Speed Of Sound Waves Research Articles

Effect of Amplitude and Frequency on the Speed of Sound Waves in Air and Water Using PhET Simulation

Sound waves can occur not only in solid medium but also in air and water mediums. The effect of amplitude and frequency on the speed of sound waves differs between air and water mediums. The speed of sound waves cannot be seen with the naked eye. A virtual lab is needed to determine the speed of sound wave propagation. The purpose of this study is to determine the effect of amplitude and frequency on the speed of sound waves in air and water medium. The research method used is a quantitative method by conducting experiments online using the PhET application. PhET is used because it can carry out interactive simulations to facilitate research that cannot be done in real terms, but must make use of an effective virtual lab. The results obtained, namely in the medium of air and water, it is proven that the amplitude and frequency are directly proportional to the speed of sound wave propagation. In conclusion, sound waves travel faster in the water medium than in the air medium. Sound waves travel faster in the water medium because in liquid the particles are closer together than in the air medium, so sound waves will travel faster.

Computational investigation of the structural, elastic, electronic, and thermodynamic properties of chloroperovskites GaXCl3 (X = Be, Ca, or Sr) using DFT framework

In this study, we employed the pseudopotential plane wave approach to examine the influence of the X atom (X = Be, Ca, or Sr) on the physical properties of isostructural chloroperovskites GaXCl3. The GGA-PBEsol functional was employed to simulate the exchange–correlation interactions. The computed equilibrium lattice parameters exhibit a high level of concordance with the existing theoretical findings. The cohesion energy and enthalpy of formation were computed to verify the energetic stability of the materials under consideration. The determined values of the single-crystal elastic constants (Cij) indicate that GaBeCl3 remains mechanically stable up to a hydrostatic pressure of 18 GPa. Similarly, GaCaCl3 preserves its stability up to 5 GPa, while GaSrCl3 remains mechanically stable up to 1.25 GPa. The projected Cij values were used to estimate several elastic moduli and related properties, including the shear and bulk moduli, sound wave speeds, Young’s modulus, Poisson’s ratio, and Debye temperature. The energy band structures of the studied compounds, as predicted by the HSE06 functional, demonstrate their wide bandgap semiconductor nature. Specifically, GaBeCl3 demonstrates an indirect bandgap of 3.828 eV, while GaCaCl3 reveals an indirect bandgap of 4.612 eV and GaSrCl3 has an indirect bandgap of 4.405 eV. The quasiharmonic Debye approach was employed to examine various thermal parameters, including the temperature dependence of the unit cell volume, bulk modulus, expansion coefficient, Debye temperature, isochoric and isobar heat capacities, Grüneisen parameter, and entropy function. It has been shown that GaBeCl3 demonstrates a lower thermal expansion coefficient and a higher Debye temperature in comparison to GaCaCl3 and GaSrCl3.

Frequency dependence of the speed of sound in metallic rods

The speed of sound waves in rods depends on the relationship between wavelength and rod dimensions. It differs from the speeds readily available in tables, and from what is often learned during most introductory courses on solid-state physics. Metallic rods with diameters in the centimetre range excited with sound waves of tens of kHz will behave as dispersive media. Here, the speed of sound in metallic titanium rods of different lengths is measured using two different methodologies: (1) from the time of flight and (2) from the wavelength and frequency of standing waves that form in the rod. The latter allows analyzing the results in light of Pochhammer-Cree dispersion. The reflection coefficient is also determined both from time and from frequency response. Two off-the-shelf piezoelectric transducers, a function generator, an oscilloscope, and a lock-in amplifier were used. We have used a low-frequency square wave (of tens of Hz) in the first case and a sine wave with frequencies that range from audible to ultrasound in the second case. Experimental results show that the speed of sound decreases as the wavelength decreases. The Pochhammer-Chree dispersion equation was numerically solved to fit the experimental data that can be used to estimate both the Young modulus and the Poisson ratio. A practical empirical formula that allows data analysis without explicitly solving the Pochhammer-Chree equation is suggested.

