Babu Mailan Chinnapandi
Elsevier BV
Abstract 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.
Anjibabu Merneedi, Nalluri Mohan Rao, L. Natrayan, L. Yuvaraj, and Prabhu Paramasivam
Hindawi Limited
This research paper deals with a numerical method which is modified and applied, by the authors to derive an eigenvalue of a thick plate having cut-out in which geometries of plate and cut-outs are different, through a deflection matching condition by including shear deformation and rotary inertia effects, with less computational efforts and high accuracy. The modified Independent Coordinate Coupling Method (ICCM) is validated with FEM package (ANSYS) and applied to know the change in eigenvalues for a plate with cut-out by varying various parameters like aspect ratios, cut-out size, and thickness ratios. Trigonometric functions considered at the boundary level conditions of a simply supported plate should be satisfied. Free vibrational exploration on a thick isotropic plate with various aspect ratios and an elliptical plate with various sizes is carried out through the modified ICCM. Independent coordinates are applied for a plate domain and for a hole domain individually followed by equating the deflection condition of hole and plate, a reduced mass to express with cut-out from which eigenvalues can be obtained. The deflection matching condition facilitates the analysis even though the geometries of plate and cut-outs are different.
L. Yuvaraj, S. Jeyanthi, Lenin Babu Mailan Chinnapandi, and Elammaran Jayamani
EDP Sciences
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.
L. Yuvaraj, S. Jeyanthi, Digvijay D. Kadam, and R. G. Ajai
Springer Singapore
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.
L Yuvaraj and S Jeyanthi
SAGE Publications
This study investigates the acoustic performance of a countersunk micro-perforated panel, along with two distinct porous materials used in a multilayer porous absorber configuration. Additive manufacturing is applied to create sub-millimeter perforation with different hole spacings on polymer micro-perforated panels. Experiments are conducted in an impedance tube, in which the effects of the perforation ratio, air gap, and varying porous layer configurations on the sound absorption capabilities are investigated. For validation, considering the converging hole profile in the micro-perforated panel, an integration method with end correction is used to calculate the tapered section impedance, and the traditional Maa theory is used for the uniform hole. The theoretical impedance of the multilayer absorber is calculated using the transfer matrix method and subsequently compared to the experimental results. The results demonstrate that the countersunk hole micro-perforated panel exhibits a significant improvement in sound absorption, and the introduction of porous materials extends the sound absorption bandwidth. Furthermore, the results indicate that the sound absorption capability depends on the porous material placement in the multilayer absorber configuration.
S. Yogeshwaran, L. Natrayan, Gobikrishnan Udhayakumar, G. Godwin, and L. Yuvaraj
Elsevier BV
Abstract Composite manufacturing is the novel branch of science, which finds its immense applications in various industries such as sporting, automotive, aerospace and marine industries. The superior properties of composites such as stiffness, better mechanical properties, low density, and light weight make it a candidate in engineering applications. The need for seeking alternate materials with increased performance in the field of composites revived this research, to prepare the Jute and Abaca fiber with tyre particles reinforcement hybrid composites by hand layup method. The resin used in the preparation of composites was epoxy. The different five proportion of fiber and matrix material such as 80:0:20, 50:30:20, 40:40:20, 30:50:20, 0:80:20 without any pretreatment and were taken as the base line reference. Subsequently the tests have conducted on the above fibers with alkali treatment and tyre particles with H2SO4 treatment to enhance the mechanical properties. Reused tyres particle was also used as reinforcement in epoxy matrix and this particle was treated with to improve ability of rubber to interact with epoxy, increasing stiffness and tensile strength. The jute fiber, abaca fiber and tyre particle were prepared with various weight ratio and then incorporated into the epoxy matrix. Samples prepared were tested to evaluate its mechanical properties such as tensile strength, flexural strength, and impact strength.
L. Yuvaraj, S. Jeyanthi, and A. Yogananda
Elsevier BV
Abstract This study aims to develop a novel acoustic panel that constitutes more natural fiber rather than a resin matrix, and the effect of perforation depth in the composite panel is investigated. Jute fiber-reinforced composite panels undergo partial perforation using a tapping machine of depth 7.5 mm, 15 mm, and 22.5 mm to the total thickness of 30 mm. The samples are tested experimentally in an impedance tube and sound transmission loss test setup to evaluate the acoustic capabilities for the frequency range of 100–1600 Hz. For validation, the intrinsic parameters are predicted from experimental sound absorption data using the inverse characterization technique. Insight of application aspect, the panel is modeled to be present in a rectangular acoustical cavity and analyzed numerically in COMSOL Multiphysics. The impedance tube test results indicate that the peak of the sound absorption coefficient increases with increases of perforation depth. Similarly, perforation depth influences the transmission loss of the panel, and significant results noticed. The use of a jute panel in rectangular enclosure results in a 3–6 dB reduction in the overall sound pressure level of one-third octave frequencies.
