Arpan Gupta

Indian Institute of Technology Delhi | IIT Delhi

Sound propagation through periodic arrangement of scatterers lead to formation of bands of frequencies, known as band gaps, where sound cannot propagate though the structure. We propose a method based on Webster horn equation, along with Floquet theorem, to predict the band gap of a one-dimensional periodic structure made of hard sound-scatterers....

Sound propagation in the sonic crystal (SC) along the symmetry direction is modeled by sound propagation through a variable cross-sectional area waveguide. A one-dimensional (1D) model based on the Webster horn equation is used to obtain sound attenuation through the SC. This model is compared with two-dimensional (2D) finite element simulation and...

This paper presents a review study on sonic crystal, their development and present status. The paper also focuses on some of the applications of sonic crystal and numerical methods to study these crystals. Sonic crystals are periodic arrangement of scatterers, whose interaction with acoustic waves leads to the formation of band gap. Band gap are re...

Sonic crystals are the periodic arrangements of scatterers embedded in a homogeneous material. Their ability to prevent sound wave to propagate in a particular range of frequency demonstrates their use as potential noise barriers. The sonic crystal considered in this work is an array of PVC cylinders (5 × 5) in air bounded by acrylic sheets. This p...

The active tuning of the bandgaps induced by the acoustic metamaterials has sparked significant interest among researchers. It opens up possibilities for programmable, multifunctional acoustic meta-devices. The static design of acoustic metamaterials, however, has limited automation capabilities, particularly for controlling sound propagation throu...

An ultra-sparse, broadband programmable Active Acoustic Meta-surface (AAMS) that is demonstrated to function as a multi-functional Active Acoustic Meta-device is developed. Functionalities Acoustic Barrier (AB), Acoustic Switch (AS), and Acoustic Transmitter (AT) have been successfully explored. AB functions at a broadband frequency of 455 to 679 H...

Active acoustic metamaterials (AAMM) have garnered special attention because of their potential as multi-function devices. In this direction, the present article demonstrates a novel AAMM that can be programmed as a multi-functional Active Acoustic Meta-device (AAMD) that can switch functionalities between Acoustic Switch (AS), Acoustic Lens (AL),...

The present work introduces a novel approach to designing metamaterial for low frequency and high frequency wave attenuation by repurposing plastic waste. The metamaterial is constructed using a duct-like structure with a periodic arrangement of bottles of different sizes. This configuration leads to the formation of a local resonant band, which sp...

The paper proposes an improvement of the acoustic environment in a sustainable building by utilizing differently sized discarded bottles. The HVAC (heating, ventilation and air conditioning) ducts in buildings serve as conduits for purified air, but they also generate noise as a result of turbulent flow caused by internal irregularities within the...

To target the problem of dimension measurement of objects in industry, a new computer vision method is proposed based upon Harris-corner detection. The proposed research delivers an alternative to the requirement of various precise measurement devices and skilled labour. In order to measure the various dimensions of an object, the proposed algorith...

IntroductionVision-based technologies are being widely used due to the availability of high-resolution cameras and open-source image processing tools. In the present work, a smartphone is used to capture video of a simple pendulum from various distances.Method Image processing techniques have been used to analyse the motion. Subtle movements of the...

Acoustic levitation involves no physical contact with the specimen, hence widely used for the bio/chemical studies, fluid physics studies etc. Standing wave acoustic levitation system works on resonance phenomenon. So, to obtain the right air gap/distance between the driver and the reflector surfaces for the levitation system's resonance condition...

Metamaterials are periodic structures made by repeating a unit cell. Such a structure shows frequency-specific wave attenuation behaviour. In this work, a 2D metamaterial foundation is proposed for the seismic protection of buildings. The paramount challenge is to offer low frequency attenuation (~ 2–8 Hz), which is the dominant excitation during a...

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 this work, linear and nonlinear vibration analyzes of a drum type washing machine having two springs and two dampers have been performed numerically. The effects of parameters such as linear spring stiffness, nonlinear spring stiffness, and damping coefficient have been investigated. A mathematical model of horizontal axis type washing machine b...

Phononic crystals have promising applications in the field of elastic waves and to attenuate the vibrations with their extraordinary feature of stop bands also known as bandgaps. Due to periodicity in structure, the wave in certain band of frequencies is not allowed to propagate. In this paper, we have proposed a phononic crystal whose unit cell is...

Due to the many irregularities and speed humps present on the roads, the conventional passive suspension system fails to provide the most comfortable ride possible. The following work proposes the use of an active suspension system to achieve a more comfortable ride. An active suspension system refers to varying the suspension characteristics like...

This paper provides a method for system identification of a motorcycle using a smartphone that has an accelerometer sensor. The objective of this study is to identify a vibrational system and its parameters and rectifying by comparing the experimental results with the simulations of the same problem. An android mobile application is used to record...