Anisotropic inflation in dipolar Bose–Einstein condensates

Early during the era of cosmic inflation, rotational invariance may have been broken, only later emerging as a feature of low-energy physics. This motivates ongoing searches for residual signatures of anisotropic space-time, for example in the power spectrum of the cosmic microwave background. We propose that dipolar Bose–Einstein condensates (BECs) furnish a laboratory quantum simulation platform for the anisotropy evolution of fluctuation spectra during inflation, exploiting the fact that the speed of dipolar condensate sound waves depends on direction. We construct the anisotropic analogue space-time metric governing sound, by linking the time-varying strength of dipolar and contact interactions in the BEC to the scale factors in different coordinate directions. Based on these, we calculate the dynamics of phonon power spectra during an inflation that renders the initially anisotropic Universe isotropic. We find that the expansion speed provides an experimental handle to control and study the degree of final residual anisotropy. Gravity analogues using dipolar condensates can thus provide tuneable experiments for a field of cosmology that was until now confined to a single experiment, our Universe.

Transonic dislocation propagation in diamond.

The motion of line defects (dislocations) has been studied for more than 60 years, but the maximum speed at which they can move is unresolved. Recent models and atomistic simulations predict the existence of a limiting velocity of dislocation motion between the transonic and subsonic ranges at which the self-energy of dislocation diverges, though they do not deny the possibility of the transonic dislocations. We used femtosecond x-ray radiography to track ultrafast dislocation motion in shock-compressed single-crystal diamond. By visualizing stacking faults extending faster than the slowest sound wave speed of diamond, we show the evidence of partial dislocations at their leading edge moving transonically. Understanding the upper limit of dislocation mobility in crystals is essential to accurately model, predict, and control the mechanical properties of materials under extreme conditions.

Ordering kinetics and steady state of Malthusian flock

We study a collection of polar self-propelled particles or polar flock on a two dimensional substrate involving birth and death. Most of the previous studies of polar flock with birth and death have focused on the steady state characteristics of Malthusian flock. We emphasize on the significance of rate of birth and death on the kinetics as well as steady state of the system. Our system is modeled using coarse-grained hydrodynamic equations of motion for local density and velocity of the flock. Results are obtained for different birth and death rates by solving the hydrodynamic equations using numerical integration and linearized calculation about the broken symmetry state. The presence of finite birth and death rate affects the density field significantly, whereas the effect on velocity field is moderate. The early time growth of velocity field slows down in the presence of finite birth and death rate, whereas at late times it approaches the value of non-conserved growth kinetics for all birth and death rates. The density field shows the strong time dependent growth kinetics. The asymptotic growth law for density depends on the birth and death rates and shows a crossover from 5/6 for the immortal flock to 1/4 for large birth and death rates. In the steady state, the presence of birth and death rate leads to the suppression of speed of sound wave, velocity, and density fluctuations in the system.

Study on Sound Propagation Performance of Mechanized Coal Gangue-Fine Sand Filling Body

In the process of continuous and high-intensity mining in soft rock coal mines, high-quality filling treatment is required for the goaf. A nondestructive acoustic velocimetry method is an excellent way to measure the quality of filling body to effectively maintain the rock stability of the mining area and decrease industrial solid waste. In this study, the gangue and fine sand are used as the filling aggregates, and the uniaxial compression test and acoustic wave test are conducted in the cementitious gangue-sand filling body with different gangue-sand ratio. The results show that the longitudinal wave velocity of the filling body is basically between 1.556 km/s and 2.413 km/s. When the gangue-sand ratio is small, and the slurry concentration is high, the early strength of the cementitious gangue-sand filling body is low, but the later strength has a good growth trend. For specimens with higher strength-filled bodies, the propagation speed of sound waves inside them is also faster, indicating a certain positive correlation between the strength of the filled body and the speed of sound waves. A mathematical equation using longitudinal wave velocity to predict the strength of filling body is established. This equation can be used to predict and judge the quality of the filling body in the mining area.