L. Natrayan, S. Yogeshwaran, L. Yuvaraj, and M. Senthil Kumar
AIP Publishing
Aluminum matrix composite currently used in engineering applications due to their desirable combination of properties. Development of aluminium matrix composite has become an essential area of research interest in material science. Aluminium based graphene composite are finding increased application in electrical, automobile and aerospace applications because of its light weight. In this present work dealt with mechanical and microstructure properties AA8030 reinforced with 5 different wt% of Graphene. The bottom pouring stir casting machine was used to fabricate AA8030-Graphene composite. Fabricated samples were tested according to the ASTM standard. The microstructure and mechanical properties such as hardness, tensile strength, flexural strength of fabricated samples were evaluated.
S. Jeyanthi, L. Yuvaraj, and Lenin Babu Mailan Chinnapandi
JVE International Ltd.
The enormous consumption of Polyurethane foam leads to severe environmental pollution and health hazards, so it is necessary to overcome this problem. This paper presents alternative and less hazardous foam that differs from traditional foams. A bio-based foam was developed either by using castor oil-based polyol or natural fibers as fillers. In the present study, rigid foam is synthesized by both castor polyol and luffa fiber, whereas for flexible foam, only luffa fiber is incorporated. Luffa fillers enhance the porosity of Polyurethane foam, which is the dominating factor influencing the value of the sound absorption coefficient. Both rigid and flexible foams were developed with 5, 10 and 15 percentages of filler loaded. The samples are tested experimentally using the two-microphone impedance tube method and the measured result was compared with the numerical result, which is predicted from COMSOL Multiphysics. The experimental results of flexible foam demonstrate good agreement with numerical results. The results indicate that the addition of Luffa fibers enhances the sound absorption performance of flexible foam and deterioration in the rigid foam because of the high viscosity of castor oil polyol.
L. Yuvaraj, S. Jeyanthi, Nikhil S. Thomas, and Vishnu Rajeev
Elsevier BV
Abstract Polyurethane foams (PU), are found in various industrial and domestic applications due to their high energy absorption and sound absorption properties, especially in shock absorbers and noise control problems. This study investigates the effect of silica gel as additive filler in castor oil-based PU foam and its mechanical and acoustical properties are evaluated. Three different loading of 5%, 10%, and 15% silica gel is used as filler. For mechanical properties, the compression test is carried out. As the percentage of filler increases, the rigidity of the foam increases. The acoustical properties of the sample are tested using the two-microphone impedance tube method. Raw PU foams are seen to exhibit a reasonable sound absorption only in higher frequencies. The results show that the sound absorption coefficient of 10% filler PU foam has comparatively better sound absorption capabilities throughout all frequencies, ranging from 200 Hz to 4000 Hz, that it is exposed to. This can be attributed to the optimum number of voids present, compared to the highest number in 15% (high porosity) and lowest in 5%. The results show that the addition of silica gel up to a certain extent enhances both, the mechanical as well as acoustic properties.
L. Yuvaraj, S. Jeyanthi, and M.C. Lenin Babu
Elsevier BV
Abstract Polyurethane (PU) is one of the most common polymer material used in day today life due to its outstanding features like light weight, cheap in cost, and remarkable sound insulation. PU is extensively used in acoustic and insulation applications because of its porous characteristics. But one of the disadvantages of using foam as the acoustic material is emission of the volatile organic compounds in indoor environments, non-biodegradability and landfill issues. To overcome this important environmental issue of the petrochemical based sound absorbing porous materials it is essential to developing green, cost-effective, efficient and bio degradable porous materials for sound absorption. This paper presents investigations on the acoustical properties of castor oil polyol based kenaf fibre reinforced thermoplastic bio-composites and concepts for highly absorbent material. The results show that castor oil based kenaffibre sample shows good acoustic properties at high frequencies and can be used as an alternative replacement to conventional synthetic fiber interior products