In this work, a drum-type horizontal axis washing machine with two springs and two dampers has been considered to study the jump resonance phenomenon. Here two springs and two dampers are used and effects of nonlinear spring stiffness on vibration level in both horizontal and vertical directions have been investigated. In this study, a mathematical...

With the internet of things (IoT) era dawning in, we are surrounded by a plethora of sensors. The present paper focuses on MEMS-based vibration measuring accelerometers, which are ubiquitously present in smartphones, tablets, smartwatches/bands, etc. These contact type vibration sensors have the unique advantage of being very small, low cost, low p...

This work investigates the co-combustion characteristics of the hydrogen-diesel dual fuel with exhaust gas recirculation (EGR). The experiments were performed on a retrofitted duel fuel compression ignition engine for the entire engine load spectra, while the maximum hydrogen energy share in the study was 30%. Further, EGR was varied up to 10% to e...

This study aims at energy harvesting mufflers that utilize thermoelectric generators (TEG) to convert waste heat from the engine exhaust into electricity and simultaneously reduce engine noise. The recovered electricity can be used to power the auxiliary units in the automobile and can effectively improve the overall efficiency of the system. In th...

Acoustic metamaterials are materials artificially engineered to control sound waves, which is not possible with conventional materials. We have proposed a design of an acoustic metamaterial plate with inbuilt Helmholtz resonators. The plate is made of Polylactic acid (PLA) which is fabricated using an additive manufacturing technique. It consists o...

Ventilators are one of the most important and complex devices in the intensive care unit (ICU). These devices are used to handle the patients in critical conditions like lungs collapse, comma, transplant surgeries, etc. But due to COVID-19 pandemic, there is a very large need of the ventilators. This paper focuses on the development of a prototype...

Yadav, SaurabhGupta, ArpanStanding wave acoustic levitation is an interesting technique to levitate small objects using sound. One of the common ways is to create a pressure node, or focal point, using standing waves, at which particles can levitate. In this study, the standing wave acoustic levitation phenomenon is studied numerically and validate...

A planar four-bar mechanism is the simplest and the smallest movable closed chain linkage. It consists of four revolute pairs and is therefore often referred to as 4R mechanism. This paper presents the kinematic and inverse dynamic force analysis of a planar four-bar mechanism (in crank rocker configuration), assuming the motion of one crank as inp...

The present work is about metamaterial-based foundation design for attenuating seismic wave propagation. Metamaterials are artificially designed structures engineered for novel properties. These artificially designed structures can exhibit properties, which can be contra-intuitive and sometimes not available in nature. These metamaterials have freq...

A mass in a mass locally resonant system has been studied using a numerical and analytical method. This study is performed to compute the band gap and transmission coefficient of a mass–spring locally resonant system. A locally resonant structure is a periodic structure which exhibits negative effective properties in a certain frequency band and re...

Acoustic panels with different configurations (layered structure with different absorbing materials) are broadly used to attenuate the noise. Multiple panels are preferred due to the presence of multiple air cavities and the repeated reflections which lead to increased sound attenuation. The paper presents an experimental study of sound propagation...

The paper discusses a simple and low-cost method to design four microphone impedance tube of measuring the acoustic properties of building materials. The acoustic properties of the material are defined by the reflection coefficient, absorption coefficient, and transmission coefficient. The experimental setup follows the ASTM-E2611 standard of four...

In the recent past, static properties of the materials primarily driven the material selection. However, what these static properties failed to satisfy found realized by their complementary parts, dynamic properties. Direct consequence of such realization vis-à-vis electromagnetic waves give evolution to Metamaterials. Metamaterials are on buzz for...

Thermoelectrictechnology has good potential for its application as automotive exhaust based thermoelectric generator (TEG). In this work, the temperature variation on the surface of the automotive exhaust thermoelectric generator (AETEG) heat exchanger has been studied.The surface of heat exchanger acts as base for applying TEG modules to recover w...

Total radiation force on a spherical levitating object, which is placed between a single axis acoustic levitator, is obtained using finite element simulation. Variation in the total radiation force on the spherical levitating object with respect to the position of the object between the driver and the reflector is studied in resonance as well as no...

The present work combines the properties of sonic crystal (SC), locally resonant sonic crystal (LRSC) and porous material in the triple panel to increase the overall sound transmission loss through the combined structure. SC is a periodic structure which is mainly used for sound reduction in a particular frequency range. In the present work, sound...

Objective The micro-structure at the interface of cortical and cancellous bone is quite complicated. The fracture mechanism at this location is necessary for understanding the comprehensive fracture of whole bone. The goal of this study is to identify fracture toughness in terms of J integral and fracture mechanism at the interface between cortical...