Coiled-up structure with porous material lining for enhanced sound absorption

This paper presents an acoustic metamaterial, coiled-up structure with porous lining (CSPL), which is constructed by adding porous material lining to a coiled-up air channel for the pursuit of broadband and low-frequency sound absorption at subwavelength scales. The porous material is fixed on both sides of the channel wall to enhance the losses of the system, and an air slit is left in the middle of the channel to regulate the impedance matching between the metamaterial and the air. A theoretical model based on double porosity theory and impedance transfer method is established to study the sound absorption performance of the metamaterial, and a finite element (FE) simulation model is constructed to reveal the underlying sound absorption mechanism. To validate these two models, the sound absorption performance of the designed sample is measured in a standing wave tube. The results show that the porous material lining not only enhances the sound energy dissipation, but also reduces the propagation speed of sound wave in the coiled channel, resulting in good low-frequency sound absorption performance of the CSPL. By adjusting the position and length of the porous lining, good sound absorption tunability can be achieved in the considered frequeny range. Moreover, the effect of acoustic properties of the porous material on the sound absorption of the CSPL is revealed and discussed in detail. Finally, several coupled CSPLs are designed to achieve broadband sound absorption in different frequency ranges. This work provides a new approach to design metamaterials for broadband low-frequency sound absorption.

Review on Wearable System for Positioning Ultrasound Scanner

Although ultrasound (US) scan or diagnosis became widely employed in the 20th century, it still plays a crucial part in modern medical diagnostics, serving as a diagnostic tool or a therapy process guide. This review provides information on current wearable technologies and applications used in external ultrasound scanning. It offers thorough explanations that could help build upon any project utilizing wearable external US devices. It touches on several aspects of US scanning and reviews basic medical procedure concepts. The paper starts with a detailed overview of ultrasound principles, including the propagation speed of sound waves, sound wave interactions, image resolution, transducers, and probe positioning. After that, it explores wearable external US mounts and wearable external US transducers applied for sonograph purposes. The subsequent section tackles artificial intelligence methods in wearable US scanners. Finally, future external US scan directions are reported, focusing on hardware and software.

Active Metadamping: A phenomenon of damping enhancement in metamaterial via feedback control

Metadamping is defined as the enhancement of dissipation (or the damped response) of an acoustic metamaterial over an equivalent phononic crystal for the same amount of prescribed damping.The emergence of metadamping and decay coefficient in conjunction with active feedback control is the prime novelty of this paper. The wave-number-dependent active metadamping is defined as the difference between the damping ratio of the active-controlled and that of the uncontrolled metamaterial to indicate its improved energy dissipation. The controller design is based on the Linear Quadratic Regulator with output feedback of velocity, and displacement as well as velocity. The damping emergence metric over the entire Brillouin zone is obtained from the dispersion relationship by applying Bloch’s theorem, and a parametric study is performed to get an insight into the metadamping phenomenon. Velocity feedback control (VC) provides the highest value of total damping ratio when compared to the case of displacement- and velocity-based feedback control (DVC) for an identical long wave sound speed; however, at the expense of reduced attenuation bandwidth. The decay coefficient of DVC is higher compared to that of VC up to a threshold of long wave speed of sound. Beyond that threshold, both VC and DVC provide almost equal decay. We identified the possibility of obtaining high damping in a stiff metamaterial via active control, which will be useful for applications in the field of vibrations and acoustics, impact mitigation, shock absorption, and vehicle dynamics.

ANALISIS FREKUENSI BUNYI DAN CEPAT RAMBAT GELOMBANG BUNYI PADA ALAT MUSIK TRADISIONAL ANGKLUNG

The research is motivated by cultural aspects that must be preserved and studied in various scientific fields, including physics. One of the interesting cultural elements to study is the traditional musical instrument, the angklung. This study aims to analyze the frequency and speed of sound waves in angklung. The benefit of this research is to get the cognitive content of science and as a form of cultural preservation of the angklung musical instrument. This type of research is quantitative with experimental methods. Collecting data is by measuring the physical quantities on the angklung. The data analysis technique used is graphical analysis and mathematical calculations. The results obtained are that the length of the angklung tube is inversely proportional to the frequency of the sound produced. Mathematical calculations can get the value of the speed of sound wave propagation according to the closed organ pipe concept. Based on the calculation results, the speed of sound waves in angklung is 340.11 m/s.
 Keywords: angklung, frequency of sound, speed of sound

Audio Signal Processing

Abstract: Audio Signal Processing is also known as Digital Analog Conversion (DAC). Sound waves are the most common example of longitudinal waves. The speed of sound waves is a particular medium depends on the properties of that temperature and the medium. Sound waves travel through air when the air elements vibrate to produce changes in pressure and density along the direction of the wave’s motion. It transforms the Analog Signal into Digital Signals, and then converted Digital Signals is sent to the Devices. Which can be used in Various things., Such as audio signal, RADAR, speed processing, voice recognition, entertainment industry, and to find defected in machines using audio signals or frequencies. The signals pay important role in our day-to-day communication, perception of environment, and entertainment. A joint time-frequency (TF) approach would be better choice to effectively process this signal. The theory of signal processing and its application to audio was largely developed at Bell Labs in the mid-20th century. Claude Shannon and Harry Nyquist’s early work on communication theory and pulse-code modulation (PCM) laid the foundations for the field.

Influence of internal wave induced sound speed variability on acoustic propagation in shallow waters of North West Bay of Bengal

This study focuses on the influence of internal wave induced sound speed variability on acoustic propagation parallel to the coast in shallow waters of North West Bay of Bengal (BoB). An acoustic transmission and reception experiment had been conducted at the site during February 2018 with simultaneous acquisition of oceanographic data, to examine propagation characteristics. The 950 Hz signal from an anchored vessel was received by an array of hydrophones moored 50 km away, with a loss of ∼ 80–95 dB with respect to the source position, receiver depth and sound speed variability. Sound speed variations in the acoustic environment were simulated using a shallow water internal wave model called WAVE to characterize the acoustic environment. Derived internal wave features from oceanographic and acoustic observations from study location during the experiment period were used to simulate the internal wave acoustic environment. Sound propagation using BELLHOP model was carried out with a simulated internal wave sound speed environment for 950 Hz source frequency. Model and observed temporal variability of transmission loss with sound speed at both source depth and thermocline depth has been addressed. Transmission loss features are comparable with field observations and model limitations are reflected in the results thus showing errors between two approaches. Range dependent bathymetry and other ocean acoustic parameters influence transmission loss at the study location. Temperature and salinity are major parameters influencing sound speed fluctuation in shallow waters, and corresponding variations are reflected in transmission loss and propagation. Finally this study provides a quantitative support in transmission loss in both modeling and experimental approaches at the study location.

Analysis of natural gas flow reversal in integrated energy system based on dynamic simulation

The inertial water hammer pressure propagates along the pipeline at the speed of sound wave, which makes the pressure along the pipeline rise or fall rapidly and the inertial water hammer pressure attenuate in the process of propagation. In the 50–60 km long pipeline, it will attenuate about 2/3-3/4. However, in the integrated energy system (IES), the length of natural gas pipeline is short, and the attenuation of water hammer pressure is small. The distance between the user end and the source end is short, so the user end will be affected by the water hammer pressure, including gas turbine, gas boiler and combined heat and power unit (CHP), which will result in its unstable operation, so it is necessary to analyze the impact of water hammer pressure in the IES. The rapid rise or fall of pressure along the pipeline caused by water hammer pressure will cause the reflux of natural gas, causing the instability of gas supply, and affect the safe operation of users. In order to solve this problem, this paper analyzes and calculates the dynamic fluctuation process of the natural gas system in the IES based on the method of characteristic which is suitable for the analysis of hyperbolic partial differential equation. In the process of modeling, the absolute value term of the simulated natural gas flow direction is retained,instead of thinking that the direction of flow is not change, and the difference method of the absolute value term is discussed and analyzed, and finally the calculation process is realized; After that, the simulation algorithm and program are used to analyze the problem of natural gas reflux caused by water hammer pressure in a specific comprehensive energy system, and the analysis and calculation are carried out to realize the real restoration of its operation state, which has important practical value.