Stress intensity factor and energy release rate are important parameters to understand the fracture behaviour of bone. The objective of this study is to predict stress intensity factor and energy release rate using finite element method, element-free Galerkin method, and extended finite element method and compare these results with the experimental...

The transportation sector of the present-day world is facing severe problems like increasing global pollution and continuous depletion of conventional energy resources; both at alarming rates; which has motivated the researchers to look for alternative fuels and study various aspects of clean burning and sustainable fuels. The vibration of the engi...

With an alarming enlargement in vehicular density, there is a threat to the environment due to toxic emissions and depleting fossil fuel reserves across the globe. This has led to the perpetual exploration of clean energy resources to establish sustainable transportation. Researchers are continuously looking for the fuels with clean emission withou...

Acoustic panels are broadly used for noise attenuation at various places. Multiple panels withcertain air gap act more efficiently due to multiple reflections in the air cavity. Different type ofabsorbing blankets has been used between the panels from last few decades to increase the noiseattenuation. However, it does not help to attenuate the noise...

We investigate single-axis acoustic levitation using standing waves to levitate particles freely in a medium bounded by a driver and a reflector. The acoustic pressure at the pressure antinode of the standing wave counteracts the downward gravitational force of the levitating object. The optimal relationship between the air gap and the driving freq...

Fuel throttle: Energy harvesters to boost next-gen cars **DECCAN CHRONICLE | SARTHAK NAG** Published Sep 4, 2018 Link: https://www.deccanchronicle.com/decaf/040918/fuel-throttle-energy-harvesters-to-boost-next-gen-cars.html

Acoustic panels are widely used for sound insulation in various applications. Sound transmission loss (STL) through the panel is due to a change in acoustic impedance as sound travels from one medium to another. In double panels, STL further increases due to multiple reflections in air cavity. Recently the sonic crystal (SC) has emerged as an inter...

Sonic crystals (SC) are man-made periodic structures where sound hard scatterers are arranged in a crystalline manner. SC reduces noise in a particular range of frequencies called as band gap. Sonic crystals have a promising application in noise shielding; however, the application is limited due to the size of structure. Particularly for low freque...

In this study, reverberation time of a lecture auditorium has been analyzed experimentally and analytically. It is well-known fact that reverberation time affects the speech intelligibility and hence should be within the range of possible optimum values. Experiments were performed to calculate the reverberation time of a lecture auditorium construc...

This chapter presents a case study approach for Modelling and Simulation of Random Excitation Technique for Measurement of Acoustic Properties like acoustic impedance and reflection coefficient. The basic theory, experimental formulation and set-up required are discussed in detail. Adequate options are suggested, if there is a variation of requirem...

With the major concern to increase the efficiency of internal combustion (IC) engines, various technologies and innovations have been implemented to improvise efficiency and reduction of emissions. Since 60–70% of the energy produced during combustion is rejected as heat through exhaust and coolant channels, it is important to recover that waste he...

The paper presents a numerical method to solve for the reliability measures of a Markovian system. The model is obtained from the field of reliability engineering for systems having constant failure and repair rates. Generally, the steady state behaviour of the system is studied due to some constraint on obtaining the transition state solution. The...

Static stall of a NACA 0012 aerofoil has been studied by simulating a two dimensional, incompressible flow over the aerofoil section at various angles of attack for a Reynold’s number of three million. An \( SST\, k - \omega \) turbulence model is used to capture the turbulence, flow separation, and associated pressure changes. The lift coefficient...

Acoustics is a mathematical study of sound waves in solids, liquids, and gases. This chapter deals with sound propagation in horns, pipes, wave guides, periodic structures, and mufflers. Aim of this chapter is to create basic understanding of acoustic processes mathematically. Some equations like Webster's horn equation, Helmholtz equation and thei...

A sonic crystal is periodic array of scatterers in which scatterers are embedded on a material having low impedance. Applications of the sonic crystals have led to a growing interest in the periodic structures embedded in a material. These periodic arrangements of scatterers have ability to stop sound waves within certain frequency bands. In this p...

This paper addresses the acoustical performance of a cylindrical expansion chamber muffler with single inlet, single outlet configuration. Analytical result for the transmission loss for the muffler has been derived by using the plane wave theory and the results are compared with the finite element analysis. The analysis for both the cases is done...

Finite element modeling (FEM) plays a significant role in the design of various devices in the engineering field of automotive, aerospace, defense etc. In the recent past, FEM is assisting engineers and healthcare professional in analyzing and designing various medical devices with advanced functionality. Computer aided engineering can predict fail...

Thermoelectric technology has good potential for its application as automotive exhaust based thermoelectric generator (TEG). In this work, the temperature variation on the surface of the automotive exhaust thermoelectric generator (AETEG) heat exchanger has been studied.The surface of heat exchanger acts as a base for applying TEG modules to recove...