Acoustic and Elastic Properties of a Blood Clot during Microbubble-Enhanced Sonothrombolysis: Hardening of the Clot with Inertial Cavitation.

Stroke is the second leading cause of death worldwide. Existing therapies present limitations, and other therapeutic alternatives are sought, such as sonothrombolysis with microbubbles (STL). The aim of this study was to evaluate the change induced by STL with or without recombinant tissue-type plasminogen activator (rtPA) on the acoustic and elastic properties of the blood clot by measuring its sound speed (SoS) and shear wave speed (SWS) with high frequency ultrasound and ultrafast imaging, respectively. An in-vitro setup was used and human blood clots were submitted to a combination of microbubbles and rtPA. The results demonstrate that STL induces a raise of SoS in the blood clot, specifically when combined with rtPA (p < 0.05). Moreover, the combination of rtPA and STL induces a hardening of the clot in comparison to rtPA alone (p < 0.05). This is the first assessment of acoustoelastic properties of blood clots during STL. The combination of rtPA and STL induce SoS and hardening of the clot, which is known to impair the penetration of thrombolytic drugs and their efficacy.

Методика расчета звукового давления в проводниках при их идентификации акустическим методом

A promising method of identifying conductors in the conditions of agricultural enterprises is the use of acoustic identification tools that allow it to be carried out without disconnecting electrical receivers from the network, without violating the insulation of the identified conductors. The design of devices for acoustic identification requires the development of a methodology for calculating the sound pressure level in conductors when an acoustic signal is applied to them, depending on such factors as the distance from the identification point to the signal source, the cross section and material of the conductor cores, its insulation material, and the frequency of the signal being supplied. (Research purpose) The research purpose is in developing a methodology for calculating the parameters of the propagation of acoustic signals in conductors when identifying them using acoustic signals. (Materials and methods) The article presents the analysis of existing methods for calculating the acoustic characteristics of solids. The article describes the developed methodology for calculating the parameters of acoustic signal propagation in conductors when identifying them using acoustic signals and tested it using practical tests. (Results and discussion) The main parameter of acoustic signals in conductors when they are identified by acoustic means is the sound pressure level. Authors have developed a method for calculating the sound pressure level in conductors, taking into account such factors as the length of the identified conductor, the frequency of the acoustic signal, the conductor cross-section, the speed of sound waves in conductive cores and insulating materials. The article presents practical experiments to test the applicability of the developed methodology. (Conclusions). To date, acoustic signals are not used to identify conductors, a method for calculating the sound pressure level in conductors has not been developed, taking into account various factors. Authors developed a methodology and performed theoretical calculations of the sound pressure level in the conductors. Based on the results of practical experiments with the use of a control and measuring device, the applicability of the proposed methodology was confirmed.

Speed of sound and shear wave speed for calf soft tissue composition and nonlinearity assessment.

The purpose of this study was threefold: (I) to study the correlation of speed-of-sound (SoS) and shear-wave-speed (SWS) ultrasound (US) in the gastrocnemius muscle, (II) to use reproducible tissue compression to characterize tissue nonlinearity effects, and (III) to compare the potential of SoS and SWS for tissue composition assessment. Twenty gastrocnemius muscles of 10 healthy young subjects (age range, 23-34 years, two females and eight males) were prospectively examined with both clinical SWS (GE Logiq E9, in m/s) and a prototype system that measures SoS (in m/s). A reflector was positioned opposite the US probe as a timing reference for SoS, with the muscle in between. Reproducible tissue compression was applied by reducing probe-reflector distance in 5 mm steps. The Ogden hyperelastic model and the acoustoelastic theory were used to characterize SoS and SWS variations with tissue compression and extract novel metrics related to tissue nonlinearity. The body fat percentage (BF%) of the subjects was estimated using bioelectrical impedance analysis. A weak negative correlation was observed between SWS and SoS (r=-0.28, P=0.002). SWS showed an increasing trend with increasing tissue compression (P=0.10) while SoS values decayed nonlinearly (P<0.001). The acoustoelastic modeling showed a weak correlation for SWS (r=-0.36, P<0.001) but a very strong correlation for SoS (r=0.86, P<0.001), which was used to extract the SoS acoustoelastic parameter. SWS showed higher variability between both calves [intraclass correlation coefficient (ICC) =0.62, P=0.08] than SoS (ICC =0.91, P<0.001). Correlations with BF% were strong and positive for SWS (r=0.60, P<0.001), moderate and negative for SoS (r=-0.43, P=0.05), and moderate positive for SoS acoustoelastic parameter (r=0.48, P=0.03). SWS and SoS provide independent information about tissue elastic properties. SWS correlated stronger with BF% than SoS, but measurements were less reliable. SoS enabled the extraction of novel metrics related to tissue nonlinearity with potential complementary information.

Estimation of the speed of sound waves using a modular 3D printed Helmholtz resonator

This work shows the redesign of an elemental experience based on the Helmholtz resonator using 3D printing. A Helmholtz resonator is based on a volume and at least one opening that can include a tube or not. The air column inside the tube can be considered the mass of the system, whereas the volume represents the system’s stiffness. Due to these analogies between acoustics and mechanics, the Helmholtz resonator is an interesting example of a harmonic oscillator. The relevance of harmonic motions is well known, and this topic is present in the syllabus of many technical and scientific education degrees. In this work, a bottle has been designed and fabricated using 3D printer technology. The design aimed to create a Helmholtz resonator with a variable frequency of resonance. Different mouthpieces have also been designed. The bottle is composed of a set of cylindrical sections that can be attached, enlarging the length of the container. For ensuring that the different parts set a tight enclosure, an O-ring seal has also been designed and fabricated. As more rings and O-seal junctions are attached, the volume of the resonator grows. By blowing the mouth of the Helmholtz resonator with different sections, different resonance frequencies can be measured. From these measurements, several parameters can be estimated indirectly, such as the speed of sound waves, the room temperature, and air density. 3D printing permits to analyse several scenarios without using uncomfortablestrategies to vary the bottle’s volume, such as water, reducing the hazard in a laboratory with electronic instrumentation.

Acoustic emission-based sound velocity characteristics of ceramic matrix composites

Based on the Christoffel equation, using the relationship between the composite stiffness matrix and the elastic constant, the orthotropic model was applied to the acoustic properties of 2D-C/SiC composites, and the expression of the material sound velocity was obtained. Through the cyclic loading and unloading test, the sound velocity changes at different stress levels during the entire tensile process were measured. The damage characterization of the sound velocity on the 2D-C/SiC composite was studied. The results show that as the stress level continues to increase, the sound velocity gradually decreases, and the material The degree of damage has a greater impact on the propagation speed of sound waves in the 2D-C/SiC composite; the unloading modulus and reloading modulus are introduced to replace the sound velocity theory to calculate the tangent modulus. It is found that the theoretical results are in good agreement with the test results, and the error increases with the increase of load; The sound wave velocity decreases with the damage of the 2D-C/SiC composite, and based on this attenuation relationship, the damage characterization based on the sound velocity was established.

Dynamic Path Planning of Underwater Vehicle Based on Pulse Lidar Profiler

In the underwater environment, the speed of light is much faster than that of sonar, so it can be used to sample and detect more intensively in space and high frequency in time. A better strategy is to integrate sonar and lidar into an integrated device. In military affairs, lidar sonar system is used for identification of underwater artificial works and fixed-point blasting. In the civil field, aquaculture, scientific research and sampling, and underwater infrastructure exploration are the main areas. This paper analyzes the application of pulse lidar profiler system integrated with multiple detection methods in the dynamic path planning of underwater vehicle. Three colors of “red, orange, red sauce” were used as the warm color light source group, and three colors of “blue, green, purple” were used as the cold color light source group. Through matrix operation, underwater objects with almost all colors can be quickly reached and superimposed. The speed of sound wave is slow, but the bypass performance is very good, which fully supplements the blind area of light source.