This paper presents the numerical simulations to determine the impact resistance of Personal Armor System Ground Troops (PASGT) helmet. Initially impact of spherical projectile on PASGT helmet travelling at 205 m/s is studied. The result of this simulation was used to verify the material data and compare the work with previous literature. Two stand...

This paper studies the impact of bullet with aluminum alloy plate fixed on all sides. Simulations were carried out to study effect of bullet impact angle and thickness of aluminium alloy plates. These simulations were performed using Finite Element Method implemented through Ansys Workbench. The target plate was struck at 0°, 15°, 30° and 45° obliq...

This paper demonstrates very simple periodic structure having ability to create band gaps at low frequency. A finite element study is used to compute transmission loss through periodic structures. This paper describes periodic structures with fluid in fluid and solid in fluid configuration. A soft material is introduced in the structure to make it...

This paper presents a computational work based on sonic crystals to reduce noise pollution using an array of trees. Sonic crystals are structure in which sound hard objects are arranged in a periodic pattern and are mainly used to control noise. Transport noise in urban area is one of the main sources of noise pollution in environment. The paper de...

Muffler is an important component in any machinery where sound is needed to be muffled or attenuated. Mufflers of various geometric configurations are available with main focus on getting maximum transmission loss without having undesirable impact on back pressure. This paper predicts the acoustical performance of a single inlet single outlet expan...

Finite element modeling (FEM) plays a significant role in the design of various devices in the engineering field of automotive, aerospace, defense etc. In the recent past, FEM is assisting engineers and healthcare professional in analyzing and designing various medical devices with advanced functionality. Computer aided engineering can predict fail...

Railways generally run at a speed of 50–100 Km/hr with lot of wind energy being wasted to overcome the drag on the vehicle. In this work, a design is proposed to extract some useful energy out of the grazing wind on the top surface. A converging air duct passage along with spiral casing is provided on top of roof which is used to drive a vertical a...

In today's hectic lifestyle, health has been seriously hampered due to sedentary work. This paper represents an idea of walking based wearable piezoelectric device that provides an alternate means for powering mobile phone batteries. Moreover, it simultaneously serves another purpose of providing an emergency torch. Since, the mechanism of the devi...

The research work presented in this paper explores the area of bio-medical imaging. In this work, a multi-component CAD (Computer Aided Design) model of human elbow structure has been developed. Biomedical images such as computerized tomography scan (CT scan) and magnetic resonance images (MRI) are taken as input data, which are further manipulated...

Biomedical image processing is an emerging field for analyzing medical images to develop models for clinical analysis and medical intervention. Recently with the development in biomechanics, the models developed can be used for mechanical stress and vibrational analysis of human body parts. In this work, computer aided design (CAD) models are devel...

Bending load is often encountered in femur bone (thigh bone) particularly in the case of lateral impact. Femur fracture is quite usual in pedestrians. It generally occurs because of bending of femur bone due to lateral impact. In order to prevent fractures in walkers and vehicle passengers from accidents, it is significant to study the bending beha...

In this paper, a numerical solution technique to stochastic partial differential equations in reliability engineering is presented. The method is based upon finite difference discretization of the governing equations for the Markovian reliability model. In realistic situations, the repair rates and failure rates of engineering system are variable....

Femur bone is one of the most commonly fractured bones of human body, especially for the elderly people. It is one of the longest and largest bones found in human beings. In this paper, vibration analysis of femur bone is studied by the help of finite element simulation to provide more insight in designing bioaided equipments or protective sports e...

Sound propagation through a waveguide is generally modeled by the Webster horn equation which assumes a planar pressure wavefront. However, most of the sources are non-planar in nature. In this work, a 1-D model is derived for sound propagation through a 2-D waveguide with circular wavefront. The model is derived from the 2-D Helmholtz equation usi...

Road accidents in mountainous regions are mainly due to blind turns and lack of visibility. In the present work, a mountainous road accident safety system is proposed by using Load gauge and Wheatstone circuit to provide an indicator on the other side of the (blind) turn. The system is based on principle of strain gauge. As the vehicle pass over th...

Femur bone is the longest and largest bone found in human body. It is also one of the most commonly fractured bones of human body, especially for the elderly. In this paper, vibration analysis of femur bone is studied by the help of finite element simulation to provide more insight in designing bio-aided equipments or protective sports equipments f...

Sonic crystals are periodic structures made of sound hard scatterers which attenuate sound in a range of frequencies. For an infinite periodic structure, this range of frequencies is known as band gap, and is determined by the geometric arrangement of the scatterers. In this paper, a parametric study on rectangular sonic crystal is presented. It is...

In this study, propagation of acoustic wave through a periodic structure has been analyzed. Such a periodic structure has been found to attenuate sound significantly in certain frequency bands, and therefore it can be used as a frequency filter and sound barrier. Experiments were performed to measure the sound attenuation by the periodic structure...